From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Kim Phillips <kim.phillips@amd.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Ian Rogers <irogers@google.com>, Ingo Molnar <mingo@redhat.com>,
Jiri Olsa <jolsa@redhat.com>,
Joao Martins <joao.m.martins@oracle.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Mark Rutland <mark.rutland@arm.com>,
Michael Petlan <mpetlan@redhat.com>,
Namhyung Kim <namhyung@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Robert Richter <robert.richter@amd.com>,
Stephane Eranian <eranian@google.com>,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org
Subject: Re: [PATCH 0/3] perf report: Add support to print a textual representation of IBS raw sample data
Date: Fri, 10 Sep 2021 11:08:02 -0300 [thread overview]
Message-ID: <YTtmwrZ6iy0TzG3l@kernel.org> (raw)
In-Reply-To: <YTth5DLWGbyAzxvQ@kernel.org>
Em Fri, Sep 10, 2021 at 10:47:16AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, Sep 09, 2021 at 04:58:12PM -0500, Kim Phillips escreveu:
> > Hi Arnaldo,
> >
> > Can you please take a look at applying this series? Its kernel-side
> > dependent series has already been applied and is in Linus' master.
>
> Sure, I'm now trying to fix this:
>
> CC /tmp/build/perf/util/amd-sample-raw.o
> util/amd-sample-raw.c: In function ‘evlist__amd_sample_raw’:
> util/amd-sample-raw.c:125:42: error: ‘ bytes’ directive output may be truncated writing 6 bytes into a region of size between 4 and 7 [-Werror=format-truncation=]
> 125 | " OpMemWidth %2d bytes", 1 << (reg.op_mem_width - 1));
> | ^~~~~~
> In file included from /usr/include/stdio.h:866,
> from util/amd-sample-raw.c:7:
> /usr/include/bits/stdio2.h:71:10: note: ‘__builtin___snprintf_chk’ output between 21 and 24 bytes into a destination of size 21
> 71 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 72 | __glibc_objsize (__s), __fmt,
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 73 | __va_arg_pack ());
> | ~~~~~~~~~~~~~~~~~
> cc1: all warnings being treated as errors
> make[4]: *** [/var/home/acme/git/perf/tools/build/Makefile.build:96: /tmp/build/perf/util/amd-sample-raw.o] Error 1
So, that trick with using sizeof and that string 3 times is cumbersome
and prone to truncation, at least the compiler can't say that the number
you're passing to %2d will have just 2 digits:
[acme@quaco c]$ cat printf.c
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
char bf[64];
int len = snprintf(bf, sizeof(bf), "%2d", atoi(argv[1]));
printf("strlen(%s): %u\n", bf, len);
return 0;
}
[acme@quaco c]$ ./printf 1234567
strlen(1234567): 7
[acme@quaco c]$
I'm trying to rework this.
- Arnaldo
next prev parent reply other threads:[~2021-09-10 14:08 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-17 22:15 [PATCH 0/3] perf report: Add support to print a textual representation of IBS raw sample data Kim Phillips
2021-08-17 22:15 ` [PATCH 1/3] perf env: Add perf_env__cpuid, perf_env__{nr_}pmu_mappings Kim Phillips
2021-08-17 22:15 ` [PATCH 2/3] perf report: Add tools/arch/x86/include/asm/amd-ibs.h Kim Phillips
2021-08-17 22:15 ` [PATCH 3/3] perf report: Add support to print a textual representation of IBS raw sample data Kim Phillips
2021-09-09 21:58 ` [PATCH 0/3] " Kim Phillips
2021-09-10 13:47 ` Arnaldo Carvalho de Melo
2021-09-10 14:08 ` Arnaldo Carvalho de Melo [this message]
2021-09-10 14:11 ` Arnaldo Carvalho de Melo
2021-09-10 14:17 ` Arnaldo Carvalho de Melo
2021-09-10 19:48 ` Another bug: " Arnaldo Carvalho de Melo
2021-09-10 20:58 ` Arnaldo Carvalho de Melo
2021-09-10 21:40 ` Arnaldo Carvalho de Melo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YTtmwrZ6iy0TzG3l@kernel.org \
--to=acme@kernel.org \
--cc=acme@redhat.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=boris.ostrovsky@oracle.com \
--cc=eranian@google.com \
--cc=irogers@google.com \
--cc=joao.m.martins@oracle.com \
--cc=jolsa@redhat.com \
--cc=kim.phillips@amd.com \
--cc=konrad.wilk@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=mpetlan@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=robert.richter@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).