[PATCH][next] perf annotate: Use struct_size() helper

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes. Also, remove unnecessary
function disasm_line_size().

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 tools/perf/util/annotate.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 76bfb4a9d94e..9330520c34a0 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -43,6 +43,7 @@
 #include <linux/string.h>
 #include <subcmd/parse-options.h>
 #include <subcmd/run-command.h>
+#include <linux/overflow.h>
 
 /* FIXME: For the HE_COLORSET */
 #include "ui/browser.h"
@@ -775,7 +776,7 @@ static int annotated_source__alloc_histograms(struct annotated_source *src,
 	if (size > (SIZE_MAX - sizeof(struct sym_hist)) / sizeof(struct sym_hist_entry))
 		return -1;
 
-	sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(struct sym_hist_entry));
+	sizeof_sym_hist = struct_size(src->histograms, addr, size);
 
 	/* Check for overflow in zalloc argument */
 	if (sizeof_sym_hist > SIZE_MAX / nr_hists)
@@ -1167,13 +1168,6 @@ static void annotation_line__exit(struct annotation_line *al)
 	zfree(&al->line);
 }
 
-static size_t disasm_line_size(int nr)
-{
-	struct annotation_line *al;
-
-	return (sizeof(struct disasm_line) + (sizeof(al->data[0]) * nr));
-}
-
 /*
  * Allocating the disasm annotation line data with
  * following structure:
@@ -1193,7 +1187,7 @@ static struct disasm_line *disasm_line__new(struct annotate_args *args)
 	if (evsel__is_group_event(args->evsel))
 		nr = args->evsel->core.nr_members;
 
-	dl = zalloc(disasm_line_size(nr));
+	dl = zalloc(struct_size(dl, al.data, nr));
 	if (!dl)
 		return NULL;
 
-- 
2.27.0