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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
  *
  * Test code for seccomp bpf.
  */
 
 #define _GNU_SOURCE
 #include <sys/types.h>
 
 /*
  * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
  * we need to use the kernel's siginfo.h file and trick glibc
  * into accepting it.
  */
 #if !__GLIBC_PREREQ(2, 26)
 # include <asm/siginfo.h>
 # define __have_siginfo_t 1
 # define __have_sigval_t 1
 # define __have_sigevent_t 1
 #endif
 
 #include <errno.h>
 #include <linux/filter.h>
 #include <sys/prctl.h>
 #include <sys/ptrace.h>
 #include <sys/user.h>
 #include <linux/prctl.h>
 #include <linux/ptrace.h>
 #include <linux/seccomp.h>
 #include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
 #include <stddef.h>
 #include <stdbool.h>
 #include <string.h>
 #include <time.h>
 #include <limits.h>
 #include <linux/elf.h>
 #include <sys/uio.h>
 #include <sys/utsname.h>
 #include <sys/fcntl.h>
 #include <sys/mman.h>
 #include <sys/times.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
 #include <linux/kcmp.h>
 #include <sys/resource.h>
 #include <sys/capability.h>
 
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <poll.h>
 
 #include "../kselftest_harness.h"
 #include "../clone3/clone3_selftests.h"
 
 /* Attempt to de-conflict with the selftests tree. */
 #ifndef SKIP
 #define SKIP(s, ...)    XFAIL(s, ##__VA_ARGS__)
 #endif
 
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
 
 #ifndef PR_SET_PTRACER
 # define PR_SET_PTRACER 0x59616d61
 #endif
 
 #ifndef PR_SET_NO_NEW_PRIVS
 #define PR_SET_NO_NEW_PRIVS 38
 #define PR_GET_NO_NEW_PRIVS 39
 #endif
 
 #ifndef PR_SECCOMP_EXT
 #define PR_SECCOMP_EXT 43
 #endif
 
 #ifndef SECCOMP_EXT_ACT
 #define SECCOMP_EXT_ACT 1
 #endif
 
 #ifndef SECCOMP_EXT_ACT_TSYNC
 #define SECCOMP_EXT_ACT_TSYNC 1
 #endif
 
 #ifndef SECCOMP_MODE_STRICT
 #define SECCOMP_MODE_STRICT 1
 #endif
 
 #ifndef SECCOMP_MODE_FILTER
 #define SECCOMP_MODE_FILTER 2
 #endif
 
 #ifndef SECCOMP_RET_ALLOW
 struct seccomp_data {
     int nr;
     __u32 arch;
     __u64 instruction_pointer;
     __u64 args[6];
 };
 #endif
 
 #ifndef SECCOMP_RET_KILL_PROCESS
 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
 #define SECCOMP_RET_KILL_THREAD  0x00000000U /* kill the thread */
 #endif
 #ifndef SECCOMP_RET_KILL
 #define SECCOMP_RET_KILL     SECCOMP_RET_KILL_THREAD
 #define SECCOMP_RET_TRAP     0x00030000U /* disallow and force a SIGSYS */
 #define SECCOMP_RET_ERRNO    0x00050000U /* returns an errno */
 #define SECCOMP_RET_TRACE    0x7ff00000U /* pass to a tracer or disallow */
 #define SECCOMP_RET_ALLOW    0x7fff0000U /* allow */
 #endif
 #ifndef SECCOMP_RET_LOG
 #define SECCOMP_RET_LOG      0x7ffc0000U /* allow after logging */
 #endif
 
 #ifndef __NR_seccomp
 # if defined(__i386__)
 #  define __NR_seccomp 354
 # elif defined(__x86_64__)
 #  define __NR_seccomp 317
 # elif defined(__arm__)
 #  define __NR_seccomp 383
 # elif defined(__aarch64__)
 #  define __NR_seccomp 277
 # elif defined(__riscv)
 #  define __NR_seccomp 277
 # elif defined(__csky__)
 #  define __NR_seccomp 277
 # elif defined(__hppa__)
 #  define __NR_seccomp 338
 # elif defined(__powerpc__)
 #  define __NR_seccomp 358
 # elif defined(__s390__)
 #  define __NR_seccomp 348
 # elif defined(__xtensa__)
 #  define __NR_seccomp 337
 # elif defined(__sh__)
 #  define __NR_seccomp 372
 # else
 #  warning "seccomp syscall number unknown for this architecture"
 #  define __NR_seccomp 0xffff
 # endif
 #endif
 
 #ifndef SECCOMP_SET_MODE_STRICT
 #define SECCOMP_SET_MODE_STRICT 0
 #endif
 
 #ifndef SECCOMP_SET_MODE_FILTER
 #define SECCOMP_SET_MODE_FILTER 1
 #endif
 
 #ifndef SECCOMP_GET_ACTION_AVAIL
 #define SECCOMP_GET_ACTION_AVAIL 2
 #endif
 
 #ifndef SECCOMP_GET_NOTIF_SIZES
 #define SECCOMP_GET_NOTIF_SIZES 3
 #endif
 
 #ifndef SECCOMP_FILTER_FLAG_TSYNC
 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
 #endif
 
 #ifndef SECCOMP_FILTER_FLAG_LOG
 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
 #endif
 
 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
 #endif
 
 #ifndef PTRACE_SECCOMP_GET_METADATA
 #define PTRACE_SECCOMP_GET_METADATA 0x420d
 
 struct seccomp_metadata {
     __u64 filter_off;       /* Input: which filter */
     __u64 flags;             /* Output: filter's flags */
 };
 #endif
 
 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
 #define SECCOMP_FILTER_FLAG_NEW_LISTENER    (1UL << 3)
 #endif
 
 #ifndef SECCOMP_RET_USER_NOTIF
 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
 
 #define SECCOMP_IOC_MAGIC       '!'
 #define SECCOMP_IO(nr)          _IO(SECCOMP_IOC_MAGIC, nr)
 #define SECCOMP_IOR(nr, type)       _IOR(SECCOMP_IOC_MAGIC, nr, type)
 #define SECCOMP_IOW(nr, type)       _IOW(SECCOMP_IOC_MAGIC, nr, type)
 #define SECCOMP_IOWR(nr, type)      _IOWR(SECCOMP_IOC_MAGIC, nr, type)
 
 /* Flags for seccomp notification fd ioctl. */
 #define SECCOMP_IOCTL_NOTIF_RECV    SECCOMP_IOWR(0, struct seccomp_notif)
 #define SECCOMP_IOCTL_NOTIF_SEND    SECCOMP_IOWR(1, \
                         struct seccomp_notif_resp)
 #define SECCOMP_IOCTL_NOTIF_ID_VALID    SECCOMP_IOW(2, __u64)
 
 struct seccomp_notif {
     __u64 id;
     __u32 pid;
     __u32 flags;
     struct seccomp_data data;
 };
 
 struct seccomp_notif_resp {
     __u64 id;
     __s64 val;
     __s32 error;
     __u32 flags;
 };
 
 struct seccomp_notif_sizes {
     __u16 seccomp_notif;
     __u16 seccomp_notif_resp;
     __u16 seccomp_data;
 };
 #endif
 
 #ifndef SECCOMP_IOCTL_NOTIF_ADDFD
 /* On success, the return value is the remote process's added fd number */
 #define SECCOMP_IOCTL_NOTIF_ADDFD   SECCOMP_IOW(3,  \
                         struct seccomp_notif_addfd)
 
 /* valid flags for seccomp_notif_addfd */
 #define SECCOMP_ADDFD_FLAG_SETFD    (1UL << 0) /* Specify remote fd */
 
 struct seccomp_notif_addfd {
     __u64 id;
     __u32 flags;
     __u32 srcfd;
     __u32 newfd;
     __u32 newfd_flags;
 };
 #endif
 
 #ifndef SECCOMP_ADDFD_FLAG_SEND
 #define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */
 #endif
 
 struct seccomp_notif_addfd_small {
     __u64 id;
     char weird[4];
 };
 #define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \
     SECCOMP_IOW(3, struct seccomp_notif_addfd_small)
 
 struct seccomp_notif_addfd_big {
     union {
         struct seccomp_notif_addfd addfd;
         char buf[sizeof(struct seccomp_notif_addfd) + 8];
     };
 };
 #define SECCOMP_IOCTL_NOTIF_ADDFD_BIG   \
     SECCOMP_IOWR(3, struct seccomp_notif_addfd_big)
 
 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
 #define PTRACE_EVENTMSG_SYSCALL_ENTRY   1
 #define PTRACE_EVENTMSG_SYSCALL_EXIT    2
 #endif
 
 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
 #endif
 
 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH
 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
 #endif
 
 #ifndef SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV
 #define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5)
 #endif
 
 #ifndef seccomp
 int seccomp(unsigned int op, unsigned int flags, void *args)
 {
     errno = 0;
     return syscall(__NR_seccomp, op, flags, args);
 }
 #endif
 
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
 #else
 #error "wut? Unknown __BYTE_ORDER__?!"
 #endif
 
 #define SIBLING_EXIT_UNKILLED   0xbadbeef
 #define SIBLING_EXIT_FAILURE    0xbadface
 #define SIBLING_EXIT_NEWPRIVS   0xbadfeed
 
 static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
 {
 #ifdef __NR_kcmp
     errno = 0;
     return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
 #else
     errno = ENOSYS;
     return -1;
 #endif
 }
 
 /* Have TH_LOG report actual location filecmp() is used. */
 #define filecmp(pid1, pid2, fd1, fd2)   ({      \
     int _ret;                   \
                             \
     _ret = __filecmp(pid1, pid2, fd1, fd2);     \
     if (_ret != 0) {                \
         if (_ret < 0 && errno == ENOSYS) {  \
             TH_LOG("kcmp() syscall missing (test is less accurate)");\
             _ret = 0;           \
         }                   \
     }                       \
     _ret; })
 
 TEST(kcmp)
 {
     int ret;
 
     ret = __filecmp(getpid(), getpid(), 1, 1);
     EXPECT_EQ(ret, 0);
     if (ret != 0 && errno == ENOSYS)
         SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)");
 }
 
 TEST(mode_strict_support)
 {
     long ret;
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support CONFIG_SECCOMP");
     }
     syscall(__NR_exit, 0);
 }
 
 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
 {
     long ret;
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support CONFIG_SECCOMP");
     }
     syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
         NULL, NULL, NULL);
     EXPECT_FALSE(true) {
         TH_LOG("Unreachable!");
     }
 }
 
 /* Note! This doesn't test no new privs behavior */
 TEST(no_new_privs_support)
 {
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     EXPECT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 }
 
 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
 TEST(mode_filter_support)
 {
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(EFAULT, errno) {
         TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
     }
 }
 
 TEST(mode_filter_without_nnp)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
     ASSERT_LE(0, ret) {
         TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
     }
     errno = 0;
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     /* Succeeds with CAP_SYS_ADMIN, fails without */
     /* TODO(wad) check caps not euid */
     if (geteuid()) {
         EXPECT_EQ(-1, ret);
         EXPECT_EQ(EACCES, errno);
     } else {
         EXPECT_EQ(0, ret);
     }
 }
 
 #define MAX_INSNS_PER_PATH 32768
 
 TEST(filter_size_limits)
 {
     int i;
     int count = BPF_MAXINSNS + 1;
     struct sock_filter allow[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_filter *filter;
     struct sock_fprog prog = { };
     long ret;
 
     filter = calloc(count, sizeof(*filter));
     ASSERT_NE(NULL, filter);
 
     for (i = 0; i < count; i++)
         filter[i] = allow[0];
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     prog.filter = filter;
     prog.len = count;
 
     /* Too many filter instructions in a single filter. */
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_NE(0, ret) {
         TH_LOG("Installing %d insn filter was allowed", prog.len);
     }
 
     /* One less is okay, though. */
     prog.len -= 1;
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
     }
 }
 
 TEST(filter_chain_limits)
 {
     int i;
     int count = BPF_MAXINSNS;
     struct sock_filter allow[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_filter *filter;
     struct sock_fprog prog = { };
     long ret;
 
     filter = calloc(count, sizeof(*filter));
     ASSERT_NE(NULL, filter);
 
     for (i = 0; i < count; i++)
         filter[i] = allow[0];
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     prog.filter = filter;
     prog.len = 1;
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     prog.len = count;
 
     /* Too many total filter instructions. */
     for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
         if (ret != 0)
             break;
     }
     ASSERT_NE(0, ret) {
         TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
                i, count, i * (count + 4));
     }
 }
 
 TEST(mode_filter_cannot_move_to_strict)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(EINVAL, errno);
 }
 
