This is the update version of the patch which I posted one year ago (https://lkml.org/lkml/2015/7/23/864). Because I couldn't received positive opinions against the previous version, I had changed the approach to another one which utilizes kexec purgatory. Then I'm back here. PATCH 1/2 is a bugfix for crash_kexec_post_notifiers boot option which allows users to call panic notifiers and kmsg dumpers before kdump. When this option is enabled, smp_send_stop() is used to stop other CPUs instead of a function provided by kdump. smp_send_stop() just stops other CPUs and doesn't other things needed for kdump. So, fix it by replacing smp_send_stop() with new appropriate one, panic_smp_send_stop(). Since panic_smp_send_stop() is architecture specific and I can't simply copy from kdump routines, only x86-specific version is provided. PATCH 2/2 makes crash_kexec_post_notifiers boot option modifiable after boot. We don't need to limit it to being modifiable at boot time. Changes in V3: - Revise comments, description, and symbol names (the logic doesn't change) - Make crash_kexec_post_notifiers boot option modifiable after boot Changes in V2: https://lkml.org/lkml/2015/7/23/864 - Replace smp_send_stop() call with crash_kexec version which saves cpu states and does cleanups instead of changing execution flow - Drop a fix for Problem 1 - Drop other patches because they aren't needed anymore V1: https://lkml.org/lkml/2015/7/10/316 --- Hidehiro Kawai (2): x86/panic: Replace smp_send_stop() with kdump friendly version kexec: Use core_param for crash_kexec_post_notifiers boot option arch/x86/kernel/crash.c | 14 ++++++++---- kernel/panic.c | 56 ++++++++++++++++++++++++++++++----------------- 2 files changed, 46 insertions(+), 24 deletions(-) -- Hidehiro Kawai Hitachi, Ltd. Research & Development Group
