proc: test /proc/self/syscall

Read from /proc/self/syscall should yield read system call and correct
args in the output as current is reading /proc/self/syscall.

Link: http://lkml.kernel.org/r/20180226212145.GB742@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan 2018-04-10 16:31:48 -07:00 committed by Linus Torvalds
parent 9cd6565558
commit c4219edf1d
3 changed files with 48 additions and 1 deletions

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@ -1 +1,2 @@
/proc-self-wchan
/proc-self-mem
/proc-self-syscall

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@ -1,6 +1,7 @@
CFLAGS += -Wall -O2
TEST_GEN_PROGS :=
TEST_GEN_PROGS += proc-self-syscall
TEST_GEN_PROGS += proc-self-wchan
include ../lib.mk

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@ -0,0 +1,45 @@
#define _GNU_SOURCE
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
static inline ssize_t sys_read(int fd, void *buf, size_t len)
{
return syscall(SYS_read, fd, buf, len);
}
int main(void)
{
char buf1[64];
char buf2[64];
int fd;
ssize_t rv;
fd = open("/proc/self/syscall", O_RDONLY);
if (fd == -1) {
if (errno == ENOENT)
return 2;
return 1;
}
/* Do direct system call as libc can wrap anything. */
snprintf(buf1, sizeof(buf1), "%ld 0x%lx 0x%lx 0x%lx",
(long)SYS_read, (long)fd, (long)buf2, (long)sizeof(buf2));
memset(buf2, 0, sizeof(buf2));
rv = sys_read(fd, buf2, sizeof(buf2));
if (rv < 0)
return 1;
if (rv < strlen(buf1))
return 1;
if (strncmp(buf1, buf2, strlen(buf1)) != 0)
return 1;
return 0;
}