diff options
Diffstat (limited to 'arch/arm/include/asm/uaccess.h')
| -rw-r--r-- | arch/arm/include/asm/uaccess.h | 45 |
1 files changed, 39 insertions, 6 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 9556d04387f7..25d21d7d6e3e 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -14,6 +14,8 @@ #include <asm/domain.h> #include <asm/unaligned.h> #include <asm/unified.h> +#include <asm/pgtable.h> +#include <asm/proc-fns.h> #include <asm/compiler.h> #include <asm/extable.h> @@ -24,9 +26,10 @@ * perform such accesses (eg, via list poison values) which could then * be exploited for priviledge escalation. */ +#if defined(CONFIG_CPU_SW_DOMAIN_PAN) + static __always_inline unsigned int uaccess_save_and_enable(void) { -#ifdef CONFIG_CPU_SW_DOMAIN_PAN unsigned int old_domain = get_domain(); /* Set the current domain access to permit user accesses */ @@ -34,19 +37,49 @@ static __always_inline unsigned int uaccess_save_and_enable(void) domain_val(DOMAIN_USER, DOMAIN_CLIENT)); return old_domain; -#else - return 0; -#endif } static __always_inline void uaccess_restore(unsigned int flags) { -#ifdef CONFIG_CPU_SW_DOMAIN_PAN /* Restore the user access mask */ set_domain(flags); -#endif } +#elif defined(CONFIG_CPU_TTBR0_PAN) + +static inline unsigned int uaccess_save_and_enable(void) +{ + unsigned int old_ttbcr = cpu_get_ttbcr(); + + /* + * Enable TTBR0 page table walks (T0SZ = 0, EDP0 = 0) and ASID from + * TTBR0 (A1 = 0). + */ + cpu_set_ttbcr(old_ttbcr & ~(TTBCR_A1 | TTBCR_EPD0 | TTBCR_T0SZ_MASK)); + isb(); + + return old_ttbcr; +} + +static inline void uaccess_restore(unsigned int flags) +{ + cpu_set_ttbcr(flags); + isb(); +} + +#else + +static inline unsigned int uaccess_save_and_enable(void) +{ + return 0; +} + +static inline void uaccess_restore(unsigned int flags) +{ +} + +#endif + /* * These two are intentionally not defined anywhere - if the kernel * code generates any references to them, that's a bug. |