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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
arch RISC-V: Fixup schedule out issue in machine_crash_shutdown() 2022-08-11 08:54:46 -07:00
block for-5.19/drivers-2022-06-02 2022-06-03 10:25:56 -07:00
certs Kbuild updates for v5.19 2022-05-26 12:09:50 -07:00
crypto This update includes the following changes: 2022-05-27 18:06:49 -07:00
Documentation A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
drivers fix for breakage in #work.fd this window 2022-06-05 17:14:03 -07:00
fs fix for breakage in #work.fd this window 2022-06-05 17:14:03 -07:00
include A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
init This set of changes updates init and user mode helper tasks to be 2022-06-03 16:03:05 -07:00
ipc These changes update the ipc sysctls so that they are fundamentally 2022-06-03 15:54:57 -07:00
kernel A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
lib Bitmap patches for 5.19-rc1 2022-06-04 14:04:27 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
net bluetooth: don't use bitmaps for random flag accesses 2022-06-05 16:28:41 -07:00
samples drm for 5.19-rc1 2022-05-25 16:18:27 -07:00
scripts A set of objtool fixes: 2022-06-05 09:45:27 -07:00
security Cleanups (and one fix) around struct mount handling. 2022-06-04 19:00:05 -07:00
sound USB / Thunderbolt changes for 5.19-rc1 2022-06-03 11:17:49 -07:00
tools A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt VFIO updates for v5.19-rc1 2022-06-01 13:49:15 -07:00
.clang-format clang-format: Fix space after for_each macros 2022-05-20 19:27:16 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
Makefile Linux 5.19-rc1 2022-06-05 17:18:54 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.