On Wed, Oct 04, 2023 at 01:17:00PM -0700, Andrew Morton wrote:
>
> The patch titled
> Subject: selftests: proc: add /proc/$(pid)/statm output validation
> has been added to the -mm mm-nonmm-unstable branch. Its filename is
> selftests-proc-add-proc-pid-statm-output-validation.patch
>
> This patch will shortly appear at
> https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-proc-add-proc-pid-statm-output-validation.patch
>
> This patch will later appear in the mm-nonmm-unstable branch at
> git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>
> Before you just go and hit "reply", please:
> a) Consider who else should be cc'ed
> b) Prefer to cc a suitable mailing list as well
> c) Ideally: find the original patch on the mailing list and do a
> reply-to-all to that, adding suitable additional cc's
>
> *** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
>
> The -mm tree is included into linux-next via the mm-everything
> branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> and is updated there every 2-3 working days
>
> ------------------------------------------------------
> From: Swarup Laxman Kotiaklapudi <[email protected]>
> Subject: selftests: proc: add /proc/$(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/$(pid)/statm and check except for 4th position, all
> other positions have value zero.
>
> Link: https://lkml.kernel.org/r/[email protected]
> Signed-off-by: Swarup Laxman Kotiaklapudi <[email protected]>
> Cc: Alexey Dobriyan <[email protected]>
> Cc: Hugh Dickins <[email protected]>
> Cc: Shuah Khan <[email protected]>
> Signed-off-by: Andrew Morton <[email protected]>
> ---
>
> tools/testing/selftests/proc/proc-empty-vm.c | 57 +++++++++++++++--
> 1 file changed, 52 insertions(+), 5 deletions(-)
>
> --- a/tools/testing/selftests/proc/proc-empty-vm.c~selftests-proc-add-proc-pid-statm-output-validation
> +++ a/tools/testing/selftests/proc/proc-empty-vm.c
> @@ -303,6 +303,56 @@ static int test_proc_pid_smaps_rollup(pi
> }
> }
>
> +static int test_proc_pid_statm(pid_t pid)
> +{
> + char buf[4096];
> + char *tok;
> + char *string;
> + int non_zero_value_indx = 4;
> + int i = 1;
> +
> + snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
> +
> + /*
> + * Output can be "0 0 0 2 0 0 0\n" where "2" can be anything.
> + */
> + int fd = open(buf, O_RDONLY);
> +
> + if (fd == -1) {
> + if (errno == ENOENT) {
> + /*
> + * /proc/${pid}/statm is under CONFIG_PROC_PAGE_MONITOR,
> + * it doesn't necessarily exist.
> + */
> + return EXIT_SUCCESS;
> + }
> + perror("open /proc/${pid}/statm");
> + return EXIT_FAILURE;
> + } else {
> + ssize_t rv = read(fd, buf, sizeof(buf));
> +
> + close(fd);
> + assert(rv);
> + string = buf;
> +
> + while ((tok = strsep(&string, " ")) != NULL) {
This is unreliable too. read() doesn't terminate the buffer so this relies
on termination from
snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
Buggy kernel could return a lot of data and overwrite it.
On Mon, Oct 09, 2023 at 09:14:53AM +0300, Alexey Dobriyan wrote:
> On Wed, Oct 04, 2023 at 01:17:00PM -0700, Andrew Morton wrote:
> > + if (errno == ENOENT) {
> > + /*
> > + * /proc/${pid}/statm is under CONFIG_PROC_PAGE_MONITOR,
> > + * it doesn't necessarily exist.
Oh, and /proc/*/statm is _not_ under CONFIG_PROC_PAGE_MONITOR,
it always exists.
eOn Mon, Oct 09, 2023 at 09:14:53AM +0300, Alexey Dobriyan wrote:
> On Wed, Oct 04, 2023 at 01:17:00PM -0700, Andrew Morton wrote:
> >
> > The patch titled
> > Subject: selftests: proc: add /proc/$(pid)/statm output validation
> > has been added to the -mm mm-nonmm-unstable branch. Its filename is
> > selftests-proc-add-proc-pid-statm-output-validation.patch
> >
> > This patch will shortly appear at
> > https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-proc-add-proc-pid-statm-output-validation.patch
> >
> > This patch will later appear in the mm-nonmm-unstable branch at
> > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> >
> > Before you just go and hit "reply", please:
> > a) Consider who else should be cc'ed
> > b) Prefer to cc a suitable mailing list as well
> > c) Ideally: find the original patch on the mailing list and do a
> > reply-to-all to that, adding suitable additional cc's
> >
> > *** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
> >
> > The -mm tree is included into linux-next via the mm-everything
> > branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> > and is updated there every 2-3 working days
> >
> > ------------------------------------------------------
> > From: Swarup Laxman Kotiaklapudi <[email protected]>
> > Subject: selftests: proc: add /proc/$(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/$(pid)/statm and check except for 4th position, all
> > other positions have value zero.
> >
> > Link: https://lkml.kernel.org/r/[email protected]
> > Signed-off-by: Swarup Laxman Kotiaklapudi <[email protected]>
> > Cc: Alexey Dobriyan <[email protected]>
> > Cc: Hugh Dickins <[email protected]>
> > Cc: Shuah Khan <[email protected]>
> > Signed-off-by: Andrew Morton <[email protected]>
> > ---
> >
> > tools/testing/selftests/proc/proc-empty-vm.c | 57 +++++++++++++++--
> > 1 file changed, 52 insertions(+), 5 deletions(-)
> >
> > --- a/tools/testing/selftests/proc/proc-empty-vm.c~selftests-proc-add-proc-pid-statm-output-validation
> > +++ a/tools/testing/selftests/proc/proc-empty-vm.c
> > @@ -303,6 +303,56 @@ static int test_proc_pid_smaps_rollup(pi
> > }
> > }
> >
> > +static int test_proc_pid_statm(pid_t pid)
> > +{
> > + char buf[4096];
> > + char *tok;
> > + char *string;
> > + int non_zero_value_indx = 4;
> > + int i = 1;
> > +
> > + snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
> > +
> > + /*
> > + * Output can be "0 0 0 2 0 0 0\n" where "2" can be anything.
> > + */
> > + int fd = open(buf, O_RDONLY);
> > +
> > + if (fd == -1) {
> > + if (errno == ENOENT) {
> > + /*
> > + * /proc/${pid}/statm is under CONFIG_PROC_PAGE_MONITOR,
> > + * it doesn't necessarily exist.
> > + */
> > + return EXIT_SUCCESS;
> > + }
> > + perror("open /proc/${pid}/statm");
> > + return EXIT_FAILURE;
> > + } else {
> > + ssize_t rv = read(fd, buf, sizeof(buf));
> > +
> > + close(fd);
> > + assert(rv);
> > + string = buf;
> > +
> > + while ((tok = strsep(&string, " ")) != NULL) {
>
> This is unreliable too. read() doesn't terminate the buffer so this relies
> on termination from
>
> snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
>
> Buggy kernel could return a lot of data and overwrite it.
Hi Alexey Dobriyan,
I will try to correct read() function.
Thanks,
Swarup
esOn Mon, Oct 09, 2023 at 12:00:04PM +0300, Alexey Dobriyan wrote:
> On Mon, Oct 09, 2023 at 09:14:53AM +0300, Alexey Dobriyan wrote:
> > On Wed, Oct 04, 2023 at 01:17:00PM -0700, Andrew Morton wrote:
>
> > > + if (errno == ENOENT) {
> > > + /*
> > > + * /proc/${pid}/statm is under CONFIG_PROC_PAGE_MONITOR,
> > > + * it doesn't necessarily exist.
>
> Oh, and /proc/*/statm is _not_ under CONFIG_PROC_PAGE_MONITOR,
> it always exists.
Hi Alexey Dobriyan,
It is my mistake, i checked the code, yes it always exists.
Thanks,
Swarup