| Message ID | 1474930756-6536-1-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Commit | c4f637077eb4504aa0109aac9983dfe85e5b2afb |
| Headers | show |
diff --git a/MdePkg/Library/BaseMemoryLibOptDxe/Arm/ScanMem.S b/MdePkg/Library/BaseMemoryLibOptDxe/Arm/ScanMem.S index dc0e74e8657c..1c269547b072 100644 --- a/MdePkg/Library/BaseMemoryLibOptDxe/Arm/ScanMem.S +++ b/MdePkg/Library/BaseMemoryLibOptDxe/Arm/ScanMem.S @@ -134,11 +134,12 @@ ASM_PFX(InternalMemScanMem8): bne 61f adds r0, r0, #1 tst r5, #CHARTSTMASK(1) // 2nd character - ittt eq - addeq r0, r0 ,#1 - tsteq r5, #(3 << 15) // 2nd & 3rd character + bne 61f + adds r0, r0 ,#1 + tst r5, #(3 << 15) // 2nd & 3rd character // If not the 3rd must be the last one - addeq r0, r0, #1 + it eq + addeq.n r0, r0, #1 61: pop {r4-r7}
The ARM ScanMem() in BaseMemoryLibOptDxe contains code from the open source cortex-strings library, and inherited a bug from it where the conditional execution of a sequence of instructions is erroneously made dependent on the same condition. Since the final 'addeq' is supposed to be dependent on the preceding 'tsteq' instruction, they cannot be part of the same IT block. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- MdePkg/Library/BaseMemoryLibOptDxe/Arm/ScanMem.S | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) -- 2.7.4 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel