tree 204175f5f1983ff920187640fc5263115400083e
parent 1ec218373b8ebda821aec00bb156a9c94fad9cd4
author Michael Neuling <mikey@neuling.org> 1447908284 +1100
committer Michael Ellerman <mpe@ellerman.id.au> 1448269591 +1100

powerpc/tm: Block signal return setting invalid MSR state

Currently we allow both the MSR T and S bits to be set by userspace on
a signal return.  Unfortunately this is a reserved configuration and
will cause a TM Bad Thing exception if attempted (via rfid).

This patch checks for this case in both the 32 and 64 bit signals
code.  If both T and S are set, we mark the context as invalid.

Found using a syscall fuzzer.

Fixes: 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>