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authorRussell King <rmk+kernel@arm.linux.org.uk>2010-08-13 23:33:46 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-08-15 22:04:24 +0100
commit41e2e8fd34fff909a0e40129f6ac4233ecfa67a9 (patch)
tree46dd3fe7a0a2ecb12325f4af96d2aedb3ff7835e
parent21d93e2e29722d7832f61cc56d73fb953ee6578e (diff)
ARM: Tighten check for allowable CPSR values
Reviewed-by: Arve Hjønnevåg <arve@android.com> Acked-by: Dima Zavin <dima@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/include/asm/ptrace.h17
1 files changed, 13 insertions, 4 deletions
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index c974be8913a7..7ce15eb15f72 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -158,15 +158,24 @@ struct pt_regs {
*/
static inline int valid_user_regs(struct pt_regs *regs)
{
- if (user_mode(regs) && (regs->ARM_cpsr & PSR_I_BIT) == 0) {
- regs->ARM_cpsr &= ~(PSR_F_BIT | PSR_A_BIT);
- return 1;
+ unsigned long mode = regs->ARM_cpsr & MODE_MASK;
+
+ /*
+ * Always clear the F (FIQ) and A (delayed abort) bits
+ */
+ regs->ARM_cpsr &= ~(PSR_F_BIT | PSR_A_BIT);
+
+ if ((regs->ARM_cpsr & PSR_I_BIT) == 0) {
+ if (mode == USR_MODE)
+ return 1;
+ if (elf_hwcap & HWCAP_26BIT && mode == USR26_MODE)
+ return 1;
}
/*
* Force CPSR to something logical...
*/
- regs->ARM_cpsr &= PSR_f | PSR_s | (PSR_x & ~PSR_A_BIT) | PSR_T_BIT | MODE32_BIT;
+ regs->ARM_cpsr &= PSR_f | PSR_s | PSR_x | PSR_T_BIT | MODE32_BIT;
if (!(elf_hwcap & HWCAP_26BIT))
regs->ARM_cpsr |= USR_MODE;