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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2013-03-12 13:00:42 +0100 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2013-05-23 08:27:57 +0200 |
| commit | 4586f9626b851a312eae3e452e2be5a5a2cf585d (patch) | |
| tree | dfc7e15f51f90a396686cfe0e5dc754ff2a13f8c | |
| parent | 2683e56174705d4c13bd773b3066eb308ae6e801 (diff) | |
| download | barebox-4586f9626b851a312eae3e452e2be5a5a2cf585d.tar.gz barebox-4586f9626b851a312eae3e452e2be5a5a2cf585d.tar.xz | |
ARM: fix the memset fix
From Kernel commit 418df63a ARM: 7670/1: fix the memset fix
| Commit 455bd4c430b0 ("ARM: 7668/1: fix memset-related crashes caused by
| recent GCC (4.7.2) optimizations") attempted to fix a compliance issue
| with the memset return value. However the memset itself became broken
| by that patch for misaligned pointers.
|
| This fixes the above by branching over the entry code from the
| misaligned fixup code to avoid reloading the original pointer.
|
| Also, because the function entry alignment is wrong in the Thumb mode
| compilation, that fixup code is moved to the end.
|
| While at it, the entry instructions are slightly reworked to help dual
| issue pipelines.
|
| Signed-off-by: Nicolas Pitre <nico@linaro.org>
| Tested-by: Alexander Holler <holler@ahsoftware.de>
| Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
| -rw-r--r-- | arch/arm/lib/memset.S | 33 |
1 files changed, 13 insertions, 20 deletions
diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S index 5e35d7f5f6..c4d2672038 100644 --- a/arch/arm/lib/memset.S +++ b/arch/arm/lib/memset.S @@ -14,31 +14,15 @@ .text .align 5 - .word 0 - -1: subs r2, r2, #4 @ 1 do we have enough - blt 5f @ 1 bytes to align with? - cmp r3, #2 @ 1 - strltb r1, [ip], #1 @ 1 - strleb r1, [ip], #1 @ 1 - strb r1, [ip], #1 @ 1 - add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3)) -/* - * The pointer is now aligned and the length is adjusted. Try doing the - * memset again. - */ ENTRY(memset) -/* - * Preserve the contents of r0 for the return value. - */ - mov ip, r0 - ands r3, ip, #3 @ 1 unaligned? - bne 1b @ 1 + ands r3, r0, #3 @ 1 unaligned? + mov ip, r0 @ preserve r0 as return value + bne 6f @ 1 /* * we know that the pointer in ip is aligned to a word boundary. */ - orr r1, r1, r1, lsl #8 +1: orr r1, r1, r1, lsl #8 orr r1, r1, r1, lsl #16 mov r3, r1 cmp r2, #16 @@ -127,5 +111,14 @@ ENTRY(memset) tst r2, #1 strneb r1, [ip], #1 mov pc, lr + +6: subs r2, r2, #4 @ 1 do we have enough + blt 5b @ 1 bytes to align with? + cmp r3, #2 @ 1 + strltb r1, [ip], #1 @ 1 + strleb r1, [ip], #1 @ 1 + strb r1, [ip], #1 @ 1 + add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3)) + b 1b ENDPROC(memset) |