ARM: Tighten check for allowable CPSR values

commit 41e2e8fd34 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Russell King
2010-08-13 23:33:46 +01:00
committed by Greg Kroah-Hartman
parent fdb6630db5
commit 4dfe0eb30a

View File

@@ -150,15 +150,24 @@ 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;