 
 TEST(mode_filter_get_seccomp)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
     EXPECT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
     EXPECT_EQ(2, ret);
 }
 
 
 TEST(ALLOW_all)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
 }
 
 TEST(empty_prog)
 {
     struct sock_filter filter[] = {
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(EINVAL, errno);
 }
 
 TEST(log_all)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
     pid_t parent = getppid();
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
 
     /* getppid() should succeed and be logged (no check for logging) */
     EXPECT_EQ(parent, syscall(__NR_getppid));
 }
 
 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
     EXPECT_EQ(0, syscall(__NR_getpid)) {
         TH_LOG("getpid() shouldn't ever return");
     }
 }
 
 /* return code >= 0x80000000 is unused. */
 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
     EXPECT_EQ(0, syscall(__NR_getpid)) {
         TH_LOG("getpid() shouldn't ever return");
     }
 }
 
 TEST_SIGNAL(KILL_all, SIGSYS)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
 }
 
 TEST_SIGNAL(KILL_one, SIGSYS)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
     pid_t parent = getppid();
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* getpid() should never return. */
     EXPECT_EQ(0, syscall(__NR_getpid));
 }
 
 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
 {
     void *fatal_address;
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         /* Only both with lower 32-bit for now. */
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
             (unsigned long)&fatal_address, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
     pid_t parent = getppid();
     struct tms timebuf;
     clock_t clock = times(&timebuf);
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     EXPECT_LE(clock, syscall(__NR_times, &timebuf));
     /* times() should never return. */
     EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
 }
 
 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
 {
 #ifndef __NR_mmap2
     int sysno = __NR_mmap;
 #else
     int sysno = __NR_mmap2;
 #endif
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         /* Only both with lower 32-bit for now. */
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
     pid_t parent = getppid();
     int fd;
     void *map1, *map2;
     int page_size = sysconf(_SC_PAGESIZE);
 
     ASSERT_LT(0, page_size);
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     ASSERT_EQ(0, ret);
 
     fd = open("/dev/zero", O_RDONLY);
     ASSERT_NE(-1, fd);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     map1 = (void *)syscall(sysno,
         NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
     EXPECT_NE(MAP_FAILED, map1);
     /* mmap2() should never return. */
     map2 = (void *)syscall(sysno,
          NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
     EXPECT_EQ(MAP_FAILED, map2);
 
     /* The test failed, so clean up the resources. */
     munmap(map1, page_size);
     munmap(map2, page_size);
     close(fd);
 }
 
 /* This is a thread task to die via seccomp filter violation. */
 void *kill_thread(void *data)
 {
     bool die = (bool)data;
 
     if (die) {
         prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
         return (void *)SIBLING_EXIT_FAILURE;
     }
 
     return (void *)SIBLING_EXIT_UNKILLED;
 }
 
 enum kill_t {
     KILL_THREAD,
     KILL_PROCESS,
     RET_UNKNOWN
 };
 
 /* Prepare a thread that will kill itself or both of us. */
 void kill_thread_or_group(struct __test_metadata *_metadata,
               enum kill_t kill_how)
 {
     pthread_t thread;
     void *status;
     /* Kill only when calling __NR_prctl. */
     struct sock_filter filter_thread[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog_thread = {
         .len = (unsigned short)ARRAY_SIZE(filter_thread),
         .filter = filter_thread,
     };
     int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAA;
     struct sock_filter filter_process[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, kill),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog_process = {
         .len = (unsigned short)ARRAY_SIZE(filter_process),
         .filter = filter_process,
     };
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
                  kill_how == KILL_THREAD ? &prog_thread
                              : &prog_process));
 
     /*
      * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
      * flag cannot be downgraded by a new filter.
      */
     if (kill_how == KILL_PROCESS)
         ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
 
     /* Start a thread that will exit immediately. */
     ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
     ASSERT_EQ(0, pthread_join(thread, &status));
     ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
 
     /* Start a thread that will die immediately. */
     ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
     ASSERT_EQ(0, pthread_join(thread, &status));
     ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
 
     /*
      * If we get here, only the spawned thread died. Let the parent know
      * the whole process didn't die (i.e. this thread, the spawner,
      * stayed running).
      */
     exit(42);
 }
 
 TEST(KILL_thread)
 {
     int status;
     pid_t child_pid;
 
     child_pid = fork();
     ASSERT_LE(0, child_pid);
     if (child_pid == 0) {
         kill_thread_or_group(_metadata, KILL_THREAD);
         _exit(38);
     }
 
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
 
     /* If only the thread was killed, we'll see exit 42. */
     ASSERT_TRUE(WIFEXITED(status));
     ASSERT_EQ(42, WEXITSTATUS(status));
 }
 
 TEST(KILL_process)
 {
     int status;
     pid_t child_pid;
 
     child_pid = fork();
     ASSERT_LE(0, child_pid);
     if (child_pid == 0) {
         kill_thread_or_group(_metadata, KILL_PROCESS);
         _exit(38);
     }
 
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
 
     /* If the entire process was killed, we'll see SIGSYS. */
     ASSERT_TRUE(WIFSIGNALED(status));
     ASSERT_EQ(SIGSYS, WTERMSIG(status));
 }
 
 TEST(KILL_unknown)
 {
     int status;
     pid_t child_pid;
 
     child_pid = fork();
     ASSERT_LE(0, child_pid);
     if (child_pid == 0) {
         kill_thread_or_group(_metadata, RET_UNKNOWN);
         _exit(38);
     }
 
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
 
     /* If the entire process was killed, we'll see SIGSYS. */
     EXPECT_TRUE(WIFSIGNALED(status)) {
         TH_LOG("Unknown SECCOMP_RET is only killing the thread?");
     }
     ASSERT_EQ(SIGSYS, WTERMSIG(status));
 }
 
 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
 TEST(arg_out_of_range)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(EINVAL, errno);
 }
 
 #define ERRNO_FILTER(name, errno)                   \
     struct sock_filter _read_filter_##name[] = {            \
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,              \
             offsetof(struct seccomp_data, nr)),     \
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),   \
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),     \
     };                              \
     struct sock_fprog prog_##name = {               \
         .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
         .filter = _read_filter_##name,              \
     }
 
 /* Make sure basic errno values are correctly passed through a filter. */
 TEST(ERRNO_valid)
 {
     ERRNO_FILTER(valid, E2BIG);
     long ret;
     pid_t parent = getppid();
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     EXPECT_EQ(-1, read(-1, NULL, 0));
     EXPECT_EQ(E2BIG, errno);
 }
 
 /* Make sure an errno of zero is correctly handled by the arch code. */
 TEST(ERRNO_zero)
 {
     ERRNO_FILTER(zero, 0);
     long ret;
     pid_t parent = getppid();
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* "errno" of 0 is ok. */
     EXPECT_EQ(0, read(-1, NULL, 0));
 }
 
 /*
  * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
  * This tests that the errno value gets capped correctly, fixed by
  * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
  */
 TEST(ERRNO_capped)
 {
     ERRNO_FILTER(capped, 4096);
     long ret;
     pid_t parent = getppid();
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     EXPECT_EQ(-1, read(-1, NULL, 0));
     EXPECT_EQ(4095, errno);
 }
 
 /*
  * Filters are processed in reverse order: last applied is executed first.
  * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
  * SECCOMP_RET_DATA mask results will follow the most recently applied
  * matching filter return (and not the lowest or highest value).
  */
 TEST(ERRNO_order)
 {
     ERRNO_FILTER(first,  11);
     ERRNO_FILTER(second, 13);
     ERRNO_FILTER(third,  12);
     long ret;
     pid_t parent = getppid();
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     EXPECT_EQ(-1, read(-1, NULL, 0));
     EXPECT_EQ(12, errno);
 }
 
 FIXTURE(TRAP) {
     struct sock_fprog prog;
 };
 
 FIXTURE_SETUP(TRAP)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
 
     memset(&self->prog, 0, sizeof(self->prog));
     self->prog.filter = malloc(sizeof(filter));
     ASSERT_NE(NULL, self->prog.filter);
     memcpy(self->prog.filter, filter, sizeof(filter));
     self->prog.len = (unsigned short)ARRAY_SIZE(filter);
 }
 
 FIXTURE_TEARDOWN(TRAP)
 {
     if (self->prog.filter)
         free(self->prog.filter);
 }
 
 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
 {
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
     ASSERT_EQ(0, ret);
     syscall(__NR_getpid);
 }
 
 /* Ensure that SIGSYS overrides SIG_IGN */
 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
 {
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     signal(SIGSYS, SIG_IGN);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
     ASSERT_EQ(0, ret);
     syscall(__NR_getpid);
 }
 
 static siginfo_t TRAP_info;
 static volatile int TRAP_nr;
 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
 {
     memcpy(&TRAP_info, info, sizeof(TRAP_info));
     TRAP_nr = nr;
 }
 
 TEST_F(TRAP, handler)
 {
     int ret, test;
     struct sigaction act;
     sigset_t mask;
 
     memset(&act, 0, sizeof(act));
     sigemptyset(&mask);
     sigaddset(&mask, SIGSYS);
 
     act.sa_sigaction = &TRAP_action;
     act.sa_flags = SA_SIGINFO;
     ret = sigaction(SIGSYS, &act, NULL);
     ASSERT_EQ(0, ret) {
         TH_LOG("sigaction failed");
     }
     ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
     ASSERT_EQ(0, ret) {
         TH_LOG("sigprocmask failed");
     }
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
     ASSERT_EQ(0, ret);
     TRAP_nr = 0;
     memset(&TRAP_info, 0, sizeof(TRAP_info));
     /* Expect the registers to be rolled back. (nr = error) may vary
      * based on arch. */
     ret = syscall(__NR_getpid);
     /* Silence gcc warning about volatile. */
     test = TRAP_nr;
     EXPECT_EQ(SIGSYS, test);
     struct local_sigsys {
         void *_call_addr;   /* calling user insn */
         int _syscall;       /* triggering system call number */
         unsigned int _arch; /* AUDIT_ARCH_* of syscall */
     } *sigsys = (struct local_sigsys *)
 #ifdef si_syscall
         &(TRAP_info.si_call_addr);
 #else
         &TRAP_info.si_pid;
 #endif
     EXPECT_EQ(__NR_getpid, sigsys->_syscall);
     /* Make sure arch is non-zero. */
     EXPECT_NE(0, sigsys->_arch);
     EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
 }
 
 FIXTURE(precedence) {
     struct sock_fprog allow;
     struct sock_fprog log;
     struct sock_fprog trace;
     struct sock_fprog error;
     struct sock_fprog trap;
     struct sock_fprog kill;
 };
 
 FIXTURE_SETUP(precedence)
 {
     struct sock_filter allow_insns[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_filter log_insns[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
     };
     struct sock_filter trace_insns[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
     };
     struct sock_filter error_insns[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
     };
     struct sock_filter trap_insns[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
     };
     struct sock_filter kill_insns[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
     };
 
     memset(self, 0, sizeof(*self));
 #define FILTER_ALLOC(_x) \
     self->_x.filter = malloc(sizeof(_x##_insns)); \
     ASSERT_NE(NULL, self->_x.filter); \
     memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
     self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
     FILTER_ALLOC(allow);
     FILTER_ALLOC(log);
     FILTER_ALLOC(trace);
     FILTER_ALLOC(error);
     FILTER_ALLOC(trap);
     FILTER_ALLOC(kill);
 }
 
 FIXTURE_TEARDOWN(precedence)
 {
 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
     FILTER_FREE(allow);
     FILTER_FREE(log);
     FILTER_FREE(trace);
     FILTER_FREE(error);
     FILTER_FREE(trap);
     FILTER_FREE(kill);
 }
 
 TEST_F(precedence, allow_ok)
 {
     pid_t parent, res = 0;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     res = syscall(__NR_getppid);
     EXPECT_EQ(parent, res);
 }
 
 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
 {
     pid_t parent, res = 0;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     res = syscall(__NR_getppid);
     EXPECT_EQ(parent, res);
     /* getpid() should never return. */
     res = syscall(__NR_getpid);
     EXPECT_EQ(0, res);
 }
 
 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
 {
     pid_t parent;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* getpid() should never return. */
     EXPECT_EQ(0, syscall(__NR_getpid));
 }
 
 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
 {
     pid_t parent;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* getpid() should never return. */
     EXPECT_EQ(0, syscall(__NR_getpid));
 }
 
 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
 {
     pid_t parent;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* getpid() should never return. */
     EXPECT_EQ(0, syscall(__NR_getpid));
 }
 
 TEST_F(precedence, errno_is_third)
 {
     pid_t parent;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     EXPECT_EQ(0, syscall(__NR_getpid));
 }
 
