From: Qi Zheng <zhengqi.arch@bytedance.com>
To: catalin.marinas@arm.com, will@kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Qi Zheng <zhengqi.arch@bytedance.com>
Subject: [RFC PATCH 0/2] arm64: run softirqs on the per-CPU IRQ stack
Date: Thu, 7 Jul 2022 19:05:09 +0800 [thread overview]
Message-ID: <20220707110511.52129-1-zhengqi.arch@bytedance.com> (raw)
Hi all,
Currently arm64 supports per-CPU IRQ stack, but softirqs are
still handled in the task context.
Since any call to local_bh_enable() at any level in the task's
call stack may trigger a softirq processing run, which could
potentially cause a task stack overflow if the combined stack
footprints exceed the stack's size. And we did encounter this
situation in the real environment:
Call trace:
dump_backtrace+0x0/0x1cc,
show_stack+0x14/0x1c,
dump_stack+0xc4/0xfc,
panic+0x150/0x2c8,
panic+0x0/0x2c8,
handle_bad_stack+0x11c/0x130,
__bad_stack+0x88/0x8c,
vsnprintf+0x2c/0x524,
vscnprintf+0x38/0x7c,
scnprintf+0x6c/0x90,
/* ... */
__do_softirq+0x1e0/0x370,
do_softirq+0x40/0x50,
__local_bh_enable_ip+0x8c/0x90,
_raw_spin_unlock_bh+0x1c/0x24,
/* ... */
process_one_work+0x1dc/0x3e4,
worker_thread+0x260/0x360,
kthread+0x118/0x128,
ret_from_fork+0x10/0x18,
So let's run these softirqs on the IRQ stack as well.
This series is based on next-20220705.
Comments and suggestions are welcome.
Thanks,
Qi.
Qi Zheng (2):
arm64: run softirqs on the per-CPU IRQ stack
arm64: support HAVE_IRQ_EXIT_ON_IRQ_STACK
arch/arm64/Kconfig | 2 ++
arch/arm64/include/asm/exception.h | 4 +++-
arch/arm64/kernel/entry-common.c | 30 ++++++++++++++++++++----------
arch/arm64/kernel/entry.S | 6 ++++--
arch/arm64/kernel/irq.c | 12 ++++++++++++
5 files changed, 41 insertions(+), 13 deletions(-)
--
2.20.1
next reply other threads:[~2022-07-07 11:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-07 11:05 Qi Zheng [this message]
2022-07-07 11:05 ` [RFC PATCH 1/2] arm64: run softirqs on the per-CPU IRQ stack Qi Zheng
2022-07-07 12:58 ` Arnd Bergmann
2022-07-07 13:43 ` Qi Zheng
2022-07-07 13:53 ` Arnd Bergmann
2022-07-07 15:05 ` Qi Zheng
2022-07-07 11:05 ` [RFC PATCH 2/2] arm64: support HAVE_IRQ_EXIT_ON_IRQ_STACK Qi Zheng
2022-07-07 12:49 ` Arnd Bergmann
2022-07-07 13:38 ` Qi Zheng
2022-07-07 14:41 ` Arnd Bergmann
2022-07-07 15:00 ` Qi Zheng
2022-07-07 20:55 ` Arnd Bergmann
2022-07-08 3:13 ` Qi Zheng
2022-07-08 8:52 ` Arnd Bergmann
2022-07-08 9:13 ` Qi Zheng
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