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authorNicholas Piggin <npiggin@gmail.com>2018-01-10 03:07:15 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2018-01-10 03:07:32 +1100
commita08f828cf47e6c605af21d2cdec68f84e799c318 (patch)
tree348e809ca069dfcb7b570fa00490ddbc3e830c1e
parentb8e90cb7bc04a509e821e82ab6ed7a8ef11ba333 (diff)
powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL
Similar to the syscall return path, in fast_exception_return we may be returning to user or kernel context. We already have a test for that, because we conditionally restore r13. So use that existing test and branch, and bifurcate the return based on that. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/kernel/entry_64.S18
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 724733b74744..2748584b767d 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -892,7 +892,7 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ACCOUNT_CPU_USER_EXIT(r13, r2, r4)
REST_GPR(13, r1)
-1:
+
mtspr SPRN_SRR1,r3
ld r2,_CCR(r1)
@@ -905,8 +905,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ld r3,GPR3(r1)
ld r4,GPR4(r1)
ld r1,GPR1(r1)
+ RFI_TO_USER
+ b . /* prevent speculative execution */
+
+1: mtspr SPRN_SRR1,r3
+
+ ld r2,_CCR(r1)
+ mtcrf 0xFF,r2
+ ld r2,_NIP(r1)
+ mtspr SPRN_SRR0,r2
- rfid
+ ld r0,GPR0(r1)
+ ld r2,GPR2(r1)
+ ld r3,GPR3(r1)
+ ld r4,GPR4(r1)
+ ld r1,GPR1(r1)
+ RFI_TO_KERNEL
b . /* prevent speculative execution */
#endif /* CONFIG_PPC_BOOK3E */