linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, jhubbard@nvidia.com,
	kirill.shutemov@linux.intel.com, linux-mm@kvack.org,
	mm-commits@vger.kernel.org, ptesarik@suse.cz,
	torvalds@linux-foundation.org, vbabka@suse.cz,
	willy@infradead.org
Subject: [patch 013/128] mm, dump_page(): do not crash with invalid mapping pointer
Date: Mon, 01 Jun 2020 21:46:03 -0700	[thread overview]
Message-ID: <20200602044603.eP8czjO7z%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org>

From: Vlastimil Babka <vbabka@suse.cz>
Subject: mm, dump_page(): do not crash with invalid mapping pointer

We have seen a following problem on a RPi4 with 1G RAM:

BUG: Bad page state in process systemd-hwdb  pfn:35601
page:ffff7e0000d58040 refcount:15 mapcount:131221 mapping:efd8fe765bc80080 index:0x1 compound_mapcount: -32767
Unable to handle kernel paging request at virtual address efd8fe765bc80080
Mem abort info:
  ESR = 0x96000004
  Exception class = DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
[efd8fe765bc80080] address between user and kernel address ranges
Internal error: Oops: 96000004 [#1] SMP
Modules linked in: btrfs libcrc32c xor xor_neon zlib_deflate raid6_pq mmc_block xhci_pci xhci_hcd usbcore sdhci_iproc sdhci_pltfm sdhci mmc_core clk_raspberrypi gpio_raspberrypi_exp pcie_brcmstb bcm2835_dma gpio_regulator phy_generic fixed sg scsi_mod efivarfs
Supported: No, Unreleased kernel
CPU: 3 PID: 408 Comm: systemd-hwdb Not tainted 5.3.18-8-default #1 SLE15-SP2 (unreleased)
Hardware name: raspberrypi rpi/rpi, BIOS 2020.01 02/21/2020
pstate: 40000085 (nZcv daIf -PAN -UAO)
pc : __dump_page+0x268/0x368
lr : __dump_page+0xc4/0x368
sp : ffff000012563860
x29: ffff000012563860 x28: ffff80003ddc4300
x27: 0000000000000010 x26: 000000000000003f
x25: ffff7e0000d58040 x24: 000000000000000f
x23: efd8fe765bc80080 x22: 0000000000020095
x21: efd8fe765bc80080 x20: ffff000010ede8b0
x19: ffff7e0000d58040 x18: ffffffffffffffff
x17: 0000000000000001 x16: 0000000000000007
x15: ffff000011689708 x14: 3030386362353637
x13: 6566386466653a67 x12: 6e697070616d2031
x11: 32323133313a746e x10: 756f6370616d2035
x9 : ffff00001168a840 x8 : ffff00001077a670
x7 : 000000000000013d x6 : ffff0000118a43b5
x5 : 0000000000000001 x4 : ffff80003dd9e2c8
x3 : ffff80003dd9e2c8 x2 : 911c8d7c2f483500
x1 : dead000000000100 x0 : efd8fe765bc80080
Call trace:
 __dump_page+0x268/0x368
 bad_page+0xd4/0x168
 check_new_page_bad+0x80/0xb8
 rmqueue_bulk.constprop.26+0x4d8/0x788
 get_page_from_freelist+0x4d4/0x1228
 __alloc_pages_nodemask+0x134/0xe48
 alloc_pages_vma+0x198/0x1c0
 do_anonymous_page+0x1a4/0x4d8
 __handle_mm_fault+0x4e8/0x560
 handle_mm_fault+0x104/0x1e0
 do_page_fault+0x1e8/0x4c0
 do_translation_fault+0xb0/0xc0
 do_mem_abort+0x50/0xb0
 el0_da+0x24/0x28
Code: f9401025 8b8018a0 9a851005 17ffffca (f94002a0)
---[ end trace 703ac54becfd8094 ]---

Besides the underlying issue with page->mapping containing a bogus value for
some reason, we can see that __dump_page() crashed by trying to read the
pointer at mapping->host, turning a recoverable warning into full Oops.

