From d8d36acb07a78d70fd49f25b2d6da12ce6e5cac3 Mon Sep 17 00:00:00 2001 From: Baptiste DURAND Date: Tue, 4 Feb 2014 21:40:01 +0100 Subject: linux-omap4 3.4: Fix random segfaults and boot issues seen with gcc 4.8 Based on work https://github.com/koenkooi/meta-beagleboard/commit/87efc663c4f76d3051cecf1e2c3e2bbd461d200b Signed-off-by: Baptiste DURAND Signed-off-by: Denys Dmytriyenko --- ...fix-memset-related-crashes-caused-by-rece.patch | 256 +++++++++++++++++++++ .../0004-ARM-7670-1-fix-the-memset-fix.patch | 83 +++++++ recipes-kernel/linux/linux-omap4_3.4.bb | 2 + 3 files changed, 341 insertions(+) create mode 100644 recipes-kernel/linux/linux-omap4-3.4/pandaboard/0003-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch create mode 100644 recipes-kernel/linux/linux-omap4-3.4/pandaboard/0004-ARM-7670-1-fix-the-memset-fix.patch diff --git a/recipes-kernel/linux/linux-omap4-3.4/pandaboard/0003-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch b/recipes-kernel/linux/linux-omap4-3.4/pandaboard/0003-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch new file mode 100644 index 00000000..7b4e6528 --- /dev/null +++ b/recipes-kernel/linux/linux-omap4-3.4/pandaboard/0003-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch @@ -0,0 +1,256 @@ +From b9ebe46e251c5c8becd02f92893ef514e834bf67 Mon Sep 17 00:00:00 2001 +From: Ivan Djelic +Date: Wed, 6 Mar 2013 20:09:27 +0100 +Subject: [PATCH 3/4] ARM: 7668/1: fix memset-related crashes caused by recent + GCC (4.7.2) optimizations + +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. + +For instance in the following function: + +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); +} + +compiled as: + +800554d0 : +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 +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} + +GCC assumes memset returns the value of pointer 'waiter' in register r0; causing +register/memory corruptions. + +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). + +Step 2 +====== +Make sure r8 is saved and restored when (! CALGN(1)+0) == 1: + +save r8: +- str lr, [sp, #-4]! ++ stmfd sp!, {r8, lr} + +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} + +Step 3 +====== +Make sure r8 is saved and restored when (! CALGN(1)+0) == 0: + +save r8: +- stmfd sp!, {r4-r7, lr} ++ stmfd sp!, {r4-r8, lr} + +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} + +Step 4 +====== +Rewrite register list "r4-r7, r8" as "r4-r8". + +Signed-off-by: Ivan Djelic +Reviewed-by: Nicolas Pitre +Signed-off-by: Dirk Behme +Signed-off-by: Russell King +Signed-off-by: Khem Raj +--- + arch/arm/lib/memset.S | 85 ++++++++++++++++++++++++++------------------------- + 1 file changed, 44 insertions(+), 41 deletions(-) + +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 @@ + */ + + 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 + + /* +- * 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 + + 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} + + #else + +@@ -74,54 +77,54 @@ ENTRY(memset) + * whole cache lines at once. + */ + +- 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 + + cmp r2, #96 +- tstgt r0, #31 ++ tstgt ip, #31 + ble 3f + +- 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 + + 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} + + 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} + + #endif + + 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) +-- +1.8.2.1 + diff --git a/recipes-kernel/linux/linux-omap4-3.4/pandaboard/0004-ARM-7670-1-fix-the-memset-fix.patch b/recipes-kernel/linux/linux-omap4-3.4/pandaboard/0004-ARM-7670-1-fix-the-memset-fix.patch new file mode 100644 index 00000000..06584135 --- /dev/null +++ b/recipes-kernel/linux/linux-omap4-3.4/pandaboard/0004-ARM-7670-1-fix-the-memset-fix.patch @@ -0,0 +1,83 @@ +From 78429023fbec3428238e8dbdd81fa67e4619d04c Mon Sep 17 00:00:00 2001 +From: Nicolas Pitre +Date: Tue, 12 Mar 2013 13:00:42 +0100 +Subject: [PATCH 4/4] 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 +Tested-by: Alexander Holler +Signed-off-by: Russell King +--- + 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) +-- +1.8.2.1 + diff --git a/recipes-kernel/linux/linux-omap4_3.4.bb b/recipes-kernel/linux/linux-omap4_3.4.bb index 449e4eb8..52629de2 100644 --- a/recipes-kernel/linux/linux-omap4_3.4.bb +++ b/recipes-kernel/linux/linux-omap4_3.4.bb @@ -13,6 +13,8 @@ SRCREV = "c34a43ec74168b892a948b45695486f1a3d700af" SRC_URI = "git://dev.omapzoom.org/pub/scm/integration/kernel-ubuntu.git;protocol=git;branch=ti-ubuntu-3.4-1487 \ file://defconfig \ + file://0003-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch \ + file://0004-ARM-7670-1-fix-the-memset-fix.patch \ " S = "${WORKDIR}/git" -- cgit v1.2.3-54-g00ecf