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authorCatalin Marinas <catalin.marinas@arm.com>2016-07-01 14:58:21 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2016-11-21 17:33:47 +0000
commitbd38967d406fb4f9fca67d612db71b5d74cfb0f5 (patch)
treefbcc9bd2e2f70c40387fe166de6f4e874c0d0bdb /arch/arm64/include/asm/futex.h
parentarm64: Update the synchronous external abort fault description (diff)
downloadlinux-dev-bd38967d406fb4f9fca67d612db71b5d74cfb0f5.tar.xz
linux-dev-bd38967d406fb4f9fca67d612db71b5d74cfb0f5.zip
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 '')
-rw-r--r--arch/arm64/include/asm/futex.h17
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;