[ Upstream commit c44e50f4a0ec00c2298f31f91bc2c3e9bbd81c7e ] During I/O and simultaneous cat of /sys/kernel/debug/lpfc/fnX/rx_monitor, a hard lockup similar to the call trace below may occur. The spin_lock_bh in lpfc_rx_monitor_report is not protecting from timer interrupts as expected, so change the strength of the spin lock to _irq. Kernel panic - not syncing: Hard LOCKUP CPU: 3 PID: 110402 Comm: cat Kdump: loaded exception RIP: native_queued_spin_lock_slowpath+91 [IRQ stack] native_queued_spin_lock_slowpath at ffffffffb814e30b _raw_spin_lock at ffffffffb89a667a lpfc_rx_monitor_record at ffffffffc0a73a36 [lpfc] lpfc_cmf_timer at ffffffffc0abbc67 [lpfc] __hrtimer_run_queues at ffffffffb8184250 hrtimer_interrupt at ffffffffb8184ab0 smp_apic_timer_interrupt at ffffffffb8a026ba apic_timer_interrupt at ffffffffb8a01c4f [End of IRQ stack] apic_timer_interrupt at ffffffffb8a01c4f lpfc_rx_monitor_report at ffffffffc0a73c80 [lpfc] lpfc_rx_monitor_read at ffffffffc0addde1 [lpfc] full_proxy_read at ffffffffb83e7fc3 vfs_read at ffffffffb833fe71 ksys_read at ffffffffb83402af do_syscall_64 at ffffffffb800430b entry_SYSCALL_64_after_hwframe at ffffffffb8a000ad Signed-off-by: Justin Tee <justin.tee@broadcom.com> Link: https://lore.kernel.org/r/20221017164323.14536-2-justintee8345@gmail.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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.
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