From d1fe111fb62a1cf0446a2919f5effbb33ad0702c Mon Sep 17 00:00:00 2001 From: luofei Date: Tue, 22 Mar 2022 14:44:38 -0700 Subject: mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler When the hwpoison page meets the filter conditions, it should not be regarded as successful memory_failure() processing for mce handler, but should return a distinct value, otherwise mce handler regards the error page has been identified and isolated, which may lead to calling set_mce_nospec() to change page attribute, etc. Here memory_failure() return -EOPNOTSUPP to indicate that the error event is filtered, mce handler should not take any action for this situation and hwpoison injector should treat as correct. Link: https://lkml.kernel.org/r/20220223082135.2769649-1-luofei@unicloud.com Signed-off-by: luofei Acked-by: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Miaohe Lin Cc: Naoya Horiguchi Cc: Thomas Gleixner Cc: Tony Luck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'mm/memory-failure.c') diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 80fc9dca4d21c..f75a2ed72e693 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1515,7 +1515,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags) if (TestClearPageHWPoison(head)) num_poisoned_pages_dec(); unlock_page(head); - return 0; + return -EOPNOTSUPP; } unlock_page(head); res = MF_FAILED; @@ -1602,7 +1602,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, goto out; if (hwpoison_filter(page)) { - rc = 0; + rc = -EOPNOTSUPP; goto unlock; } @@ -1671,6 +1671,10 @@ static DEFINE_MUTEX(mf_mutex); * * Must run in process context (e.g. a work queue) with interrupts * enabled and no spinlocks hold. + * + * Return: 0 for successfully handled the memory error, + * -EOPNOTSUPP for memory_filter() filtered the error event, + * < 0(except -EOPNOTSUPP) on failure. */ int memory_failure(unsigned long pfn, int flags) { @@ -1836,6 +1840,7 @@ try_again: num_poisoned_pages_dec(); unlock_page(p); put_page(p); + res = -EOPNOTSUPP; goto unlock_mutex; } -- cgit v1.2.3