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| author | Nicholas Piggin <npiggin@gmail.com> | 2020-04-29 16:56:53 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-07 11:00:41 +1000 |
| commit | c44dc6323cd49d8d742c37e234b952e822c35de4 (patch) | |
| tree | c8a0eb0e95f2e30949fdf3684967bd355b7e16ee /arch/powerpc/kernel/entry_64.S | |
| parent | 53459dc9709db2141d784702abbd43e8fcac8e6d (diff) | |
| download | linux-c44dc6323cd49d8d742c37e234b952e822c35de4.tar.gz | |
powerpc/64s/kuap: Restore AMR in fast_interrupt_return
Interrupts that use fast_interrupt_return actually do lock AMR, but
they have been ones which tend to come from userspace (or kernel bugs)
in radix mode. With kuap on hash, segment interrupts are taken in
kernel often, which quickly breaks due to the missing restore.
Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200429065654.1677541-6-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 9a1e5d636dea99..b3c9f15089b64c 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -472,15 +472,17 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) #ifdef CONFIG_PPC_BOOK3S /* * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not - * touched, AMR not set, no exit work created, then this can be used. + * touched, no exit work created, then this can be used. */ .balign IFETCH_ALIGN_BYTES .globl fast_interrupt_return fast_interrupt_return: _ASM_NOKPROBE_SYMBOL(fast_interrupt_return) + kuap_check_amr r3, r4 ld r4,_MSR(r1) andi. r0,r4,MSR_PR bne .Lfast_user_interrupt_return + kuap_restore_amr r3 andi. r0,r4,MSR_RI li r3,0 /* 0 return value, no EMULATE_STACK_STORE */ bne+ .Lfast_kernel_interrupt_return |