~kris/suckless

slock

3abbffa4934a62146e995ee7c2cf3ba50991b4ad — FRIGN 10 years ago 6a52a85 
Simplify the oom-taming-function

There really is no need to source a defined variable from a linux
header. The OOM-rank ranges from -1000 to 1000, so we can safely
hardcode -1000, which is a sane thing to do given slock is suid and
we don't want to play around too much here anyway.

On another notice, let's not forget that this still is a shitty
heuristic. The OOM-killer still can kill us (thus I also changed
the wording in the error-message. We do not disable the OOM-killer,
we're just hiding.
patch browse .tar.gz .zip 
1 files changed, 6 insertions(+), 14 deletions(-)

M slock.c

M slock.c => slock.c +6 -14
@@ 60,28 60,20 @@ die(const char *errstr, ...)

#ifdef __linux__
#include <fcntl.h>
#include <linux/oom.h>

static void
dontkillme(void)
{
	int fd;
	int length;
	char value[64];

	fd = open("/proc/self/oom_score_adj", O_WRONLY);
	if (fd < 0 && errno == ENOENT)
	if (fd < 0 && errno == ENOENT) {
		return;

	/* convert OOM_SCORE_ADJ_MIN to string for writing */
	length = snprintf(value, sizeof(value), "%d\n", OOM_SCORE_ADJ_MIN);

	/* bail on truncation */
	if (length >= sizeof(value))
		die("buffer too small\n");

	if (fd < 0 || write(fd, value, length) != length || close(fd) != 0)
		die("cannot disable the out-of-memory killer for this process (make sure to suid or sgid slock)\n");
	}
	if (fd < 0 || write(fd, "-1000\n", (sizeof("-1000\n") - 1)) !=
	    (sizeof("-1000\n") - 1) || close(fd) != 0) {
		die("can't tame the oom-killer. is suid or sgid set?\n");
	}
}
#endif