Re: [hackers] Re: [slock] [PATCH] Slightly safer OOM killer disablement

From: Dimitris Papastamos <sin_AT_2f30.org>
Date: Fri, 19 Jun 2015 12:44:47 +0100

On Fri, Jun 19, 2015 at 11:42:15PM +1200, David Phillips wrote:
> Resubmitting after talking with the guys in IRC, and after noticing
> that whitespace got messed with in my original patch.
>
> --
> Four word witty remark

> 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

Looks good to me.
Received on Fri Jun 19 2015 - 13:44:47 CEST

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