Messages in this thread | | | Date | Thu, 24 Aug 2023 15:52:05 +0300 (EEST) | From | Ilpo Järvinen <> | Subject | Re: [PATCH 1/3] selftests/resctrl: Fix schemata write error check |
| |
Ki,
You're lacking a few people from the To/Cc list. Please see KERNEL SELFTEST FRAMEWORK entry in MAINTAINERS.
On Thu, 24 Aug 2023, Wieczor-Retman, Maciej wrote:
> Writing bitmasks to the schemata can fail when the bitmask doesn't > adhere to some constraints defined by what a particular CPU supports. > Some example of constraints are max length or being having contiguous
"being having" is not good English.
> bits. The driver should properly return errors when any rule concerning > bitmask format is broken. > > Resctrl FS returns error codes from fprintf() only when fclose() is > called.
I wonder if this is actually related to libc doing buffering between fprintf() and the actual write() syscall.
> Current error checking scheme allows invalid bitmasks to be > written into schemata file and the selftest doesn't notice because the > fclose() error code isn't checked. > > Add error check to the fclose() call. > > Add perror() just after fprintf so a proper error message can be seen. > > Signed-off-by: Wieczor-Retman, Maciej <maciej.wieczor-retman@intel.com> > --- > tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c > index bd36ee206602..a6d0b632cbc6 100644 > --- a/tools/testing/selftests/resctrl/resctrlfs.c > +++ b/tools/testing/selftests/resctrl/resctrlfs.c > @@ -532,13 +532,17 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val) > } > > if (fprintf(fp, "%s\n", schema) < 0) { > - sprintf(reason, "Failed to write schemata in control group"); > + sprintf(reason, "fprintf() failed with error : %s", > + strerror(errno));
These should use snprintf() to make sure the buffer does not overflow.
> fclose(fp); > ret = -1; > > goto out; > } > - fclose(fp); > + ret = fclose(fp); > + if (ret) > + sprintf(reason, "Failed to write schemata in control group : %s", > + strerror(errno)); > > out: > ksft_print_msg("Write schema \"%s\" to resctrl FS%s%s\n", >
-- i.
| |