Commit b5a63254 authored Aug 03, 2010 by Dave Martin Committed by Arnaldo Carvalho de Melo Aug 04, 2010

perf events: Fix mmap offset determination



Fix buggy-looking code which unnecessarily adjusts the file offset
fields read from /proc/*/maps.

This may have gone unnoticed since the offset is usually 0 (and the
logic in util/symbol.c may work incorrectly for other offset values).

Commiter note:

This fixes a bug introduced in 4af8b35d, there is no need to shift pgoff
twice, the show_map_vma routine in fs/proc/task_mmu.c already converts
it from the number of pages to the size in bytes, and that is what
appears in /proc/PID/map.

Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Will Deacon <Will.Deacon@arm.com>
LKML-Reference: <1280836116-6654-2-git-send-email-dave.martin@linaro.org>
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 12a81c8d

tools/perf/util/event.c

+1 −7

Original line number	Diff line number	Diff line
		@@ -151,7 +151,6 @@ static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
		continue;
		pbf += n + 3;
		if (pbf == 'x') { / vm_exec */
		u64 vm_pgoff;
		char *execname = strchr(bf, '/');

		/* Catch VDSO */
		@@ -162,12 +161,7 @@ static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
		continue;

		pbf += 3;
		n = hex2u64(pbf, &vm_pgoff);
		/* pgoff is in bytes, not pages */
		if (n >= 0)
		ev.mmap.pgoff = vm_pgoff << getpagesize();
		else
		ev.mmap.pgoff = 0;
		n = hex2u64(pbf, &ev.mmap.pgoff);

		size = strlen(execname);
		execname[size - 1] = '\0'; /* Remove \n */