It can be expected that when page is reported as bad state for some reason, the
pointers there should not be trusted blindly. So this patch treats all data in
__dump_page() that depends on page->mapping as lava, using
probe_kernel_read_strict(). Ideally this would include the dentry->d_parent
recursively, but that would mean changing printk handler for %pd. Chances of
reaching the dentry printing part with an initially bogus mapping pointer
should be rather low, though.

Also prefix printing mapping->a_ops with a description of what is being
printed.  In case the value is bogus, %ps will print raw value instead of
the symbol name and then it's not obvious at all that it's printing a_ops.

Link: http://lkml.kernel.org/r/20200331165454.12263-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Petr Tesarik <ptesarik@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/debug.c |   56 +++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 50 insertions(+), 6 deletions(-)

--- a/mm/debug.c~mm-dump_page-do-not-crash-with-invalid-mapping-pointer
+++ a/mm/debug.c
@@ -110,13 +110,57 @@ void __dump_page(struct page *page, cons
 	else if (PageAnon(page))
 		type = "anon ";
 	else if (mapping) {
-		if (mapping->host && mapping->host->i_dentry.first) {
-			struct dentry *dentry;
-			dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias);
-			pr_warn("%ps name:\"%pd\"\n", mapping->a_ops, dentry);
-		} else
-			pr_warn("%ps\n", mapping->a_ops);
+		const struct inode *host;
+		const struct address_space_operations *a_ops;
+		const struct hlist_node *dentry_first;
+		const 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 (probe_kernel_read_strict(&host, &mapping->host,
+						sizeof(struct inode *)) ||
+		    probe_kernel_read_strict(&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");
+			goto out_mapping;
+		}
+
+		if (!host) {
+			pr_warn("mapping->a_ops:%ps\n", a_ops);
+			goto out_mapping;
+		}
+
+		if (probe_kernel_read_strict(&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);
+			goto out_mapping;
+		}
+
+		if (!dentry_first) {
+			pr_warn("mapping->a_ops:%ps\n", a_ops);
+			goto out_mapping;
+		}
+
+		dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias);
+		if (probe_kernel_read_strict(&dentry, dentry_ptr,
+							sizeof(struct dentry))) {
+			pr_warn("mapping->aops:%ps with invalid mapping->host->i_dentry.first %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);
+		}
 	}
+out_mapping:
 	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
 
 	pr_warn("%sflags: %#lx(%pGp)%s\n", type, page->flags, &page->flags,
_


  parent reply	other threads:[~2020-06-02  4:46 UTC|newest]

