ia64: scrub ia64 from poison.h

Link: https://lkml.kernel.org/r/c72e5467-06a8-4739-ae6a-7c84c96cad77@p183
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <akpm@linux

ia64: scrub ia64 from poison.h

Link: https://lkml.kernel.org/r/c72e5467-06a8-4739-ae6a-7c84c96cad77@p183
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

slab: delete useless RED_INACTIVE and RED_ACTIVE

These seem useless since we use the SLUB_RED_INACTIVE and SLUB_RED_ACTIVE,
so just delete them, no functional change.

Reviewed-by: Vlastimil Babka <

slab: delete useless RED_INACTIVE and RED_ACTIVE

These seem useless since we use the SLUB_RED_INACTIVE and SLUB_RED_ACTIVE,
so just delete them, no functional change.

Reviewed-by: Vlastimil Babka <[email protected]>
Signed-off-by: Chengming Zhou <[email protected]>
Reviewed-by: Christoph Lameter (Ampere) <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>

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stackdepot: use variable size records for non-evictable entries

With the introduction of stack depot evictions, each stack record is now
fixed size, so that future reuse after an eviction can safely

stackdepot: use variable size records for non-evictable entries

With the introduction of stack depot evictions, each stack record is now
fixed size, so that future reuse after an eviction can safely store
differently sized stack traces. In all cases that do not make use of
evictions, this wastes lots of space.

Fix it by re-introducing variable size stack records (up to the max
allowed size) for entries that will never be evicted. We know if an entry
will never be evicted if the flag STACK_DEPOT_FLAG_GET is not provided,
since a later stack_depot_put() attempt is undefined behavior.

With my current kernel config that enables KASAN and also SLUB owner
tracking, I observe (after a kernel boot) a whopping reduction of 296
stack depot pools, which translates into 4736 KiB saved. The savings here
are from SLUB owner tracking only, because KASAN generic mode still uses
refcounting.

Before:

pools: 893
allocations: 29841
frees: 6524
in_use: 23317
freelist_size: 3454

After:

pools: 597
refcounted_allocations: 17547
refcounted_frees: 6477
refcounted_in_use: 11070
freelist_size: 3497
persistent_count: 12163
persistent_bytes: 1717008

[[email protected]: fix -Wstringop-overflow warning]
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CABXGCsOzpRPZGg23QqJAzKnqkZPKzvieeg=W7sgjgi3q0pBo0g@mail.gmail.com/
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CABXGCsOzpRPZGg23QqJAzKnqkZPKzvieeg=W7sgjgi3q0pBo0g@mail.gmail.com/
Fixes: 108be8def46e ("lib/stackdepot: allow users to evict stack traces")
Signed-off-by: Marco Elver <[email protected]>
Reviewed-by: Andrey Konovalov <[email protected]>
Tested-by: Mikhail Gavrilov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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net: page_pool: record pools per netdev

Link the page pools with netdevs. This needs to be netns compatible
so we have two options. Either we record the pools per netns and
have to worry about movin

net: page_pool: record pools per netdev

Link the page pools with netdevs. This needs to be netns compatible
so we have two options. Either we record the pools per netns and
have to worry about moving them as the netdev gets moved.
Or we record them directly on the netdev so they move with the netdev
without any extra work.

Implement the latter option. Since pools may outlast netdev we need
a place to store orphans. In time honored tradition use loopback
for this purpose.

Reviewed-by: Mina Almasry <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: introduce skb_poison_list and use in kfree_skb_list

First user of skb_poison_list is in kfree_skb_list_reason, to catch bugs
earlier like introduced in commit eedade12f4cb ("net: kfree_skb_list

net: introduce skb_poison_list and use in kfree_skb_list

First user of skb_poison_list is in kfree_skb_list_reason, to catch bugs
earlier like introduced in commit eedade12f4cb ("net: kfree_skb_list use
kmem_cache_free_bulk"). For completeness mentioned bug have been fixed in
commit f72ff8b81ebc ("net: fix kfree_skb_list use of skb_mark_not_on_list").

In case of a bug like mentioned commit we would have seen OOPS with:
general protection fault, probably for non-canonical address 0xdead000000000870
And content of one the registers e.g. R13: dead000000000800

In this case skb->len is at offset 112 bytes (0x70) why fault happens at
0x800+0x70 = 0x870

Signed-off-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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fs: Use CHECK_DATA_CORRUPTION() when kernel bugs are detected

Currently, filp_close() and generic_shutdown_super() use printk() to log
messages when bugs are detected. This is problematic because in

fs: Use CHECK_DATA_CORRUPTION() when kernel bugs are detected

Currently, filp_close() and generic_shutdown_super() use printk() to log
messages when bugs are detected. This is problematic because infrastructure
like syzkaller has no idea that this message indicates a bug.
In addition, some people explicitly want their kernels to BUG() when kernel
data corruption has been detected (CONFIG_BUG_ON_DATA_CORRUPTION).
And finally, when generic_shutdown_super() detects remaining inodes on a
system without CONFIG_BUG_ON_DATA_CORRUPTION, it would be nice if later
accesses to a busy inode would at least crash somewhat cleanly rather than
walking through freed memory.

