diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2020-04-29 09:56:54 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-28 16:24:37 +0300 |
| commit | d4539074b0e9c5fa6508e8c33aaf51abc8ff6e91 (patch) | |
| tree | 4f5914349c6615225839c54d5b37fff58f75a96d | |
| parent | 579940bb451c2dd33396d2d56ce6ef5d92154b3b (diff) | |
| download | linux-d4539074b0e9c5fa6508e8c33aaf51abc8ff6e91.tar.xz | |
powerpc/64s/kuap: Conditionally restore AMR in kuap_restore_amr asm
Similar to the C code change, make the AMR restore conditional on
whether the register has changed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200429065654.1677541-7-npiggin@gmail.com
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kup-radix.h | 10 | ||||
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 8 | ||||
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 4 |
3 files changed, 13 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h index 820169bac6c4..3ee1ec60be84 100644 --- a/arch/powerpc/include/asm/book3s/64/kup-radix.h +++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h @@ -12,13 +12,17 @@ #ifdef __ASSEMBLY__ -.macro kuap_restore_amr gpr +.macro kuap_restore_amr gpr1, gpr2 #ifdef CONFIG_PPC_KUAP BEGIN_MMU_FTR_SECTION_NESTED(67) - ld \gpr, STACK_REGS_KUAP(r1) + mfspr \gpr1, SPRN_AMR + ld \gpr2, STACK_REGS_KUAP(r1) + cmpd \gpr1, \gpr2 + beq 998f isync - mtspr SPRN_AMR, \gpr + mtspr SPRN_AMR, \gpr2 /* No isync required, see kuap_restore_amr() */ +998: END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67) #endif .endm diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index b3c9f15089b6..9d49338e0c85 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -479,11 +479,11 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) fast_interrupt_return: _ASM_NOKPROBE_SYMBOL(fast_interrupt_return) kuap_check_amr r3, r4 - ld r4,_MSR(r1) - andi. r0,r4,MSR_PR + ld r5,_MSR(r1) + andi. r0,r5,MSR_PR bne .Lfast_user_interrupt_return - kuap_restore_amr r3 - andi. r0,r4,MSR_RI + kuap_restore_amr r3, r4 + andi. r0,r5,MSR_RI li r3,0 /* 0 return value, no EMULATE_STACK_STORE */ bne+ .Lfast_kernel_interrupt_return addi r3,r1,STACK_FRAME_OVERHEAD diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 72036082dbaf..e70ebb5c318c 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -971,7 +971,7 @@ EXC_COMMON_BEGIN(system_reset_common) ld r10,SOFTE(r1) stb r10,PACAIRQSOFTMASK(r13) - kuap_restore_amr r10 + kuap_restore_amr r9, r10 EXCEPTION_RESTORE_REGS RFI_TO_USER_OR_KERNEL @@ -2784,7 +2784,7 @@ EXC_COMMON_BEGIN(soft_nmi_common) ld r10,SOFTE(r1) stb r10,PACAIRQSOFTMASK(r13) - kuap_restore_amr r10 + kuap_restore_amr r9, r10 EXCEPTION_RESTORE_REGS hsrr=0 RFI_TO_KERNEL |