Merge tag 'perf-urgent-for-mingo-4.14-20171027' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

- Fix memory corruption in the annotation routines because of zero
  length symbols (asm ones) (Ravi Bangoria)

- Fix printing garbage as an error message when re-running the
  lexer events matcher (Jiri Olsa)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 4397a8b6e6cd..aa66791b1bfc 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -606,9 +606,19 @@ static struct arch *arch__find(const char *name)
 int symbol__alloc_hist(struct symbol *sym)
 {
 	struct annotation *notes = symbol__annotation(sym);
-	const size_t size = symbol__size(sym);
+	size_t size = symbol__size(sym);
 	size_t sizeof_sym_hist;
 
+	/*
+	 * Add buffer of one element for zero length symbol.
+	 * When sample is taken from first instruction of
+	 * zero length symbol, perf still resolves it and
+	 * shows symbol name in perf report and allows to
+	 * annotate it.
+	 */
+	if (size == 0)
+		size = 1;
+
 	/* Check for overflow when calculating sizeof_sym_hist */
 	if (size > (SIZE_MAX - sizeof(struct sym_hist)) / sizeof(struct sym_hist_entry))
 		return -1;