linux-kernel - [PATCH] trace/ftrace.c: remove redundant swap function

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed,  9 Sep 2015 23:27:02 +0200
From:	Rasmus Villemoes <linux@...musvillemoes.dk>
To:	Steven Rostedt <rostedt@...dmis.org>,
	Ingo Molnar <mingo@...hat.com>
Cc:	Rasmus Villemoes <linux@...musvillemoes.dk>,
	linux-kernel@...r.kernel.org
Subject: [PATCH] trace/ftrace.c: remove redundant swap function

To cover the common case of sorting an array of pointers, Daniel
Wagner recently modified the library sort() to use a specific swap
function for size==8, in addition to the size==4 case which was
already handled. Since sizeof(long) is either 4 or 8,
ftrace_swap_ips() is redundant and we can just let sort() pick an
appropriate and fast swap callback.

Signed-off-by: Rasmus Villemoes <linux@...musvillemoes.dk>
---
 kernel/trace/ftrace.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b0623ac785a2..186bafa9935d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4783,17 +4783,6 @@ static int ftrace_cmp_ips(const void *a, const void *b)
 	return 0;
 }
 
-static void ftrace_swap_ips(void *a, void *b, int size)
-{
-	unsigned long *ipa = a;
-	unsigned long *ipb = b;
-	unsigned long t;
-
-	t = *ipa;
-	*ipa = *ipb;
-	*ipb = t;
-}
-
 static int ftrace_process_locs(struct module *mod,
 			       unsigned long *start,
 			       unsigned long *end)
@@ -4813,7 +4802,7 @@ static int ftrace_process_locs(struct module *mod,
 		return 0;
 
 	sort(start, count, sizeof(*start),
-	     ftrace_cmp_ips, ftrace_swap_ips);
+	     ftrace_cmp_ips, NULL);
 
 	start_pg = ftrace_allocate_pages(count);
 	if (!start_pg)
-- 
2.1.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/