To address all three, use CHECK_DATA_CORRUPTION() when kernel bugs are
detected.

Signed-off-by: Jann Horn <[email protected]>
Reviewed-by: Christian Brauner (Microsoft) <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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bpf: Add verifier check for BPF_PTR_POISON retval and arg

BPF_PTR_POISON was added in commit c0a5a21c25f37 ("bpf: Allow storing
referenced kptr in map") to denote a bpf_func_proto btf_id which the
v

bpf: Add verifier check for BPF_PTR_POISON retval and arg

BPF_PTR_POISON was added in commit c0a5a21c25f37 ("bpf: Allow storing
referenced kptr in map") to denote a bpf_func_proto btf_id which the
verifier will replace with a dynamically-determined btf_id at verification
time.

This patch adds verifier 'poison' functionality to BPF_PTR_POISON in
order to prepare for expanded use of the value to poison ret- and
arg-btf_id in ongoing work, namely rbtree and linked list patchsets
[0, 1]. Specifically, when the verifier checks helper calls, it assumes
that BPF_PTR_POISON'ed ret type will be replaced with a valid type before
- or in lieu of - the default ret_btf_id logic. Similarly for arg btf_id.

If poisoned btf_id reaches default handling block for either, consider
this a verifier internal error and fail verification. Otherwise a helper
w/ poisoned btf_id but no verifier logic replacing the type will cause a
crash as the invalid pointer is dereferenced.

Also move BPF_PTR_POISON to existing include/linux/posion.h header and
remove unnecessary shift.

[0]: lore.kernel.org/bpf/[email protected]
[1]: lore.kernel.org/bpf/[email protected]

Signed-off-by: Dave Marchevsky <[email protected]>
Acked-by: Kumar Kartikeya Dwivedi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

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mm: add a signature in struct page

This is needed by the page_pool to avoid recycling a page not allocated
via page_pool.

The page->signature field is aliased to page->lru.next and
page->compound_h

mm: add a signature in struct page

This is needed by the page_pool to avoid recycling a page not allocated
via page_pool.

The page->signature field is aliased to page->lru.next and
page->compound_head, but it can't be set by mistake because the
signature value is a bad pointer, and can't trigger a false positive
in PageTail() because the last bit is 0.

Co-developed-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Matteo Croce <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO

CONFIG_PAGE_POISONING_ZERO uses the zero pattern instead of 0xAA. It was
introduced by commit 1414c7f4f7d7 ("mm/page_poisoning.c: allow for zero
p

mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO

CONFIG_PAGE_POISONING_ZERO uses the zero pattern instead of 0xAA. It was
introduced by commit 1414c7f4f7d7 ("mm/page_poisoning.c: allow for zero
poisoning"), noting that using zeroes retains the benefit of sanitizing
content of freed pages, with the benefit of not having to zero them again
on alloc, and the downside of making some forms of corruption (stray
writes of NULLs) harder to detect than with the 0xAA pattern. Together
with CONFIG_PAGE_POISONING_NO_SANITY it made possible to sanitize the
contents on free without checking it back on alloc.

These days we have the init_on_free() option to achieve sanitization with
zeroes and to save clearing on alloc (and without checking on alloc).
Arguably if someone does choose to check the poison for corruption on
alloc, the savings of not clearing the page are secondary, and it makes
sense to always use the 0xAA poison pattern. Thus, remove the
CONFIG_PAGE_POISONING_ZERO option for being redundant.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Laura Abbott <[email protected]>
Cc: Mateusz Nosek <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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include/linux/poison.h: remove obsolete comment

When the definition was changed, the comment became stale. Just remove
it since there isn't anything useful to say here.

Fixes: b8a0255db958 ("inclu

include/linux/poison.h: remove obsolete comment

When the definition was changed, the comment became stale. Just remove
it since there isn't anything useful to say here.

