Re: [PATCH] x86/ftrace: Fix objtool vmlinux.o __fentry__ warning

[Josh Poimboeuf]

On Wed, Jun 01, 2022 at 09:30:53AM -0700, Josh Poimboeuf wrote:
> The 'save_mcount_regs' macro does funny things with the frame pointer,
> which objtool doesn't approve of.  So OBJECT_FILES_NON_STANDARD is used
> with CONFIG_FRAME_POINTER to tell objtool to skip the entire file when
> frame pointers are enabled.
> 
> However, the file-wide OBJECT_FILES_NON_STANDARD annotation is now
> deprecated, because it doesn't work for IBT, where objtool runs on
> vmlinux.o.  Use more fine-grained function-specific annotations
> instead.
> 
> Fixes the following warning:
> 
>   vmlinux.o: warning: objtool: __fentry__+0x16: return with modified stack frame
> 
> Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

NACK - I just found another robot warning for this one.

-- 
Josh