[SRU][Trusty][lts-backport-utopic][PATCH 0/2] powerpc/tm: Fixes for LP:1520411

[Joseph Salisbury]

BugLink: http://bugs.launchpad.net/bugs/1520411

== Justification ==
These two commits fix local DoS (userspace can crash the OS) on powerpc POWER8
cpus for any kernel v3.9+.  The commits cherry pick cleanly on X, W, and V.
The commits also pick cleanly to Trusty and lts-backport-utopic.  However they 
need slighlty different formatting due to a difference in restore_tm_user_regs().
This is the other SRU request for the bug, specific to Trusty and lts-backport-utopic.  

These commits are in mainline as of 4.4-rc3.  They have also been cc'd to stable, but have 
not landed in any stable repos as of yet.


== Fixes ==
commit d2b9d2a5ad5ef04ff978c9923d19730cb05efd55
Author: Michael Neuling <mikey at neuling.org>
Date:   Thu Nov 19 15:44:44 2015 +1100

    powerpc/tm: Block signal return setting invalid MSR state

commit 7f821fc9c77a9b01fe7b1d6e72717b33d8d64142
Author: Michael Neuling <mikey at neuling.org>
Date:   Thu Nov 19 15:44:45 2015 +1100

    powerpc/tm: Check for already reclaimed tasks


== Test Case ==
A test kernel was built with these patches and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.


Michael Neuling (2):
  powerpc/tm: Block signal return setting invalid MSR state
  powerpc/tm: Check for already reclaimed tasks

 arch/powerpc/include/asm/reg.h  |  1 +
 arch/powerpc/kernel/process.c   | 18 ++++++++++++++++++
 arch/powerpc/kernel/signal_32.c | 14 +++++++++-----
 arch/powerpc/kernel/signal_64.c |  4 ++++
 4 files changed, 32 insertions(+), 5 deletions(-)

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1.9.1