linux/tools/testing/selftests/proc/proc-self-wchan.c
Alexey Dobriyan 9cd6565558 proc: test /proc/self/wchan
This patch starts testing /proc.  Many more tests to come (I promise).

Read from /proc/self/wchan should always return "0" as current is in
TASK_RUNNING state while reading /proc/self/wchan.

Link: http://lkml.kernel.org/r/20180226212006.GA742@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>
2018-04-11 10:28:34 -07:00

26 lines
368 B
C

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
int main(void)
{
char buf[64];
int fd;
fd = open("/proc/self/wchan", O_RDONLY);
if (fd == -1) {
if (errno == ENOENT)
return 2;
return 1;
}
buf[0] = '\0';
if (read(fd, buf, sizeof(buf)) != 1)
return 1;
if (buf[0] != '0')
return 1;
return 0;
}