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authorNicholas Piggin <npiggin@gmail.com>2021-10-05 00:56:38 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2021-10-07 19:54:54 +1100
commit3e607dc4df180b72a38e75030cb0f94d12808712 (patch)
tree85b66f19b02db04975ac438c4097adcb6b09c732 /arch
parent548b762763b885b81850db676258df47c55dd5f9 (diff)
downloadlinux-3e607dc4df180b72a38e75030cb0f94d12808712.tar.gz
powerpc/64s: fix program check interrupt emergency stack path
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
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S17
1 files changed, 10 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 37859e62a8dc..024d9231f88c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1665,27 +1665,30 @@ 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 */