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| author | Andreas Larsson <andreas@gaisler.com> | 2014-08-29 17:08:21 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-10-31 15:05:17 +0100 |
| commit | 9e9b1c45d28215e49d10e3595cf4ee67480adf2f (patch) | |
| tree | e1d2294229a969c591929f5258dbd2f97bf26da9 | |
| parent | 0f4b3a2ea626749e2a04181d2488876b5460463b (diff) | |
| download | lwn-9e9b1c45d28215e49d10e3595cf4ee67480adf2f.tar.gz lwn-9e9b1c45d28215e49d10e3595cf4ee67480adf2f.zip | |
sparc: Let memset return the address argument
[ 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>
| -rw-r--r-- | arch/sparc/lib/memset.S | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/sparc/lib/memset.S b/arch/sparc/lib/memset.S index 99c017be8719..f75e6906df14 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: |