Re: [PATCH 3/7] objtool: Add support for intra-function calls

From: Peter Zijlstra
Date: Fri Apr 03 2020 - 08:41:19 EST


On Fri, Apr 03, 2020 at 09:01:38AM +0100, Julien Thierry wrote:
>
> Last I found is in qcom_link_stack_sanitization() [2], but that's just a
> workaround for a very specific hardware. In my local tree I just put the
> function as STACK_FRAME_NON_STANDARD. But the code just saves the return
> address, has 16 call instructions that just call the instruction after them,
> restores the return address and lets the C-function return normally (and it
> somehow fixes something for that hardware).
>
That sounds very much like the RSB flushing we do.