Well, neither have outputs, doh, so they both need volatile don't they? Adding an output for the %rax result would prevent the call from being omitted without

Well, neither have outputs, doh, so they both need volatile don't they? Adding an output for the %rax result would prevent the call from being omitted without volatile (assuming it is actually consumed by something), but it could still be reordered, right? I suppose with general syscalls that might be okay, but certainly not with sys_exit(). They also need memory clobbers, but I don't think memory clobbers would necessarily prevent reordering? In the case of the ARM bug though, it did: https://lore.kernel.org/lkml/Zqa4SAyPKPuaXdgg@mozart.vkv.me/ https://lore.kernel.org/lkml/Zqa4SAyPKPuaXdgg@mozart.vkv.me/