Thread overview: 137+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-02  4:44 incoming Andrew Morton
2020-06-02  4:45 ` [patch 001/128] squashfs: migrate from ll_rw_block usage to BIO Andrew Morton
2020-06-02  4:45 ` [patch 002/128] ocfs2: add missing annotation for dlm_empty_lockres() Andrew Morton
2020-06-02  4:45 ` [patch 003/128] ocfs2: mount shared volume without ha stack Andrew Morton
2020-06-02  4:45 ` [patch 004/128] arch/parisc/include/asm/pgtable.h: remove unused `old_pte' Andrew Morton
2020-06-02  4:45 ` [patch 005/128] vfs: track per-sb writeback errors and report them to syncfs Andrew Morton
2020-06-02  4:45 ` [patch 006/128] fs/buffer.c: record blockdev write errors in super_block that it backs Andrew Morton
2020-06-02  4:45 ` [patch 007/128] usercopy: mark dma-kmalloc caches as usercopy caches Andrew Morton
2020-06-02  4:45 ` [patch 008/128] mm/slub.c: fix corrupted freechain in deactivate_slab() Andrew Morton
2020-06-02  4:45 ` [patch 009/128] slub: Remove userspace notifier for cache add/remove Andrew Morton
2020-06-02  4:45 ` [patch 010/128] slub: remove kmalloc under list_lock from list_slab_objects() V2 Andrew Morton
2020-06-02  4:45 ` [patch 011/128] mm/slub: fix stack overruns with SLUB_STATS Andrew Morton
2020-06-02  4:46 ` [patch 012/128] Documentation/vm/slub.rst: s/Toggle/Enable/ Andrew Morton
2020-06-02 13:10   ` Rafael Aquini
2020-06-02  4:46 ` Andrew Morton [this message]
2020-06-02  4:46 ` [patch 014/128] mm: move readahead prototypes from mm.h Andrew Morton
2020-06-02  4:46 ` [patch 015/128] mm: return void from various readahead functions Andrew Morton
2020-06-02  4:46 ` [patch 016/128] mm: ignore return value of ->readpages Andrew Morton
2020-06-02  4:46 ` [patch 017/128] mm: move readahead nr_pages check into read_pages Andrew Morton
2020-06-02  4:46 ` [patch 018/128] mm: add new readahead_control API Andrew Morton
2020-06-02  4:46 ` [patch 019/128] mm: use readahead_control to pass arguments Andrew Morton
2020-06-02  4:46 ` [patch 020/128] mm: rename various 'offset' parameters to 'index' Andrew Morton
2020-06-02  4:46 ` [patch 021/128] mm: rename readahead loop variable to 'i' Andrew Morton
2020-06-02  4:46 ` [patch 022/128] mm: remove 'page_offset' from readahead loop Andrew Morton
2020-06-02  4:46 ` [patch 023/128] mm: put readahead pages in cache earlier Andrew Morton
2020-06-02  4:46 ` [patch 024/128] mm: add readahead address space operation Andrew Morton
2020-06-02  4:46 ` [patch 025/128] mm: move end_index check out of readahead loop Andrew Morton
2020-06-02  4:46 ` [patch 026/128] mm: add page_cache_readahead_unbounded Andrew Morton
2020-06-02  4:46 ` [patch 027/128] mm: document why we don't set PageReadahead Andrew Morton
2020-06-02  4:46 ` [patch 028/128] mm: use memalloc_nofs_save in readahead path Andrew Morton
2020-06-02  4:47 ` [patch 029/128] fs: convert mpage_readpages to mpage_readahead Andrew Morton
2020-06-02  4:47 ` [patch 030/128] btrfs: convert from readpages to readahead Andrew Morton
2020-06-02  4:47 ` [patch 031/128] erofs: convert uncompressed files " Andrew Morton
2020-06-02  4:47 ` [patch 032/128] erofs: convert compressed " Andrew Morton
2020-06-02  4:47 ` [patch 033/128] ext4: convert " Andrew Morton
2020-06-02  4:47 ` [patch 034/128] ext4: pass the inode to ext4_mpage_readpages Andrew Morton
