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authorMarc Zyngier <Marc.Zyngier@arm.com>2013-11-04 11:42:29 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-04 10:55:46 -0800
commit45a8ae89ee0f4d4b33f75b2e619f4112810ff822 (patch)
tree8d832025a8a95859b52ff03db5a08d8413c8aec4 /arch
parent853e96428c8e8f2ac95e1b6a144114340694a244 (diff)
ARM: 7876/1: clear Thumb-2 IT state on exception handling
commit e16b31bf47738f4498d7ce632e12d7d2a6a2492a upstream. The exception handling code fails to clear the IT state, potentially leading to incorrect execution of the fixup if the size of the IT block is more than one. Let fixup_exception do the IT sanitizing if a fixup has been found, and restore CPSR from the stack when returning from a data abort. Cc: Will Deacon <will.deacon@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/kernel/entry-armv.S1
-rw-r--r--arch/arm/mm/extable.c7
2 files changed, 7 insertions, 1 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index d43c7e54ec6..32640ae7750 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -192,6 +192,7 @@ __dabt_svc:
svc_entry
mov r2, sp
dabt_helper
+ THUMB( ldr r5, [sp, #S_PSR] ) @ potentially updated CPSR
svc_exit r5 @ return from exception
UNWIND(.fnend )
ENDPROC(__dabt_svc)
diff --git a/arch/arm/mm/extable.c b/arch/arm/mm/extable.c
index 9d285626bc7..312e15e6d00 100644
--- a/arch/arm/mm/extable.c
+++ b/arch/arm/mm/extable.c
@@ -9,8 +9,13 @@ int fixup_exception(struct pt_regs *regs)
const struct exception_table_entry *fixup;
fixup = search_exception_tables(instruction_pointer(regs));
- if (fixup)
+ if (fixup) {
regs->ARM_pc = fixup->fixup;
+#ifdef CONFIG_THUMB2_KERNEL
+ /* Clear the IT state to avoid nasty surprises in the fixup */
+ regs->ARM_cpsr &= ~PSR_IT_MASK;
+#endif
+ }
return fixup != NULL;
}