This patchset enables IPI_CPU_CRASH_STOP IPI to be pseudo-NMI. This allows kdump to collect system information even when the CPU is in a HARDLOCKUP state.
Only IPI_CPU_CRASH_STOP uses NMI and the other IPIs remain normal IRQs. The patch has been tested on FX1000. It also uses some of Sumit's IPI patch set for NMI.[1] [1] https://lore.kernel.org/lkml/[email protected]/ $ echo 1 > /proc/sys/kernel/panic_on_rcu_stal $ echo HARDLOCKUP > /sys/kernel/debug/provoke-crash/DIRECT : kernel panics and crash kernel boot : makedumpfile saves the system state at HARDLOCKUP in vmcore. crash utility: #7 [fffffe00290afd30] lkdtm_HARDLOCKUP at fffffe0010857ee8 #8 [fffffe00290afd40] direct_entry at fffffe0010857c94 #9 [fffffe00290afd90] full_proxy_write at fffffe001055dea0 #10 [fffffe00290afdd0] vfs_write at fffffe001047533c #11 [fffffe00290afe10] ksys_write at fffffe001047563c #12 [fffffe00290afe60] __arm64_sys_write at fffffe00104756e8 #13 [fffffe00290afe70] do_el0_svc at fffffe00101590cc #14 [fffffe00290afea0] el0_svc at fffffe0010147a30 #15 [fffffe00290afeb0] el0_sync_handler at fffffe001014835c #16 [fffffe00290afff0] el0_sync at fffffe0010142c14 Changes in v1: - Rebased to head of upstream master. - Rebased to Sumit's latest IPIs patch-set [1]. [1] https://lore.kernel.org/lkml/[email protected]/ - Add conditional branch of local_irq_disable(). Sumit Garg (1): irqchip/gic-v3: Enable support for SGIs to act as NMIs Yuichi Ito (2): arch64: smp: Register IPI_CPU_CRASH_STOP IPI as pseudo-NMI arch64: smp: Disable priority masking when received NMI on PSR.I section arch/arm64/kernel/smp.c | 44 +++++++++++++++++++++++++++++++++++--------- drivers/irqchip/irq-gic-v3.c | 29 +++++++++++++++++++++-------- 2 files changed, 56 insertions(+), 17 deletions(-) -- 1.8.3.1
