Re: [PATCH v2 26/33] s390/ftrace: Unpoison ftrace_regs in kprobe_ftrace_handler()

[Alexander Potapenko]

On Tue, Nov 21, 2023 at 11:02 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote:
>
> s390 uses assembly code to initialize ftrace_regs and call
> kprobe_ftrace_handler(). Therefore, from the KMSAN's point of view,
> ftrace_regs is poisoned on kprobe_ftrace_handler() entry. This causes
> KMSAN warnings when running the ftrace testsuite.
>
> Fix by trusting the assembly code and always unpoisoning ftrace_regs in
> kprobe_ftrace_handler().
>
> Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>