Patchwork [meta-fsl-arm,2/2] linux-imx_3.0.35: Backport two patches to fix a boot issue

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Submitter Andrei Gherzan
Date July 15, 2013, 10:07 p.m.
Message ID <1373926030-22473-2-git-send-email-andrei.gherzan@windriver.com>
Download mbox | patch
Permalink /patch/53719/
State Superseded
Delegated to: Otavio Salvador
Headers show

Comments

Andrei Gherzan - July 15, 2013, 10:07 p.m.
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@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
Fabio Estevam - July 15, 2013, 11:03 p.m.
Hi Andrei,

On Mon, Jul 15, 2013 at 7:07 PM, Andrei Gherzan
<andrei.gherzan@windriver.com> wrote:
> 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

Thanks for the patch, but these two patches have already been applied:
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/log/?h=imx_3.0.35_4.0.0
Otavio Salvador - July 15, 2013, 11:08 p.m.
On Mon, Jul 15, 2013 at 8:03 PM, Fabio Estevam <festevam@gmail.com> wrote:
> Hi Andrei,
>
> On Mon, Jul 15, 2013 at 7:07 PM, Andrei Gherzan
> <andrei.gherzan@windriver.com> wrote:
>> 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
>
> Thanks for the patch, but these two patches have already been applied:
> http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/log/?h=imx_3.0.35_4.0.0

And the Yocto respective recipe already updated as well.

--
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://projetos.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750
Andrei Gherzan - July 16, 2013, 9:55 a.m.
On Tue, Jul 16, 2013 at 2:08 AM, Otavio Salvador <otavio@ossystems.com.br>wrote:

> On Mon, Jul 15, 2013 at 8:03 PM, Fabio Estevam <festevam@gmail.com> wrote:
> > Hi Andrei,
> >
> > On Mon, Jul 15, 2013 at 7:07 PM, Andrei Gherzan
> > <andrei.gherzan@windriver.com> wrote:
> >> 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
> >
> > Thanks for the patch, but these two patches have already been applied:
> >
> http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/log/?h=imx_3.0.35_4.0.0
>
> And the Yocto respective recipe already updated as well.
>
> --


Great. Drop this then.

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@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@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>
+---
+ 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@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@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(-)
+
+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"