| From 66092ded03a5b1feac9b9a1f0eb6ac48ed2c1555 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 5 Oct 2021 00:56:38 +1000 |
| Subject: powerpc/64s: fix program check interrupt emergency stack path |
| |
| From: Nicholas Piggin <npiggin@gmail.com> |
| |
| [ Upstream commit 3e607dc4df180b72a38e75030cb0f94d12808712 ] |
| |
| Emergency stack path was jumping into a 3: label inside the |
| __GEN_COMMON_BODY macro for the normal path after it had finished, |
| rather than jumping over it. By a small miracle this is the correct |
| place to build up a new interrupt frame with the existing stack |
| pointer, so things basically worked okay with an added weird looking |
| 700 trap frame on top (which had the wrong ->nip so it didn't decode |
| bug messages either). |
| |
| Fix this by avoiding using numeric labels when jumping over non-trivial |
| macros. |
| |
| Before: |
| |
| LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV |
| Modules linked in: |
| CPU: 0 PID: 88 Comm: sh Not tainted 5.15.0-rc2-00034-ge057cdade6e5 #2637 |
| NIP: 7265677368657265 LR: c00000000006c0c8 CTR: c0000000000097f0 |
| REGS: c0000000fffb3a50 TRAP: 0700 Not tainted |
| MSR: 9000000000021031 <SF,HV,ME,IR,DR,LE> CR: 00000700 XER: 20040000 |
| CFAR: c0000000000098b0 IRQMASK: 0 |
| GPR00: c00000000006c964 c0000000fffb3cf0 c000000001513800 0000000000000000 |
| GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299 |
| GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8 |
| GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001 |
| GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8 |
| GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158 |
| GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300 |
| GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80 |
| NIP [7265677368657265] 0x7265677368657265 |
| LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10 |
| Call Trace: |
| [c0000000fffb3cf0] [c00000000000bdac] soft_nmi_common+0x13c/0x1d0 (unreliable) |
| --- interrupt: 700 at decrementer_common_virt+0xb8/0x230 |
| NIP: c0000000000098b8 LR: c00000000006c0c8 CTR: c0000000000097f0 |
| REGS: c0000000fffb3d60 TRAP: 0700 Not tainted |
| MSR: 9000000000021031 <SF,HV,ME,IR,DR,LE> CR: 22424282 XER: 20040000 |
| CFAR: c0000000000098b0 IRQMASK: 0 |
| GPR00: c00000000006c964 0000000000002400 c000000001513800 0000000000000000 |
| GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299 |
| GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8 |
| GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001 |
| GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8 |
| GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158 |
| GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300 |
| GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80 |
| NIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230 |
| LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10 |
| --- interrupt: 700 |
| Instruction dump: |
| XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX |
| XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX |
| ---[ end trace 6d28218e0cc3c949 ]--- |
| |
| After: |
| |
| ------------[ cut here ]------------ |
| kernel BUG at arch/powerpc/kernel/exceptions-64s.S:491! |
| Oops: Exception in kernel mode, sig: 5 [#1] |
| LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV |
| Modules linked in: |
| CPU: 0 PID: 88 Comm: login Not tainted 5.15.0-rc2-00034-ge057cdade6e5-dirty #2638 |
| NIP: c0000000000098b8 LR: c00000000006bf04 CTR: c0000000000097f0 |
| REGS: c0000000fffb3d60 TRAP: 0700 Not tainted |
| MSR: 9000000000021031 <SF,HV,ME,IR,DR,LE> CR: 24482227 XER: 00040000 |
| CFAR: c0000000000098b0 IRQMASK: 0 |
| GPR00: c00000000006bf04 0000000000002400 c000000001513800 c000000001271868 |
| GPR04: 00000000100f0d29 0000000042000000 0000000000000007 0000000000000009 |
| GPR08: 00000000100f0d29 0000000024482227 0000000000002710 c000000000181b3c |
| GPR12: 9000000000009033 c0000000016b0000 00000000100f0d29 c000000005b22f00 |
| GPR16: 00000000ffff0000 0000000000000001 0000000000000009 00000000100eed90 |
| GPR20: 00000000100eed90 0000000010000000 000000001000a49c 00000000100f1430 |
| GPR24: c000000001271868 0000000002000000 0000000000000215 0000000000000300 |
| GPR28: c000000001271800 0000000042000000 00000000100f0d29 c000000080647860 |
| NIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230 |
| LR [c00000000006bf04] ___do_page_fault+0x234/0xb10 |
| Call Trace: |
| Instruction dump: |
| 4182000c 39400001 48000008 894d0932 714a0001 39400008 408225fc 718a4000 |
| 7c2a0b78 3821fcf0 41c20008 e82d0910 <0981fcf0> f92101a0 f9610170 f9810178 |
| ---[ end trace a5dbd1f5ea4ccc51 ]--- |
| |
| Fixes: 0a882e28468f4 ("powerpc/64s/exception: remove bad stack branch") |
| Signed-off-by: Nicholas Piggin <npiggin@gmail.com> |
| Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
| Link: https://lore.kernel.org/r/20211004145642.1331214-2-npiggin@gmail.com |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/powerpc/kernel/exceptions-64s.S | 17 ++++++++++------- |
| 1 file changed, 10 insertions(+), 7 deletions(-) |
| |
| diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S |
| index 9d3b468bd2d7..10df278dc3fb 100644 |
| --- a/arch/powerpc/kernel/exceptions-64s.S |
| +++ b/arch/powerpc/kernel/exceptions-64s.S |
| @@ -1715,27 +1715,30 @@ EXC_COMMON_BEGIN(program_check_common) |
| */ |
| |
| andi. r10,r12,MSR_PR |
| - bne 2f /* If userspace, go normal path */ |
| + bne .Lnormal_stack /* If userspace, go normal path */ |
| |
| andis. r10,r12,(SRR1_PROGTM)@h |
| - bne 1f /* If TM, emergency */ |
| + bne .Lemergency_stack /* If TM, emergency */ |
| |
| cmpdi r1,-INT_FRAME_SIZE /* check if r1 is in userspace */ |
| - blt 2f /* normal path if not */ |
| + blt .Lnormal_stack /* normal path if not */ |
| |
| /* Use the emergency stack */ |
| -1: andi. r10,r12,MSR_PR /* Set CR0 correctly for label */ |
| +.Lemergency_stack: |
| + andi. r10,r12,MSR_PR /* Set CR0 correctly for label */ |
| /* 3 in EXCEPTION_PROLOG_COMMON */ |
| mr r10,r1 /* Save r1 */ |
| ld r1,PACAEMERGSP(r13) /* Use emergency stack */ |
| subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */ |
| __ISTACK(program_check)=0 |
| __GEN_COMMON_BODY program_check |
| - b 3f |
| -2: |
| + b .Ldo_program_check |
| + |
| +.Lnormal_stack: |
| __ISTACK(program_check)=1 |
| __GEN_COMMON_BODY program_check |
| -3: |
| + |
| +.Ldo_program_check: |
| addi r3,r1,STACK_FRAME_OVERHEAD |
| bl program_check_exception |
| REST_NVGPRS(r1) /* instruction emulation may change GPRs */ |
| -- |
| 2.33.0 |
| |