| Message ID | 20210401165110.3952103-1-pcc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: fix inline asm in load_unaligned_zeropad() | expand |
On Thu, 1 Apr 2021 09:51:10 -0700, Peter Collingbourne wrote: > 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. Applied to arm64 (for-next/fixes), thanks! [1/1] arm64: fix inline asm in load_unaligned_zeropad() https://git.kernel.org/arm64/c/185f2e5f51c2 Cheers,
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;
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 --- arch/arm64/include/asm/word-at-a-time.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)