linux-stable.git/Documentation/vm, branch linux-5.18.y

mm/memory-failure: disable unpoison once hw error happens

2022-06-29T07:04:41+00:00

commit 67f22ba7750f940bcd7e1b12720896c505c2d63f upstream.

Currently unpoison_memory(unsigned long pfn) is designed for soft
poison(hwpoison-inject) only.  Since 17fae1294ad9d, the KPTE gets cleared
on a x86 platform once hardware memory corrupts.

Unpoisoning a hardware corrupted page puts page back buddy only, the
kernel has a chance to access the page with *NOT PRESENT* KPTE.  This
leads BUG during accessing on the corrupted KPTE.

Suggested by David&Naoya, disable unpoison mechanism when a real HW error
happens to avoid BUG like this:

 Unpoison: Software-unpoisoned page 0x61234
 BUG: unable to handle page fault for address: ffff888061234000
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 2c01067 P4D 2c01067 PUD 107267063 PMD 10382b063 PTE 800fffff9edcb062
 Oops: 0002 [#1] PREEMPT SMP NOPTI
 CPU: 4 PID: 26551 Comm: stress Kdump: loaded Tainted: G   M       OE     5.18.0.bm.1-amd64 #7
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
 RIP: 0010:clear_page_erms+0x7/0x10
 Code: ...
 RSP: 0000:ffffc90001107bc8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000901 RCX: 0000000000001000
 RDX: ffffea0001848d00 RSI: ffffea0001848d40 RDI: ffff888061234000
 RBP: ffffea0001848d00 R08: 0000000000000901 R09: 0000000000001276
 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000001
 R13: 0000000000000000 R14: 0000000000140dca R15: 0000000000000001
 FS:  00007fd8b2333740(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffff888061234000 CR3: 00000001023d2005 CR4: 0000000000770ee0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  
  prep_new_page+0x151/0x170
  get_page_from_freelist+0xca0/0xe20
  ? sysvec_apic_timer_interrupt+0xab/0xc0
  ? asm_sysvec_apic_timer_interrupt+0x1b/0x20
  __alloc_pages+0x17e/0x340
  __folio_alloc+0x17/0x40
  vma_alloc_folio+0x84/0x280
  __handle_mm_fault+0x8d4/0xeb0
  handle_mm_fault+0xd5/0x2a0
  do_user_addr_fault+0x1d0/0x680
  ? kvm_read_and_reset_apf_flags+0x3b/0x50
  exc_page_fault+0x78/0x170
  asm_exc_page_fault+0x27/0x30

Link: https://lkml.kernel.org/r/20220615093209.259374-2-pizhenwei@bytedance.com
Fixes: 847ce401df392 ("HWPOISON: Add unpoisoning support")
Fixes: 17fae1294ad9d ("x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisoned")
Signed-off-by: zhenwei pi 
Acked-by: David Hildenbrand 
Acked-by: Naoya Horiguchi 
Reviewed-by: Miaohe Lin 
Reviewed-by: Oscar Salvador 
Cc: Greg Kroah-Hartman 
Cc: 	[5.8+]
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

docs: vm/page_owner: use literal blocks for param description

2022-04-27T20:28:48+00:00

Sphinx generates hard-to-read lists of parameters at the bottom of the
page.  Fix them by putting literal-block markers of "::" in front of
them.

Link: https://lkml.kernel.org/r/cfd3bcc0-b51d-0c68-c065-ca1c4c202447@gmail.com
Signed-off-by: Akira Yokosawa 
Fixes: 57f2b54a9379 ("Documentation/vm/page_owner.rst: update the documentation")
Cc: Shenghong Han 
Cc: Haowen Bai 
Cc: Jonathan Corbet 
Cc: Alex Shi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

doc/vm/page_owner.rst: remove content related to -c option

2022-04-01T18:46:09+00:00

-c option has been removed from page_owner_sort.c.

Remove the usage of -c option from Documentation.

