Provide arm64 implementation of user_access_region_active. Check the status of PAN or SW PAN if needed.
Signed-off-by: Julien Thierry <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> --- arch/arm64/include/asm/sysreg.h | 2 ++ arch/arm64/include/asm/uaccess.h | 12 ++++++++++++ 2 files changed, 14 insertions(+) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 72dc4c0..f0b2f32 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -114,6 +114,8 @@ #define SYS_DC_CSW sys_insn(1, 0, 7, 10, 2) #define SYS_DC_CISW sys_insn(1, 0, 7, 14, 2) +#define SYS_PSTATE_PAN sys_reg(3, 0, 4, 2, 3) + #define SYS_OSDTRRX_EL1 sys_reg(2, 0, 0, 0, 2) #define SYS_MDCCINT_EL1 sys_reg(2, 0, 0, 2, 0) #define SYS_MDSCR_EL1 sys_reg(2, 0, 0, 2, 2) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 6a70c75..1a8acc9 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -225,6 +225,18 @@ static inline void uaccess_enable_not_uao(void) __uaccess_enable(ARM64_ALT_PAN_NOT_UAO); } +#define unsafe_user_region_active uaccess_region_active +static inline bool uaccess_region_active(void) +{ + if (system_uses_ttbr0_pan()) { + return read_sysreg(ttbr1_el1) & TTBR_ASID_MASK; + } else if (cpus_have_const_cap(ARM64_ALT_PAN_NOT_UAO) && + alternatives_applied) { + return !read_sysreg_s(SYS_PSTATE_PAN); + } + return false; +} + /* * Sanitise a uaccess pointer such that it becomes NULL if above the * current addr_limit. -- 1.9.1
