tree 784726977cc27d6b407a9fb466a3da61b4e4f697
parent cf5b1bc7502fa1397bf0733eb33009f21c3eb0a0
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1380611495 +1000
committer chrmhoffmann <chrmhoffmann@gmail.com> 1586074829 +0200

powerpc: Restore registers on error exit from csum_partial_copy_generic()

commit 8f21bd0090052e740944f9397e2be5ac7957ded7 upstream.

The csum_partial_copy_generic() function saves the PowerPC non-volatile
r14, r15, and r16 registers for the main checksum-and-copy loop.
Unfortunately, it fails to restore them upon error exit from this loop,
which results in silent corruption of these registers in the presumably
rare event of an access exception within that loop.

This commit therefore restores these register on error exit from the loop.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: register name macros use lower-case 'r']
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>