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Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
-rw-r--r--arch/arm64/include/asm/uaccess.h9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 01ade20d5456..59fda5292936 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -105,16 +105,18 @@ static inline void set_fs(mm_segment_t fs)
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
static inline void __uaccess_ttbr0_disable(void)
{
- unsigned long ttbr;
+ unsigned long flags, ttbr;
+ local_irq_save(flags);
ttbr = read_sysreg(ttbr1_el1);
+ ttbr &= ~TTBR_ASID_MASK;
/* reserved_ttbr0 placed before swapper_pg_dir */
write_sysreg(ttbr - RESERVED_TTBR0_SIZE, ttbr0_el1);
isb();
/* Set reserved ASID */
- ttbr &= ~TTBR_ASID_MASK;
write_sysreg(ttbr, ttbr1_el1);
isb();
+ local_irq_restore(flags);
}
static inline void __uaccess_ttbr0_enable(void)
@@ -127,10 +129,11 @@ static inline void __uaccess_ttbr0_enable(void)
* roll-over and an update of 'ttbr0'.
*/
local_irq_save(flags);
- ttbr0 = current_thread_info()->ttbr0;
+ ttbr0 = READ_ONCE(current_thread_info()->ttbr0);
/* Restore active ASID */
ttbr1 = read_sysreg(ttbr1_el1);
+ ttbr1 &= ~TTBR_ASID_MASK; /* safety measure */
ttbr1 |= ttbr0 & TTBR_ASID_MASK;
write_sysreg(ttbr1, ttbr1_el1);
isb();