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linux-mainline-3.8: Fix random segfaults and boot issues seen with gc…
…c-4.8 These are backports from 3.9, tested boot on beaglebone Signed-off-by: Khem Raj <raj.khem@gmail.com>
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...ux/linux-mainline-3.8/arm/0003-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,256 @@ | ||
| From 59b6bffc07adfa8848519c6c07fff8ad44fa1df8 Mon Sep 17 00:00:00 2001 | ||
| From: Ivan Djelic <ivan.djelic@parrot.com> | ||
| Date: Wed, 6 Mar 2013 20:09:27 +0100 | ||
| Subject: [PATCH] ARM: 7668/1: fix memset-related crashes caused by recent GCC | ||
| (4.7.2) optimizations | ||
|
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| Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on | ||
| assumptions about the implementation of memset and similar functions. | ||
| The current ARM optimized memset code does not return the value of | ||
| its first argument, as is usually expected from standard implementations. | ||
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| For instance in the following function: | ||
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| void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) | ||
| { | ||
| memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); | ||
| waiter->magic = waiter; | ||
| INIT_LIST_HEAD(&waiter->list); | ||
| } | ||
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|
||
| compiled as: | ||
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| 800554d0 <debug_mutex_lock_common>: | ||
| 800554d0: e92d4008 push {r3, lr} | ||
| 800554d4: e1a00001 mov r0, r1 | ||
| 800554d8: e3a02010 mov r2, #16 ; 0x10 | ||
| 800554dc: e3a01011 mov r1, #17 ; 0x11 | ||
| 800554e0: eb04426e bl 80165ea0 <memset> | ||
| 800554e4: e1a03000 mov r3, r0 | ||
| 800554e8: e583000c str r0, [r3, #12] | ||
| 800554ec: e5830000 str r0, [r3] | ||
| 800554f0: e5830004 str r0, [r3, #4] | ||
| 800554f4: e8bd8008 pop {r3, pc} | ||
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| GCC assumes memset returns the value of pointer 'waiter' in register r0; causing | ||
| register/memory corruptions. | ||
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| This patch fixes the return value of the assembly version of memset. | ||
| It adds a 'mov' instruction and merges an additional load+store into | ||
| existing load/store instructions. | ||
| For ease of review, here is a breakdown of the patch into 4 simple steps: | ||
|
|
||
| Step 1 | ||
| ====== | ||
| Perform the following substitutions: | ||
| ip -> r8, then | ||
| r0 -> ip, | ||
| and insert 'mov ip, r0' as the first statement of the function. | ||
| At this point, we have a memset() implementation returning the proper result, | ||
| but corrupting r8 on some paths (the ones that were using ip). | ||
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||
| Step 2 | ||
| ====== | ||
| Make sure r8 is saved and restored when (! CALGN(1)+0) == 1: | ||
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| save r8: | ||
| - str lr, [sp, #-4]! | ||
| + stmfd sp!, {r8, lr} | ||
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||
| and restore r8 on both exit paths: | ||
| - ldmeqfd sp!, {pc} @ Now <64 bytes to go. | ||
| + ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go. | ||
| (...) | ||
| tst r2, #16 | ||
| stmneia ip!, {r1, r3, r8, lr} | ||
| - ldr lr, [sp], #4 | ||
| + ldmfd sp!, {r8, lr} | ||
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||
| Step 3 | ||
| ====== | ||
| Make sure r8 is saved and restored when (! CALGN(1)+0) == 0: | ||
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| save r8: | ||
| - stmfd sp!, {r4-r7, lr} | ||
| + stmfd sp!, {r4-r8, lr} | ||
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||
| and restore r8 on both exit paths: | ||
