sparc/kernel/sys_sparc_32.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* linux/arch/sparc/kernel/sys_sparc.c
0003  *
0004  * This file contains various random system calls that
0005  * have a non-standard calling sequence on the Linux/sparc
0006  * platform.
0007  */
0008
0009 #include <linux/errno.h>
0010 #include <linux/types.h>
0011 #include <linux/sched/signal.h>
0012 #include <linux/sched/mm.h>
0013 #include <linux/sched/debug.h>
0014 #include <linux/mm.h>
0015 #include <linux/fs.h>
0016 #include <linux/file.h>
0017 #include <linux/sem.h>
0018 #include <linux/msg.h>
0019 #include <linux/shm.h>
0020 #include <linux/stat.h>
0021 #include <linux/syscalls.h>
0022 #include <linux/mman.h>
0023 #include <linux/utsname.h>
0024 #include <linux/smp.h>
0025 #include <linux/ipc.h>
0026
0027 #include <linux/uaccess.h>
0028 #include <asm/unistd.h>
0029
0030 #include "systbls.h"
0031
0032 /* #define DEBUG_UNIMP_SYSCALL */
0033
0034 /* XXX Make this per-binary type, this way we can detect the type of
0035  * XXX a binary.  Every Sparc executable calls this very early on.
0036  */
0037 SYSCALL_DEFINE0(getpagesize)
0038 {
0039     return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
0040 }
0041
0042 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
0043 {
0044     struct vm_unmapped_area_info info;
0045
0046     if (flags & MAP_FIXED) {
0047         /* We do not accept a shared mapping if it would violate
0048          * cache aliasing constraints.
0049          */
0050         if ((flags & MAP_SHARED) &&
0051             ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
0052             return -EINVAL;
0053         return addr;
0054     }
0055
0056     /* See asm-sparc/uaccess.h */
0057     if (len > TASK_SIZE - PAGE_SIZE)
0058         return -ENOMEM;
0059     if (!addr)
0060         addr = TASK_UNMAPPED_BASE;
0061
0062     info.flags = 0;
0063     info.length = len;
0064     info.low_limit = addr;
0065     info.high_limit = TASK_SIZE;
0066     info.align_mask = (flags & MAP_SHARED) ?
0067         (PAGE_MASK & (SHMLBA - 1)) : 0;
0068     info.align_offset = pgoff << PAGE_SHIFT;
0069     return vm_unmapped_area(&info);
0070 }
0071
0072 /*
0073  * sys_pipe() is the normal C calling standard for creating
0074  * a pipe. It's not the way unix traditionally does this, though.
0075  */
0076 SYSCALL_DEFINE0(sparc_pipe)
0077 {
0078     int fd[2];
0079     int error;
0080
0081     error = do_pipe_flags(fd, 0);
0082     if (error)
0083         goto out;
0084     current_pt_regs()->u_regs[UREG_I1] = fd[1];
0085     error = fd[0];
0086 out:
0087     return error;
0088 }
0089
0090 int sparc_mmap_check(unsigned long addr, unsigned long len)
0091 {
0092     /* See asm-sparc/uaccess.h */
0093     if (len > TASK_SIZE - PAGE_SIZE || addr + len > TASK_SIZE - PAGE_SIZE)
0094         return -EINVAL;
0095
0096     return 0;
0097 }
0098
0099 /* Linux version of mmap */
0100
0101 SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
0102     unsigned long, prot, unsigned long, flags, unsigned long, fd,
0103     unsigned long, pgoff)
0104 {
0105     /* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
0106        we have. */
0107     return ksys_mmap_pgoff(addr, len, prot, flags, fd,
0108                    pgoff >> (PAGE_SHIFT - 12));
0109 }
0110
0111 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
0112     unsigned long, prot, unsigned long, flags, unsigned long, fd,
0113     unsigned long, off)
0114 {
0115     /* no alignment check? */
0116     return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
0117 }
0118
0119 SYSCALL_DEFINE5(sparc_remap_file_pages, unsigned long, start, unsigned long, size,
0120                unsigned long, prot, unsigned long, pgoff,
0121                unsigned long, flags)
0122 {
0123     /* This works on an existing mmap so we don't need to validate
0124      * the range as that was done at the original mmap call.
0125      */
0126     return sys_remap_file_pages(start, size, prot,
0127                     (pgoff >> (PAGE_SHIFT - 12)), flags);
0128 }
0129
0130 SYSCALL_DEFINE0(nis_syscall)
0131 {
0132     static int count = 0;
0133     struct pt_regs *regs = current_pt_regs();
0134
0135     if (count++ > 5)
0136         return -ENOSYS;
0137     printk ("%s[%d]: Unimplemented SPARC system call %d\n",
0138         current->comm, task_pid_nr(current), (int)regs->u_regs[1]);
0139 #ifdef DEBUG_UNIMP_SYSCALL
0140     show_regs (regs);
0141 #endif
0142     return -ENOSYS;
0143 }
0144
0145 /* #define DEBUG_SPARC_BREAKPOINT */
0146
0147 asmlinkage void
0148 sparc_breakpoint (struct pt_regs *regs)
0149 {
0150
0151 #ifdef DEBUG_SPARC_BREAKPOINT
0152         printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
0153 #endif
0154     force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);
0155
0156 #ifdef DEBUG_SPARC_BREAKPOINT
0157     printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);
0158 #endif
0159 }
0160
0161 SYSCALL_DEFINE3(sparc_sigaction, int, sig,
0162         struct old_sigaction __user *,act,
0163         struct old_sigaction __user *,oact)
0164 {
0165     WARN_ON_ONCE(sig >= 0);
0166     return sys_sigaction(-sig, act, oact);
0167 }
0168
0169 SYSCALL_DEFINE5(rt_sigaction, int, sig,
0170          const struct sigaction __user *, act,
0171          struct sigaction __user *, oact,
0172          void __user *, restorer,
0173          size_t, sigsetsize)
0174 {
0175     struct k_sigaction new_ka, old_ka;
0176     int ret;
0177
0178     /* XXX: Don't preclude handling different sized sigset_t's.  */
0179     if (sigsetsize != sizeof(sigset_t))
0180         return -EINVAL;
0181
0182     if (act) {
0183         new_ka.ka_restorer = restorer;
0184         if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
0185             return -EFAULT;
0186     }
0187
0188     ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
0189
0190     if (!ret && oact) {
0191         if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
0192             return -EFAULT;
0193     }
0194
0195     return ret;
0196 }
0197
0198 SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
0199 {
0200     int nlen, err;
0201     char tmp[__NEW_UTS_LEN + 1];
0202
0203     if (len < 0)
0204         return -EINVAL;
0205
0206     down_read(&uts_sem);
0207
0208     nlen = strlen(utsname()->domainname) + 1;
0209     err = -EINVAL;
0210     if (nlen > len)
0211         goto out_unlock;
0212     memcpy(tmp, utsname()->domainname, nlen);
0213
0214     up_read(&uts_sem);
0215
0216     if (copy_to_user(name, tmp, nlen))
0217         return -EFAULT;
0218     return 0;
0219
0220 out_unlock:
0221     up_read(&uts_sem);
0222     return err;
0223 }