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ARM: Tighten check for allowable CPSR values

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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>
This commit is contained in:
Russell King 2010-08-13 23:33:46 +01:00
parent 21d93e2e29
commit 41e2e8fd34
1 changed files with 13 additions and 4 deletions
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17
arch/arm/include/asm/ptrace.h
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@ -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;