 TEST_F(precedence, errno_is_third_in_any_order)
 {
     pid_t parent;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     EXPECT_EQ(0, syscall(__NR_getpid));
 }
 
 TEST_F(precedence, trace_is_fourth)
 {
     pid_t parent;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* No ptracer */
     EXPECT_EQ(-1, syscall(__NR_getpid));
 }
 
 TEST_F(precedence, trace_is_fourth_in_any_order)
 {
     pid_t parent;
     long ret;
 
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* No ptracer */
     EXPECT_EQ(-1, syscall(__NR_getpid));
 }
 
 TEST_F(precedence, log_is_fifth)
 {
     pid_t mypid, parent;
     long ret;
 
     mypid = getpid();
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* Should also work just fine */
     EXPECT_EQ(mypid, syscall(__NR_getpid));
 }
 
 TEST_F(precedence, log_is_fifth_in_any_order)
 {
     pid_t mypid, parent;
     long ret;
 
     mypid = getpid();
     parent = getppid();
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
     ASSERT_EQ(0, ret);
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
     ASSERT_EQ(0, ret);
     /* Should work just fine. */
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* Should also work just fine */
     EXPECT_EQ(mypid, syscall(__NR_getpid));
 }
 
 #ifndef PTRACE_O_TRACESECCOMP
 #define PTRACE_O_TRACESECCOMP   0x00000080
 #endif
 
 /* Catch the Ubuntu 12.04 value error. */
 #if PTRACE_EVENT_SECCOMP != 7
 #undef PTRACE_EVENT_SECCOMP
 #endif
 
 #ifndef PTRACE_EVENT_SECCOMP
 #define PTRACE_EVENT_SECCOMP 7
 #endif
 
 #define PTRACE_EVENT_MASK(status) ((status) >> 16)
 bool tracer_running;
 void tracer_stop(int sig)
 {
     tracer_running = false;
 }
 
 typedef void tracer_func_t(struct __test_metadata *_metadata,
                pid_t tracee, int status, void *args);
 
 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
         tracer_func_t tracer_func, void *args, bool ptrace_syscall)
 {
     int ret = -1;
     struct sigaction action = {
         .sa_handler = tracer_stop,
     };
 
     /* Allow external shutdown. */
     tracer_running = true;
     ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
 
     errno = 0;
     while (ret == -1 && errno != EINVAL)
         ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
     ASSERT_EQ(0, ret) {
         kill(tracee, SIGKILL);
     }
     /* Wait for attach stop */
     wait(NULL);
 
     ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
                               PTRACE_O_TRACESYSGOOD :
                               PTRACE_O_TRACESECCOMP);
     ASSERT_EQ(0, ret) {
         TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
         kill(tracee, SIGKILL);
     }
     ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
              tracee, NULL, 0);
     ASSERT_EQ(0, ret);
 
     /* Unblock the tracee */
     ASSERT_EQ(1, write(fd, "A", 1));
     ASSERT_EQ(0, close(fd));
 
     /* Run until we're shut down. Must assert to stop execution. */
     while (tracer_running) {
         int status;
 
         if (wait(&status) != tracee)
             continue;
 
         if (WIFSIGNALED(status)) {
             /* Child caught a fatal signal. */
             return;
         }
         if (WIFEXITED(status)) {
             /* Child exited with code. */
             return;
         }
 
         /* Check if we got an expected event. */
         ASSERT_EQ(WIFCONTINUED(status), false);
         ASSERT_EQ(WIFSTOPPED(status), true);
         ASSERT_EQ(WSTOPSIG(status) & SIGTRAP, SIGTRAP) {
             TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
         }
 
         tracer_func(_metadata, tracee, status, args);
 
         ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
                  tracee, NULL, 0);
         ASSERT_EQ(0, ret);
     }
     /* Directly report the status of our test harness results. */
     syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
 }
 
 /* Common tracer setup/teardown functions. */
 void cont_handler(int num)
 { }
 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
               tracer_func_t func, void *args, bool ptrace_syscall)
 {
     char sync;
     int pipefd[2];
     pid_t tracer_pid;
     pid_t tracee = getpid();
 
     /* Setup a pipe for clean synchronization. */
     ASSERT_EQ(0, pipe(pipefd));
 
     /* Fork a child which we'll promote to tracer */
     tracer_pid = fork();
     ASSERT_LE(0, tracer_pid);
     signal(SIGALRM, cont_handler);
     if (tracer_pid == 0) {
         close(pipefd[0]);
         start_tracer(_metadata, pipefd[1], tracee, func, args,
                  ptrace_syscall);
         syscall(__NR_exit, 0);
     }
     close(pipefd[1]);
     prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
     read(pipefd[0], &sync, 1);
     close(pipefd[0]);
 
     return tracer_pid;
 }
 
 void teardown_trace_fixture(struct __test_metadata *_metadata,
                 pid_t tracer)
 {
     if (tracer) {
         int status;
         /*
          * Extract the exit code from the other process and
          * adopt it for ourselves in case its asserts failed.
          */
         ASSERT_EQ(0, kill(tracer, SIGUSR1));
         ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
         if (WEXITSTATUS(status))
             _metadata->passed = 0;
     }
 }
 
 /* "poke" tracer arguments and function. */
 struct tracer_args_poke_t {
     unsigned long poke_addr;
 };
 
 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
          void *args)
 {
     int ret;
     unsigned long msg;
     struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
 
     ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
     EXPECT_EQ(0, ret);
     /* If this fails, don't try to recover. */
     ASSERT_EQ(0x1001, msg) {
         kill(tracee, SIGKILL);
     }
     /*
      * Poke in the message.
      * Registers are not touched to try to keep this relatively arch
      * agnostic.
      */
     ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
     EXPECT_EQ(0, ret);
 }
 
 FIXTURE(TRACE_poke) {
     struct sock_fprog prog;
     pid_t tracer;
     long poked;
     struct tracer_args_poke_t tracer_args;
 };
 
 FIXTURE_SETUP(TRACE_poke)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
 
     self->poked = 0;
     memset(&self->prog, 0, sizeof(self->prog));
     self->prog.filter = malloc(sizeof(filter));
     ASSERT_NE(NULL, self->prog.filter);
     memcpy(self->prog.filter, filter, sizeof(filter));
     self->prog.len = (unsigned short)ARRAY_SIZE(filter);
 
     /* Set up tracer args. */
     self->tracer_args.poke_addr = (unsigned long)&self->poked;
 
     /* Launch tracer. */
     self->tracer = setup_trace_fixture(_metadata, tracer_poke,
                        &self->tracer_args, false);
 }
 
 FIXTURE_TEARDOWN(TRACE_poke)
 {
     teardown_trace_fixture(_metadata, self->tracer);
     if (self->prog.filter)
         free(self->prog.filter);
 }
 
 TEST_F(TRACE_poke, read_has_side_effects)
 {
     ssize_t ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(0, self->poked);
     ret = read(-1, NULL, 0);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(0x1001, self->poked);
 }
 
 TEST_F(TRACE_poke, getpid_runs_normally)
 {
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     EXPECT_EQ(0, self->poked);
     EXPECT_NE(0, syscall(__NR_getpid));
     EXPECT_EQ(0, self->poked);
 }
 
 #if defined(__x86_64__)
 # define ARCH_REGS      struct user_regs_struct
 # define SYSCALL_NUM(_regs) (_regs).orig_rax
 # define SYSCALL_RET(_regs) (_regs).rax
 #elif defined(__i386__)
 # define ARCH_REGS      struct user_regs_struct
 # define SYSCALL_NUM(_regs) (_regs).orig_eax
 # define SYSCALL_RET(_regs) (_regs).eax
 #elif defined(__arm__)
 # define ARCH_REGS      struct pt_regs
 # define SYSCALL_NUM(_regs) (_regs).ARM_r7
 # ifndef PTRACE_SET_SYSCALL
 #  define PTRACE_SET_SYSCALL   23
 # endif
 # define SYSCALL_NUM_SET(_regs, _nr)    \
         EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr))
 # define SYSCALL_RET(_regs) (_regs).ARM_r0
 #elif defined(__aarch64__)
 # define ARCH_REGS      struct user_pt_regs
 # define SYSCALL_NUM(_regs) (_regs).regs[8]
 # ifndef NT_ARM_SYSTEM_CALL
 #  define NT_ARM_SYSTEM_CALL 0x404
 # endif
 # define SYSCALL_NUM_SET(_regs, _nr)                \
     do {                            \
         struct iovec __v;               \
         typeof(_nr) __nr = (_nr);           \
         __v.iov_base = &__nr;               \
         __v.iov_len = sizeof(__nr);         \
         EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee,   \
                     NT_ARM_SYSTEM_CALL, &__v)); \
     } while (0)
 # define SYSCALL_RET(_regs) (_regs).regs[0]
 #elif defined(__riscv) && __riscv_xlen == 64
 # define ARCH_REGS      struct user_regs_struct
 # define SYSCALL_NUM(_regs) (_regs).a7
 # define SYSCALL_RET(_regs) (_regs).a0
 #elif defined(__csky__)
 # define ARCH_REGS      struct pt_regs
 #  if defined(__CSKYABIV2__)
 #   define SYSCALL_NUM(_regs)   (_regs).regs[3]
 #  else
 #   define SYSCALL_NUM(_regs)   (_regs).regs[9]
 #  endif
 # define SYSCALL_RET(_regs) (_regs).a0
 #elif defined(__hppa__)
 # define ARCH_REGS      struct user_regs_struct
 # define SYSCALL_NUM(_regs) (_regs).gr[20]
 # define SYSCALL_RET(_regs) (_regs).gr[28]
 #elif defined(__powerpc__)
 # define ARCH_REGS      struct pt_regs
 # define SYSCALL_NUM(_regs) (_regs).gpr[0]
 # define SYSCALL_RET(_regs) (_regs).gpr[3]
 # define SYSCALL_RET_SET(_regs, _val)               \
     do {                            \
         typeof(_val) _result = (_val);          \
         if ((_regs.trap & 0xfff0) == 0x3000) {      \
             /*                  \
              * scv 0 system call uses -ve result    \
              * for error, so no need to adjust. \
              */                 \
             SYSCALL_RET(_regs) = _result;       \
         } else {                    \
             /*                  \
              * A syscall error is signaled by the   \
              * CR0 SO bit and the code is stored as \
              * a positive value.            \
              */                 \
             if (_result < 0) {          \
                 SYSCALL_RET(_regs) = -_result;  \
                 (_regs).ccr |= 0x10000000;  \
             } else {                \
                 SYSCALL_RET(_regs) = _result;   \
                 (_regs).ccr &= ~0x10000000; \
             }                   \
         }                       \
     } while (0)
 # define SYSCALL_RET_SET_ON_PTRACE_EXIT
 #elif defined(__s390__)
 # define ARCH_REGS      s390_regs
 # define SYSCALL_NUM(_regs) (_regs).gprs[2]
 # define SYSCALL_RET_SET(_regs, _val)           \
         TH_LOG("Can't modify syscall return on this architecture")
 #elif defined(__mips__)
 # include <asm/unistd_nr_n32.h>
 # include <asm/unistd_nr_n64.h>
 # include <asm/unistd_nr_o32.h>
 # define ARCH_REGS      struct pt_regs
 # define SYSCALL_NUM(_regs)             \
     ({                      \
         typeof((_regs).regs[2]) _nr;        \
         if ((_regs).regs[2] == __NR_O32_Linux)  \
             _nr = (_regs).regs[4];      \
         else                    \
             _nr = (_regs).regs[2];      \
         _nr;                    \
     })
 # define SYSCALL_NUM_SET(_regs, _nr)            \
     do {                        \
         if ((_regs).regs[2] == __NR_O32_Linux)  \
             (_regs).regs[4] = _nr;      \
         else                    \
             (_regs).regs[2] = _nr;      \
     } while (0)
 # define SYSCALL_RET_SET(_regs, _val)           \
         TH_LOG("Can't modify syscall return on this architecture")
 #elif defined(__xtensa__)
 # define ARCH_REGS      struct user_pt_regs
 # define SYSCALL_NUM(_regs) (_regs).syscall
 /*
  * On xtensa syscall return value is in the register
  * a2 of the current window which is not fixed.
  */
 #define SYSCALL_RET(_regs)  (_regs).a[(_regs).windowbase * 4 + 2]
 #elif defined(__sh__)
 # define ARCH_REGS      struct pt_regs
 # define SYSCALL_NUM(_regs) (_regs).regs[3]
 # define SYSCALL_RET(_regs) (_regs).regs[0]
 #else
 # error "Do not know how to find your architecture's registers and syscalls"
 #endif
 
 /*
  * Most architectures can change the syscall by just updating the
  * associated register. This is the default if not defined above.
  */
 #ifndef SYSCALL_NUM_SET
 # define SYSCALL_NUM_SET(_regs, _nr)        \
     do {                    \
         SYSCALL_NUM(_regs) = (_nr); \
     } while (0)
 #endif
 /*
  * Most architectures can change the syscall return value by just
  * writing to the SYSCALL_RET register. This is the default if not
  * defined above. If an architecture cannot set the return value
  * (for example when the syscall and return value register is
  * shared), report it with TH_LOG() in an arch-specific definition
  * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined.
  */
 #if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET)
 # error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch"
 #endif
 #ifndef SYSCALL_RET_SET
 # define SYSCALL_RET_SET(_regs, _val)       \
     do {                    \
         SYSCALL_RET(_regs) = (_val);    \
     } while (0)
 #endif
 
 /* When the syscall return can't be changed, stub out the tests for it. */
 #ifndef SYSCALL_RET
 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
 #else
 # define EXPECT_SYSCALL_RETURN(val, action)     \
     do {                        \
         errno = 0;              \
         if (val < 0) {              \
             EXPECT_EQ(-1, action);      \
             EXPECT_EQ(-(val), errno);   \
         } else {                \
             EXPECT_EQ(val, action);     \
         }                   \
     } while (0)
 #endif
 
 /*
  * Some architectures (e.g. powerpc) can only set syscall
  * return values on syscall exit during ptrace.
  */
 const bool ptrace_entry_set_syscall_nr = true;
 const bool ptrace_entry_set_syscall_ret =
 #ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT
     true;
 #else
     false;
 #endif
 
 /*
  * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
  * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
  */
 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
 # define ARCH_GETREGS(_regs)    ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
 # define ARCH_SETREGS(_regs)    ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
 #else
 # define ARCH_GETREGS(_regs)    ({                  \
         struct iovec __v;                   \
         __v.iov_base = &(_regs);                \
         __v.iov_len = sizeof(_regs);                \
         ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v);    \
     })
 # define ARCH_SETREGS(_regs)    ({                  \
         struct iovec __v;                   \
         __v.iov_base = &(_regs);                \
         __v.iov_len = sizeof(_regs);                \
         ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v);    \
     })
 #endif
 
 /* Architecture-specific syscall fetching routine. */
 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
 {
     ARCH_REGS regs;
 
     EXPECT_EQ(0, ARCH_GETREGS(regs)) {
         return -1;
     }
 
     return SYSCALL_NUM(regs);
 }
 
 /* Architecture-specific syscall changing routine. */
 void __change_syscall(struct __test_metadata *_metadata,
             pid_t tracee, long *syscall, long *ret)
 {
     ARCH_REGS orig, regs;
 
     /* Do not get/set registers if we have nothing to do. */
     if (!syscall && !ret)
         return;
 
     EXPECT_EQ(0, ARCH_GETREGS(regs)) {
         return;
     }
     orig = regs;
 
     if (syscall)
         SYSCALL_NUM_SET(regs, *syscall);
 
     if (ret)
         SYSCALL_RET_SET(regs, *ret);
 
     /* Flush any register changes made. */
     if (memcmp(&orig, &regs, sizeof(orig)) != 0)
         EXPECT_EQ(0, ARCH_SETREGS(regs));
 }
 
 /* Change only syscall number. */
 void change_syscall_nr(struct __test_metadata *_metadata,
                pid_t tracee, long syscall)
 {
     __change_syscall(_metadata, tracee, &syscall, NULL);
 }
 
 /* Change syscall return value (and set syscall number to -1). */
 void change_syscall_ret(struct __test_metadata *_metadata,
             pid_t tracee, long ret)
 {
     long syscall = -1;
 
     __change_syscall(_metadata, tracee, &syscall, &ret);
 }
 
 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
             int status, void *args)
 {
     int ret;
     unsigned long msg;
 
     EXPECT_EQ(PTRACE_EVENT_MASK(status), PTRACE_EVENT_SECCOMP) {
         TH_LOG("Unexpected ptrace event: %d", PTRACE_EVENT_MASK(status));
         return;
     }
 
     /* Make sure we got the right message. */
     ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
     EXPECT_EQ(0, ret);
 
     /* Validate and take action on expected syscalls. */
     switch (msg) {
     case 0x1002:
         /* change getpid to getppid. */
         EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
         change_syscall_nr(_metadata, tracee, __NR_getppid);
         break;
     case 0x1003:
         /* skip gettid with valid return code. */
         EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
         change_syscall_ret(_metadata, tracee, 45000);
         break;
     case 0x1004:
         /* skip openat with error. */
         EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
         change_syscall_ret(_metadata, tracee, -ESRCH);
         break;
     case 0x1005:
         /* do nothing (allow getppid) */
         EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
         break;
     default:
         EXPECT_EQ(0, msg) {
             TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
             kill(tracee, SIGKILL);
         }
     }
 
 }
 
 FIXTURE(TRACE_syscall) {
     struct sock_fprog prog;
     pid_t tracer, mytid, mypid, parent;
     long syscall_nr;
 };
 
 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
            int status, void *args)
 {
     int ret;
     unsigned long msg;
     static bool entry;
     long syscall_nr_val, syscall_ret_val;
     long *syscall_nr = NULL, *syscall_ret = NULL;
     FIXTURE_DATA(TRACE_syscall) *self = args;
 
     EXPECT_EQ(WSTOPSIG(status) & 0x80, 0x80) {
         TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
         return;
     }
 
     /*
      * The traditional way to tell PTRACE_SYSCALL entry/exit
      * is by counting.
      */
     entry = !entry;
 
     /* Make sure we got an appropriate message. */
     ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
     EXPECT_EQ(0, ret);
     EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
             : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
 
     /*
      * Some architectures only support setting return values during
      * syscall exit under ptrace, and on exit the syscall number may
      * no longer be available. Therefore, save the initial sycall
      * number here, so it can be examined during both entry and exit
      * phases.
      */
     if (entry)
         self->syscall_nr = get_syscall(_metadata, tracee);
 
     /*
      * Depending on the architecture's syscall setting abilities, we
      * pick which things to set during this phase (entry or exit).
      */
     if (entry == ptrace_entry_set_syscall_nr)
         syscall_nr = &syscall_nr_val;
     if (entry == ptrace_entry_set_syscall_ret)
         syscall_ret = &syscall_ret_val;
 
     /* Now handle the actual rewriting cases. */
     switch (self->syscall_nr) {
     case __NR_getpid:
         syscall_nr_val = __NR_getppid;
         /* Never change syscall return for this case. */
         syscall_ret = NULL;
         break;
     case __NR_gettid:
         syscall_nr_val = -1;
         syscall_ret_val = 45000;
         break;
     case __NR_openat:
         syscall_nr_val = -1;
         syscall_ret_val = -ESRCH;
         break;
     default:
         /* Unhandled, do nothing. */
         return;
     }
 
     __change_syscall(_metadata, tracee, syscall_nr, syscall_ret);
 }
 
 FIXTURE_VARIANT(TRACE_syscall) {
     /*
      * All of the SECCOMP_RET_TRACE behaviors can be tested with either
      * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL.
      * This indicates if we should use SECCOMP_RET_TRACE (false), or
      * ptrace (true).
      */
     bool use_ptrace;
 };
 
 FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) {
     .use_ptrace = true,
 };
 
 FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) {
     .use_ptrace = false,
 };
 
 FIXTURE_SETUP(TRACE_syscall)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     /* Prepare some testable syscall results. */
     self->mytid = syscall(__NR_gettid);
     ASSERT_GT(self->mytid, 0);
     ASSERT_NE(self->mytid, 1) {
         TH_LOG("Running this test as init is not supported. :)");
     }
 
     self->mypid = getpid();
     ASSERT_GT(self->mypid, 0);
     ASSERT_EQ(self->mytid, self->mypid);
 
     self->parent = getppid();
     ASSERT_GT(self->parent, 0);
     ASSERT_NE(self->parent, self->mypid);
 
     /* Launch tracer. */
     self->tracer = setup_trace_fixture(_metadata,
                        variant->use_ptrace ? tracer_ptrace
                                    : tracer_seccomp,
                        self, variant->use_ptrace);
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     /* Do not install seccomp rewrite filters, as we'll use ptrace instead. */
     if (variant->use_ptrace)
         return;
 
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret);
 }
 
 FIXTURE_TEARDOWN(TRACE_syscall)
 {
     teardown_trace_fixture(_metadata, self->tracer);
 }
 
 TEST(negative_ENOSYS)
 {
     /*
      * There should be no difference between an "internal" skip
      * and userspace asking for syscall "-1".
      */
     errno = 0;
     EXPECT_EQ(-1, syscall(-1));
     EXPECT_EQ(errno, ENOSYS);
     /* And no difference for "still not valid but not -1". */
     errno = 0;
     EXPECT_EQ(-1, syscall(-101));
     EXPECT_EQ(errno, ENOSYS);
 }
 
 TEST_F(TRACE_syscall, negative_ENOSYS)
 {
     negative_ENOSYS(_metadata);
 }
 
 TEST_F(TRACE_syscall, syscall_allowed)
 {
     /* getppid works as expected (no changes). */
     EXPECT_EQ(self->parent, syscall(__NR_getppid));
     EXPECT_NE(self->mypid, syscall(__NR_getppid));
 }
 
 TEST_F(TRACE_syscall, syscall_redirected)
 {
     /* getpid has been redirected to getppid as expected. */
     EXPECT_EQ(self->parent, syscall(__NR_getpid));
     EXPECT_NE(self->mypid, syscall(__NR_getpid));
 }
 
 TEST_F(TRACE_syscall, syscall_errno)
 {
     /* Tracer should skip the open syscall, resulting in ESRCH. */
     EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
 }
 
 TEST_F(TRACE_syscall, syscall_faked)
 {
     /* Tracer skips the gettid syscall and store altered return value. */
     EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
 }
 
 TEST_F_SIGNAL(TRACE_syscall, kill_immediate, SIGSYS)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_mknodat, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     /* Install "kill on mknodat" filter. */
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     /* This should immediately die with SIGSYS, regardless of tracer. */
     EXPECT_EQ(-1, syscall(__NR_mknodat, -1, NULL, 0, 0));
 }
 
 TEST_F(TRACE_syscall, skip_after)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     /* Install additional "errno on getppid" filter. */
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     /* Tracer will redirect getpid to getppid, and we should see EPERM. */
     errno = 0;
     EXPECT_EQ(-1, syscall(__NR_getpid));
     EXPECT_EQ(EPERM, errno);
 }
 
 TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     /* Install additional "death on getppid" filter. */
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
     ASSERT_EQ(0, ret);
 
     /* Tracer will redirect getpid to getppid, and we should die. */
     EXPECT_NE(self->mypid, syscall(__NR_getpid));
 }
 
 TEST(seccomp_syscall)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     /* Reject insane operation. */
     ret = seccomp(-1, 0, &prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Did not reject crazy op value!");
     }
 
     /* Reject strict with flags or pointer. */
     ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Did not reject mode strict with flags!");
     }
     ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Did not reject mode strict with uargs!");
     }
 
     /* Reject insane args for filter. */
     ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Did not reject crazy filter flags!");
     }
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
     EXPECT_EQ(EFAULT, errno) {
         TH_LOG("Did not reject NULL filter!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
     EXPECT_EQ(0, errno) {
         TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
             strerror(errno));
     }
 }
 
 TEST(seccomp_syscall_mode_lock)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     EXPECT_EQ(0, ret) {
         TH_LOG("Could not install filter!");
     }
 
     /* Make sure neither entry point will switch to strict. */
     ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Switched to mode strict!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Switched to mode strict!");
     }
 }
 
 /*
  * Test detection of known and unknown filter flags. Userspace needs to be able
  * to check if a filter flag is supported by the current kernel and a good way
  * of doing that is by attempting to enter filter mode, with the flag bit in
  * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
  * that the flag is valid and EINVAL indicates that the flag is invalid.
  */
 TEST(detect_seccomp_filter_flags)
 {
     unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
                  SECCOMP_FILTER_FLAG_LOG,
                  SECCOMP_FILTER_FLAG_SPEC_ALLOW,
                  SECCOMP_FILTER_FLAG_NEW_LISTENER,
                  SECCOMP_FILTER_FLAG_TSYNC_ESRCH };
     unsigned int exclusive[] = {
                 SECCOMP_FILTER_FLAG_TSYNC,
                 SECCOMP_FILTER_FLAG_NEW_LISTENER };
     unsigned int flag, all_flags, exclusive_mask;
     int i;
     long ret;
 
