lkml.org 
[lkml]   [2023]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: + selftests-proc-add-proc-pid-statm-output-validation.patch added to mm-nonmm-unstable branch
On Wed, Oct 04, 2023 at 01:17:00PM -0700, Andrew Morton wrote:
>
> The patch titled
> Subject: selftests: proc: add /proc/$(pid)/statm output validation
> has been added to the -mm mm-nonmm-unstable branch. Its filename is
> selftests-proc-add-proc-pid-statm-output-validation.patch
>
> This patch will shortly appear at
> https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-proc-add-proc-pid-statm-output-validation.patch
>
> This patch will later appear in the mm-nonmm-unstable branch at
> git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>
> Before you just go and hit "reply", please:
> a) Consider who else should be cc'ed
> b) Prefer to cc a suitable mailing list as well
> c) Ideally: find the original patch on the mailing list and do a
> reply-to-all to that, adding suitable additional cc's
>
> *** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
>
> The -mm tree is included into linux-next via the mm-everything
> branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> and is updated there every 2-3 working days
>
> ------------------------------------------------------
> From: Swarup Laxman Kotiaklapudi <swarupkotikalapudi@gmail.com>
> Subject: selftests: proc: add /proc/$(pid)/statm output validation
> Date: Wed, 4 Oct 2023 01:13:19 +0530
>
> Add /proc/${pid}/statm validation
>
> /proc/$(pid)/statm output is expected to be:
> "0 0 0 * 0 0 0\n"
> Here * can be any value
>
> Read output of /proc/$(pid)/statm and check except for 4th position, all
> other positions have value zero.
>
> Link: https://lkml.kernel.org/r/20231003194319.602646-1-swarupkotikalapudi@gmail.com
> Signed-off-by: Swarup Laxman Kotiaklapudi <swarupkotikalapudi@gmail.com>
> Cc: Alexey Dobriyan <adobriyan@gmail.com>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: Shuah Khan <shuah@kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>
> tools/testing/selftests/proc/proc-empty-vm.c | 57 +++++++++++++++--
> 1 file changed, 52 insertions(+), 5 deletions(-)
>
> --- a/tools/testing/selftests/proc/proc-empty-vm.c~selftests-proc-add-proc-pid-statm-output-validation
> +++ a/tools/testing/selftests/proc/proc-empty-vm.c
> @@ -303,6 +303,56 @@ static int test_proc_pid_smaps_rollup(pi
> }
> }
>
> +static int test_proc_pid_statm(pid_t pid)
> +{
> + char buf[4096];
> + char *tok;
> + char *string;
> + int non_zero_value_indx = 4;
> + int i = 1;
> +
> + snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
> +
> + /*
> + * Output can be "0 0 0 2 0 0 0\n" where "2" can be anything.
> + */
> + int fd = open(buf, O_RDONLY);
> +
> + if (fd == -1) {
> + if (errno == ENOENT) {
> + /*
> + * /proc/${pid}/statm is under CONFIG_PROC_PAGE_MONITOR,
> + * it doesn't necessarily exist.
> + */
> + return EXIT_SUCCESS;
> + }
> + perror("open /proc/${pid}/statm");
> + return EXIT_FAILURE;
> + } else {
> + ssize_t rv = read(fd, buf, sizeof(buf));
> +
> + close(fd);
> + assert(rv);
> + string = buf;
> +
> + while ((tok = strsep(&string, " ")) != NULL) {

This is unreliable too. read() doesn't terminate the buffer so this relies
on termination from

snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);

Buggy kernel could return a lot of data and overwrite it.

\
 
 \ /
  Last update: 2023-10-09 08:15    [W:0.047 / U:26.552 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site