2020-06-02  4:47 ` [patch 035/128] f2fs: convert from readpages to readahead Andrew Morton
2020-06-02  4:47 ` [patch 036/128] f2fs: pass the inode to f2fs_mpage_readpages Andrew Morton
2020-06-02  4:47 ` [patch 037/128] fuse: convert from readpages to readahead Andrew Morton
2020-06-02  4:47 ` [patch 038/128] iomap: " Andrew Morton
2020-06-02  4:47 ` [patch 039/128] include/linux/pagemap.h: introduce attach/detach_page_private Andrew Morton
2020-06-02  4:47 ` [patch 040/128] md: remove __clear_page_buffers and use attach/detach_page_private Andrew Morton
2020-06-02  4:47 ` [patch 041/128] btrfs: " Andrew Morton
2020-06-02 14:19   ` David Sterba
2020-06-02  4:47 ` [patch 042/128] fs/buffer.c: " Andrew Morton
2020-06-02  4:47 ` [patch 043/128] f2fs: " Andrew Morton
2020-06-02  4:47 ` [patch 044/128] iomap: " Andrew Morton
2020-06-02 16:23   ` Darrick J. Wong
2020-06-02  4:47 ` [patch 045/128] ntfs: replace attach_page_buffers with attach_page_private Andrew Morton
2020-06-02  4:48 ` [patch 046/128] orangefs: use attach/detach_page_private Andrew Morton
2020-06-02  4:48 ` [patch 047/128] buffer_head.h: remove attach_page_buffers Andrew Morton
2020-06-02  4:48 ` [patch 048/128] mm/migrate.c: call detach_page_private to cleanup code Andrew Morton
2020-06-02  4:48 ` [patch 049/128] mm_types.h: change set_page_private to inline function Andrew Morton
2020-06-02  4:48 ` [patch 050/128] mm/filemap.c: remove misleading comment Andrew Morton
2020-06-02  4:48 ` [patch 051/128] mm/page-writeback.c: remove unused variable Andrew Morton
2020-06-02  4:48 ` [patch 052/128] mm/writeback: replace PF_LESS_THROTTLE with PF_LOCAL_THROTTLE Andrew Morton
2020-06-02  4:48 ` [patch 053/128] mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead Andrew Morton
2020-06-02  4:48 ` [patch 054/128] mm/gup.c: update the documentation Andrew Morton
2020-06-02  4:48 ` [patch 055/128] mm/gup: introduce pin_user_pages_unlocked Andrew Morton
2020-06-02  4:48 ` [patch 056/128] ivtv: convert get_user_pages() --> pin_user_pages() Andrew Morton
2020-06-02  4:48 ` [patch 057/128] mm/gup.c: further document vma_permits_fault() Andrew Morton
2020-06-02  4:48 ` [patch 058/128] mm/swapfile: use list_{prev,next}_entry() instead of open-coding Andrew Morton
2020-06-02  4:48 ` [patch 059/128] mm/swap_state: fix a data race in swapin_nr_pages Andrew Morton
2020-06-02  4:48 ` [patch 060/128] mm: swap: properly update readahead statistics in unuse_pte_range() Andrew Morton
2020-06-02  4:48 ` [patch 061/128] mm/swapfile.c: offset is only used when there is more slots Andrew Morton
2020-06-02  4:48 ` [patch 062/128] mm/swapfile.c: explicitly show ssd/non-ssd is handled mutually exclusive Andrew Morton
2020-06-02  4:48 ` [patch 063/128] mm/swapfile.c: remove the unnecessary goto for SSD case Andrew Morton
2020-06-02  4:48 ` [patch 064/128] mm/swapfile.c: simplify the calculation of n_goal Andrew Morton
2020-06-02  4:48 ` [patch 065/128] mm/swapfile.c: remove the extra check in scan_swap_map_slots() Andrew Morton
2020-06-02  4:49 ` [patch 066/128] mm/swapfile.c: found_free could be represented by (tmp < max) Andrew Morton
2020-06-02  4:49 ` [patch 067/128] mm/swapfile.c: tmp is always smaller than max Andrew Morton
2020-06-02  4:49 ` [patch 068/128] mm/swapfile.c: omit a duplicate code by compare tmp and max first Andrew Morton
2020-06-02  4:49 ` [patch 069/128] swap: try to scan more free slots even when fragmented Andrew Morton
