mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 03:27:39 +00:00
88 lines
3.9 KiB
C
88 lines
3.9 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2022 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/calls/calls.h"
|
|
#include "libc/calls/struct/seccomp.internal.h"
|
|
#include "libc/calls/syscall-sysv.internal.h"
|
|
#include "libc/dce.h"
|
|
#include "libc/errno.h"
|
|
#include "libc/intrin/describeflags.h"
|
|
#include "libc/intrin/strace.h"
|
|
#include "libc/sysv/consts/pr.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
|
|
/**
|
|
* Tunes Linux security policy.
|
|
*
|
|
* This system call was first introduced in Linux 3.17. We polyfill
|
|
* automatically features like SECCOMP_SET_MODE_STRICT, for kernels
|
|
* dating back to 2.6.23, whenever possible.
|
|
*
|
|
* @raise ENOSYS on non-Linux.
|
|
*/
|
|
int seccomp(unsigned operation, unsigned flags, void *args) {
|
|
int rc;
|
|
if (IsLinux()) {
|
|
#ifdef __x86_64__
|
|
asm volatile("syscall"
|
|
: "=a"(rc)
|
|
: "0"(317), "D"(operation), "S"(flags), "d"(args)
|
|
: "rcx", "r11", "memory");
|
|
if (rc == -ENOSYS) {
|
|
if (operation == SECCOMP_SET_MODE_STRICT) {
|
|
asm volatile("syscall"
|
|
: "=a"(rc)
|
|
: "0"(157), "D"(PR_SET_SECCOMP), "S"(SECCOMP_MODE_STRICT)
|
|
: "rcx", "r11", "memory");
|
|
} else if (operation == SECCOMP_SET_MODE_FILTER && !flags) {
|
|
asm volatile("syscall"
|
|
: "=a"(rc)
|
|
: "0"(157), "D"(PR_SET_SECCOMP), "S"(SECCOMP_MODE_FILTER),
|
|
"d"(args)
|
|
: "rcx", "r11", "memory");
|
|
}
|
|
}
|
|
if (rc > -4096u) {
|
|
errno = -rc;
|
|
rc = -1;
|
|
}
|
|
#elif defined(__aarch64__)
|
|
if (IsLinux()) {
|
|
register long r0 asm("x0") = (long)operation;
|
|
register long r1 asm("x1") = (long)flags;
|
|
register long r2 asm("x2") = (long)args;
|
|
register long res_x0 asm("x0");
|
|
asm volatile("mov\tx8,%1\n\t"
|
|
"svc\t0"
|
|
: "=r"(res_x0)
|
|
: "i"(211), "r"(r0), "r"(r1), "r"(r2)
|
|
: "x8", "memory");
|
|
rc = _sysret(res_x0);
|
|
} else {
|
|
rc = enosys();
|
|
}
|
|
#else
|
|
#error "arch unsupported"
|
|
#endif
|
|
} else {
|
|
rc = enosys();
|
|
}
|
|
STRACE("seccomp(%s, %#x, %p) → %d% m", _DescribeSeccompOperation(operation),
|
|
flags, args, rc);
|
|
return rc;
|
|
}
|