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authorDavid S. Miller <davem@davemloft.net>2015-12-03 21:03:21 -0500
committerDavid S. Miller <davem@davemloft.net>2015-12-03 21:09:12 -0500
commitf188b951f33a0464338f94f928338f84fc0e4392 (patch)
tree17ad63719242b1de0266627a1dc92ba869a3ba4e /arch/powerpc/kernel/process.c
parent6b20da4d8f3f6a3be9f67e3207f435cfaa5f7f97 (diff)
parent071f5d105a0ae93aeb02197c4ee3557e8cc57a21 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/ethernet/renesas/ravb_main.c kernel/bpf/syscall.c net/ipv4/ipmr.c All three conflicts were cases of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/powerpc/kernel/process.c')
-rw-r--r--arch/powerpc/kernel/process.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 75b6676c1a0b..646bf4d222c1 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -551,6 +551,24 @@ static void tm_reclaim_thread(struct thread_struct *thr,
msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1;
}
+ /*
+ * Use the current MSR TM suspended bit to track if we have
+ * checkpointed state outstanding.
+ * On signal delivery, we'd normally reclaim the checkpointed
+ * state to obtain stack pointer (see:get_tm_stackpointer()).
+ * This will then directly return to userspace without going
+ * through __switch_to(). However, if the stack frame is bad,
+ * we need to exit this thread which calls __switch_to() which
+ * will again attempt to reclaim the already saved tm state.
+ * Hence we need to check that we've not already reclaimed
+ * this state.
+ * We do this using the current MSR, rather tracking it in
+ * some specific thread_struct bit, as it has the additional
+ * benifit of checking for a potential TM bad thing exception.
+ */
+ if (!MSR_TM_SUSPENDED(mfmsr()))
+ return;
+
tm_reclaim(thr, thr->regs->msr, cause);
/* Having done the reclaim, we now have the checkpointed