search for: __xray_set_handler

...%rax > testq %rax, %rax > je .Ltmp0 > > // assume that %r10d has the function id. > movl %r10d, %edi > xor %esi,%esi > callq *%rax > What happens if someone unsets the handler function (i.e. calls __xray_remove_handler() ) or changes the handler (i.e. calls __xray_set_handler() with a different pointer to function) between "movq _ZN6__xray19XRayPatchedFunctionE(%rip), %rax" and "callq *%rax" ? I understood that the old handler will still be called, but isn't it a problem? What if the code removing the handler starts destructing some objects aft...

> On 30 Jul 2016, at 05:07, Serge Rogatch via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Thanks for pointing this out, Tim. Then maybe this approach is not the best choice for x86, though ideally measuring is needed, it is just that on ARM the current x86 approach is not applicable because ARM doesn't have a single return instruction (such as RETQ on x86_64), furthermore,

Thanks for pointing this out, Tim. Then maybe this approach is not the best choice for x86, though ideally measuring is needed, it is just that on ARM the current x86 approach is not applicable because ARM doesn't have a single return instruction (such as RETQ on x86_64), furthermore, the return instructions on ARM can be conditional. I have another question: what happens if the instrumented

...> // assume that %r10d has the function id. >> > movl %r10d, %edi >> > xor %esi,%esi >> > callq *%rax >> > What happens if someone unsets the handler function (i.e. calls >> __xray_remove_handler() ) or changes the handler (i.e. calls >> __xray_set_handler() with a different pointer to function) between "movq >> _ZN6__xray19XRayPatchedFunctionE(%rip), %rax" and "callq *%rax" ? I >> understood that the old handler will still be called, but isn't it a >> problem? What if the code removing the handler starts de...