| Message ID | 20200403131006.123243-1-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d16a58f8854b194c964a4bbe8156ec624ebfdbd2 |
| Headers | show |
| Series | powerpc: improve ppc_save_regs | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (d0c12846a3a24cd6d68b608c866712bc7e471634) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 1 warnings, 0 checks, 23 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
On Fri, 2020-04-03 at 13:10:05 UTC, Nicholas Piggin wrote: > Make ppc_save_regs a bit more useful: > - Set NIP to our caller rather rather than the caller's caller (which is > what we save to LR in the stack frame). > - Set SOFTE to the current irq soft-mask state rather than > uninitialised. > - Zero CFAR rather than leave it uninitialised. > > In qemu, injecting a nmi to an idle CPU gives a nicer stack trace (note > NIP, IRQMASK, CFAR). > > Oops: System Reset, sig: 6 [#1] > LE PAGE_SIZE=64K MMU=Hash PREEMPT SMP NR_CPUS=2048 NUMA PowerNV > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc2-00429-ga76e38fd80bf #1277 > NIP: c0000000000b6e5c LR: c0000000000b6e5c CTR: c000000000b06270 > REGS: c00000000173fb08 TRAP: 0100 Not tainted > MSR: 9000000000001033 <SF,HV,ME,IR,DR,RI,LE> CR: 28000224 XER: 00000000 > CFAR: c0000000016a2128 IRQMASK: c00000000173fc80 > GPR00: c0000000000b6e5c c00000000173fc80 c000000001743400 c00000000173fb08 > GPR04: 0000000000000000 0000000000000000 0000000000000008 0000000000000001 > GPR08: 00000001fea80000 0000000000000000 0000000000000000 ffffffffffffffff > GPR12: c000000000b06270 c000000001930000 00000000300026c0 0000000000000000 > GPR16: 0000000000000000 0000000000000000 0000000000000003 c0000000016a2128 > GPR20: c0000001ffc97148 0000000000000001 c000000000f289a8 0000000000080000 > GPR24: c0000000016e1480 000000011dc870ba 0000000000000000 0000000000000003 > GPR28: c0000000016a2128 c0000001ffc97148 c0000000016a2260 0000000000000003 > NIP [c0000000000b6e5c] power9_idle_type+0x5c/0x70 > LR [c0000000000b6e5c] power9_idle_type+0x5c/0x70 > Call Trace: > [c00000000173fc80] [c0000000000b6e5c] power9_idle_type+0x5c/0x70 (unreliable) > [c00000000173fcb0] [c000000000b062b0] stop_loop+0x40/0x60 > [c00000000173fce0] [c000000000b022d8] cpuidle_enter_state+0xa8/0x660 > [c00000000173fd60] [c000000000b0292c] cpuidle_enter+0x4c/0x70 > [c00000000173fda0] [c00000000017624c] call_cpuidle+0x4c/0x90 > [c00000000173fdc0] [c000000000176768] do_idle+0x338/0x460 > [c00000000173fe60] [c000000000176b3c] cpu_startup_entry+0x3c/0x40 > [c00000000173fe90] [c0000000000126b4] rest_init+0x124/0x140 > [c00000000173fed0] [c0000000010948d4] start_kernel+0x938/0x988 > [c00000000173ff90] [c00000000000cdcc] start_here_common+0x1c/0x20 > > Oops: System Reset, sig: 6 [#1] > LE PAGE_SIZE=64K MMU=Hash PREEMPT SMP NR_CPUS=2048 NUMA PowerNV > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc2-00430-gddce91b8712f #1278 > NIP: c00000000001d150 LR: c0000000000b6e5c CTR: c000000000b06270 > REGS: c00000000173fb08 TRAP: 0100 Not tainted > MSR: 9000000000001033 <SF,HV,ME,IR,DR,RI,LE> CR: 28000224 XER: 00000000 > CFAR: 0000000000000000 IRQMASK: 1 > GPR00: c0000000000b6e5c c00000000173fc80 c000000001743400 c00000000173fb08 > GPR04: 0000000000000000 0000000000000000 0000000000000008 0000000000000001 > GPR08: 00000001fea80000 0000000000000000 0000000000000000 ffffffffffffffff > GPR12: c000000000b06270 c000000001930000 00000000300026c0 0000000000000000 > GPR16: 0000000000000000 0000000000000000 0000000000000003 c0000000016a2128 > GPR20: c0000001ffc97148 0000000000000001 c000000000f289a8 0000000000080000 > GPR24: c0000000016e1480 00000000b68db8ce 0000000000000000 0000000000000003 > GPR28: c0000000016a2128 c0000001ffc97148 c0000000016a2260 0000000000000003 > NIP [c00000000001d150] replay_system_reset+0x30/0xa0 > LR [c0000000000b6e5c] power9_idle_type+0x5c/0x70 > Call Trace: > [c00000000173fc80] [c0000000000b6e5c] power9_idle_type+0x5c/0x70 (unreliable) > [c00000000173fcb0] [c000000000b062b0] stop_loop+0x40/0x60 > [c00000000173fce0] [c000000000b022d8] cpuidle_enter_state+0xa8/0x660 > [c00000000173fd60] [c000000000b0292c] cpuidle_enter+0x4c/0x70 > [c00000000173fda0] [c00000000017624c] call_cpuidle+0x4c/0x90 > [c00000000173fdc0] [c000000000176768] do_idle+0x338/0x460 > [c00000000173fe60] [c000000000176b38] cpu_startup_entry+0x38/0x40 > [c00000000173fe90] [c0000000000126b4] rest_init+0x124/0x140 > [c00000000173fed0] [c0000000010948d4] start_kernel+0x938/0x988 > [c00000000173ff90] [c00000000000cdcc] start_here_common+0x1c/0x20 > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/d16a58f8854b194c964a4bbe8156ec624ebfdbd2 cheers
diff --git a/arch/powerpc/kernel/ppc_save_regs.S b/arch/powerpc/kernel/ppc_save_regs.S index f3bd0bbf2ae8..2d4d21bb46a9 100644 --- a/arch/powerpc/kernel/ppc_save_regs.S +++ b/arch/powerpc/kernel/ppc_save_regs.S @@ -55,14 +55,17 @@ _GLOBAL(ppc_save_regs) PPC_STL r29,29*SZL(r3) PPC_STL r30,30*SZL(r3) PPC_STL r31,31*SZL(r3) + lbz r0,PACAIRQSOFTMASK(r13) + PPC_STL r0,SOFTE-STACK_FRAME_OVERHEAD(r3) #endif /* go up one stack frame for SP */ PPC_LL r4,0(r1) PPC_STL r4,1*SZL(r3) /* get caller's LR */ PPC_LL r0,LRSAVE(r4) - PPC_STL r0,_NIP-STACK_FRAME_OVERHEAD(r3) PPC_STL r0,_LINK-STACK_FRAME_OVERHEAD(r3) + mflr r0 + PPC_STL r0,_NIP-STACK_FRAME_OVERHEAD(r3) mfmsr r0 PPC_STL r0,_MSR-STACK_FRAME_OVERHEAD(r3) mfctr r0 @@ -73,4 +76,5 @@ _GLOBAL(ppc_save_regs) PPC_STL r0,_CCR-STACK_FRAME_OVERHEAD(r3) li r0,0 PPC_STL r0,_TRAP-STACK_FRAME_OVERHEAD(r3) + PPC_STL r0,ORIG_GPR3-STACK_FRAME_OVERHEAD(r3) blr
Make ppc_save_regs a bit more useful: - Set NIP to our caller rather rather than the caller's caller (which is what we save to LR in the stack frame). - Set SOFTE to the current irq soft-mask state rather than uninitialised. - Zero CFAR rather than leave it uninitialised. In qemu, injecting a nmi to an idle CPU gives a nicer stack trace (note NIP, IRQMASK, CFAR). Oops: System Reset, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash PREEMPT SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc2-00429-ga76e38fd80bf #1277 NIP: c0000000000b6e5c LR: c0000000000b6e5c CTR: c000000000b06270 REGS: c00000000173fb08 TRAP: 0100 Not tainted MSR: 9000000000001033 <SF,HV,ME,IR,DR,RI,LE> CR: 28000224 XER: 00000000 CFAR: c0000000016a2128 IRQMASK: c00000000173fc80 GPR00: c0000000000b6e5c c00000000173fc80 c000000001743400 c00000000173fb08 GPR04: 0000000000000000 