[meta-freescale] [meta-fsl-arm][PATCH 2/2] linux-imx_3.0.35: Backport two patches to fix a boot issue
Andrei Gherzan
andrei.gherzan at windriver.com
Mon Jul 15 15:07:10 PDT 2013
Backport two patches to fix a boot issue with ARM boards
when gcc 4.8 is used.
Without the integrated backports:
ARM: 7670/1: fix the memset fix
ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations
The following trap will be seen on boot:
[<c00fc3b8>] (kmem_cache_alloc_trace+0x54/0x210) from [<c039f074>] (con_insert_unipair+0xcc/0x11c)
[<c039f074>] (con_insert_unipair+0xcc/0x11c) from [<c039fec8>] (con_set_default_unimap+0xfc/0x198)
[<c039fec8>] (con_set_default_unimap+0xfc/0x198) from [<c07ee258>] (console_map_init+0x44/0x58)
[<c07ee258>] (console_map_init+0x44/0x58) from [<c07ee738>] (vty_init+0x16c/0x1b0)
[<c07ee738>] (vty_init+0x16c/0x1b0) from [<c07edb68>] (tty_init+0x108/0x148)
[<c07edb68>] (tty_init+0x108/0x148) from [<c07eead0>] (chr_dev_init+0xb4/0xd8)
[<c07eead0>] (chr_dev_init+0xb4/0xd8) from [<c0008a18>] (do_one_initcall+0x11c/0x18c)
[<c0008a18>] (do_one_initcall+0x11c/0x18c) from [<c07d89d0>] (kernel_init_freeable+0x16c/0x254)
[<c07d89d0>] (kernel_init_freeable+0x16c/0x254) from [<c05a3810>] (kernel_init+0x18/0x160)
[<c05a3810>] (kernel_init+0x18/0x160) from [<c000e530>] (ret_from_fork+0x14/0x20)
Code: e593a000 e35a0000 0a000020 e5943014 (e79a1003)
---[ end trace e6c62de166779f86 ]---
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Signed-off-by: Andrei Gherzan <andrei.gherzan at windriver.com>
---
...fix-memset-related-crashes-caused-by-rece.patch | 255 ++++++++++++++++++++
.../0001-ARM-7670-1-fix-the-memset-fix.patch | 83 +++++++
recipes-kernel/linux/linux-imx_3.0.35.bb | 4 +
3 files changed, 342 insertions(+)
create mode 100644 recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch
create mode 100644 recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7670-1-fix-the-memset-fix.patch
diff --git a/recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch b/recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch
new file mode 100644
index 0000000..a76b320
--- /dev/null
+++ b/recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch
@@ -0,0 +1,255 @@
+From 8215b0e1525d9a36e5873ef59e4f197d5d6d317d Mon Sep 17 00:00:00 2001
+From: Ivan Djelic <ivan.djelic at parrot.com>
+Date: Wed, 6 Mar 2013 20:09:27 +0100
+Subject: [PATCH 1/1] 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 <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}
+
+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 <ivan.djelic at parrot.com>
+Reviewed-by: Nicolas Pitre <nico at linaro.org>
+Signed-off-by: Dirk Behme <dirk.behme at gmail.com>
+Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
+---
+ 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)
+--
+1.7.9.5
+
diff --git a/recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7670-1-fix-the-memset-fix.patch b/recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7670-1-fix-the-memset-fix.patch
new file mode 100644
index 0000000..d8aeebb
--- /dev/null
+++ b/recipes-kernel/linux/linux-imx-3.0.35/0001-ARM-7670-1-fix-the-memset-fix.patch
@@ -0,0 +1,83 @@
+From f20047520a57322f05d95a18a5fbd082fb15cb87 Mon Sep 17 00:00:00 2001
+From: Nicolas Pitre <nicolas.pitre at linaro.org>
+Date: Tue, 12 Mar 2013 13:00:42 +0100
+Subject: [PATCH 1/1] 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 at linaro.org>
+Tested-by: Alexander Holler <holler at ahsoftware.de>
+Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
+---
+ 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)
+--
+1.7.9.5
+
diff --git a/recipes-kernel/linux/linux-imx_3.0.35.bb b/recipes-kernel/linux/linux-imx_3.0.35.bb
index 8a4c0ef..1488480 100644
--- a/recipes-kernel/linux/linux-imx_3.0.35.bb
+++ b/recipes-kernel/linux/linux-imx_3.0.35.bb
@@ -10,3 +10,7 @@ COMPATIBLE_MACHINE = "(mx6)"
# Revision of 4.0.0 branch
SRCREV = "08814d923d74509cfaab96c1eb121f4bf961d942"
LOCALVERSION = "-4.0.0+yocto"
+
+SRC_URI += " \
+ file://0001-ARM-7668-1-fix-memset-related-crashes-caused-by-rece.patch \
+ file://0001-ARM-7670-1-fix-the-memset-fix.patch"
--
1.7.9.5
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