Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1382098 > unrolled thread
| Started by | Colin King <colin.king@canonical.com> |
|---|---|
| First post | 2016-04-19 01:10 +0200 |
| Last post | 2016-04-23 15:10 +0200 |
| Articles | 4 — 3 participants |
Back to article view | Back to linux.kernel
[PATCH] perf jit: memset variable st using the correct size Colin King <colin.king@canonical.com> - 2016-04-19 01:10 +0200
Re: [PATCH] perf jit: memset variable st using the correct size rnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-19 15:50 +0200
Re: [PATCH] perf jit: memset variable st using the correct size rnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-19 16:00 +0200
[tip:perf/core] perf jit: memset() variable 'st' using the correct size tip-bot for Colin Ian King <tipbot@zytor.com> - 2016-04-23 15:10 +0200
| From | Colin King <colin.king@canonical.com> |
|---|---|
| Date | 2016-04-19 01:10 +0200 |
| Subject | [PATCH] perf jit: memset variable st using the correct size |
| Message-ID | <rpqsP-5sV-19@gated-at.bofh.it> |
From: Colin Ian King <colin.king@canonical.com> The current code is memsetting the struct stat variable st with the size of stat (which turns out to be 1 byte) rather than the size of variable sz. Signed-off-by: Colin Ian King <colin.king@canonical.com> --- tools/perf/util/jitdump.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c index 52fcef3..86afe96 100644 --- a/tools/perf/util/jitdump.c +++ b/tools/perf/util/jitdump.c @@ -412,7 +412,7 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr) return -1; } if (stat(filename, &st)) - memset(&st, 0, sizeof(stat)); + memset(&st, 0, sizeof(st)); event->mmap2.header.type = PERF_RECORD_MMAP2; event->mmap2.header.misc = PERF_RECORD_MISC_USER; @@ -500,7 +500,7 @@ static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr) size++; /* for \0 */ if (stat(filename, &st)) - memset(&st, 0, sizeof(stat)); + memset(&st, 0, sizeof(st)); size = PERF_ALIGN(size, sizeof(u64)); -- 2.7.4
[toc] | [next] | [standalone]
| From | rnaldo Carvalho de Melo <acme@kernel.org> |
|---|---|
| Date | 2016-04-19 15:50 +0200 |
| Message-ID | <rpEcp-7GG-1@gated-at.bofh.it> |
| In reply to | #1382098 |
Em Tue, Apr 19, 2016 at 12:07:18AM +0100, Colin King escreveu: > From: Colin Ian King <colin.king@canonical.com> > > The current code is memsetting the struct stat variable st with > the size of stat (which turns out to be 1 byte) rather than the > size of variable sz. Thanks, applied. - Arnaldo > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > tools/perf/util/jitdump.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c > index 52fcef3..86afe96 100644 > --- a/tools/perf/util/jitdump.c > +++ b/tools/perf/util/jitdump.c > @@ -412,7 +412,7 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr) > return -1; > } > if (stat(filename, &st)) > - memset(&st, 0, sizeof(stat)); > + memset(&st, 0, sizeof(st)); > > event->mmap2.header.type = PERF_RECORD_MMAP2; > event->mmap2.header.misc = PERF_RECORD_MISC_USER; > @@ -500,7 +500,7 @@ static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr) > size++; /* for \0 */ > > if (stat(filename, &st)) > - memset(&st, 0, sizeof(stat)); > + memset(&st, 0, sizeof(st)); > > size = PERF_ALIGN(size, sizeof(u64)); > > -- > 2.7.4
[toc] | [prev] | [next] | [standalone]
| From | rnaldo Carvalho de Melo <acme@kernel.org> |
|---|---|
| Date | 2016-04-19 16:00 +0200 |
| Message-ID | <rpEm6-7KL-23@gated-at.bofh.it> |
| In reply to | #1382527 |
Em Tue, Apr 19, 2016 at 10:47:41AM -0300, rnaldo Carvalho de Melo escreveu:
> Em Tue, Apr 19, 2016 at 12:07:18AM +0100, Colin King escreveu:
> > From: Colin Ian King <colin.king@canonical.com>
> >
> > The current code is memsetting the struct stat variable st with
> > the size of stat (which turns out to be 1 byte) rather than the
> > size of variable sz.
>
> Thanks, applied.
