Xianting Tian ad943893d5 RISC-V: Fixup schedule out issue in machine_crash_shutdown() ... Current task of executing crash kexec will be schedule out when panic is triggered by RCU Stall, as it needs to wait rcu completion. It lead to inability to enter the crash system. The implementation of machine_crash_shutdown() is non-standard for RISC-V according to other Arch's implementation(eg, x86, arm64), we need to send IPI to stop secondary harts. [224521.877268] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: [224521.883471] rcu: 0-...0: (3 GPs behind) idle=cfa/0/0x1 softirq=3968793/3968793 fqs=2495 [224521.891742] (detected by 2, t=5255 jiffies, g=60855593, q=328) [224521.897754] Task dump for CPU 0: [224521.901074] task:swapper/0 state:R running task stack: 0 pid: 0 ppid: 0 flags:0x00000008 [224521.911090] Call Trace: [224521.913638] [<ffffffe000c432de>] __schedule+0x208/0x5ea [224521.918957] Kernel panic - not syncing: RCU Stall [224521.923773] bad: scheduling from the idle thread! [224521.928571] CPU: 2 PID: 0 Comm: swapper/2 Kdump: loaded Tainted: G O 5.10.113-yocto-standard #1 [224521.938658] Call Trace: [224521.941200] [<ffffffe00020395c>] walk_stackframe+0x0/0xaa [224521.946689] [<ffffffe000c34f8e>] show_stack+0x32/0x3e [224521.951830] [<ffffffe000c39020>] dump_stack_lvl+0x7e/0xa2 [224521.957317] [<ffffffe000c39058>] dump_stack+0x14/0x1c [224521.962459] [<ffffffe000243884>] dequeue_task_idle+0x2c/0x40 [224521.968207] [<ffffffe000c434f4>] __schedule+0x41e/0x5ea [224521.973520] [<ffffffe000c43826>] schedule+0x34/0xe4 [224521.978487] [<ffffffe000c46cae>] schedule_timeout+0xc6/0x170 [224521.984234] [<ffffffe000c4491e>] wait_for_completion+0x98/0xf2 [224521.990157] [<ffffffe00026d9e2>] __wait_rcu_gp+0x148/0x14a [224521.995733] [<ffffffe0002761c4>] synchronize_rcu+0x5c/0x66 [224522.001307] [<ffffffe00026f1a6>] rcu_sync_enter+0x54/0xe6 [224522.006795] [<ffffffe00025a436>] percpu_down_write+0x32/0x11c [224522.012629] [<ffffffe000c4266a>] _cpu_down+0x92/0x21a [224522.017771] [<ffffffe000219a0a>] smp_shutdown_nonboot_cpus+0x90/0x118 [224522.024299] [<ffffffe00020701e>] machine_crash_shutdown+0x30/0x4a [224522.030483] [<ffffffe00029a3f8>] __crash_kexec+0x62/0xa6 [224522.035884] [<ffffffe000c3515e>] panic+0xfa/0x2b6 [224522.040678] [<ffffffe0002772be>] rcu_sched_clock_irq+0xc26/0xcb8 [224522.046774] [<ffffffe00027fc7a>] update_process_times+0x62/0x8a [224522.052785] [<ffffffe00028d522>] tick_sched_timer+0x9e/0x102 [224522.058533] [<ffffffe000280c3a>] __hrtimer_run_queues+0x16a/0x318 [224522.064716] [<ffffffe0002812ec>] hrtimer_interrupt+0xd4/0x228 [224522.070551] [<ffffffe0009a69b6>] riscv_timer_interrupt+0x3c/0x48 [224522.076646] [<ffffffe000268f8c>] handle_percpu_devid_irq+0xb0/0x24c [224522.083004] [<ffffffe00026428e>] __handle_domain_irq+0xa8/0x122 [224522.089014] [<ffffffe00062f954>] riscv_intc_irq+0x38/0x60 [224522.094501] [<ffffffe000201bd4>] ret_from_exception+0x0/0xc [224522.100161] [<ffffffe000c42146>] rcu_eqs_enter.constprop.0+0x8c/0xb8 With the patch, it can enter crash system when RCU Stall occur. Fixes: e53d28180d ("RISC-V: Add kdump support") Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Link: https://lore.kernel.org/r/20220811074150.3020189-4-xianting.tian@linux.alibaba.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>		2022-08-11 08:54:46 -07:00
..
boot	riscv: dts: icicle: sort nodes alphabetically	2022-06-01 15:28:51 -07:00
configs	RISC-V: configs: Configs that had RPMSG_CHAR now get RPMSG_CTRL	2022-04-26 08:19:53 -07:00
errata	riscv: add memory-type errata for T-Head	2022-05-11 21:36:33 -07:00
include	riscv: Move alternative length validation into subsection	2022-06-02 15:55:22 -07:00
kernel	RISC-V: Fixup schedule out issue in machine_crash_shutdown()	2022-08-11 08:54:46 -07:00
kvm	RISC-V: KVM: Introduce ISA extension register	2022-05-20 09:09:20 +05:30
lib	riscv: Fixed misaligned memory access. Fixed pointer comparison.	2022-03-10 10:24:04 -08:00
mm	riscv: mm: init: make pt_ops_set_[early|late|fixmap] static	2022-06-02 14:50:41 -07:00
net	riscv, bpf: Implement more atomic operations for RV64	2022-04-11 16:54:54 +02:00
purgatory	RISC-V: Add purgatory	2022-05-19 12:18:59 -07:00
Kbuild	riscv: move errata/ and kvm/ builds to arch/riscv/Kbuild	2022-06-01 22:26:32 -07:00
Kconfig	RISC-V: Only default to spinwait on SBI-0.1 and M-mode	2022-06-01 18:59:26 -07:00
Kconfig.debug	RISC-V: Remove EARLY_PRINTK support	2018-12-17 10:23:46 -08:00
Kconfig.erratas	riscv: add memory-type errata for T-Head	2022-05-11 21:36:33 -07:00
Kconfig.socs	RISC-V Patches for the 5.19 Merge Window, Part 1	2022-05-31 14:10:54 -07:00
Makefile	riscv: move errata/ and kvm/ builds to arch/riscv/Kbuild	2022-06-01 22:26:32 -07:00