diff options
Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 40 |
1 files changed, 34 insertions, 6 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index fc0f9eb66039..59fda5292936 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -105,17 +105,23 @@ 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; - /* reserved_ttbr0 placed at the end of swapper_pg_dir */ - ttbr = read_sysreg(ttbr1_el1) + SWAPPER_DIR_SIZE; - write_sysreg(ttbr, ttbr0_el1); + 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 */ + write_sysreg(ttbr, ttbr1_el1); isb(); + local_irq_restore(flags); } static inline void __uaccess_ttbr0_enable(void) { - unsigned long flags; + unsigned long flags, ttbr0, ttbr1; /* * Disable interrupts to avoid preemption between reading the 'ttbr0' @@ -123,7 +129,17 @@ static inline void __uaccess_ttbr0_enable(void) * roll-over and an update of 'ttbr0'. */ local_irq_save(flags); - write_sysreg(current_thread_info()->ttbr0, ttbr0_el1); + 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(); + + /* Restore user page table */ + write_sysreg(ttbr0, ttbr0_el1); isb(); local_irq_restore(flags); } @@ -155,6 +171,18 @@ static inline bool uaccess_ttbr0_enable(void) } #endif +static inline void __uaccess_disable_hw_pan(void) +{ + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, + CONFIG_ARM64_PAN)); +} + +static inline void __uaccess_enable_hw_pan(void) +{ + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, + CONFIG_ARM64_PAN)); +} + #define __uaccess_disable(alt) \ do { \ if (!uaccess_ttbr0_disable()) \ |