BTW, its a obvious bug, but I'll add this to the changeset log to
enlighten others ;-)
[acme@jouet c]$ cc -pedantic sizeof_function.c -o sizeof_function
sizeof_function.c: In function ‘main’:
sizeof_function.c:8:46: warning: invalid application of ‘sizeof’ to a function type [-Wpointer-arith]
printf("sizeof(stat)=%zd, stat=%p\n", sizeof(stat), stat);
^
[acme@jouet c]$ ./sizeof_function
sizeof(stat)=1, stat=0x40063
As my expectation was for this to return sizeof(void *) :-\
- Arnaldo
> - Arnaldo
>
> > Signed-off-by: Colin Ian King <colin.king@canonical.com>
> > ---
> > tools/perf/util/jitdump.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
> > index 52fcef3..86afe96 100644
> > --- a/tools/perf/util/jitdump.c
> > +++ b/tools/perf/util/jitdump.c
> > @@ -412,7 +412,7 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
> > return -1;
> > }
> > if (stat(filename, &st))
> > - memset(&st, 0, sizeof(stat));
> > + memset(&st, 0, sizeof(st));
> >
> > event->mmap2.header.type = PERF_RECORD_MMAP2;
> > event->mmap2.header.misc = PERF_RECORD_MISC_USER;
> > @@ -500,7 +500,7 @@ static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr)
> > size++; /* for \0 */
> >
> > if (stat(filename, &st))
> > - memset(&st, 0, sizeof(stat));
> > + memset(&st, 0, sizeof(st));
> >
> > size = PERF_ALIGN(size, sizeof(u64));
> >
> > --
> > 2.7.4
[toc] | [prev] | [next] | [standalone]
| From | tip-bot for Colin Ian King <tipbot@zytor.com> |
|---|---|
| Date | 2016-04-23 15:10 +0200 |
| Subject | [tip:perf/core] perf jit: memset() variable 'st' using the correct size |
| Message-ID | <rr5tT-3ws-3@gated-at.bofh.it> |
| In reply to | #1382098 |
Commit-ID: f56ebf20d0f535f5da7cfcf0000ab3e0af133f81
Gitweb: http://git.kernel.org/tip/f56ebf20d0f535f5da7cfcf0000ab3e0af133f81
Author: Colin Ian King <colin.king@canonical.com>
AuthorDate: Tue, 19 Apr 2016 00:07:18 +0100
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 19 Apr 2016 12:37:01 -0300
perf jit: memset() variable 'st' using the correct size
The current code is memsetting the 'struct stat' variable 'st' with the size of
'stat' (which turns out to be 1 byte) rather than the size of variable 'sz'.
Committer notes:
sizeof(function) isn't valid, the result depends on the compiler used, with
gcc, enabling pedantic warnings we get:
$ cat sizeof_function.c
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
int main(void)
{
printf("sizeof(stat)=%zd, stat=%p\n", sizeof(stat), stat);
return 0;
}
$ readelf -sW sizeof_function | grep -w stat
49: 0000000000400630 16 FUNC WEAK HIDDEN 13 stat
$ cc -pedantic sizeof_function.c -o sizeof_function
sizeof_function.c: In function ‘main’:
sizeof_function.c:8:46: warning: invalid application of ‘sizeof’ to a function type [-Wpointer-arith]
printf("sizeof(stat)=%zd, stat=%p\n", sizeof(stat), stat);
^
$ ./sizeof_function
sizeof(stat)=1, stat=0x400630
$
Standard C, section 6.5.3.4:
"The sizeof operator shall not be applied to an expression that has function
type or an incomplete type, to the parenthesized name of such a type,
or to an expression that designates a bit-field member."
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Fixes: 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support")
Link: http://lkml.kernel.org/r/1461020838-9260-1-git-send-email-colin.king@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/jitdump.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
index 52fcef3..86afe96 100644
--- a/tools/perf/util/jitdump.c
+++ b/tools/perf/util/jitdump.c
@@ -412,7 +412,7 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
return -1;
}
if (stat(filename, &st))
- memset(&st, 0, sizeof(stat));
+ memset(&st, 0, sizeof(st));
event->mmap2.header.type = PERF_RECORD_MMAP2;
event->mmap2.header.misc = PERF_RECORD_MISC_USER;
@@ -500,7 +500,7 @@ static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr)
size++; /* for \0 */
if (stat(filename, &st))
- memset(&st, 0, sizeof(stat));
+ memset(&st, 0, sizeof(st));
size = PERF_ALIGN(size, sizeof(u64));
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web