linux-arch.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jonas Bonn <jonas@southpole.se>
To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Cc: Jonas Bonn <jonas@southpole.se>
Subject: [PATCH 6/6] openrisc: use scratch regs in atomic syscall
Date: Tue,  8 May 2012 11:54:05 +0200	[thread overview]
Message-ID: <1336470845-13859-7-git-send-email-jonas@southpole.se> (raw)
In-Reply-To: <1336470845-13859-1-git-send-email-jonas@southpole.se>


The function sys_or1k_atomic was using call-saved registers without
restoring their value before returning.  This is a faux pas: either
we need to restore their values or use scratch regs; the latter is
less code so that's the route this patch takes.

Thanks to David Hennerström for doing most of the heavy-lifting in
tracking this one down.

Reported-by: Davd Hennerström <david.hennerstrom@aacmicrotec.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
---
 arch/openrisc/kernel/entry.S |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index 6e61af8..ddfcaa8 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -1117,10 +1117,10 @@ ENTRY(sys_rt_sigreturn)
 ENTRY(sys_or1k_atomic)
 	/* FIXME: This ignores r3 and always does an XCHG */
 	DISABLE_INTERRUPTS(r17,r19)
-	l.lwz	r30,0(r4)
-	l.lwz	r28,0(r5)
-	l.sw	0(r4),r28
-	l.sw	0(r5),r30
+	l.lwz	r29,0(r4)
+	l.lwz	r27,0(r5)
+	l.sw	0(r4),r27
+	l.sw	0(r5),r29
 	ENABLE_INTERRUPTS(r17)
 	l.jr	r9
 	 l.or	r11,r0,r0
-- 
1.7.0.4

  parent reply	other threads:[~2012-05-08  9:54 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-08  9:53 [PATCH 0/6] OpenRISC patches for review Jonas Bonn
2012-05-08  9:54 ` [PATCH 1/6] openrisc: implement irqdomains Jonas Bonn
2012-05-08  9:54   ` Jonas Bonn
2012-05-08  9:54 ` [PATCH 2/6] openrisc: remove unnecessary includes Jonas Bonn
2012-05-08  9:54   ` Jonas Bonn
2012-05-08  9:54 ` [PATCH 3/6] openrisc/mm/fault.c: Port OOM changes to do_page_fault Jonas Bonn
2012-05-08  9:54   ` Jonas Bonn
2012-05-08  9:54 ` [PATCH 4/6] openrisc: header file cleanups Jonas Bonn
2012-05-08  9:54   ` Jonas Bonn
2012-05-08  9:54 ` [PATCH 5/6] openrisc: provide dma_map_ops Jonas Bonn
2012-05-08  9:54   ` Jonas Bonn
2012-05-08  9:54 ` Jonas Bonn [this message]
2012-05-08  9:54   ` [PATCH 6/6] openrisc: use scratch regs in atomic syscall Jonas Bonn
2012-05-08 11:24 ` [PATCH 0/6] OpenRISC patches for review Arnd Bergmann

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=1336470845-13859-7-git-send-email-jonas@southpole.se \
    --to=jonas@southpole.se \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@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;
as well as URLs for NNTP newsgroup(s).