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

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: 08e1c01d6a ("powerpc/ptrace: Enable support for TM SPR state")
Cc: stable@vger.kernel.org # v4.8+
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>
This commit is contained in:
Gustavo Romero 2017-07-19 01:44:13 -04:00 committed by Michael Ellerman
parent c9c98bc5cc
commit cd63f3cf1d
1 changed files with 10 additions and 3 deletions

View File

@ -127,12 +127,19 @@ static void flush_tmregs_to_thread(struct task_struct *tsk)
* 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) { }