| bgt 3b | ||
| - ldmeqfd sp!, {r4-r7, pc} | ||
| + ldmeqfd sp!, {r4-r8, pc} | ||
| (...) | ||
| tst r2, #16 | ||
| stmneia ip!, {r4-r7} | ||
| - ldmfd sp!, {r4-r7, lr} | ||
| + ldmfd sp!, {r4-r8, lr} | ||
|
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||
| Step 4 | ||
| ====== | ||
| Rewrite register list "r4-r7, r8" as "r4-r8". | ||
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||
| Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com> | ||
| Reviewed-by: Nicolas Pitre <nico@linaro.org> | ||
| Signed-off-by: Dirk Behme <dirk.behme@gmail.com> | ||
| Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> | ||
| Signed-off-by: Khem Raj <raj.khem@gmail.com> | ||
| --- | ||
| arch/arm/lib/memset.S | 85 +++++++++++++++++++++++++------------------------ | ||
| 1 file changed, 44 insertions(+), 41 deletions(-) | ||
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||
| diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S | ||
| index 650d592..d912e73 100644 | ||
| --- a/arch/arm/lib/memset.S | ||
| +++ b/arch/arm/lib/memset.S | ||
| @@ -19,9 +19,9 @@ | ||
| 1: subs r2, r2, #4 @ 1 do we have enough | ||
| blt 5f @ 1 bytes to align with? | ||
| cmp r3, #2 @ 1 | ||
| - strltb r1, [r0], #1 @ 1 | ||
| - strleb r1, [r0], #1 @ 1 | ||
| - strb r1, [r0], #1 @ 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 | ||
| @@ -29,10 +29,14 @@ | ||
| */ | ||
|
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||
| ENTRY(memset) | ||
| - ands r3, r0, #3 @ 1 unaligned? | ||
| +/* | ||
| + * Preserve the contents of r0 for the return value. | ||
| + */ | ||
| + mov ip, r0 | ||
| + ands r3, ip, #3 @ 1 unaligned? | ||
| bne 1b @ 1 | ||
| /* | ||
| - * we know that the pointer in r0 is aligned to a word boundary. | ||
| + * we know that the pointer in ip is aligned to a word boundary. | ||
| */ | ||
| orr r1, r1, r1, lsl #8 | ||
| orr r1, r1, r1, lsl #16 | ||
| @@ -43,29 +47,28 @@ ENTRY(memset) | ||
| #if ! CALGN(1)+0 | ||
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||
| /* | ||
| - * We need an extra register for this loop - save the return address and | ||
| - * use the LR | ||
| + * We need 2 extra registers for this loop - use r8 and the LR | ||
| */ | ||
| - str lr, [sp, #-4]! | ||
| - mov ip, r1 | ||
| + stmfd sp!, {r8, lr} | ||
| + mov r8, r1 | ||
| mov lr, r1 | ||
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||
| 2: subs r2, r2, #64 | ||
| - stmgeia r0!, {r1, r3, ip, lr} @ 64 bytes at a time. | ||
| - stmgeia r0!, {r1, r3, ip, lr} | ||
| - stmgeia r0!, {r1, r3, ip, lr} | ||
| - stmgeia r0!, {r1, r3, ip, lr} | ||
| + stmgeia ip!, {r1, r3, r8, lr} @ 64 bytes at a time. | ||
| + stmgeia ip!, {r1, r3, r8, lr} | ||
| + stmgeia ip!, {r1, r3, r8, lr} | ||
| + stmgeia ip!, {r1, r3, r8, lr} | ||
| bgt 2b | ||
| - ldmeqfd sp!, {pc} @ Now <64 bytes to go. | ||
| + ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go. | ||
| /* | ||
| * No need to correct the count; we're only testing bits from now on | ||
| */ | ||
| tst r2, #32 | ||
| - stmneia r0!, {r1, r3, ip, lr} | ||
| - stmneia r0!, {r1, r3, ip, lr} | ||
| + stmneia ip!, {r1, r3, r8, lr} | ||
| + stmneia ip!, {r1, r3, r8, lr} | ||
| tst r2, #16 | ||
| - stmneia r0!, {r1, r3, ip, lr} | ||
| - ldr lr, [sp], #4 | ||
| + stmneia ip!, {r1, r3, r8, lr} | ||
| + ldmfd sp!, {r8, lr} | ||
|
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| #else | ||
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| @@ -74,54 +77,54 @@ ENTRY(memset) | ||
| * whole cache lines at once. | ||
| */ | ||
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| - stmfd sp!, {r4-r7, lr} | ||
| + stmfd sp!, {r4-r8, lr} | ||
| mov r4, r1 | ||
| mov r5, r1 | ||
| mov r6, r1 | ||
| mov r7, r1 | ||
| - mov ip, r1 | ||
| + mov r8, r1 | ||
| mov lr, r1 | ||
|
