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authorNicholas Piggin <npiggin@gmail.com>2016-07-25 14:26:51 +1000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2016-08-29 12:47:56 +1000
commitcc7786d3ee7e3c979799db834b528db2c0834c2e (patch)
tree5983f225848f30047b2f61ec6c04c7d779a302ac
parent7c379526d7e71d2041c8ca0bd9af4888916a14b9 (diff)
powerpc/tm: do not use r13 for tabort_syscall
tabort_syscall runs with RI=1, so a nested recoverable machine check will load the paca into r13 and overwrite what we loaded it with, because exceptions returning to privileged mode do not restore r13. Fixes: b4b56f9ecab4 (powerpc/tm: Abort syscalls in active transactions) Cc: stable@vger.kernel.org Signed-off-by: Nick Piggin <npiggin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/kernel/entry_64.S12
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6b8bc0dd09d4..5afd03e5e8b8 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -368,13 +368,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
tabort_syscall:
/* Firstly we need to enable TM in the kernel */
mfmsr r10
- li r13, 1
- rldimi r10, r13, MSR_TM_LG, 63-MSR_TM_LG
+ li r9, 1
+ rldimi r10, r9, MSR_TM_LG, 63-MSR_TM_LG
mtmsrd r10, 0
/* tabort, this dooms the transaction, nothing else */
- li r13, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
- TABORT(R13)
+ li r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
+ TABORT(R9)
/*
* Return directly to userspace. We have corrupted user register state,
@@ -382,8 +382,8 @@ tabort_syscall:
* resume after the tbegin of the aborted transaction with the
* checkpointed register state.
*/
- li r13, MSR_RI
- andc r10, r10, r13
+ li r9, MSR_RI
+ andc r10, r10, r9
mtmsrd r10, 1
mtspr SPRN_SRR0, r11
mtspr SPRN_SRR1, r12