Re: [PATCH v2 1/2] s390/signal: Fix incorrect return address in signal frame

[sashiko-bot@kernel.org]

> exit_to_user_mode_loop() can call arch_do_signal_or_restart() multiple
> times when signals are pending.
> 
> If the first call set up a vDSO system call restart by saving the real
> user return address and adjusting psw.addr so it points to the vDSO stub,
> a second call builds the signal frame with the wrong return address.
> 
> Restore psw.addr from arch_data, and set the return code to -EINTR before
> building the signal frame.
> 
> This requires restart_block.arch_data to be properly initialized for all
> tasks. Move the initialization in copy_thread() in front of the kernel
> thread check, so that it also covers kernel threads and their children
> (PID 1, usermode helpers). Only PID 0 is left uninitialized, since it
> never returns to user space.
> 
> Fixes: df29a7440c4b ("s390/signal: switch to using vdso for sigreturn and syscall restart")
> Cc: stable@vger.kernel.org
> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261013133453.2288894-1-hca@linux.ibm.com?part=1