[hackers] [slock] Slightly safer OOM killer disablement in linux || David Phillips

From: <git_AT_suckless.org>
Date: Mon, 6 Jul 2015 11:27:03 +0200 (CEST)

commit 0edbd2e0164a8c6cbad415e38083469041f29996
Author: David Phillips <dbphillipsnz_AT_gmail.com>
AuthorDate: Fri Jun 19 23:42:15 2015 +1200
Commit: Markus Teich <markus.teich_AT_stusta.mhn.de>
CommitDate: Mon Jul 6 11:15:07 2015 +0200

    Slightly safer OOM killer disablement in linux

diff --git a/slock.c b/slock.c
index d6053af..b3bee92 100644
--- a/slock.c
+++ b/slock.c
_AT_@ -60,16 +60,27 @@ 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)
                 return;
- if (fd < 0 || write(fd, "-1000\n", 6) != 6 || close(fd) != 0)
+
+ /* 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\n");
 }
 #endif
Received on Mon Jul 06 2015 - 11:27:03 CEST