Fixes: b8a0255db958 ("include/linux/poison.h: use POISON_POINTER_DELTA for poison pointers")
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Vasily Kulikov <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

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lib/list: tweak LIST_POISON2 for better code generation on x86_64

list_del() poisoning can generate 2 64-bit immediate loads but it also can
generate one 64-bit immediate load and an addition:

48

lib/list: tweak LIST_POISON2 for better code generation on x86_64

list_del() poisoning can generate 2 64-bit immediate loads but it also can
generate one 64-bit immediate load and an addition:

48 b8 00 01 00 00 00 00 ad de movabs rax,0xdead000000000100
48 89 47 58 mov QWORD PTR [rdi+0x58],rax
48 05 00 01 00 00 <=====> add rax,0x100
48 89 47 60 mov QWORD PTR [rdi+0x60],rax

However on x86_64 not all constants are equal: those within [-128, 127]
range can be added with shorter "add r64, imm32" instruction:

48 b8 00 01 00 00 00 00 ad de movabs rax,0xdead000000000100
48 89 47 58 mov QWORD PTR [rdi+0x58],rax
48 83 c0 22 <======> add rax,0x22
48 89 47 60 mov QWORD PTR [rdi+0x60],rax

Patch saves 2 bytes per some LIST_POISON2 usage.

(Slightly disappointing) space savings on F29 x86_64 config:

add/remove: 0/0 grow/shrink: 0/2164 up/down: 0/-5184 (-5184)
Function old new delta
zstd_get_workspace 548 546 -2
...
mlx4_delete_all_resources_for_slave 4826 4804 -22
Total: Before=83304131, After=83298947, chg -0.01%

New constants are:

0xdead000000000100
0xdead000000000122

Note: LIST_POISON1 can't be changed to ...11 because something in page
allocator requires low bit unset.

Link: http://lkml.kernel.org/r/20190513191502.GA8492@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Vasiliy Kulikov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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Drop flex_arrays

All existing users have been converted to generic radix trees

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Kent Overstreet <kent.o

Drop flex_arrays

All existing users have been converted to generic radix trees

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Kent Overstreet <[email protected]>
Acked-by: Dave Hansen <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: Marcelo Ricardo Leitner <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Neil Horman <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: Pravin B Shelar <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Stephen Smalley <[email protected]>
Cc: Vlad Yasevich <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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mm/page_poison: update comment after code moved

mm/debug-pagealloc.c is no more, so of course header now needs to be
updated. This seems like something checkpatch should be able to catch -
worth lo

mm/page_poison: update comment after code moved

mm/debug-pagealloc.c is no more, so of course header now needs to be
updated. This seems like something checkpatch should be able to catch -
worth looking into?

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 8823b1dbc05f ("mm/page_poison.c: enable PAGE_POISONING as a separate option")
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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locking/mutex: Initialize mutex_waiter::ww_ctx with poison when debugging

Help catch cases where mutex_lock is used directly on w/w mutexes, which
otherwise result in the w/w tasks reading uninitial

locking/mutex: Initialize mutex_waiter::ww_ctx with poison when debugging

Help catch cases where mutex_lock is used directly on w/w mutexes, which
otherwise result in the w/w tasks reading uninitialized data.

Signed-off-by: Nicolai Hähnle <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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mm/page_poisoning.c: allow for zero poisoning

By default, page poisoning uses a poison value (0xaa) on free. If this
is changed to 0, the page is not only sanitized but zeroing on alloc
with __GFP_

mm/page_poisoning.c: allow for zero poisoning

By default, page poisoning uses a poison value (0xaa) on free. If this
is changed to 0, the page is not only sanitized but zeroing on alloc
with __GFP_ZERO can be skipped as well. The tradeoff is that detecting
corruption from the poisoning is harder to detect. This feature also
cannot be used with hibernation since pages are not guaranteed to be
zeroed after hibernation.

Credit to Grsecurity/PaX team for inspiring this work

Signed-off-by: Laura Abbott <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Mathias Krause <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Jianyu Zhan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

include/linux/poison.h: use POISON_POINTER_DELTA for poison pointers

TIMER_ENTRY_STATIC and TAIL_MAPPING are defined as poison pointers which
should point to nowhere. Redefine them using POISON_POI

include/linux/poison.h: use POISON_POINTER_DELTA for poison pointers

TIMER_ENTRY_STATIC and TAIL_MAPPING are defined as poison pointers which
should point to nowhere. Redefine them using POISON_POINTER_DELTA
arithmetics to make sure they really point to non-mappable area declared
by the target architecture.

Signed-off-by: Vasily Kulikov <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Solar Designer <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

mm: sanitize page->mapping for tail pages

We don't define meaning of page->mapping for tail pages. Currently it's
always NULL, which can be inconsistent with head page and potentially
lead to probl

mm: sanitize page->mapping for tail pages

We don't define meaning of page->mapping for tail pages. Currently it's
always NULL, which can be inconsistent with head page and potentially
lead to problems.

