On Fri, 11 Mar 2022 12:47:33 +1000, Nicholas Piggin wrote:

Commit cf13435b730a ("powerpc/tm: Fix userspace r13 corruption") fixes
a problem in treclaim where a SLB miss can occur on the
thread_struct->ckpt_regs while SCRATCH0 is live with the saved user r13
value, clobbering it with the kernel r13 and ultimately resulting in
kernel r13 being stored in ckpt_regs.

There is an equivalent problem in trechkpt where the user r13 value is
loaded into r13 from chkpt_regs to be recheckpointed, but a SLB miss
could occur on ckpt_regs accesses after that, which will result in r13
being clobbered with a kernel value and that will get recheckpointed and
then restored to user registers.

[...]

Applied to powerpc/next.

[1/1] powerpc/tm: Fix more userspace r13 corruption
      https://git.kernel.org/powerpc/c/9d71165d3934e607070c4e48458c0cf161b1baea

cheers