0000000000000000 0000000000000008 0000000000000001 GPR08: 00000001fea80000 0000000000000000 0000000000000000 ffffffffffffffff GPR12: c000000000b06270 c000000001930000 00000000300026c0 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000003 c0000000016a2128 GPR20: c0000001ffc97148 0000000000000001 c000000000f289a8 0000000000080000 GPR24: c0000000016e1480 000000011dc870ba 0000000000000000 0000000000000003 GPR28: c0000000016a2128 c0000001ffc97148 c0000000016a2260 0000000000000003 NIP [c0000000000b6e5c] power9_idle_type+0x5c/0x70 LR [c0000000000b6e5c] power9_idle_type+0x5c/0x70 Call Trace: [c00000000173fc80] [c0000000000b6e5c] power9_idle_type+0x5c/0x70 (unreliable) [c00000000173fcb0] [c000000000b062b0] stop_loop+0x40/0x60 [c00000000173fce0] [c000000000b022d8] cpuidle_enter_state+0xa8/0x660 [c00000000173fd60] [c000000000b0292c] cpuidle_enter+0x4c/0x70 [c00000000173fda0] [c00000000017624c] call_cpuidle+0x4c/0x90 [c00000000173fdc0] [c000000000176768] do_idle+0x338/0x460 [c00000000173fe60] [c000000000176b3c] cpu_startup_entry+0x3c/0x40 [c00000000173fe90] [c0000000000126b4] rest_init+0x124/0x140 [c00000000173fed0] [c0000000010948d4] start_kernel+0x938/0x988 [c00000000173ff90] [c00000000000cdcc] start_here_common+0x1c/0x20 Oops: System Reset, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash PREEMPT SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc2-00430-gddce91b8712f #1278 NIP: c00000000001d150 LR: c0000000000b6e5c CTR: c000000000b06270 REGS: c00000000173fb08 TRAP: 0100 Not tainted MSR: 9000000000001033 <SF,HV,ME,IR,DR,RI,LE> CR: 28000224 XER: 00000000 CFAR: 0000000000000000 IRQMASK: 1 GPR00: c0000000000b6e5c c00000000173fc80 c000000001743400 c00000000173fb08 GPR04: 0000000000000000 0000000000000000 0000000000000008 0000000000000001 GPR08: 00000001fea80000 0000000000000000 0000000000000000 ffffffffffffffff GPR12: c000000000b06270 c000000001930000 00000000300026c0 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000003 c0000000016a2128 GPR20: c0000001ffc97148 0000000000000001 c000000000f289a8 0000000000080000 GPR24: c0000000016e1480 00000000b68db8ce 0000000000000000 0000000000000003 GPR28: c0000000016a2128 c0000001ffc97148 c0000000016a2260 0000000000000003 NIP [c00000000001d150] replay_system_reset+0x30/0xa0 LR [c0000000000b6e5c] power9_idle_type+0x5c/0x70 Call Trace: [c00000000173fc80] [c0000000000b6e5c] power9_idle_type+0x5c/0x70 (unreliable) [c00000000173fcb0] [c000000000b062b0] stop_loop+0x40/0x60 [c00000000173fce0] [c000000000b022d8] cpuidle_enter_state+0xa8/0x660 [c00000000173fd60] [c000000000b0292c] cpuidle_enter+0x4c/0x70 [c00000000173fda0] [c00000000017624c] call_cpuidle+0x4c/0x90 [c00000000173fdc0] [c000000000176768] do_idle+0x338/0x460 [c00000000173fe60] [c000000000176b38] cpu_startup_entry+0x38/0x40 [c00000000173fe90] [c0000000000126b4] rest_init+0x124/0x140 [c00000000173fed0] [c0000000010948d4] start_kernel+0x938/0x988 [c00000000173ff90] [c00000000000cdcc] start_here_common+0x1c/0x20 Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- This becomes more important after implementing irq replay in C. arch/powerpc/kernel/ppc_save_regs.S | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)