Re: [PATCH 4/7] objtool: Add support for return trampoline call

From: Peter Zijlstra
Date: Thu Apr 02 2020 - 11:27:25 EST


On Thu, Apr 02, 2020 at 10:22:17AM +0200, Alexandre Chartre wrote:
> With retpoline, the return instruction is used to branch to an address
> stored on the stack. So, unlike a regular return instruction, when a
> retpoline return instruction is reached the stack has been modified
> compared to what we have when the function was entered.
>
> Provide the mechanism to explicitly call-out such return instruction
> so that objtool can correctly handle them.

https://lkml.kernel.org/r/20200331222703.GH2452@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

And also, the split out version:

https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=core/objtool&id=ec9d9549901dfd2ff411676dfc624e50219e4d5a