This work is coauthored by
        Shenghong Han
        Yixuan Cao
        Chongxi Zhao
        Jiajian Ye
        Yuhong Feng
        Yongqiang Liu

Link: https://lkml.kernel.org/r/20220326085920.1470081-2-zhangyinan2019@email.szu.edu.cn
Signed-off-by: Yinan Zhang 
Cc: Jonathan Corbet 
Cc: Stephen Rothwell 
Cc: Sean Anderson 
Cc: Tang Bin 
Cc: Zhenliang Wei 
Cc: Georgi Djakov 
Cc: Chongxi Zhao 
Cc: Jiajian Ye 
Cc: Yixuan Cao 
Cc: Yuhong Feng 
Cc: Yongqiang Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/munlock: update Documentation/vm/unevictable-lru.rst

2022-04-01T18:46:09+00:00

Update Documentation/vm/unevictable-lru.rst to reflect the changes made
by the mm/munlock series: keeping an mlock_count instead of page_mlock()
(formerly try_to_munlock()) and munlock_vma_pages_all() etc.  Also make
other little updates or cleanups wherever noticed.

But, I apologize, this is already out of date, in that "folio" appears
nowhere: 5.18 will be in a transitional state from "page" to "folio",
and documenting its current mix of the two does not help to understand
"the Unevictable LRU".  Should be revisited when naming is more settled.

Link: https://lkml.kernel.org/r/3753962-d491-bf60-f59f-51bfe84fd6a0@google.com
Signed-off-by: Hugh Dickins 
Cc: Jonathan Corbet 
Cc: Randy Dunlap 
Cc: Matthew Wilcox 
Cc: Michal Hocko 
Cc: Vlastimil Babka 
Cc: "Kirill A. Shutemov" 
Cc: David Hildenbrand 
Cc: Alistair Popple 
Cc: Johannes Weiner 
Cc: Rik van Riel 
Cc: Suren Baghdasaryan 
Cc: Yu Zhao 
Cc: Greg Thelen 
Cc: Shakeel Butt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'ras_core_for_v5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-03-25T19:34:53+00:00

Pull RAS updates from Borislav Petkov:

 - More noinstr fixes

 - Add an erratum workaround for Intel CPUs which, in certain
   circumstances, end up consuming an unrelated uncorrectable memory
   error when using fast string copy insns

 - Remove the MCE tolerance level control as it is not really needed or
   used anymore

* tag 'ras_core_for_v5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Remove the tolerance level control
  x86/mce: Work around an erratum on fast string copy instructions
  x86/mce: Use arch atomic and bit helpers

tools/vm/page_owner_sort.c: support for user-defined culling rules

2022-03-25T02:06:45+00:00

When viewing page owner information, we may want to cull blocks of
information with our own rules.  So it is important to enhance culling
function to provide the support for customizing culling rules.
Therefore, following adjustments are made:

1. Add --cull option to support the culling of blocks of information
   with user-defined culling rules.

	./page_owner_sort   --cull=
	./page_owner_sort   --cull 

   is a single argument in the form of a comma-separated list to
  specify individual culling rules, by the sequence of keys k1,k2, ....
  Mixed use of abbreviated and complete-form of keys is allowed.

  For reference, please see the document(Documentation/vm/page_owner.rst).

Now, assuming two blocks in the input file are as follows:

	Page allocated via order 0, mask xxxx, pid 1, tgid 1 (task_name_demo)
	PFN xxxx
	 prep_new_page+0xd0/0xf8
	 get_page_from_freelist+0x4a0/0x1290
	 __alloc_pages+0x168/0x340
	 alloc_pages+0xb0/0x158

	Page allocated via order 0, mask xxxx, pid 32, tgid 32 (task_name_demo)
	PFN xxxx
	 prep_new_page+0xd0/0xf8
	 get_page_from_freelist+0x4a0/0x1290
	 __alloc_pages+0x168/0x340
	 alloc_pages+0xb0/0x158

If we want to cull the blocks by stacktrace and task command name, we can
use this command:

	./page_owner_sort   --cull=stacktrace,name

The output would be like:

	2 times, 2 pages, task_comm_name: task_name_demo
	 prep_new_page+0xd0/0xf8
	 get_page_from_freelist+0x4a0/0x1290
	 __alloc_pages+0x168/0x340
	 alloc_pages+0xb0/0x158

As we can see, these two blocks are culled successfully, for they share
the same pid and task command name.

However, if we want to cull the blocks by pid, stacktrace and task command
name, we can this command:

	./page_owner_sort   --cull=stacktrace,name,pid

The output would be like:

	1 times, 1 pages, PID 1, task_comm_name: task_name_demo
	 prep_new_page+0xd0/0xf8
	 get_page_from_freelist+0x4a0/0x1290
	 __alloc_pages+0x168/0x340
	 alloc_pages+0xb0/0x158

	1 times, 1 pages, PID 32, task_comm_name: task_name_demo
	 prep_new_page+0xd0/0xf8
	 get_page_from_freelist+0x4a0/0x1290
	 __alloc_pages+0x168/0x340
	 alloc_pages+0xb0/0x158

As we can see, these two blocks are failed to cull, for their PIDs are
different.

