59 lines
1.6 KiB
C
59 lines
1.6 KiB
C
/*
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* Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <unistd.h>
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#include <sys/syscall.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <string.h>
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#include <stdio.h>
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static inline ssize_t sys_read(int fd, void *buf, size_t len)
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{
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return syscall(SYS_read, fd, buf, len);
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}
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int main(void)
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{
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char buf1[64];
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char buf2[64];
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int fd;
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ssize_t rv;
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fd = open("/proc/self/syscall", O_RDONLY);
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if (fd == -1) {
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if (errno == ENOENT)
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return 4;
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return 1;
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}
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/* Do direct system call as libc can wrap anything. */
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snprintf(buf1, sizeof(buf1), "%ld 0x%lx 0x%lx 0x%lx",
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(long)SYS_read, (long)fd, (long)buf2, (long)sizeof(buf2));
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memset(buf2, 0, sizeof(buf2));
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rv = sys_read(fd, buf2, sizeof(buf2));
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if (rv < 0)
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return 1;
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if (rv < strlen(buf1))
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return 1;
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if (strncmp(buf1, buf2, strlen(buf1)) != 0)
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return 1;
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return 0;
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}
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