On Thu, Nov 07, 2013 at 12:09:59PM +0100, Eric Bénard wrote: > From: Nicolas Pitre <[email protected]> > > 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. > > * For stable 3.4.x : > this patch allows the kernel to boot when compiled with recent GCC > (tested with gcc 4.8.1 on and ARMv7 target) > > This patch is in master : > 418df63a ARM: 7670/1: fix the memset fix > and depends on : > 455bd4c ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) > optimizations
Thanks Eric, I'm queuing both of these commits for the 3.5 kernel. Cheers, -- Luis > > Signed-off-by: Nicolas Pitre <[email protected]> Tested-by: Alexander > Holler <[email protected]> Signed-off-by: Russell King > <[email protected]> Cc: <[email protected]> # 3.4.x: > 455bd4c ARM: 7668/1: fix memset-related crashes caused by recent GCC > (4.7.2) optimizations Cc: <[email protected]> # 3.4.x --- > arch/arm/lib/memset.S | 33 +++++++++++++-------------------- 1 file > changed, 13 insertions(+), 20 deletions(-) > > diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S > index d912e73..94b0650 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 > @@ -127,4 +111,13 @@ 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) > -- > 1.8.3.1 > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
