search for: xray_trampoline_x86

> On 4 Aug 2016, at 06:27, Serge Rogatch <serge.rogatch at gmail.com> wrote: > > Hi Dean, > > I have a question about the following piece of code in compiler-rt/trunk/lib/xray/xray_trampoline_x86.S : > movq _ZN6__xray19XRayPatchedFunctionE(%rip), %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 __x...

> 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

...erris at gmail.com> > wrote: > >> >> > On 4 Aug 2016, at 06:27, Serge Rogatch <serge.rogatch at gmail.com> wrote: >> > >> > Hi Dean, >> > >> > I have a question about the following piece of code in >> compiler-rt/trunk/lib/xray/xray_trampoline_x86.S : >> > movq _ZN6__xray19XRayPatchedFunctionE(%rip), %rax >> > testq %rax, %rax >> > je .Ltmp0 >> > >> > // assume that %r10d has the function id. >> > movl %r10d, %edi >> > xor %esi,%esi >> > callq *%rax &...