diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2016-07-01 14:58:21 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-11-21 17:33:47 +0000 |
| commit | bd38967d406fb4f9fca67d612db71b5d74cfb0f5 (patch) | |
| tree | fbcc9bd2e2f70c40387fe166de6f4e874c0d0bdb /arch/arm64/include/asm/futex.h | |
| parent | a8ada146f5179793bbaff3c936d73147ccd47ba2 (diff) | |
arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
This patch moves the directly coded alternatives for turning PAN on/off
into separate uaccess_{enable,disable} macros or functions. The asm
macros take a few arguments which will be used in subsequent patches.
Note that any (unlikely) access that the compiler might generate between
uaccess_enable() and uaccess_disable(), other than those explicitly
specified by the user access code, will not be protected by PAN.
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/futex.h')
| -rw-r--r-- | arch/arm64/include/asm/futex.h | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h index f2585cdd32c2..85c4a8981d47 100644 --- a/arch/arm64/include/asm/futex.h +++ b/arch/arm64/include/asm/futex.h @@ -21,15 +21,12 @@ #include <linux/futex.h> #include <linux/uaccess.h> -#include <asm/alternative.h> -#include <asm/cpufeature.h> #include <asm/errno.h> -#include <asm/sysreg.h> #define __futex_atomic_op(insn, ret, oldval, uaddr, tmp, oparg) \ +do { \ + uaccess_enable(); \ asm volatile( \ - ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, \ - CONFIG_ARM64_PAN) \ " prfm pstl1strm, %2\n" \ "1: ldxr %w1, %2\n" \ insn "\n" \ @@ -44,11 +41,11 @@ " .popsection\n" \ _ASM_EXTABLE(1b, 4b) \ _ASM_EXTABLE(2b, 4b) \ - ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \ - CONFIG_ARM64_PAN) \ : "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp) \ : "r" (oparg), "Ir" (-EFAULT) \ - : "memory") + : "memory"); \ + uaccess_disable(); \ +} while (0) static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) @@ -118,8 +115,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; + uaccess_enable(); asm volatile("// futex_atomic_cmpxchg_inatomic\n" -ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN) " prfm pstl1strm, %2\n" "1: ldxr %w1, %2\n" " sub %w3, %w1, %w4\n" @@ -134,10 +131,10 @@ ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN) " .popsection\n" _ASM_EXTABLE(1b, 4b) _ASM_EXTABLE(2b, 4b) -ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) : "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp) : "r" (oldval), "r" (newval), "Ir" (-EFAULT) : "memory"); + uaccess_disable(); *uval = val; return ret; |