From: luofei luofei@unicloud.com
[ Upstream commit d1fe111fb62a1cf0446a2919f5effbb33ad0702c ]
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 luofei@unicloud.com Acked-by: Borislav Petkov bp@suse.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: H. Peter Anvin hpa@zytor.com Cc: Ingo Molnar mingo@redhat.com Cc: Miaohe Lin linmiaohe@huawei.com Cc: Naoya Horiguchi naoya.horiguchi@nec.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Tony Luck tony.luck@intel.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/cpu/mce/core.c | 8 +++++--- drivers/base/memory.c | 2 ++ mm/hwpoison-inject.c | 3 ++- mm/madvise.c | 2 ++ mm/memory-failure.c | 9 +++++++-- 5 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index e23e74e2f928..848cfb013f58 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1297,10 +1297,12 @@ static void kill_me_maybe(struct callback_head *cb)
/* * -EHWPOISON from memory_failure() means that it already sent SIGBUS - * to the current process with the proper error info, so no need to - * send SIGBUS here again. + * to the current process with the proper error info, + * -EOPNOTSUPP means hwpoison_filter() filtered the error event, + * + * In both cases, no further processing is required. */ - if (ret == -EHWPOISON) + if (ret == -EHWPOISON || ret == -EOPNOTSUPP) return;
if (p->mce_vaddr != (void __user *)-1l) { diff --git a/drivers/base/memory.c b/drivers/base/memory.c index c0d501a3a714..c778d1df7455 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -555,6 +555,8 @@ static ssize_t hard_offline_page_store(struct device *dev, return -EINVAL; pfn >>= PAGE_SHIFT; ret = memory_failure(pfn, 0); + if (ret == -EOPNOTSUPP) + ret = 0; return ret ? ret : count; }
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c index aff4d27ec235..a1d6fc3c78b9 100644 --- a/mm/hwpoison-inject.c +++ b/mm/hwpoison-inject.c @@ -48,7 +48,8 @@ static int hwpoison_inject(void *data, u64 val)
inject: pr_info("Injecting memory failure at pfn %#lx\n", pfn); - return memory_failure(pfn, 0); + err = memory_failure(pfn, 0); + return (err == -EOPNOTSUPP) ? 0 : err; }
static int hwpoison_unpoison(void *data, u64 val) diff --git a/mm/madvise.c b/mm/madvise.c index 8e5ca01a6cc0..882767d58c27 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -968,6 +968,8 @@ static int madvise_inject_error(int behavior, pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", pfn, start); ret = memory_failure(pfn, MF_COUNT_INCREASED); + if (ret == -EOPNOTSUPP) + ret = 0; }
if (ret) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index e6425d959fa9..5664bafd5e77 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1444,7 +1444,7 @@ 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; @@ -1525,7 +1525,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, goto out;
if (hwpoison_filter(page)) { - rc = 0; + rc = -EOPNOTSUPP; goto unlock; }
@@ -1594,6 +1594,10 @@ 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) { @@ -1742,6 +1746,7 @@ int memory_failure(unsigned long pfn, int flags) num_poisoned_pages_dec(); unlock_page(p); put_page(p); + res = -EOPNOTSUPP; goto unlock_mutex; }