lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 7 Mar 2022 23:47:24 +0800 From: Lecopzer Chen <lecopzer.chen@...iatek.com> To: <linux-kernel@...r.kernel.org> CC: <lecopzer.chen@...iatek.com>, <acme@...nel.org>, <akpm@...ux-foundation.org>, <alexander.shishkin@...ux.intel.com>, <catalin.marinas@....com>, <davem@...emloft.net>, <jolsa@...hat.com>, <jthierry@...hat.com>, <keescook@...omium.org>, <kernelfans@...il.com>, <linux-arm-kernel@...ts.infradead.org>, <linux-mediatek@...ts.infradead.org>, <linux-perf-users@...r.kernel.org>, <mark.rutland@....com>, <masahiroy@...nel.org>, <matthias.bgg@...il.com>, <maz@...nel.org>, <mcgrof@...nel.org>, <mingo@...hat.com>, <namhyung@...nel.org>, <nixiaoming@...wei.com>, <peterz@...radead.org>, <pmladek@...e.com>, <sparclinux@...r.kernel.org>, <sumit.garg@...aro.org>, <wangqing@...o.com>, <will@...nel.org>, <yj.chiang@...iatek.com> Subject: [PATCH v2 0/5] Suppot hld based on Pseudo-NMI for arm64 As we already used hld internally for arm64 since 2020, there still doesn't have a proper commit on the upstream and we badly need it. This serise rework on 5.17-rc7 from [1] and the origin author is Pingfan Liu <kernelfans@...il.com> Sumit Garg <sumit.garg@...aro.org> Qoute from [1]: > Hard lockup detector is helpful to diagnose unpaired irq enable/disable. > But the current watchdog framework can not cope with arm64 hw perf event > easily. > On arm64, when lockup_detector_init()->watchdog_nmi_probe(), PMU is not > ready until device_initcall(armv8_pmu_driver_init). And it is deeply > integrated with the driver model and cpuhp. Hence it is hard to push the > initialization of armv8_pmu_driver_init() before smp_init(). > But it is easy to take an opposite approach by enabling watchdog_hld to > get the capability of PMU async. > The async model is achieved by expanding watchdog_nmi_probe() with > -EBUSY, and a re-initializing work_struct which waits on a > wait_queue_head. [1] https://lore.kernel.org/lkml/20211014024155.15253-1-kernelfans@gmail.com/ v2: 1. Tweak commit message in patch 01/02/04/05 2. Remove vobose WARN in patch 04 within watchdog core. 3. Change from three states variable: detector_delay_init_state to two states variable: lockup_detector_pending_init Thanks Petr Mladek <pmladek@...e.com> for the idea. > 1. lockup_detector_work() called before lockup_detector_check(). > In this case, wait_event() will wait until lockup_detector_check() > clears detector_delay_pending_init and calls wake_up(). > 2. lockup_detector_check() called before lockup_detector_work(). > In this case, wait_even() will immediately continue because > it will see cleared detector_delay_pending_init. 4. Add comment in code in patch 04/05 for two states variable changing. Lecopzer Chen (4): kernel/watchdog: remove WATCHDOG_DEFAULT kernel/watchdog: change watchdog_nmi_enable() to void kernel/watchdog: Adapt the watchdog_hld interface for async model arm64: Enable perf events based hard lockup detector Pingfan Liu (1): kernel/watchdog_hld: Ensure CPU-bound context when creating hardlockup detector event arch/arm64/Kconfig | 2 + arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/perf_event.c | 12 +++++- arch/sparc/kernel/nmi.c | 8 ++-- drivers/perf/arm_pmu.c | 5 +++ include/linux/nmi.h | 5 ++- include/linux/perf/arm_pmu.h | 2 + kernel/watchdog.c | 67 +++++++++++++++++++++++++++++++--- kernel/watchdog_hld.c | 8 +++- 9 files changed, 95 insertions(+), 15 deletions(-) -- 2.25.1
Powered by blists - more mailing lists