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authorNicholas Piggin <npiggin@gmail.com>2020-04-03 23:10:05 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2020-04-04 21:40:57 +1100
commitd16a58f8854b194c964a4bbe8156ec624ebfdbd2 (patch)
treeaa24b4ea457b16e83aa8e45716b81ba3e7f56e78 /arch/powerpc/kernel/ppc_save_regs.S
parentRevert "powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled" (diff)
downloadlinux-dev-d16a58f8854b194c964a4bbe8156ec624ebfdbd2.tar.xz
linux-dev-d16a58f8854b194c964a4bbe8156ec624ebfdbd2.zip
powerpc: Improve ppc_save_regs()
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> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200403131006.123243-1-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/ppc_save_regs.S')
-rw-r--r--arch/powerpc/kernel/ppc_save_regs.S6
1 files changed, 5 insertions, 1 deletions
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