From f56ebf20d0f535f5da7cfcf0000ab3e0af133f81 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Tue, 19 Apr 2016 00:07:18 +0100 Subject: [PATCH] perf jit: memset() variable 'st' using the correct size MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 #include #include #include 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 Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Peter Zijlstra Cc: Stephane Eranian 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 --- 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 52fcef3074fe..86afe9618bb0 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)); -- 2.39.2