2. Add explanations of --cull options to the document.

This work is coauthored by
	Yixuan Cao
	Shenghong Han
	Yinan Zhang
	Chongxi Zhao
	Yuhong Feng

Link: https://lkml.kernel.org/r/20220312145834.624-1-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye 
Cc: Yixuan Cao 
Cc: Shenghong Han 
Cc: Yinan Zhang 
Cc: Chongxi Zhao 
Cc: Yuhong Feng 
Cc: Stephen Rothwell 
Cc: Sean Anderson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tools/vm/page_owner_sort.c: support for selecting by PID, TGID or task command name

2022-03-25T02:06:45+00:00

When viewing page owner information, we may also need to select the blocks
by PID, TGID or task command name, which helps to get more accurate page
allocation information as needed.

Therefore, following adjustments are made:

1. Add three new options, including --pid, --tgid and --name, to support
   the selection of information blocks by a specific pid, tgid and task
   command name. In addtion, multiple options are allowed to be used at
   the same time.

	./page_owner_sort [input] [output] --pid 
	./page_owner_sort [input] [output] --tgid 
	./page_owner_sort [input] [output] --name 

   Assuming a scenario when a multi-threaded program, ./demo (PID =
   5280), is running, and ./demo creates a child process (PID = 5281).

	$ps
	PID   TTY        TIME   CMD
	5215  pts/0    00:00:00  bash
	5280  pts/0    00:00:00  ./demo
	5281  pts/0    00:00:00  ./demo
	5282  pts/0    00:00:00  ps

   It would be better to filter out the records with tgid=5280 and the
   task name "demo" when debugging the parent process, and the specific
   usage is

	./page_owner_sort [input] [output] --tgid 5280 --name demo

2. Add explanations of three new options, including --pid, --tgid and
   --name, to the document.

This work is coauthored by
	Shenghong Han ,
	Yixuan Cao ,
	Yinan Zhang ,
	Chongxi Zhao ,
	Yuhong Feng .

Link: https://lkml.kernel.org/r/1646835223-7584-1-git-send-email-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye 
Cc: Sean Anderson 
Cc: Stephen Rothwell 
Cc: Zhenliang Wei 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tools/vm/page_owner_sort: support for sorting by task command name

2022-03-25T02:06:45+00:00

When viewing page owner information, we may also need to the block to be
sorted by task command name.  Therefore, the following adjustments are
made:

1. Add a member variable to record task command name of block.

2. Add a new -n option to sort the information of blocks by task command
   name.

3. Add -n option explanation in the document.

Link: https://lkml.kernel.org/r/20220306030640.43054-2-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye 
Cc: Stephen Rothwell 
Cc: Sean Anderson 
Cc: Yixuan Cao 
Cc: Zhenliang Wei 
Cc: 
Cc: 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tools/vm/page_owner_sort.c: support sorting by tgid and update documentation

2022-03-25T02:06:45+00:00

When the "page owner" information is read, the information sorted
by TGID is expected.

As a result, the following adjustments have been made:

1. Add a new -P option to sort the information of blocks by TGID in
   ascending order.

2. Adjust the order of member variables in block_list strust to avoid
   one 4 byte hole.

3. Add -P option explanation in the document.

Link: https://lkml.kernel.org/r/20220301151438.166118-3-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye 
Cc: Stephen Rothwell 
Cc: Yixuan Cao 
Cc: Zhenliang Wei 
Cc: Yinan Zhang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tools/vm/page_owner_sort.c: fix comments

2022-03-25T02:06:45+00:00

Two adjustments are made:

1. Correct a grammatical error: replace the "what" in "Do the job what
   you want to debug" with "that".

2. Replace "has not been" with "has been" in the description of the -f
   option: According to Commit b1c9ba071e7d ("tools/vm/page_owner_sort.c:
   fix the instructions for use"), the description of the "-f" option is
   "Filter out the information of blocks whose memory has been released."

Link: https://lkml.kernel.org/r/20220301151438.166118-1-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye 
Cc: Stephen Rothwell 
Cc: Yinan Zhang 
Cc: Yixuan Cao 
Cc: Zhenliang Wei 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds