Messages in this thread Patch in this message | | | From | Zhiquan Li <> | Subject | [PATCH v2] x86/mce: Set PG_hwpoison page flag to avoid the capture kernel panic | Date | Mon, 27 Mar 2023 10:33:58 +0800 |
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Kdump can exclude the HWPosion page to avoid touch the error page again, the prerequisite is the PG_hwpoison page flag is set. However, for some MCE fatal error cases, there is no opportunity to queue a task for calling memory_failure(), as a result, the capture kernel touches the error page again and panics.
Add function mce_set_page_hwpoison_now() which marks a page as HWPoison before kernel panic() for MCE error, so that the dump program can check and skip the error page and prevent the capture kernel panic.
[Tony: Changed TestSetPageHWPoison() to SetPageHWPoison()]
Co-developed-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Zhiquan Li <zhiquan1.li@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
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Changes since V1: - Rebased to latest tip/ras/core (based on v6.3-rc1). - Revised the commit message as per Naoya's suggestion. - Removed 'TODO' from comment, as previously discussed, there is nothing more to do at this time. Link: https://lore.kernel.org/all/20230127015030.30074-1-tony.luck@intel.com/ --- arch/x86/kernel/cpu/mce/core.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 7832a69d170e..dea393ca949b 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -156,6 +156,22 @@ void mce_unregister_decode_chain(struct notifier_block *nb) } EXPORT_SYMBOL_GPL(mce_unregister_decode_chain); +/* + * Kdump can exclude the HWPosion page to avoid touch the error page again, + * the prerequisite is the PG_hwpoison page flag is set. However, for some + * MCE fatal error cases, there are no opportunity to queue a task + * for calling memory_failure(), as a result, the capture kernel panics. + * This function marks the page as HWPoison before kernel panic() for MCE. + */ +static void mce_set_page_hwpoison_now(unsigned long pfn) +{ + struct page *p; + + p = pfn_to_online_page(pfn); + if (p) + SetPageHWPoison(p); +} + static void __print_mce(struct mce *m) { pr_emerg(HW_ERR "CPU %d: Machine Check%s: %Lx Bank %d: %016Lx\n", @@ -286,6 +302,8 @@ static noinstr void mce_panic(const char *msg, struct mce *final, char *exp) if (!fake_panic) { if (panic_timeout == 0) panic_timeout = mca_cfg.panic_timeout; + if (final && (final->status & MCI_STATUS_ADDRV)) + mce_set_page_hwpoison_now(final->addr >> PAGE_SHIFT); panic(msg); } else pr_emerg(HW_ERR "Fake kernel panic: %s\n", msg); -- 2.25.1
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