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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 21:39:33 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 21:39:33 +0300 |
commit | 81e11336d97e7a4c25a65c302ef2bf9cd9808ed4 (patch) | |
tree | 44e069e0bb26068137a1bda7ca5125c5b068b4ab /mm/debug.c | |
parent | 5631c5e0eb9035d92ceb20fcd9cdb7779a3f5cc7 (diff) | |
parent | 912c05720f00d039103d356a59c37dc7c3995e01 (diff) | |
download | linux-81e11336d97e7a4c25a65c302ef2bf9cd9808ed4.tar.xz |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
- a few MM hotfixes
- kthread, tools, scripts, ntfs and ocfs2
- some of MM
Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
mm: vmscan: consistent update to pgrefill
mm/vmscan.c: fix typo
khugepaged: khugepaged_test_exit() check mmget_still_valid()
khugepaged: retract_page_tables() remember to test exit
khugepaged: collapse_pte_mapped_thp() protect the pmd lock
khugepaged: collapse_pte_mapped_thp() flush the right range
mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
mm: thp: replace HTTP links with HTTPS ones
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
mm/page_alloc.c: skip setting nodemask when we are in interrupt
mm/page_alloc: fallbacks at most has 3 elements
mm/page_alloc: silence a KASAN false positive
mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
mm/page_alloc.c: simplify pageblock bitmap access
mm/page_alloc.c: extract the common part in pfn_to_bitidx()
mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
mm/shuffle: remove dynamic reconfiguration
mm/memory_hotplug: document why shuffle_zone() is relevant
mm/page_alloc: remove nr_free_pagecache_pages()
mm: remove vm_total_pages
...
Diffstat (limited to 'mm/debug.c')
-rw-r--r-- | mm/debug.c | 83 |
1 files changed, 42 insertions, 41 deletions
diff --git a/mm/debug.c b/mm/debug.c index 4f376514744d..ca8d1cacdecc 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -69,8 +69,19 @@ void __dump_page(struct page *page, const char *reason) } if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) { - /* Corrupt page, cannot call page_mapping */ - mapping = page->mapping; + /* + * Corrupt page, so we cannot call page_mapping. Instead, do a + * safe subset of the steps that page_mapping() does. Caution: + * this will be misleading for tail pages, PageSwapCache pages, + * and potentially other situations. (See the page_mapping() + * implementation for what's missing here.) + */ + unsigned long tmp = (unsigned long)page->mapping; + + if (tmp & PAGE_MAPPING_ANON) + mapping = NULL; + else + mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS); head = page; compound = false; } else { @@ -84,86 +95,76 @@ void __dump_page(struct page *page, const char *reason) */ mapcount = PageSlab(head) ? 0 : page_mapcount(page); - if (compound) + pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", + page, page_ref_count(head), mapcount, mapping, + page_to_pgoff(page), page_to_pfn(page)); + if (compound) { if (hpage_pincount_available(page)) { - pr_warn("page:%px refcount:%d mapcount:%d mapping:%p " - "index:%#lx head:%px order:%u " - "compound_mapcount:%d compound_pincount:%d\n", - page, page_ref_count(head), mapcount, - mapping, page_to_pgoff(page), head, - compound_order(head), compound_mapcount(page), - compound_pincount(page)); + pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n", + head, compound_order(head), + head_mapcount(head), + head_pincount(head)); } else { - pr_warn("page:%px refcount:%d mapcount:%d mapping:%p " - "index:%#lx head:%px order:%u " - "compound_mapcount:%d\n", - page, page_ref_count(head), mapcount, - mapping, page_to_pgoff(page), head, - compound_order(head), compound_mapcount(page)); + pr_warn("head:%p order:%u compound_mapcount:%d\n", + head, compound_order(head), + head_mapcount(head)); } - else - pr_warn("page:%px refcount:%d mapcount:%d mapping:%p index:%#lx\n", - page, page_ref_count(page), mapcount, - mapping, page_to_pgoff(page)); + } if (PageKsm(page)) type = "ksm "; else if (PageAnon(page)) type = "anon "; else if (mapping) { - const struct inode *host; + struct inode *host; const struct address_space_operations *a_ops; - const struct hlist_node *dentry_first; - const struct dentry *dentry_ptr; + struct hlist_node *dentry_first; + struct dentry *dentry_ptr; struct dentry dentry; /* * mapping can be invalid pointer and we don't want to crash * accessing it, so probe everything depending on it carefully */ - if (copy_from_kernel_nofault(&host, &mapping->host, - sizeof(struct inode *)) || - copy_from_kernel_nofault(&a_ops, &mapping->a_ops, - sizeof(struct address_space_operations *))) { - pr_warn("failed to read mapping->host or a_ops, mapping not a valid kernel address?\n"); + if (get_kernel_nofault(host, &mapping->host) || + get_kernel_nofault(a_ops, &mapping->a_ops)) { + pr_warn("failed to read mapping contents, not a valid kernel address?\n"); goto out_mapping; } if (!host) { - pr_warn("mapping->a_ops:%ps\n", a_ops); + pr_warn("aops:%ps\n", a_ops); goto out_mapping; } - if (copy_from_kernel_nofault(&dentry_first, - &host->i_dentry.first, sizeof(struct hlist_node *))) { - pr_warn("mapping->a_ops:%ps with invalid mapping->host inode address %px\n", - a_ops, host); + if (get_kernel_nofault(dentry_first, &host->i_dentry.first)) { + pr_warn("aops:%ps with invalid host inode %px\n", + a_ops, host); goto out_mapping; } if (!dentry_first) { - pr_warn("mapping->a_ops:%ps\n", a_ops); + pr_warn("aops:%ps ino:%lx\n", a_ops, host->i_ino); goto out_mapping; } dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); - if (copy_from_kernel_nofault(&dentry, dentry_ptr, - sizeof(struct dentry))) { - pr_warn("mapping->aops:%ps with invalid mapping->host->i_dentry.first %px\n", - a_ops, dentry_ptr); + if (get_kernel_nofault(dentry, dentry_ptr)) { + pr_warn("aops:%ps with invalid dentry %px\n", a_ops, + dentry_ptr); } else { /* * if dentry is corrupted, the %pd handler may still * crash, but it's unlikely that we reach here with a * corrupted struct page */ - pr_warn("mapping->aops:%ps dentry name:\"%pd\"\n", - a_ops, &dentry); + pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", + a_ops, host->i_ino, &dentry); } } out_mapping: BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); - pr_warn("%sflags: %#lx(%pGp)%s\n", type, page->flags, &page->flags, + pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags, page_cma ? " CMA" : ""); hex_only: |