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| author | Peter Collingbourne <pcc@google.com> | 2021-04-01 09:51:10 -0700 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-04-01 18:16:14 +0100 |
| commit | 185f2e5f51c2029efd9dd26cceb968a44fe053c6 (patch) | |
| tree | 5e63148fa791e725ad9f47b29ca6d8f213cb5b12 | |
| parent | 20109a859a9b514eb10c22b8a14b5704ffe93897 (diff) | |
| download | linux-185f2e5f51c2029efd9dd26cceb968a44fe053c6.tar.bz2 | |
arm64: fix inline asm in load_unaligned_zeropad()
The inline asm's addr operand is marked as input-only, however in
the case where an exception is taken it may be modified by the BIC
instruction on the exception path. Fix the problem by using a temporary
register as the destination register for the BIC instruction.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: stable@vger.kernel.org
Link: https://linux-review.googlesource.com/id/I84538c8a2307d567b4f45bb20b715451005f9617
Link: https://lore.kernel.org/r/20210401165110.3952103-1-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/word-at-a-time.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/arm64/include/asm/word-at-a-time.h b/arch/arm64/include/asm/word-at-a-time.h index 3333950b5909..ea487218db79 100644 --- a/arch/arm64/include/asm/word-at-a-time.h +++ b/arch/arm64/include/asm/word-at-a-time.h @@ -53,7 +53,7 @@ static inline unsigned long find_zero(unsigned long mask) */ static inline unsigned long load_unaligned_zeropad(const void *addr) { - unsigned long ret, offset; + unsigned long ret, tmp; /* Load word from unaligned pointer addr */ asm( @@ -61,9 +61,9 @@ static inline unsigned long load_unaligned_zeropad(const void *addr) "2:\n" " .pushsection .fixup,\"ax\"\n" " .align 2\n" - "3: and %1, %2, #0x7\n" - " bic %2, %2, #0x7\n" - " ldr %0, [%2]\n" + "3: bic %1, %2, #0x7\n" + " ldr %0, [%1]\n" + " and %1, %2, #0x7\n" " lsl %1, %1, #0x3\n" #ifndef __AARCH64EB__ " lsr %0, %0, %1\n" @@ -73,7 +73,7 @@ static inline unsigned long load_unaligned_zeropad(const void *addr) " b 2b\n" " .popsection\n" _ASM_EXTABLE(1b, 3b) - : "=&r" (ret), "=&r" (offset) + : "=&r" (ret), "=&r" (tmp) : "r" (addr), "Q" (*(unsigned long *)addr)); return ret; |