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| cmp r2, #96 | ||
| - tstgt r0, #31 | ||
| + tstgt ip, #31 | ||
| ble 3f | ||
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| - and ip, r0, #31 | ||
| - rsb ip, ip, #32 | ||
| - sub r2, r2, ip | ||
| - movs ip, ip, lsl #(32 - 4) | ||
| - stmcsia r0!, {r4, r5, r6, r7} | ||
| - stmmiia r0!, {r4, r5} | ||
| - tst ip, #(1 << 30) | ||
| - mov ip, r1 | ||
| - strne r1, [r0], #4 | ||
| + and r8, ip, #31 | ||
| + rsb r8, r8, #32 | ||
| + sub r2, r2, r8 | ||
| + movs r8, r8, lsl #(32 - 4) | ||
| + stmcsia ip!, {r4, r5, r6, r7} | ||
| + stmmiia ip!, {r4, r5} | ||
| + tst r8, #(1 << 30) | ||
| + mov r8, r1 | ||
| + strne r1, [ip], #4 | ||
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| 3: subs r2, r2, #64 | ||
| - stmgeia r0!, {r1, r3-r7, ip, lr} | ||
| - stmgeia r0!, {r1, r3-r7, ip, lr} | ||
| + stmgeia ip!, {r1, r3-r8, lr} | ||
| + stmgeia ip!, {r1, r3-r8, lr} | ||
| bgt 3b | ||
| - ldmeqfd sp!, {r4-r7, pc} | ||
| + ldmeqfd sp!, {r4-r8, pc} | ||
|
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| tst r2, #32 | ||
| - stmneia r0!, {r1, r3-r7, ip, lr} | ||
| + stmneia ip!, {r1, r3-r8, lr} | ||
| tst r2, #16 | ||
| - stmneia r0!, {r4-r7} | ||
| - ldmfd sp!, {r4-r7, lr} | ||
| + stmneia ip!, {r4-r7} | ||
| + ldmfd sp!, {r4-r8, lr} | ||
|
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| #endif | ||
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| 4: tst r2, #8 | ||
| - stmneia r0!, {r1, r3} | ||
| + stmneia ip!, {r1, r3} | ||
| tst r2, #4 | ||
| - strne r1, [r0], #4 | ||
| + strne r1, [ip], #4 | ||
| /* | ||
| * When we get here, we've got less than 4 bytes to zero. We | ||
| * may have an unaligned pointer as well. | ||
| */ | ||
| 5: tst r2, #2 | ||
| - strneb r1, [r0], #1 | ||
| - strneb r1, [r0], #1 | ||
| + strneb r1, [ip], #1 | ||
| + strneb r1, [ip], #1 | ||
| tst r2, #1 | ||
| - strneb r1, [r0], #1 | ||
| + strneb r1, [ip], #1 | ||
| mov pc, lr | ||
| ENDPROC(memset) | ||
| -- | ||
| 1.7.9.5 | ||
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83 changes: 83 additions & 0 deletions
83
...-bsp/recipes-kernel/linux/linux-mainline-3.8/arm/0004-ARM-7670-1-fix-the-memset-fix.patch
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,83 @@ | ||
| From 418df63adac56841ef6b0f1fcf435bc64d4ed177 Mon Sep 17 00:00:00 2001 | ||
| From: Nicolas Pitre <nicolas.pitre@linaro.org> | ||
| Date: Tue, 12 Mar 2013 13:00:42 +0100 | ||
| Subject: [PATCH] ARM: 7670/1: fix the memset fix | ||
|
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||
| 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. | ||
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| This fixes the above by branching over the entry code from the | ||
| misaligned fixup code to avoid reloading the original pointer. | ||
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| Also, because the function entry alignment is wrong in the Thumb mode | ||
| compilation, that fixup code is moved to the end. | ||
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| While at it, the entry instructions are slightly reworked to help dual | ||
| issue pipelines. | ||
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| 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> | ||
| --- | ||
| arch/arm/lib/memset.S | 33 +++++++++++++-------------------- | ||
| 1 file changed, 13 insertions(+), 20 deletions(-) | ||
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| 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 @@ | ||
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| .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. | ||
| - */ | ||
|
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| 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) | ||
| -- | ||
| 1.7.9.5 | ||
|
|
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