Patch "powerpc/tm: Fix saving of TM SPRs in core dump" has been added to the 4.12-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    powerpc/tm: Fix saving of TM SPRs in core dump

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     powerpc-tm-fix-saving-of-tm-sprs-in-core-dump.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From cd63f3cf1d59b7ad8419eba1cac8f9126e79cc43 Mon Sep 17 00:00:00 2001
From: Gustavo Romero <gromero@linux.vnet.ibm.com>
Date: Wed, 19 Jul 2017 01:44:13 -0400
Subject: powerpc/tm: Fix saving of TM SPRs in core dump

From: Gustavo Romero <gromero@linux.vnet.ibm.com>

commit cd63f3cf1d59b7ad8419eba1cac8f9126e79cc43 upstream.

Currently flush_tmregs_to_thread() does not save the TM SPRs (TFHAR,
TFIAR, TEXASR) to the thread struct, unless the process is currently
inside a suspended transaction.

If the process is core dumping, and the TM SPRs have changed since the
last time the process was context switched, then we will save stale
values of the TM SPRs to the core dump.

Fix it by saving the live register state to the thread struct in that
case.

Fixes: 08e1c01d6aed ("powerpc/ptrace: Enable support for TM SPR state")
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kernel/ptrace.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -127,12 +127,19 @@ static void flush_tmregs_to_thread(struc
 	 * If task is not current, it will have been flushed already to
 	 * it's thread_struct during __switch_to().
 	 *
-	 * A reclaim flushes ALL the state.
+	 * A reclaim flushes ALL the state or if not in TM save TM SPRs
+	 * in the appropriate thread structures from live.
 	 */
 
-	if (tsk == current && MSR_TM_SUSPENDED(mfmsr()))
-		tm_reclaim_current(TM_CAUSE_SIGNAL);
+	if (tsk != current)
+		return;
 
+	if (MSR_TM_SUSPENDED(mfmsr())) {
+		tm_reclaim_current(TM_CAUSE_SIGNAL);
+	} else {
+		tm_enable();
+		tm_save_sprs(&(tsk->thread));
+	}
 }
 #else
 static inline void flush_tmregs_to_thread(struct task_struct *tsk) { }


Patches currently in stable-queue which might be from gromero@linux.vnet.ibm.com are

queue-4.12/powerpc-tm-fix-saving-of-tm-sprs-in-core-dump.patch