public inbox for stable@vger.kernel.org
 help / color / mirror / Atom feed
From: Huacai Chen <chenhc@lemote.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: John Crispin <john@phrozen.org>,
	"Steven J . Hill" <Steven.Hill@cavium.com>,
	linux-mips@linux-mips.org, Fuxin Zhang <zhangfx@lemote.com>,
	Zhangjin Wu <wuzhangjin@gmail.com>,
	Huacai Chen <chenhc@lemote.com>,
	stable@vger.kernel.org
Subject: [PATCH] MIPS: Fix a long-standing mistake in mips_atomic_set()
Date: Thu, 22 Jun 2017 18:45:45 +0800	[thread overview]
Message-ID: <1498128345-6827-1-git-send-email-chenhc@lemote.com> (raw)

This mistake comes from the commit f1e39a4a616cd99 ("MIPS: Rewrite
sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler"). In the
common case 'bnez' should be 'beqz' (as same as older kernels before
2.6.32), otherwise this syscall may cause an endless loop.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhc@lemote.com>
---
 arch/mips/kernel/syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 1dfa7f5..95e1b30 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -134,7 +134,7 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new)
 		"1:	ll	%[old], (%[addr])			\n"
 		"	move	%[tmp], %[new]				\n"
 		"2:	sc	%[tmp], (%[addr])			\n"
-		"	bnez	%[tmp], 4f				\n"
+		"	beqz	%[tmp], 4f				\n"
 		"3:							\n"
 		"	.insn						\n"
 		"	.subsection 2					\n"
-- 
2.7.0

             reply	other threads:[~2017-06-22 10:45 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-22 10:45 Huacai Chen [this message]
2017-06-22 12:31 ` [PATCH] MIPS: Fix a long-standing mistake in mips_atomic_set() James Hogan
2017-06-22 12:50   ` Ralf Baechle

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1498128345-6827-1-git-send-email-chenhc@lemote.com \
    --to=chenhc@lemote.com \
    --cc=Steven.Hill@cavium.com \
    --cc=john@phrozen.org \
    --cc=linux-mips@linux-mips.org \
    --cc=ralf@linux-mips.org \
    --cc=stable@vger.kernel.org \
    --cc=wuzhangjin@gmail.com \
    --cc=zhangfx@lemote.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox