This is a note to let you know that I've just added the patch titled
ARM: 7325/1: fix v7 boot with lockdep enabled
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-7325-1-fix-v7-boot-with-lockdep-enabled.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 8e43a905dd574f54c5715d978318290ceafbe275 Mon Sep 17 00:00:00 2001
From: Rabin Vincent <[email protected]>
Date: Wed, 15 Feb 2012 16:01:42 +0100
Subject: ARM: 7325/1: fix v7 boot with lockdep enabled
From: Rabin Vincent <[email protected]>
commit 8e43a905dd574f54c5715d978318290ceafbe275 upstream.
Bootup with lockdep enabled has been broken on v7 since b46c0f74657d
("ARM: 7321/1: cache-v7: Disable preemption when reading CCSIDR").
This is because v7_setup (which is called very early during boot) calls
v7_flush_dcache_all, and the save_and_disable_irqs added by that patch
ends up attempting to call into lockdep C code (trace_hardirqs_off())
when we are in no position to execute it (no stack, MMU off).
Fix this by using a notrace variant of save_and_disable_irqs. The code
already uses the notrace variant of restore_irqs.
Reviewed-by: Nicolas Pitre <[email protected]>
Acked-by: Stephen Boyd <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Rabin Vincent <[email protected]>
Signed-off-by: Russell King <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/arm/include/asm/assembler.h | 5 +++++
arch/arm/mm/cache-v7.S | 2 +-
2 files changed, 6 insertions(+), 1 deletion(-)
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -137,6 +137,11 @@
disable_irq
.endm
+ .macro save_and_disable_irqs_notrace, oldcpsr
+ mrs \oldcpsr, cpsr
+ disable_irq_notrace
+ .endm
+
/*
* Restore interrupt state previously stored in a register. We don't
* guarantee that this will preserve the flags.
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -55,7 +55,7 @@ loop1:
cmp r1, #2 @ see what cache we have at
this level
blt skip @ skip if no cache, or just
i-cache
#ifdef CONFIG_PREEMPT
- save_and_disable_irqs r9 @ make cssr&csidr read atomic
+ save_and_disable_irqs_notrace r9 @ make cssr&csidr read atomic
#endif
mcr p15, 2, r10, c0, c0, 0 @ select current cache level in
cssr
isb @ isb to sych the new cssr&csidr
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/arm-7325-1-fix-v7-boot-with-lockdep-enabled.patch
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