diff options
Diffstat (limited to 'mm/memory-failure.c')
| -rw-r--r-- | mm/memory-failure.c | 92 |
1 files changed, 50 insertions, 42 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index a7b8ccd29b6f..b91a33fb6c69 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -124,7 +124,7 @@ const struct attribute_group memory_failure_attr_group = { .attrs = memory_failure_attr, }; -static struct ctl_table memory_failure_table[] = { +static const struct ctl_table memory_failure_table[] = { { .procname = "memory_failure_early_kill", .data = &sysctl_memory_failure_early_kill, @@ -419,18 +419,18 @@ static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma, pud = pud_offset(p4d, address); if (!pud_present(*pud)) return 0; - if (pud_devmap(*pud)) + if (pud_trans_huge(*pud)) return PUD_SHIFT; pmd = pmd_offset(pud, address); if (!pmd_present(*pmd)) return 0; - if (pmd_devmap(*pmd)) + if (pmd_trans_huge(*pmd)) return PMD_SHIFT; pte = pte_offset_map(pmd, address); if (!pte) return 0; ptent = ptep_get(pte); - if (pte_present(ptent) && pte_devmap(ptent)) + if (pte_present(ptent)) ret = PAGE_SHIFT; pte_unmap(pte); return ret; @@ -881,12 +881,17 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn, mmap_read_lock(p->mm); ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwpoison_walk_ops, (void *)&priv); + /* + * ret = 1 when CMCI wins, regardless of whether try_to_unmap() + * succeeds or fails, then kill the process with SIGBUS. + * ret = 0 when poison page is a clean page and it's dropped, no + * SIGBUS is needed. + */ if (ret == 1 && priv.tk.addr) kill_proc(&priv.tk, pfn, flags); - else - ret = 0; mmap_read_unlock(p->mm); - return ret > 0 ? -EHWPOISON : -EFAULT; + + return ret > 0 ? -EHWPOISON : 0; } /* @@ -1556,11 +1561,35 @@ static int get_hwpoison_page(struct page *p, unsigned long flags) return ret; } -void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu) +int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill) { - if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) { - struct address_space *mapping; + enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON; + struct address_space *mapping; + + if (folio_test_swapcache(folio)) { + pr_err("%#lx: keeping poisoned page in swap cache\n", pfn); + ttu &= ~TTU_HWPOISON; + } + + /* + * Propagate the dirty bit from PTEs to struct page first, because we + * need this to decide if we should kill or just drop the page. + * XXX: the dirty test could be racy: set_page_dirty() may not always + * be called inside page lock (it's recommended but not enforced). + */ + mapping = folio_mapping(folio); + if (!must_kill && !folio_test_dirty(folio) && mapping && + mapping_can_writeback(mapping)) { + if (folio_mkclean(folio)) { + folio_set_dirty(folio); + } else { + ttu &= ~TTU_HWPOISON; + pr_info("%#lx: corrupted page was clean: dropped without side effects\n", + pfn); + } + } + if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) { /* * For hugetlb folios in shared mappings, try_to_unmap * could potentially call huge_pmd_unshare. Because of @@ -1572,7 +1601,7 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu) if (!mapping) { pr_info("%#lx: could not lock mapping for mapped hugetlb folio\n", folio_pfn(folio)); - return; + return -EBUSY; } try_to_unmap(folio, ttu|TTU_RMAP_LOCKED); @@ -1580,6 +1609,8 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu) } else { try_to_unmap(folio, ttu); } + + return folio_mapped(folio) ? -EBUSY : 0; } /* @@ -1589,8 +1620,6 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu) static bool hwpoison_user_mappings(struct folio *folio, struct page *p, unsigned long pfn, int flags) { - enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON; - struct address_space *mapping; LIST_HEAD(tokill); bool unmap_success; int forcekill; @@ -1613,29 +1642,6 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p, if (!folio_mapped(folio)) return true; - if (folio_test_swapcache(folio)) { - pr_err("%#lx: keeping poisoned page in swap cache\n", pfn); - ttu &= ~TTU_HWPOISON; - } - - /* - * Propagate the dirty bit from PTEs to struct page first, because we - * need this to decide if we should kill or just drop the page. - * XXX: the dirty test could be racy: set_page_dirty() may not always - * be called inside page lock (it's recommended but not enforced). - */ - mapping = folio_mapping(folio); - if (!(flags & MF_MUST_KILL) && !folio_test_dirty(folio) && mapping && - mapping_can_writeback(mapping)) { - if (folio_mkclean(folio)) { - folio_set_dirty(folio); - } else { - ttu &= ~TTU_HWPOISON; - pr_info("%#lx: corrupted page was clean: dropped without side effects\n", - pfn); - } - } - /* * First collect all the processes that have the page * mapped in dirty form. This has to be done before try_to_unmap, @@ -1643,9 +1649,7 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p, */ collect_procs(folio, p, &tokill, flags & MF_ACTION_REQUIRED); - unmap_poisoned_folio(folio, ttu); - - unmap_success = !folio_mapped(folio); + unmap_success = !unmap_poisoned_folio(folio, pfn, flags & MF_MUST_KILL); if (!unmap_success) pr_err("%#lx: failed to unmap page (folio mapcount=%d)\n", pfn, folio_mapcount(folio)); @@ -2211,9 +2215,13 @@ static void kill_procs_now(struct page *p, unsigned long pfn, int flags, * Must run in process context (e.g. a work queue) with interrupts * enabled and no spinlocks held. * - * Return: 0 for successfully handled the memory error, - * -EOPNOTSUPP for hwpoison_filter() filtered the error event, - * < 0(except -EOPNOTSUPP) on failure. + * Return: + * 0 - success, + * -ENXIO - memory not managed by the kernel + * -EOPNOTSUPP - hwpoison_filter() filtered the error event, + * -EHWPOISON - the page was already poisoned, potentially + * kill process, + * other negative values - failure. */ int memory_failure(unsigned long pfn, int flags) { |