Matthew DeVore has uploaded this change for review. ( https://review.gerrithub.io/c/ffilz/nfs-ganesha/+/502162 ) Change subject: Specify & for inline asm output operands ...................................................................... Specify & for inline asm output operands According to inline asm documentation for GCC: Means (in a particular alternative) that this operand is an earlyclobber operand, which is written before the instruction is finished using the input operands. Therefore, this operand may not lie in a register that is read by the instruction or as part of any memory address. Source: https://gcc.gnu.org/onlinedocs/gcc/Modifiers.html This applies to many of the inline assembly snippets in atomic_x86_64.h. The output operand at %1 is often used as the destination operand in the first instruction. This could clobber the register which stores the pointer to %0, which will result in an illegal operation in the lock... instruction later on. I discovered this while trying to build and run on macOS. While this may not be affecting any supported platforms, it could cause problems (an illegal memory access) if the compiler behavior ever changes, so it's probably best to fix it. Change-Id: I13762d2ec11488b2a54472f0f5afe12ce0a3a0c9 Signed-off-by: Matthew DeVore <matvore(a)google.com&gt; --- M src/include/atomic_x86_64.h 1 file changed, 15 insertions(+), 15 deletions(-) git pull ssh://review.gerrithub.io:29418/ffilz/nfs-ganesha refs/changes/62/502162/1 -- To view, visit https://review.gerrithub.io/c/ffilz/nfs-ganesha/+/502162 To unsubscribe, or for help writing mail filters, visit https://review.gerrithub.io/settings Gerrit-Project: ffilz/nfs-ganesha Gerrit-Branch: next Gerrit-Change-Id: I13762d2ec11488b2a54472f0f5afe12ce0a3a0c9 Gerrit-Change-Number: 502162 Gerrit-PatchSet: 1 Gerrit-Owner: Matthew DeVore <matvore(a)google.com&gt; Gerrit-MessageType: newchange