     /* Test detection of individual known-good filter flags */
     for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
         int bits = 0;
 
         flag = flags[i];
         /* Make sure the flag is a single bit! */
         while (flag) {
             if (flag & 0x1)
                 bits ++;
             flag >>= 1;
         }
         ASSERT_EQ(1, bits);
         flag = flags[i];
 
         ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
         ASSERT_NE(ENOSYS, errno) {
             TH_LOG("Kernel does not support seccomp syscall!");
         }
         EXPECT_EQ(-1, ret);
         EXPECT_EQ(EFAULT, errno) {
             TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
                    flag);
         }
 
         all_flags |= flag;
     }
 
     /*
      * Test detection of all known-good filter flags combined. But
      * for the exclusive flags we need to mask them out and try them
      * individually for the "all flags" testing.
      */
     exclusive_mask = 0;
     for (i = 0; i < ARRAY_SIZE(exclusive); i++)
         exclusive_mask |= exclusive[i];
     for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
         flag = all_flags & ~exclusive_mask;
         flag |= exclusive[i];
 
         ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
         EXPECT_EQ(-1, ret);
         EXPECT_EQ(EFAULT, errno) {
             TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
                    flag);
         }
     }
 
     /* Test detection of an unknown filter flags, without exclusives. */
     flag = -1;
     flag &= ~exclusive_mask;
     ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
                flag);
     }
 
     /*
      * Test detection of an unknown filter flag that may simply need to be
      * added to this test
      */
     flag = flags[ARRAY_SIZE(flags) - 1] << 1;
     ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?",
                flag);
     }
 }
 
 TEST(TSYNC_first)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
     long ret;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
               &prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     EXPECT_EQ(0, ret) {
         TH_LOG("Could not install initial filter with TSYNC!");
     }
 }
 
 #define TSYNC_SIBLINGS 2
 struct tsync_sibling {
     pthread_t tid;
     pid_t system_tid;
     sem_t *started;
     pthread_cond_t *cond;
     pthread_mutex_t *mutex;
     int diverge;
     int num_waits;
     struct sock_fprog *prog;
     struct __test_metadata *metadata;
 };
 
 /*
  * To avoid joining joined threads (which is not allowed by Bionic),
  * make sure we both successfully join and clear the tid to skip a
  * later join attempt during fixture teardown. Any remaining threads
  * will be directly killed during teardown.
  */
 #define PTHREAD_JOIN(tid, status)                   \
     do {                                \
         int _rc = pthread_join(tid, status);            \
         if (_rc) {                      \
             TH_LOG("pthread_join of tid %u failed: %d\n",   \
                 (unsigned int)tid, _rc);        \
         } else {                        \
             tid = 0;                    \
         }                           \
     } while (0)
 
 FIXTURE(TSYNC) {
     struct sock_fprog root_prog, apply_prog;
     struct tsync_sibling sibling[TSYNC_SIBLINGS];
     sem_t started;
     pthread_cond_t cond;
     pthread_mutex_t mutex;
     int sibling_count;
 };
 
 FIXTURE_SETUP(TSYNC)
 {
     struct sock_filter root_filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_filter apply_filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
 
     memset(&self->root_prog, 0, sizeof(self->root_prog));
     memset(&self->apply_prog, 0, sizeof(self->apply_prog));
     memset(&self->sibling, 0, sizeof(self->sibling));
     self->root_prog.filter = malloc(sizeof(root_filter));
     ASSERT_NE(NULL, self->root_prog.filter);
     memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
     self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
 
     self->apply_prog.filter = malloc(sizeof(apply_filter));
     ASSERT_NE(NULL, self->apply_prog.filter);
     memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
     self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
 
     self->sibling_count = 0;
     pthread_mutex_init(&self->mutex, NULL);
     pthread_cond_init(&self->cond, NULL);
     sem_init(&self->started, 0, 0);
     self->sibling[0].tid = 0;
     self->sibling[0].cond = &self->cond;
     self->sibling[0].started = &self->started;
     self->sibling[0].mutex = &self->mutex;
     self->sibling[0].diverge = 0;
     self->sibling[0].num_waits = 1;
     self->sibling[0].prog = &self->root_prog;
     self->sibling[0].metadata = _metadata;
     self->sibling[1].tid = 0;
     self->sibling[1].cond = &self->cond;
     self->sibling[1].started = &self->started;
     self->sibling[1].mutex = &self->mutex;
     self->sibling[1].diverge = 0;
     self->sibling[1].prog = &self->root_prog;
     self->sibling[1].num_waits = 1;
     self->sibling[1].metadata = _metadata;
 }
 
 FIXTURE_TEARDOWN(TSYNC)
 {
     int sib = 0;
 
     if (self->root_prog.filter)
         free(self->root_prog.filter);
     if (self->apply_prog.filter)
         free(self->apply_prog.filter);
 
     for ( ; sib < self->sibling_count; ++sib) {
         struct tsync_sibling *s = &self->sibling[sib];
 
         if (!s->tid)
             continue;
         /*
          * If a thread is still running, it may be stuck, so hit
          * it over the head really hard.
          */
         pthread_kill(s->tid, 9);
     }
     pthread_mutex_destroy(&self->mutex);
     pthread_cond_destroy(&self->cond);
     sem_destroy(&self->started);
 }
 
 void *tsync_sibling(void *data)
 {
     long ret = 0;
     struct tsync_sibling *me = data;
 
     me->system_tid = syscall(__NR_gettid);
 
     pthread_mutex_lock(me->mutex);
     if (me->diverge) {
         /* Just re-apply the root prog to fork the tree */
         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
                 me->prog, 0, 0);
     }
     sem_post(me->started);
     /* Return outside of started so parent notices failures. */
     if (ret) {
         pthread_mutex_unlock(me->mutex);
         return (void *)SIBLING_EXIT_FAILURE;
     }
     do {
         pthread_cond_wait(me->cond, me->mutex);
         me->num_waits = me->num_waits - 1;
     } while (me->num_waits);
     pthread_mutex_unlock(me->mutex);
 
     ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
     if (!ret)
         return (void *)SIBLING_EXIT_NEWPRIVS;
     read(-1, NULL, 0);
     return (void *)SIBLING_EXIT_UNKILLED;
 }
 
 void tsync_start_sibling(struct tsync_sibling *sibling)
 {
     pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
 }
 
 TEST_F(TSYNC, siblings_fail_prctl)
 {
     long ret;
     void *status;
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     /* Check prctl failure detection by requesting sib 0 diverge. */
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     ASSERT_EQ(0, ret) {
         TH_LOG("setting filter failed");
     }
 
     self->sibling[0].diverge = 1;
     tsync_start_sibling(&self->sibling[0]);
     tsync_start_sibling(&self->sibling[1]);
 
     while (self->sibling_count < TSYNC_SIBLINGS) {
         sem_wait(&self->started);
         self->sibling_count++;
     }
 
     /* Signal the threads to clean up*/
     pthread_mutex_lock(&self->mutex);
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
 
     /* Ensure diverging sibling failed to call prctl. */
     PTHREAD_JOIN(self->sibling[0].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
     PTHREAD_JOIN(self->sibling[1].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
 }
 
 TEST_F(TSYNC, two_siblings_with_ancestor)
 {
     long ret;
     void *status;
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
     }
     tsync_start_sibling(&self->sibling[0]);
     tsync_start_sibling(&self->sibling[1]);
 
     while (self->sibling_count < TSYNC_SIBLINGS) {
         sem_wait(&self->started);
         self->sibling_count++;
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
               &self->apply_prog);
     ASSERT_EQ(0, ret) {
         TH_LOG("Could install filter on all threads!");
     }
     /* Tell the siblings to test the policy */
     pthread_mutex_lock(&self->mutex);
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
     /* Ensure they are both killed and don't exit cleanly. */
     PTHREAD_JOIN(self->sibling[0].tid, &status);
     EXPECT_EQ(0x0, (long)status);
     PTHREAD_JOIN(self->sibling[1].tid, &status);
     EXPECT_EQ(0x0, (long)status);
 }
 
 TEST_F(TSYNC, two_sibling_want_nnp)
 {
     void *status;
 
     /* start siblings before any prctl() operations */
     tsync_start_sibling(&self->sibling[0]);
     tsync_start_sibling(&self->sibling[1]);
     while (self->sibling_count < TSYNC_SIBLINGS) {
         sem_wait(&self->started);
         self->sibling_count++;
     }
 
     /* Tell the siblings to test no policy */
     pthread_mutex_lock(&self->mutex);
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
 
     /* Ensure they are both upset about lacking nnp. */
     PTHREAD_JOIN(self->sibling[0].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
     PTHREAD_JOIN(self->sibling[1].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
 }
 
 TEST_F(TSYNC, two_siblings_with_no_filter)
 {
     long ret;
     void *status;
 
     /* start siblings before any prctl() operations */
     tsync_start_sibling(&self->sibling[0]);
     tsync_start_sibling(&self->sibling[1]);
     while (self->sibling_count < TSYNC_SIBLINGS) {
         sem_wait(&self->started);
         self->sibling_count++;
     }
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
               &self->apply_prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     ASSERT_EQ(0, ret) {
         TH_LOG("Could install filter on all threads!");
     }
 
     /* Tell the siblings to test the policy */
     pthread_mutex_lock(&self->mutex);
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
 
     /* Ensure they are both killed and don't exit cleanly. */
     PTHREAD_JOIN(self->sibling[0].tid, &status);
     EXPECT_EQ(0x0, (long)status);
     PTHREAD_JOIN(self->sibling[1].tid, &status);
     EXPECT_EQ(0x0, (long)status);
 }
 
 TEST_F(TSYNC, two_siblings_with_one_divergence)
 {
     long ret;
     void *status;
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
     }
     self->sibling[0].diverge = 1;
     tsync_start_sibling(&self->sibling[0]);
     tsync_start_sibling(&self->sibling[1]);
 
     while (self->sibling_count < TSYNC_SIBLINGS) {
         sem_wait(&self->started);
         self->sibling_count++;
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
               &self->apply_prog);
     ASSERT_EQ(self->sibling[0].system_tid, ret) {
         TH_LOG("Did not fail on diverged sibling.");
     }
 
     /* Wake the threads */
     pthread_mutex_lock(&self->mutex);
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
 
     /* Ensure they are both unkilled. */
     PTHREAD_JOIN(self->sibling[0].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
     PTHREAD_JOIN(self->sibling[1].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
 }
 
 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err)
 {
     long ret, flags;
     void *status;
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
     }
     self->sibling[0].diverge = 1;
     tsync_start_sibling(&self->sibling[0]);
     tsync_start_sibling(&self->sibling[1]);
 
     while (self->sibling_count < TSYNC_SIBLINGS) {
         sem_wait(&self->started);
         self->sibling_count++;
     }
 
     flags = SECCOMP_FILTER_FLAG_TSYNC | \
         SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
     ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog);
     ASSERT_EQ(ESRCH, errno) {
         TH_LOG("Did not return ESRCH for diverged sibling.");
     }
     ASSERT_EQ(-1, ret) {
         TH_LOG("Did not fail on diverged sibling.");
     }
 
     /* Wake the threads */
     pthread_mutex_lock(&self->mutex);
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
 
     /* Ensure they are both unkilled. */
     PTHREAD_JOIN(self->sibling[0].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
     PTHREAD_JOIN(self->sibling[1].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
 }
 
 TEST_F(TSYNC, two_siblings_not_under_filter)
 {
     long ret, sib;
     void *status;
     struct timespec delay = { .tv_nsec = 100000000 };
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     /*
      * Sibling 0 will have its own seccomp policy
      * and Sibling 1 will not be under seccomp at
      * all. Sibling 1 will enter seccomp and 0
      * will cause failure.
      */
     self->sibling[0].diverge = 1;
     tsync_start_sibling(&self->sibling[0]);
     tsync_start_sibling(&self->sibling[1]);
 
     while (self->sibling_count < TSYNC_SIBLINGS) {
         sem_wait(&self->started);
         self->sibling_count++;
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
     }
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
               &self->apply_prog);
     ASSERT_EQ(ret, self->sibling[0].system_tid) {
         TH_LOG("Did not fail on diverged sibling.");
     }
     sib = 1;
     if (ret == self->sibling[0].system_tid)
         sib = 0;
 
     pthread_mutex_lock(&self->mutex);
 
     /* Increment the other siblings num_waits so we can clean up
      * the one we just saw.
      */
     self->sibling[!sib].num_waits += 1;
 
