shared/sysdep/stub_64.h

0001 /*
0002  * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
0003  * Licensed under the GPL
0004  */
0005
0006 #ifndef __SYSDEP_STUB_H
0007 #define __SYSDEP_STUB_H
0008
0009 #include <sysdep/ptrace_user.h>
0010 #include <generated/asm-offsets.h>
0011 #include <linux/stddef.h>
0012
0013 #define STUB_MMAP_NR __NR_mmap
0014 #define MMAP_OFFSET(o) (o)
0015
0016 #define __syscall_clobber "r11","rcx","memory"
0017 #define __syscall "syscall"
0018
0019 static inline long stub_syscall0(long syscall)
0020 {
0021     long ret;
0022
0023     __asm__ volatile (__syscall
0024         : "=a" (ret)
0025         : "0" (syscall) : __syscall_clobber );
0026
0027     return ret;
0028 }
0029
0030 static inline long stub_syscall2(long syscall, long arg1, long arg2)
0031 {
0032     long ret;
0033
0034     __asm__ volatile (__syscall
0035         : "=a" (ret)
0036         : "0" (syscall), "D" (arg1), "S" (arg2) : __syscall_clobber );
0037
0038     return ret;
0039 }
0040
0041 static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
0042 {
0043     long ret;
0044
0045     __asm__ volatile (__syscall
0046         : "=a" (ret)
0047         : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3)
0048         : __syscall_clobber );
0049
0050     return ret;
0051 }
0052
0053 static inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
0054                  long arg4)
0055 {
0056     long ret;
0057
0058     __asm__ volatile ("movq %5,%%r10 ; " __syscall
0059         : "=a" (ret)
0060         : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
0061           "g" (arg4)
0062         : __syscall_clobber, "r10" );
0063
0064     return ret;
0065 }
0066
0067 static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
0068                  long arg4, long arg5)
0069 {
0070     long ret;
0071
0072     __asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; " __syscall
0073         : "=a" (ret)
0074         : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
0075           "g" (arg4), "g" (arg5)
0076         : __syscall_clobber, "r10", "r8" );
0077
0078     return ret;
0079 }
0080
0081 static inline void trap_myself(void)
0082 {
0083     __asm("int3");
0084 }
0085
0086 static inline void remap_stack_and_trap(void)
0087 {
0088     __asm__ volatile (
0089         "movq %0,%%rax ;"
0090         "movq %%rsp,%%rdi ;"
0091         "andq %1,%%rdi ;"
0092         "movq %2,%%r10 ;"
0093         "movq %%rdi,%%r8 ; addq %3,%%r8 ; movq (%%r8),%%r8 ;"
0094         "movq %%rdi,%%r9 ; addq %4,%%r9 ; movq (%%r9),%%r9 ;"
0095         __syscall ";"
0096         "movq %%rsp,%%rdi ; andq %1,%%rdi ;"
0097         "addq %5,%%rdi ; movq %%rax, (%%rdi) ;"
0098         "int3"
0099         : :
0100         "g" (STUB_MMAP_NR),
0101         "g" (~(UM_KERN_PAGE_SIZE - 1)),
0102         "g" (MAP_FIXED | MAP_SHARED),
0103         "g" (UML_STUB_FIELD_FD),
0104         "g" (UML_STUB_FIELD_OFFSET),
0105         "g" (UML_STUB_FIELD_CHILD_ERR),
0106         "S" (UM_KERN_PAGE_SIZE),
0107         "d" (PROT_READ | PROT_WRITE)
0108         :
0109         __syscall_clobber, "r10", "r8", "r9");
0110 }
0111
0112 static __always_inline void *get_stub_page(void)
0113 {
0114     unsigned long ret;
0115
0116     asm volatile (
0117         "movq %%rsp,%0 ;"
0118         "andq %1,%0"
0119         : "=a" (ret)
0120         : "g" (~(UM_KERN_PAGE_SIZE - 1)));
0121
0122     return (void *)ret;
0123 }
0124 #endif