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Subject[PATCH 3.13 035/162] sparc: Let memset return the address argument
Date
3.13.11.11 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andreas Larsson <andreas@gaisler.com>

[ Upstream commit 74cad25c076a2f5253312c2fe82d1a4daecc1323 ]

This makes memset follow the standard (instead of returning 0 on success). This
is needed when certain versions of gcc optimizes around memset calls and assume
that the address argument is preserved in %o0.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
arch/sparc/lib/memset.S | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/arch/sparc/lib/memset.S b/arch/sparc/lib/memset.S
index 99c017b..f75e690 100644
--- a/arch/sparc/lib/memset.S
+++ b/arch/sparc/lib/memset.S
@@ -3,8 +3,9 @@
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
*
- * Returns 0, if ok, and number of bytes not yet set if exception
- * occurs and we were called as clear_user.
+ * Calls to memset returns initial %o0. Calls to bzero returns 0, if ok, and
+ * number of bytes not yet set if exception occurs and we were called as
+ * clear_user.
*/

#include <asm/ptrace.h>
@@ -65,6 +66,8 @@ __bzero_begin:
.globl __memset_start, __memset_end
__memset_start:
memset:
+ mov %o0, %g1
+ mov 1, %g4
and %o1, 0xff, %g3
sll %g3, 8, %g2
or %g3, %g2, %g3
@@ -89,6 +92,7 @@ memset:
sub %o0, %o2, %o0

__bzero:
+ clr %g4
mov %g0, %g3
1:
cmp %o1, 7
@@ -151,8 +155,8 @@ __bzero:
bne,a 8f
EX(stb %g3, [%o0], and %o1, 1)
8:
- retl
- clr %o0
+ b 0f
+ nop
7:
be 13b
orcc %o1, 0, %g0
@@ -164,6 +168,12 @@ __bzero:
bne 8b
EX(stb %g3, [%o0 - 1], add %o1, 1)
0:
+ andcc %g4, 1, %g0
+ be 5f
+ nop
+ retl
+ mov %g1, %o0
+5:
retl
clr %o0
__memset_end:
--
1.9.1


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