diff options
| author | Michael Neuling <mikey@neuling.org> | 2017-10-12 21:17:19 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-10-21 09:36:28 +1100 |
| commit | 92fb8690bd04cb421d987d246deac60eef85d272 (patch) | |
| tree | 22a6b0e98a096b34dd91adb60f505106a97078f5 /arch/powerpc/kernel/process.c | |
| parent | 54820530c5faa9fd78e1c08cb6449100b1a19157 (diff) | |
powerpc/tm: P9 disable transactionally suspended sigcontexts
Unfortunately userspace can construct a sigcontext which enables
suspend. Thus userspace can force Linux into a path where trechkpt is
executed.
This patch blocks this from happening on POWER9 by sanity checking
sigcontexts passed in.
ptrace doesn't have this problem as only MSR SE and BE can be changed
via ptrace.
This patch also adds a number of WARN_ON()s in case we ever enter
suspend when we shouldn't. This should not happen, but if it does the
symptoms are soft lockup warnings which are not obviously TM related,
so the WARN_ON()s should make it obvious what's happening.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index b02807ea54dc..c051dc2b42ad 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -910,6 +910,8 @@ static inline void tm_reclaim_task(struct task_struct *tsk) if (!MSR_TM_ACTIVE(thr->regs->msr)) goto out_and_saveregs; + WARN_ON(tm_suspend_disabled); + TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, " "ccr=%lx, msr=%lx, trap=%lx)\n", tsk->pid, thr->regs->nip, |