From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Linux MIPS <linux-mips@linux-mips.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Michael Clark <michaeljclark@mac.com>,
Paul Burton <paul.burton@mips.com>,
RISC-V Patches <patches@groups.riscv.org>,
Linux RISC-V <linux-riscv@lists.infradead.org>
Subject: [PATCH 4.19 75/78] MIPS: fix truncation in __cmpxchg_small for short values
Date: Mon, 4 Mar 2019 09:22:58 +0100 [thread overview]
Message-ID: <20190304081628.949874227@linuxfoundation.org> (raw)
In-Reply-To: <20190304081625.508788074@linuxfoundation.org>
4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael Clark <michaeljclark@mac.com>
commit 94ee12b507db8b5876e31c9d6c9d84f556a4b49f upstream.
__cmpxchg_small erroneously uses u8 for load comparison which can
be either char or short. This patch changes the local variable to
u32 which is sufficiently sized, as the loaded value is already
masked and shifted appropriately. Using an integer size avoids
any unnecessary canonicalization from use of non native widths.
This patch is part of a series that adapts the MIPS small word
atomics code for xchg and cmpxchg on short and char to RISC-V.
Cc: RISC-V Patches <patches@groups.riscv.org>
Cc: Linux RISC-V <linux-riscv@lists.infradead.org>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Signed-off-by: Michael Clark <michaeljclark@mac.com>
[paul.burton@mips.com:
- Fix varialble typo per Jonas Gorski.
- Consolidate load variable with other declarations.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 3ba7f44d2b19 ("MIPS: cmpxchg: Implement 1 byte & 2 byte cmpxchg()")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/mips/kernel/cmpxchg.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/arch/mips/kernel/cmpxchg.c
+++ b/arch/mips/kernel/cmpxchg.c
@@ -54,10 +54,9 @@ unsigned long __xchg_small(volatile void
unsigned long __cmpxchg_small(volatile void *ptr, unsigned long old,
unsigned long new, unsigned int size)
{
- u32 mask, old32, new32, load32;
+ u32 mask, old32, new32, load32, load;
volatile u32 *ptr32;
unsigned int shift;
- u8 load;
/* Check that ptr is naturally aligned */
WARN_ON((unsigned long)ptr & (size - 1));
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
parent reply other threads:[~2019-03-04 8:31 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20190304081625.508788074@linuxfoundation.org>]
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=20190304081628.949874227@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@linux-mips.org \
--cc=linux-riscv@lists.infradead.org \
--cc=michaeljclark@mac.com \
--cc=patches@groups.riscv.org \
--cc=paul.burton@mips.com \
--cc=stable@vger.kernel.org \
/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