2020-06-02  4:49 ` [patch 070/128] mm/swapfile.c: classify SWAP_MAP_XXX to make it more readable Andrew Morton
2020-06-02  4:49 ` [patch 071/128] mm/swapfile.c: __swap_entry_free() always free 1 entry Andrew Morton
2020-06-02  4:49 ` [patch 072/128] mm/swapfile.c: use prandom_u32_max() Andrew Morton
2020-06-02  4:49 ` [patch 073/128] swap: reduce lock contention on swap cache from swap slots allocation Andrew Morton
2020-06-02  4:49 ` [patch 074/128] mm: swapfile: fix /proc/swaps heading and Size/Used/Priority alignment Andrew Morton
2020-06-02  4:49 ` [patch 075/128] include/linux/swap.h: delete meaningless __add_to_swap_cache() declaration Andrew Morton
2020-06-02  4:49 ` [patch 076/128] mm, memcg: add workingset_restore in memory.stat Andrew Morton
2020-06-02  4:49 ` [patch 077/128] mm: memcontrol: simplify value comparison between count and limit Andrew Morton
2020-06-02  4:49 ` [patch 078/128] memcg: expose root cgroup's memory.stat Andrew Morton
2020-06-02  4:49 ` [patch 079/128] mm/memcg: prepare for swap over-high accounting and penalty calculation Andrew Morton
2020-06-02  4:49 ` [patch 080/128] mm/memcg: move penalty delay clamping out of calculate_high_delay() Andrew Morton
2020-06-02  4:49 ` [patch 081/128] mm/memcg: move cgroup high memory limit setting into struct page_counter Andrew Morton
2020-06-02  4:49 ` [patch 082/128] mm/memcg: automatically penalize tasks with high swap use Andrew Morton
2020-06-02  4:49 ` [patch 083/128] memcg: fix memcg_kmem_bypass() for remote memcg charging Andrew Morton
2020-06-02  4:49 ` [patch 084/128] x86: mm: ptdump: calculate effective permissions correctly Andrew Morton
2020-06-02  4:50 ` [patch 085/128] mm: ptdump: expand type of 'val' in note_page() Andrew Morton
2020-06-02  4:50 ` [patch 086/128] /proc/PID/smaps: Add PMD migration entry parsing Andrew Morton
2020-06-02  4:50 ` [patch 087/128] mm/memory: remove unnecessary pte_devmap case in copy_one_pte() Andrew Morton
2020-06-02  4:50 ` [patch 088/128] mm, memory_failure: don't send BUS_MCEERR_AO for action required error Andrew Morton
2020-06-02  4:50 ` [patch 089/128] x86/hyperv: use vmalloc_exec for the hypercall page Andrew Morton
2020-06-02  4:50 ` [patch 090/128] x86: fix vmap arguments in map_irq_stack Andrew Morton
2020-06-02  4:50 ` [patch 091/128] staging: android: ion: use vmap instead of vm_map_ram Andrew Morton
2020-06-02  4:50 ` [patch 092/128] staging: media: ipu3: use vmap instead of reimplementing it Andrew Morton
2020-06-02  4:50 ` [patch 093/128] dma-mapping: use vmap insted " Andrew Morton
2020-06-02  4:50 ` [patch 094/128] powerpc: add an ioremap_phb helper Andrew Morton
2020-06-02  4:50 ` [patch 095/128] powerpc: remove __ioremap_at and __iounmap_at Andrew Morton
2020-06-02  4:50 ` [patch 096/128] mm: remove __get_vm_area Andrew Morton
2020-06-02  4:50 ` [patch 097/128] mm: unexport unmap_kernel_range_noflush Andrew Morton
2020-06-02  4:50 ` [patch 098/128] mm: rename CONFIG_PGTABLE_MAPPING to CONFIG_ZSMALLOC_PGTABLE_MAPPING Andrew Morton
2020-06-02  4:50 ` [patch 099/128] mm: only allow page table mappings for built-in zsmalloc Andrew Morton
2020-06-02  4:51 ` [patch 100/128] mm: pass addr as unsigned long to vb_free Andrew Morton
2020-06-02  4:51 ` [patch 101/128] mm: remove vmap_page_range_noflush and vunmap_page_range Andrew Morton
2020-06-02  4:51 ` [patch 102/128] mm: rename vmap_page_range to map_kernel_range Andrew Morton
2020-06-02  4:51 ` [patch 103/128] mm: don't return the number of pages from map_kernel_range{,_noflush} Andrew Morton
2020-06-02  4:51 ` [patch 104/128] mm: remove map_vm_range Andrew Morton
2020-06-02  4:51 ` [patch 105/128] mm: remove unmap_vmap_area Andrew Morton
2020-06-02  4:51 ` [patch 106/128] mm: remove the prot argument from vm_map_ram Andrew Morton
2020-06-02  4:51 ` [patch 107/128] mm: enforce that vmap can't map pages executable Andrew Morton
2020-06-02  4:51 ` [patch 108/128] gpu/drm: remove the powerpc hack in drm_legacy_sg_alloc Andrew Morton
2020-06-02  4:51 ` [patch 109/128] mm: remove the pgprot argument to __vmalloc Andrew Morton
2020-06-02  4:51 ` [patch 110/128] mm: remove the prot argument to __vmalloc_node Andrew Morton
2020-06-02  4:51 ` [patch 111/128] mm: remove both instances of __vmalloc_node_flags Andrew Morton
2020-06-02  4:51 ` [patch 112/128] mm: remove __vmalloc_node_flags_caller Andrew Morton
2020-06-02  4:51 ` [patch 113/128] mm: switch the test_vmalloc module to use __vmalloc_node Andrew Morton
2020-06-02  4:52 ` [patch 114/128] mm: remove vmalloc_user_node_flags Andrew Morton
2020-06-02  4:52 ` [patch 115/128] arm64: use __vmalloc_node in arch_alloc_vmap_stack Andrew Morton
2020-06-02  4:52 ` [patch 116/128] powerpc: use __vmalloc_node in alloc_vm_stack Andrew Morton
2020-06-02  4:52 ` [patch 117/128] s390: use __vmalloc_node in stack_alloc Andrew Morton
2020-06-02  4:52 ` [patch 118/128] mm: add functions to track page directory modifications Andrew Morton
2020-06-02  4:52 ` [patch 119/128] mm/vmalloc: track which page-table levels were modified Andrew Morton
2020-06-02  4:52 ` [patch 120/128] mm/ioremap: " Andrew Morton
2020-06-02  4:52 ` [patch 121/128] x86/mm/64: implement arch_sync_kernel_mappings() Andrew Morton
2020-06-02  4:52 ` [patch 122/128] x86/mm/32: " Andrew Morton
2020-06-02  4:52 ` [patch 123/128] mm: remove vmalloc_sync_(un)mappings() Andrew Morton
2020-06-02  4:52 ` [patch 124/128] x86/mm: remove vmalloc faulting Andrew Morton
2020-06-02  4:52 ` [patch 125/128] kasan: fix clang compilation warning due to stack protector Andrew Morton
2020-06-02  4:52 ` [patch 126/128] ubsan: entirely disable alignment checks under UBSAN_TRAP Andrew Morton
2020-06-02  4:52 ` [patch 127/128] mm/mm_init.c: report kasan-tag information stored in page->flags Andrew Morton
2020-06-02  4:52 ` [patch 128/128] kasan: move kasan_report() into report.c Andrew Morton
2020-06-02 20:08 ` incoming Andrew Morton
2020-06-02 20:45   ` incoming Linus Torvalds
2020-06-02 21:38     ` incoming Andrew Morton
2020-06-02 22:18       ` incoming Linus Torvalds
2020-06-02 20:09 incoming Andrew Morton
2020-06-02 20:10 ` [patch 013/128] mm, dump_page(): do not crash with invalid mapping pointer Andrew Morton

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200602044603.eP8czjO7z%akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=jhubbard@nvidia.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-mm@kvack.org \
    --cc=mm-commits@vger.kernel.org \
    --cc=ptesarik@suse.cz \
    --cc=torvalds@linux-foundation.org \
    --cc=vbabka@suse.cz \
    --cc=willy@infradead.org \
    --subject='Re: [patch 013/128] mm, dump_page(): do not crash with invalid mapping pointer' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox