LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
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 11:17:11 -0300	[thread overview]
Message-ID: <YTto5xw/XSMuiGrG@kernel.org> (raw)
In-Reply-To: <YTtnpAcaCNYozoJF@kernel.org>

Em Fri, Sep 10, 2021 at 11:11:48AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Sep 10, 2021 at 11:08:02AM -0300, Arnaldo Carvalho de Melo escreveu:
> > 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.
> 
> So below is the minimal fix, the other cases the compiler somehow thinks
> its ok, so I'll keep as is, will just remove the sizeof(string) to
> sizeof(var), as I did below for the offending case.

End result:

diff --git a/tools/perf/util/amd-sample-raw.c b/tools/perf/util/amd-sample-raw.c
index fc1f670e88562b2e..fbb7d61c50489374 100644
--- a/tools/perf/util/amd-sample-raw.c
+++ b/tools/perf/util/amd-sample-raw.c
@@ -106,7 +106,7 @@ static void pr_ibs_op_data2(union ibs_op_data2 reg)
 static void pr_ibs_op_data3(union ibs_op_data3 reg)
 {
 	char l2_miss_str[sizeof(" L2Miss _")] = "";
-	char op_mem_width_str[sizeof(" OpMemWidth __ bytes")] = "";
+	char op_mem_width_str[sizeof(" OpMemWidth _____ bytes")] = "";
 	char op_dc_miss_open_mem_reqs_str[sizeof(" OpDcMissOpenMemReqs __")] = "";
 
 	/*
@@ -114,14 +114,13 @@ static void pr_ibs_op_data3(union ibs_op_data3 reg)
 	 * Ignore L2Miss and OpDcMissOpenMemReqs (and opdata2) if DcMissNoMabAlloc or SwPf set
 	 */
 	if (!(cpu_family == 0x19 && cpu_model < 0x10 && (reg.dc_miss_no_mab_alloc || reg.sw_pf))) {
-		snprintf(l2_miss_str, sizeof(" L2Miss _"),
-			 " L2Miss %d", reg.l2_miss);
-		snprintf(op_dc_miss_open_mem_reqs_str, sizeof(" OpDcMissOpenMemReqs __"),
+		snprintf(l2_miss_str, sizeof(l2_miss_str), " L2Miss %d", reg.l2_miss);
+		snprintf(op_dc_miss_open_mem_reqs_str, sizeof(op_dc_miss_open_mem_reqs_str),
 			 " OpDcMissOpenMemReqs %2d", reg.op_dc_miss_open_mem_reqs);
 	}
 
 	if (reg.op_mem_width)
-		snprintf(op_mem_width_str, sizeof(" OpMemWidth __ bytes"),
+		snprintf(op_mem_width_str, sizeof(op_mem_width_str),
 			 " OpMemWidth %2d bytes", 1 << (reg.op_mem_width - 1));
 
 	printf("ibs_op_data3:\t%016llx LdOp %d StOp %d DcL1TlbMiss %d DcL2TlbMiss %d "

  reply	other threads:[~2021-09-10 14:17 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-17 22:15 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
2021-09-10 14:11       ` Arnaldo Carvalho de Melo
2021-09-10 14:17         ` Arnaldo Carvalho de Melo [this message]
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=YTto5xw/XSMuiGrG@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 \
    --subject='Re: [PATCH 0/3] perf report: Add support to print a textual representation of IBS raw sample data' \
    /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

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).