     /* Signal the thread to clean up*/
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
     PTHREAD_JOIN(self->sibling[sib].tid, &status);
     EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
     /* Poll for actual task death. pthread_join doesn't guarantee it. */
     while (!kill(self->sibling[sib].system_tid, 0))
         nanosleep(&delay, NULL);
     /* Switch to the remaining sibling */
     sib = !sib;
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
               &self->apply_prog);
     ASSERT_EQ(0, ret) {
         TH_LOG("Expected the remaining sibling to sync");
     };
 
     pthread_mutex_lock(&self->mutex);
 
     /* If remaining sibling didn't have a chance to wake up during
      * the first broadcast, manually reduce the num_waits now.
      */
     if (self->sibling[sib].num_waits > 1)
         self->sibling[sib].num_waits = 1;
     ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
         TH_LOG("cond broadcast non-zero");
     }
     pthread_mutex_unlock(&self->mutex);
     PTHREAD_JOIN(self->sibling[sib].tid, &status);
     EXPECT_EQ(0, (long)status);
     /* Poll for actual task death. pthread_join doesn't guarantee it. */
     while (!kill(self->sibling[sib].system_tid, 0))
         nanosleep(&delay, NULL);
 
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
               &self->apply_prog);
     ASSERT_EQ(0, ret);  /* just us chickens */
 }
 
 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
 TEST(syscall_restart)
 {
     long ret;
     unsigned long msg;
     pid_t child_pid;
     int pipefd[2];
     int status;
     siginfo_t info = { };
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
              offsetof(struct seccomp_data, nr)),
 
 #ifdef __NR_sigreturn
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0),
 #endif
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
 
         /* Allow __NR_write for easy logging. */
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
         /* The nanosleep jump target. */
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
         /* The restart_syscall jump target. */
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
 #if defined(__arm__)
     struct utsname utsbuf;
 #endif
 
     ASSERT_EQ(0, pipe(pipefd));
 
     child_pid = fork();
     ASSERT_LE(0, child_pid);
     if (child_pid == 0) {
         /* Child uses EXPECT not ASSERT to deliver status correctly. */
         char buf = ' ';
         struct timespec timeout = { };
 
         /* Attach parent as tracer and stop. */
         EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
         EXPECT_EQ(0, raise(SIGSTOP));
 
         EXPECT_EQ(0, close(pipefd[1]));
 
         EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
             TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
         }
 
         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
         EXPECT_EQ(0, ret) {
             TH_LOG("Failed to install filter!");
         }
 
         EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
             TH_LOG("Failed to read() sync from parent");
         }
         EXPECT_EQ('.', buf) {
             TH_LOG("Failed to get sync data from read()");
         }
 
         /* Start nanosleep to be interrupted. */
         timeout.tv_sec = 1;
         errno = 0;
         EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
             TH_LOG("Call to nanosleep() failed (errno %d)", errno);
         }
 
         /* Read final sync from parent. */
         EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
             TH_LOG("Failed final read() from parent");
         }
         EXPECT_EQ('!', buf) {
             TH_LOG("Failed to get final data from read()");
         }
 
         /* Directly report the status of our test harness results. */
         syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
                              : EXIT_FAILURE);
     }
     EXPECT_EQ(0, close(pipefd[0]));
 
     /* Attach to child, setup options, and release. */
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
     ASSERT_EQ(true, WIFSTOPPED(status));
     ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
                 PTRACE_O_TRACESECCOMP));
     ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
     ASSERT_EQ(1, write(pipefd[1], ".", 1));
 
     /* Wait for nanosleep() to start. */
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
     ASSERT_EQ(true, WIFSTOPPED(status));
     ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
     ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
     ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
     ASSERT_EQ(0x100, msg);
     ret = get_syscall(_metadata, child_pid);
     EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep);
 
     /* Might as well check siginfo for sanity while we're here. */
     ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
     ASSERT_EQ(SIGTRAP, info.si_signo);
     ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
     EXPECT_EQ(0, info.si_errno);
     EXPECT_EQ(getuid(), info.si_uid);
     /* Verify signal delivery came from child (seccomp-triggered). */
     EXPECT_EQ(child_pid, info.si_pid);
 
     /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
     ASSERT_EQ(0, kill(child_pid, SIGSTOP));
     ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
     ASSERT_EQ(true, WIFSTOPPED(status));
     ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
     ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
     /*
      * There is no siginfo on SIGSTOP any more, so we can't verify
      * signal delivery came from parent now (getpid() == info.si_pid).
      * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
      * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
      */
     EXPECT_EQ(SIGSTOP, info.si_signo);
 
     /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
     ASSERT_EQ(0, kill(child_pid, SIGCONT));
     ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
     ASSERT_EQ(true, WIFSTOPPED(status));
     ASSERT_EQ(SIGCONT, WSTOPSIG(status));
     ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
 
     /* Wait for restart_syscall() to start. */
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
     ASSERT_EQ(true, WIFSTOPPED(status));
     ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
     ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
     ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
 
     ASSERT_EQ(0x200, msg);
     ret = get_syscall(_metadata, child_pid);
 #if defined(__arm__)
     /*
      * FIXME:
      * - native ARM registers do NOT expose true syscall.
      * - compat ARM registers on ARM64 DO expose true syscall.
      */
     ASSERT_EQ(0, uname(&utsbuf));
     if (strncmp(utsbuf.machine, "arm", 3) == 0) {
         EXPECT_EQ(__NR_nanosleep, ret);
     } else
 #endif
     {
         EXPECT_EQ(__NR_restart_syscall, ret);
     }
 
     /* Write again to end test. */
     ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
     ASSERT_EQ(1, write(pipefd[1], "!", 1));
     EXPECT_EQ(0, close(pipefd[1]));
 
     ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
     if (WIFSIGNALED(status) || WEXITSTATUS(status))
         _metadata->passed = 0;
 }
 
 TEST_SIGNAL(filter_flag_log, SIGSYS)
 {
     struct sock_filter allow_filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_filter kill_filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog allow_prog = {
         .len = (unsigned short)ARRAY_SIZE(allow_filter),
         .filter = allow_filter,
     };
     struct sock_fprog kill_prog = {
         .len = (unsigned short)ARRAY_SIZE(kill_filter),
         .filter = kill_filter,
     };
     long ret;
     pid_t parent = getppid();
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret);
 
     /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
     ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
               &allow_prog);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     EXPECT_NE(0, ret) {
         TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
     }
     EXPECT_EQ(EINVAL, errno) {
         TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
     }
 
     /* Verify that a simple, permissive filter can be added with no flags */
     ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
     EXPECT_EQ(0, ret);
 
     /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
               &allow_prog);
     ASSERT_NE(EINVAL, errno) {
         TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
     }
     EXPECT_EQ(0, ret);
 
     /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
     ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
               &kill_prog);
     EXPECT_EQ(0, ret);
 
     EXPECT_EQ(parent, syscall(__NR_getppid));
     /* getpid() should never return. */
     EXPECT_EQ(0, syscall(__NR_getpid));
 }
 
 TEST(get_action_avail)
 {
     __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
                 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
                 SECCOMP_RET_LOG,   SECCOMP_RET_ALLOW };
     __u32 unknown_action = 0x10000000U;
     int i;
     long ret;
 
     ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
     ASSERT_NE(ENOSYS, errno) {
         TH_LOG("Kernel does not support seccomp syscall!");
     }
     ASSERT_NE(EINVAL, errno) {
         TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
     }
     EXPECT_EQ(ret, 0);
 
     for (i = 0; i < ARRAY_SIZE(actions); i++) {
         ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
         EXPECT_EQ(ret, 0) {
             TH_LOG("Expected action (0x%X) not available!",
                    actions[i]);
         }
     }
 
     /* Check that an unknown action is handled properly (EOPNOTSUPP) */
     ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
     EXPECT_EQ(ret, -1);
     EXPECT_EQ(errno, EOPNOTSUPP);
 }
 
 TEST(get_metadata)
 {
     pid_t pid;
     int pipefd[2];
     char buf;
     struct seccomp_metadata md;
     long ret;
 
     /* Only real root can get metadata. */
     if (geteuid()) {
         SKIP(return, "get_metadata requires real root");
         return;
     }
 
     ASSERT_EQ(0, pipe(pipefd));
 
     pid = fork();
     ASSERT_GE(pid, 0);
     if (pid == 0) {
         struct sock_filter filter[] = {
             BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
         };
         struct sock_fprog prog = {
             .len = (unsigned short)ARRAY_SIZE(filter),
             .filter = filter,
         };
 
         /* one with log, one without */
         EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
                      SECCOMP_FILTER_FLAG_LOG, &prog));
         EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
 
         EXPECT_EQ(0, close(pipefd[0]));
         ASSERT_EQ(1, write(pipefd[1], "1", 1));
         ASSERT_EQ(0, close(pipefd[1]));
 
         while (1)
             sleep(100);
     }
 
     ASSERT_EQ(0, close(pipefd[1]));
     ASSERT_EQ(1, read(pipefd[0], &buf, 1));
 
     ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
     ASSERT_EQ(pid, waitpid(pid, NULL, 0));
 
     /* Past here must not use ASSERT or child process is never killed. */
 
     md.filter_off = 0;
     errno = 0;
     ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
     EXPECT_EQ(sizeof(md), ret) {
         if (errno == EINVAL)
             SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
     }
 
     EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
     EXPECT_EQ(md.filter_off, 0);
 
     md.filter_off = 1;
     ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
     EXPECT_EQ(sizeof(md), ret);
     EXPECT_EQ(md.flags, 0);
     EXPECT_EQ(md.filter_off, 1);
 
 skip:
     ASSERT_EQ(0, kill(pid, SIGKILL));
 }
 
 static int user_notif_syscall(int nr, unsigned int flags)
 {
     struct sock_filter filter[] = {
         BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
             offsetof(struct seccomp_data, nr)),
         BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
 
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
 
     return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
 }
 
 #define USER_NOTIF_MAGIC INT_MAX
 TEST(user_notification_basic)
 {
     pid_t pid;
     long ret;
     int status, listener;
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
     struct pollfd pollfd;
 
     struct sock_filter filter[] = {
         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
     };
     struct sock_fprog prog = {
         .len = (unsigned short)ARRAY_SIZE(filter),
         .filter = filter,
     };
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     /* Check that we get -ENOSYS with no listener attached */
     if (pid == 0) {
         if (user_notif_syscall(__NR_getppid, 0) < 0)
             exit(1);
         ret = syscall(__NR_getppid);
         exit(ret >= 0 || errno != ENOSYS);
     }
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     /* Add some no-op filters for grins. */
     EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
     EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
     EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
     EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
 
     /* Check that the basic notification machinery works */
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     /* Installing a second listener in the chain should EBUSY */
     EXPECT_EQ(user_notif_syscall(__NR_getppid,
                      SECCOMP_FILTER_FLAG_NEW_LISTENER),
           -1);
     EXPECT_EQ(errno, EBUSY);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         ret = syscall(__NR_getppid);
         exit(ret != USER_NOTIF_MAGIC);
     }
 
     pollfd.fd = listener;
     pollfd.events = POLLIN | POLLOUT;
 
     EXPECT_GT(poll(&pollfd, 1, -1), 0);
     EXPECT_EQ(pollfd.revents, POLLIN);
 
     /* Test that we can't pass garbage to the kernel. */
     memset(&req, 0, sizeof(req));
     req.pid = -1;
     errno = 0;
     ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
     EXPECT_EQ(-1, ret);
     EXPECT_EQ(EINVAL, errno);
 
     if (ret) {
         req.pid = 0;
         EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     }
 
     pollfd.fd = listener;
     pollfd.events = POLLIN | POLLOUT;
 
     EXPECT_GT(poll(&pollfd, 1, -1), 0);
     EXPECT_EQ(pollfd.revents, POLLOUT);
 
     EXPECT_EQ(req.data.nr,  __NR_getppid);
 
     resp.id = req.id;
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
 
     /* check that we make sure flags == 0 */
     resp.flags = 1;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
     EXPECT_EQ(errno, EINVAL);
 
     resp.flags = 0;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 }
 
 TEST(user_notification_with_tsync)
 {
     int ret;
     unsigned int flags;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     /* these were exclusive */
     flags = SECCOMP_FILTER_FLAG_NEW_LISTENER |
         SECCOMP_FILTER_FLAG_TSYNC;
     ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags));
     ASSERT_EQ(EINVAL, errno);
 
     /* but now they're not */
     flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
     ret = user_notif_syscall(__NR_getppid, flags);
     close(ret);
     ASSERT_LE(0, ret);
 }
 
 TEST(user_notification_kill_in_middle)
 {
     pid_t pid;
     long ret;
     int listener;
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     /*
      * Check that nothing bad happens when we kill the task in the middle
      * of a syscall.
      */
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         ret = syscall(__NR_getppid);
         exit(ret != USER_NOTIF_MAGIC);
     }
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
 
     EXPECT_EQ(kill(pid, SIGKILL), 0);
     EXPECT_EQ(waitpid(pid, NULL, 0), pid);
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
 
     resp.id = req.id;
     ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
     EXPECT_EQ(ret, -1);
     EXPECT_EQ(errno, ENOENT);
 }
 
 static int handled = -1;
 
 static void signal_handler(int signal)
 {
     if (write(handled, "c", 1) != 1)
         perror("write from signal");
 }
 
 TEST(user_notification_signal)
 {
     pid_t pid;
     long ret;
     int status, listener, sk_pair[2];
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
     char c;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
 
     listener = user_notif_syscall(__NR_gettid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         close(sk_pair[0]);
         handled = sk_pair[1];
         if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
             perror("signal");
             exit(1);
         }
         /*
          * ERESTARTSYS behavior is a bit hard to test, because we need
          * to rely on a signal that has not yet been handled. Let's at
          * least check that the error code gets propagated through, and
          * hope that it doesn't break when there is actually a signal :)
          */
         ret = syscall(__NR_gettid);
         exit(!(ret == -1 && errno == 512));
     }
 
     close(sk_pair[1]);
 
     memset(&req, 0, sizeof(req));
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
 
     EXPECT_EQ(kill(pid, SIGUSR1), 0);
 
     /*
      * Make sure the signal really is delivered, which means we're not
      * stuck in the user notification code any more and the notification
      * should be dead.
      */
     EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
 
     resp.id = req.id;
     resp.error = -EPERM;
     resp.val = 0;
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
     EXPECT_EQ(errno, ENOENT);
 
     memset(&req, 0, sizeof(req));
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
 
     resp.id = req.id;
     resp.error = -512; /* -ERESTARTSYS */
     resp.val = 0;
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 }
 
 TEST(user_notification_closed_listener)
 {
     pid_t pid;
     long ret;
     int status, listener;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     /*
      * Check that we get an ENOSYS when the listener is closed.
      */
     pid = fork();
     ASSERT_GE(pid, 0);
     if (pid == 0) {
         close(listener);
         ret = syscall(__NR_getppid);
         exit(ret != -1 && errno != ENOSYS);
     }
 
     close(listener);
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 }
 
 /*
  * Check that a pid in a child namespace still shows up as valid in ours.
  */
 TEST(user_notification_child_pid_ns)
 {
     pid_t pid;
     int status, listener;
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
 
     ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) {
         if (errno == EINVAL)
             SKIP(return, "kernel missing CLONE_NEWUSER support");
     };
 
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0)
         exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     EXPECT_EQ(req.pid, pid);
 
     resp.id = req.id;
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
     close(listener);
 }
 
 /*
  * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
  * invalid.
  */
 TEST(user_notification_sibling_pid_ns)
 {
     pid_t pid, pid2;
     int status, listener;
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
 
     ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         ASSERT_EQ(unshare(CLONE_NEWPID), 0);
 
         pid2 = fork();
         ASSERT_GE(pid2, 0);
 
         if (pid2 == 0)
             exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
 
         EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
         EXPECT_EQ(true, WIFEXITED(status));
         EXPECT_EQ(0, WEXITSTATUS(status));
         exit(WEXITSTATUS(status));
     }
 
     /* Create the sibling ns, and sibling in it. */
     ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
         if (errno == EPERM)
             SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
     }
     ASSERT_EQ(errno, 0);
 
     pid2 = fork();
     ASSERT_GE(pid2, 0);
 
     if (pid2 == 0) {
         ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
         /*
          * The pid should be 0, i.e. the task is in some namespace that
          * we can't "see".
          */
         EXPECT_EQ(req.pid, 0);
 
         resp.id = req.id;
         resp.error = 0;
         resp.val = USER_NOTIF_MAGIC;
 
         ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
         exit(0);
     }
 
     close(listener);
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 }
 
 TEST(user_notification_fault_recv)
 {
     pid_t pid;
     int status, listener;
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
 
     ASSERT_EQ(unshare(CLONE_NEWUSER), 0) {
         if (errno == EINVAL)
             SKIP(return, "kernel missing CLONE_NEWUSER support");
     }
 
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0)
         exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
 
     /* Do a bad recv() */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
     EXPECT_EQ(errno, EFAULT);
 
     /* We should still be able to receive this notification, though. */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     EXPECT_EQ(req.pid, pid);
 
     resp.id = req.id;
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 }
 
 TEST(seccomp_get_notif_sizes)
 {
     struct seccomp_notif_sizes sizes;
 
     ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
     EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
     EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
 }
 
 TEST(user_notification_continue)
 {
     pid_t pid;
     long ret;
     int status, listener;
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
     struct pollfd pollfd;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         int dup_fd, pipe_fds[2];
         pid_t self;
 
         ASSERT_GE(pipe(pipe_fds), 0);
 
         dup_fd = dup(pipe_fds[0]);
         ASSERT_GE(dup_fd, 0);
         EXPECT_NE(pipe_fds[0], dup_fd);
 
         self = getpid();
         ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0);
         exit(0);
     }
 
     pollfd.fd = listener;
     pollfd.events = POLLIN | POLLOUT;
 
     EXPECT_GT(poll(&pollfd, 1, -1), 0);
     EXPECT_EQ(pollfd.revents, POLLIN);
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
 
     pollfd.fd = listener;
     pollfd.events = POLLIN | POLLOUT;
 
     EXPECT_GT(poll(&pollfd, 1, -1), 0);
     EXPECT_EQ(pollfd.revents, POLLOUT);
 
     EXPECT_EQ(req.data.nr, __NR_dup);
 
     resp.id = req.id;
     resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
 
     /*
      * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
      * args be set to 0.
      */
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
     EXPECT_EQ(errno, EINVAL);
 
     resp.error = USER_NOTIF_MAGIC;
     resp.val = 0;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
     EXPECT_EQ(errno, EINVAL);
 
     resp.error = 0;
     resp.val = 0;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
         if (errno == EINVAL)
             SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
     }
 
 skip:
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status)) {
         if (WEXITSTATUS(status) == 2) {
             SKIP(return, "Kernel does not support kcmp() syscall");
             return;
         }
     }
 }
 
 TEST(user_notification_filter_empty)
 {
     pid_t pid;
     long ret;
     int status;
     struct pollfd pollfd;
     struct __clone_args args = {
         .flags = CLONE_FILES,
         .exit_signal = SIGCHLD,
     };
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     pid = sys_clone3(&args, sizeof(args));
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         int listener;
 
         listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
         if (listener < 0)
             _exit(EXIT_FAILURE);
 
         if (dup2(listener, 200) != 200)
             _exit(EXIT_FAILURE);
 
         close(listener);
 
         _exit(EXIT_SUCCESS);
     }
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     /*
      * The seccomp filter has become unused so we should be notified once
      * the kernel gets around to cleaning up task struct.
      */
     pollfd.fd = 200;
     pollfd.events = POLLHUP;
 
     EXPECT_GT(poll(&pollfd, 1, 2000), 0);
     EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
 }
 
 static void *do_thread(void *data)
 {
     return NULL;
 }
 
 TEST(user_notification_filter_empty_threaded)
 {
     pid_t pid;
     long ret;
     int status;
     struct pollfd pollfd;
     struct __clone_args args = {
         .flags = CLONE_FILES,
         .exit_signal = SIGCHLD,
     };
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     pid = sys_clone3(&args, sizeof(args));
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         pid_t pid1, pid2;
         int listener, status;
         pthread_t thread;
 
         listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
         if (listener < 0)
             _exit(EXIT_FAILURE);
 
         if (dup2(listener, 200) != 200)
             _exit(EXIT_FAILURE);
 
         close(listener);
 
         pid1 = fork();
         if (pid1 < 0)
             _exit(EXIT_FAILURE);
 
         if (pid1 == 0)
             _exit(EXIT_SUCCESS);
 
         pid2 = fork();
         if (pid2 < 0)
             _exit(EXIT_FAILURE);
 
         if (pid2 == 0)
             _exit(EXIT_SUCCESS);
 
         if (pthread_create(&thread, NULL, do_thread, NULL) ||
             pthread_join(thread, NULL))
             _exit(EXIT_FAILURE);
 
         if (pthread_create(&thread, NULL, do_thread, NULL) ||
             pthread_join(thread, NULL))
             _exit(EXIT_FAILURE);
 
         if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) ||
             WEXITSTATUS(status))
             _exit(EXIT_FAILURE);
 
         if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) ||
             WEXITSTATUS(status))
             _exit(EXIT_FAILURE);
 
         exit(EXIT_SUCCESS);
     }
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     /*
      * The seccomp filter has become unused so we should be notified once
      * the kernel gets around to cleaning up task struct.
      */
     pollfd.fd = 200;
     pollfd.events = POLLHUP;
 
     EXPECT_GT(poll(&pollfd, 1, 2000), 0);
     EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
 }
 
 TEST(user_notification_addfd)
 {
     pid_t pid;
     long ret;
     int status, listener, memfd, fd, nextfd;
     struct seccomp_notif_addfd addfd = {};
     struct seccomp_notif_addfd_small small = {};
     struct seccomp_notif_addfd_big big = {};
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
     /* 100 ms */
     struct timespec delay = { .tv_nsec = 100000000 };
 
     /* There may be arbitrary already-open fds at test start. */
     memfd = memfd_create("test", 0);
     ASSERT_GE(memfd, 0);
     nextfd = memfd + 1;
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     /* fd: 4 */
     /* Check that the basic notification machinery works */
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_EQ(listener, nextfd++);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         /* fds will be added and this value is expected */
         if (syscall(__NR_getppid) != USER_NOTIF_MAGIC)
             exit(1);
 
         /* Atomic addfd+send is received here. Check it is a valid fd */
         if (fcntl(syscall(__NR_getppid), F_GETFD) == -1)
             exit(1);
 
         exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
     }
 
     ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
 
     addfd.srcfd = memfd;
     addfd.newfd = 0;
     addfd.id = req.id;
     addfd.flags = 0x0;
 
     /* Verify bad newfd_flags cannot be set */
     addfd.newfd_flags = ~O_CLOEXEC;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
     EXPECT_EQ(errno, EINVAL);
     addfd.newfd_flags = O_CLOEXEC;
 
     /* Verify bad flags cannot be set */
     addfd.flags = 0xff;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
     EXPECT_EQ(errno, EINVAL);
     addfd.flags = 0;
 
     /* Verify that remote_fd cannot be set without setting flags */
     addfd.newfd = 1;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
     EXPECT_EQ(errno, EINVAL);
     addfd.newfd = 0;
 
     /* Verify small size cannot be set */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1);
     EXPECT_EQ(errno, EINVAL);
 
     /* Verify we can't send bits filled in unknown buffer area */
     memset(&big, 0xAA, sizeof(big));
     big.addfd = addfd;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1);
     EXPECT_EQ(errno, E2BIG);
 
 
     /* Verify we can set an arbitrary remote fd */
     fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
     EXPECT_EQ(fd, nextfd++);
     EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
 
     /* Verify we can set an arbitrary remote fd with large size */
     memset(&big, 0x0, sizeof(big));
     big.addfd = addfd;
     fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big);
     EXPECT_EQ(fd, nextfd++);
 
     /* Verify we can set a specific remote fd */
     addfd.newfd = 42;
     addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
     fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
     EXPECT_EQ(fd, 42);
     EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
 
     /* Resume syscall */
     resp.id = req.id;
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     /*
      * This sets the ID of the ADD FD to the last request plus 1. The
      * notification ID increments 1 per notification.
      */
     addfd.id = req.id + 1;
 
     /* This spins until the underlying notification is generated */
     while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
            errno != -EINPROGRESS)
         nanosleep(&delay, NULL);
 
     memset(&req, 0, sizeof(req));
     ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     ASSERT_EQ(addfd.id, req.id);
 
     /* Verify we can do an atomic addfd and send */
     addfd.newfd = 0;
     addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
     fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
     /*
      * Child has earlier "low" fds and now 42, so we expect the next
      * lowest available fd to be assigned here.
      */
     EXPECT_EQ(fd, nextfd++);
     ASSERT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
 
     /*
      * This sets the ID of the ADD FD to the last request plus 1. The
      * notification ID increments 1 per notification.
      */
     addfd.id = req.id + 1;
 
     /* This spins until the underlying notification is generated */
     while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
            errno != -EINPROGRESS)
         nanosleep(&delay, NULL);
 
     memset(&req, 0, sizeof(req));
     ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     ASSERT_EQ(addfd.id, req.id);
 
     resp.id = req.id;
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     /* Wait for child to finish. */
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     close(memfd);
 }
 
 TEST(user_notification_addfd_rlimit)
 {
     pid_t pid;
     long ret;
     int status, listener, memfd;
     struct seccomp_notif_addfd addfd = {};
     struct seccomp_notif req = {};
     struct seccomp_notif_resp resp = {};
     const struct rlimit lim = {
         .rlim_cur   = 0,
         .rlim_max   = 0,
     };
 
     memfd = memfd_create("test", 0);
     ASSERT_GE(memfd, 0);
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     /* Check that the basic notification machinery works */
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0)
         exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
 
 
     ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
 
     ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0);
 
     addfd.srcfd = memfd;
     addfd.newfd_flags = O_CLOEXEC;
     addfd.newfd = 0;
     addfd.id = req.id;
     addfd.flags = 0;
 
     /* Should probably spot check /proc/sys/fs/file-nr */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
     EXPECT_EQ(errno, EMFILE);
 
     addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
     EXPECT_EQ(errno, EMFILE);
 
     addfd.newfd = 100;
     addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
     EXPECT_EQ(errno, EBADF);
 
     resp.id = req.id;
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     /* Wait for child to finish. */
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     close(memfd);
 }
 
 /* Make sure PTRACE_O_SUSPEND_SECCOMP requires CAP_SYS_ADMIN. */
 FIXTURE(O_SUSPEND_SECCOMP) {
     pid_t pid;
 };
 
 FIXTURE_SETUP(O_SUSPEND_SECCOMP)
 {
     ERRNO_FILTER(block_read, E2BIG);
     cap_value_t cap_list[] = { CAP_SYS_ADMIN };
     cap_t caps;
 
     self->pid = 0;
 
     /* make sure we don't have CAP_SYS_ADMIN */
     caps = cap_get_proc();
     ASSERT_NE(NULL, caps);
     ASSERT_EQ(0, cap_set_flag(caps, CAP_EFFECTIVE, 1, cap_list, CAP_CLEAR));
     ASSERT_EQ(0, cap_set_proc(caps));
     cap_free(caps);
 
     ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
     ASSERT_EQ(0, prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_block_read));
 
     self->pid = fork();
     ASSERT_GE(self->pid, 0);
 
     if (self->pid == 0) {
         while (1)
             pause();
         _exit(127);
     }
 }
 
 FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP)
 {
     if (self->pid)
         kill(self->pid, SIGKILL);
 }
 
 TEST_F(O_SUSPEND_SECCOMP, setoptions)
 {
     int wstatus;
 
     ASSERT_EQ(0, ptrace(PTRACE_ATTACH, self->pid, NULL, 0));
     ASSERT_EQ(self->pid, wait(&wstatus));
     ASSERT_EQ(-1, ptrace(PTRACE_SETOPTIONS, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP));
     if (errno == EINVAL)
         SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
     ASSERT_EQ(EPERM, errno);
 }
 
 TEST_F(O_SUSPEND_SECCOMP, seize)
 {
     int ret;
 
     ret = ptrace(PTRACE_SEIZE, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP);
     ASSERT_EQ(-1, ret);
     if (errno == EINVAL)
         SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
     ASSERT_EQ(EPERM, errno);
 }
 
 /*
  * get_nth - Get the nth, space separated entry in a file.
  *
  * Returns the length of the read field.
  * Throws error if field is zero-lengthed.
  */
 static ssize_t get_nth(struct __test_metadata *_metadata, const char *path,
              const unsigned int position, char **entry)
 {
     char *line = NULL;
     unsigned int i;
     ssize_t nread;
     size_t len = 0;
     FILE *f;
 
     f = fopen(path, "r");
     ASSERT_NE(f, NULL) {
         TH_LOG("Could not open %s: %s", path, strerror(errno));
     }
 
     for (i = 0; i < position; i++) {
         nread = getdelim(&line, &len, ' ', f);
         ASSERT_GE(nread, 0) {
             TH_LOG("Failed to read %d entry in file %s", i, path);
         }
     }
     fclose(f);
 
     ASSERT_GT(nread, 0) {
         TH_LOG("Entry in file %s had zero length", path);
     }
 
     *entry = line;
     return nread - 1;
 }
 
 /* For a given PID, get the task state (D, R, etc...) */
 static char get_proc_stat(struct __test_metadata *_metadata, pid_t pid)
 {
     char proc_path[100] = {0};
     char status;
     char *line;
 
     snprintf(proc_path, sizeof(proc_path), "/proc/%d/stat", pid);
     ASSERT_EQ(get_nth(_metadata, proc_path, 3, &line), 1);
 
     status = *line;
     free(line);
 
     return status;
 }
 
 TEST(user_notification_fifo)
 {
     struct seccomp_notif_resp resp = {};
     struct seccomp_notif req = {};
     int i, status, listener;
     pid_t pid, pids[3];
     __u64 baseid;
     long ret;
     /* 100 ms */
     struct timespec delay = { .tv_nsec = 100000000 };
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret) {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     /* Setup a listener */
     listener = user_notif_syscall(__NR_getppid,
                       SECCOMP_FILTER_FLAG_NEW_LISTENER);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         ret = syscall(__NR_getppid);
         exit(ret != USER_NOTIF_MAGIC);
     }
 
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     baseid = req.id + 1;
 
     resp.id = req.id;
     resp.error = 0;
     resp.val = USER_NOTIF_MAGIC;
 
     /* check that we make sure flags == 0 */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     /* Start children, and generate notifications */
     for (i = 0; i < ARRAY_SIZE(pids); i++) {
         pid = fork();
         if (pid == 0) {
             ret = syscall(__NR_getppid);
             exit(ret != USER_NOTIF_MAGIC);
         }
         pids[i] = pid;
     }
 
     /* This spins until all of the children are sleeping */
 restart_wait:
     for (i = 0; i < ARRAY_SIZE(pids); i++) {
         if (get_proc_stat(_metadata, pids[i]) != 'S') {
             nanosleep(&delay, NULL);
             goto restart_wait;
         }
     }
 
     /* Read the notifications in order (and respond) */
     for (i = 0; i < ARRAY_SIZE(pids); i++) {
         memset(&req, 0, sizeof(req));
         EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
         EXPECT_EQ(req.id, baseid + i);
         resp.id = req.id;
         EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
     }
 
     /* Make sure notifications were received */
     for (i = 0; i < ARRAY_SIZE(pids); i++) {
         EXPECT_EQ(waitpid(pids[i], &status, 0), pids[i]);
         EXPECT_EQ(true, WIFEXITED(status));
         EXPECT_EQ(0, WEXITSTATUS(status));
     }
 }
 
 /* get_proc_syscall - Get the syscall in progress for a given pid
  *
  * Returns the current syscall number for a given process
  * Returns -1 if not in syscall (running or blocked)
  */
 static long get_proc_syscall(struct __test_metadata *_metadata, int pid)
 {
     char proc_path[100] = {0};
     long ret = -1;
     ssize_t nread;
     char *line;
 
     snprintf(proc_path, sizeof(proc_path), "/proc/%d/syscall", pid);
     nread = get_nth(_metadata, proc_path, 1, &line);
     ASSERT_GT(nread, 0);
 
     if (!strncmp("running", line, MIN(7, nread)))
         ret = strtol(line, NULL, 16);
 
     free(line);
     return ret;
 }
 
 /* Ensure non-fatal signals prior to receive are unmodified */
 TEST(user_notification_wait_killable_pre_notification)
 {
     struct sigaction new_action = {
         .sa_handler = signal_handler,
     };
     int listener, status, sk_pair[2];
     pid_t pid;
     long ret;
     char c;
     /* 100 ms */
     struct timespec delay = { .tv_nsec = 100000000 };
 
     ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret)
     {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
 
     listener = user_notif_syscall(
         __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
                       SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
     ASSERT_GE(listener, 0);
 
     /*
      * Check that we can kill the process with SIGUSR1 prior to receiving
      * the notification. SIGUSR1 is wired up to a custom signal handler,
      * and make sure it gets called.
      */
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         close(sk_pair[0]);
         handled = sk_pair[1];
 
         /* Setup the non-fatal sigaction without SA_RESTART */
         if (sigaction(SIGUSR1, &new_action, NULL)) {
             perror("sigaction");
             exit(1);
         }
 
         ret = syscall(__NR_getppid);
         /* Make sure we got a return from a signal interruption */
         exit(ret != -1 || errno != EINTR);
     }
 
     /*
      * Make sure we've gotten to the seccomp user notification wait
      * from getppid prior to sending any signals
      */
     while (get_proc_syscall(_metadata, pid) != __NR_getppid &&
            get_proc_stat(_metadata, pid) != 'S')
         nanosleep(&delay, NULL);
 
     /* Send non-fatal kill signal */
     EXPECT_EQ(kill(pid, SIGUSR1), 0);
 
     /* wait for process to exit (exit checks for EINTR) */
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 
     EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
 }
 
 /* Ensure non-fatal signals after receive are blocked */
 TEST(user_notification_wait_killable)
 {
     struct sigaction new_action = {
         .sa_handler = signal_handler,
     };
     struct seccomp_notif_resp resp = {};
     struct seccomp_notif req = {};
     int listener, status, sk_pair[2];
     pid_t pid;
     long ret;
     char c;
     /* 100 ms */
     struct timespec delay = { .tv_nsec = 100000000 };
 
     ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret)
     {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
 
     listener = user_notif_syscall(
         __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
                       SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         close(sk_pair[0]);
         handled = sk_pair[1];
 
         /* Setup the sigaction without SA_RESTART */
         if (sigaction(SIGUSR1, &new_action, NULL)) {
             perror("sigaction");
             exit(1);
         }
 
         /* Make sure that the syscall is completed (no EINTR) */
         ret = syscall(__NR_getppid);
         exit(ret != USER_NOTIF_MAGIC);
     }
 
     /*
      * Get the notification, to make move the notifying process into a
      * non-preemptible (TASK_KILLABLE) state.
      */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     /* Send non-fatal kill signal */
     EXPECT_EQ(kill(pid, SIGUSR1), 0);
 
     /*
      * Make sure the task enters moves to TASK_KILLABLE by waiting for
      * D (Disk Sleep) state after receiving non-fatal signal.
      */
     while (get_proc_stat(_metadata, pid) != 'D')
         nanosleep(&delay, NULL);
 
     resp.id = req.id;
     resp.val = USER_NOTIF_MAGIC;
     /* Make sure the notification is found and able to be replied to */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
 
     /*
      * Make sure that the signal handler does get called once we're back in
      * userspace.
      */
     EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
     /* wait for process to exit (exit checks for USER_NOTIF_MAGIC) */
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFEXITED(status));
     EXPECT_EQ(0, WEXITSTATUS(status));
 }
 
 /* Ensure fatal signals after receive are not blocked */
 TEST(user_notification_wait_killable_fatal)
 {
     struct seccomp_notif req = {};
     int listener, status;
     pid_t pid;
     long ret;
     /* 100 ms */
     struct timespec delay = { .tv_nsec = 100000000 };
 
     ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
     ASSERT_EQ(0, ret)
     {
         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
     }
 
     listener = user_notif_syscall(
         __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
                       SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
     ASSERT_GE(listener, 0);
 
     pid = fork();
     ASSERT_GE(pid, 0);
 
     if (pid == 0) {
         /* This should never complete as it should get a SIGTERM */
         syscall(__NR_getppid);
         exit(1);
     }
 
     while (get_proc_stat(_metadata, pid) != 'S')
         nanosleep(&delay, NULL);
 
     /*
      * Get the notification, to make move the notifying process into a
      * non-preemptible (TASK_KILLABLE) state.
      */
     EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
     /* Kill the process with a fatal signal */
     EXPECT_EQ(kill(pid, SIGTERM), 0);
 
     /*
      * Wait for the process to exit, and make sure the process terminated
      * due to the SIGTERM signal.
      */
     EXPECT_EQ(waitpid(pid, &status, 0), pid);
     EXPECT_EQ(true, WIFSIGNALED(status));
     EXPECT_EQ(SIGTERM, WTERMSIG(status));
 }
 
 /*
  * TODO:
  * - expand NNP testing
  * - better arch-specific TRACE and TRAP handlers.
  * - endianness checking when appropriate
  * - 64-bit arg prodding
  * - arch value testing (x86 modes especially)
  * - verify that FILTER_FLAG_LOG filters generate log messages
  * - verify that RET_LOG generates log messages
  */
 
 TEST_HARNESS_MAIN