Let's poison the pointer to catch all illigal uses.

page_rmapping(), page_mapping() and page_anon_vma() are changed to look
on head page.

The only illegal use I've caught so far is __GPF_COMP pages from sound
subsystem, mapped with PTEs. do_shared_fault() is changed to use
page_rmapping() instead of direct access to fault_page->mapping.

Signed-off-by: Kirill A. Shutemov <[email protected]>
Reviewed-by: Jérôme Glisse <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Steve Capper <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Jerome Marchand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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include/linux/poison.h: remove not-used poison pointer macros

Signed-off-by: Vasily Kulikov <[email protected]>
Cc: Solar Designer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc:

include/linux/poison.h: remove not-used poison pointer macros

Signed-off-by: Vasily Kulikov <[email protected]>
Cc: Solar Designer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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include/linux/poison.h: fix LIST_POISON{1,2} offset

Poison pointer values should be small enough to find a room in
non-mmap'able/hardly-mmap'able space. E.g. on x86 "poison pointer space"
is locat

include/linux/poison.h: fix LIST_POISON{1,2} offset

Poison pointer values should be small enough to find a room in
non-mmap'able/hardly-mmap'able space. E.g. on x86 "poison pointer space"
is located starting from 0x0. Given unprivileged users cannot mmap
anything below mmap_min_addr, it should be safe to use poison pointers
lower than mmap_min_addr.

The current poison pointer values of LIST_POISON{1,2} might be too big for
mmap_min_addr values equal or less than 1 MB (common case, e.g. Ubuntu
uses only 0x10000). There is little point to use such a big value given
the "poison pointer space" below 1 MB is not yet exhausted. Changing it
to a smaller value solves the problem for small mmap_min_addr setups.

The values are suggested by Solar Designer:
http://www.openwall.com/lists/oss-security/2015/05/02/6

Signed-off-by: Vasily Kulikov <[email protected]>
Cc: Solar Designer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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memblock: Kill sentinel entries at the end of static region arrays

memblock no longer depends on having one more entry at the end during
addition making the sentinel entries at the end of region arr

memblock: Kill sentinel entries at the end of static region arrays

memblock no longer depends on having one more entry at the end during
addition making the sentinel entries at the end of region arrays not
too useful. Remove the sentinels. This eases further updates.

Signed-off-by: Tejun Heo <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Yinghai Lu <[email protected]>

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mm/memblock.c: avoid abuse of RED_INACTIVE

RED_INACTIVE is a slab thing, and reusing it for memblock was
inappropriate, because memblock is dealing with phys_addr_t's which have a
Kconfigurable size

mm/memblock.c: avoid abuse of RED_INACTIVE

RED_INACTIVE is a slab thing, and reusing it for memblock was
inappropriate, because memblock is dealing with phys_addr_t's which have a
Kconfigurable sizeof().

Create a new poison type for this application. Fixes the sparse warning

warning: cast truncates bits from constant value (9f911029d74e35b becomes 9d74e35b)

Reported-by: H Hartley Sweeten <[email protected]>
Tested-by: H Hartley Sweeten <[email protected]>
Acked-by: Pekka Enberg <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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hugetlb, rmap: add reverse mapping for hugepage

This patch adds reverse mapping feature for hugepage by introducing
mapcount for shared/private-mapped hugepage and anon_vma for
private-mapped hugepa

hugetlb, rmap: add reverse mapping for hugepage

This patch adds reverse mapping feature for hugepage by introducing
mapcount for shared/private-mapped hugepage and anon_vma for
private-mapped hugepage.

While hugepage is not currently swappable, reverse mapping can be useful
for memory error handler.

Without this patch, memory error handler cannot identify processes
using the bad hugepage nor unmap it from them. That is:
- for shared hugepage:
we can collect processes using a hugepage through pagecache,
but can not unmap the hugepage because of the lack of mapcount.
- for privately mapped hugepage:
we can neither collect processes nor unmap the hugepage.
This patch solves these problems.

This patch include the bug fix given by commit 23be7468e8, so reverts it.

Dependency:
"hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h"

ChangeLog since May 24.
- create hugetlb_inline.h and move is_vm_hugetlb_index() in it.
- move functions setting up anon_vma for hugepage into mm/rmap.c.

ChangeLog since May 13.
- rebased to 2.6.34
- fix logic error (in case that private mapping and shared mapping coexist)
- move is_vm_hugetlb_page() into include/linux/mm.h to use this function
from linear_page_index()
- define and use linear_hugepage_index() instead of compound_order()
- use page_move_anon_rmap() in hugetlb_cow()
- copy exclusive switch of __set_page_anon_rmap() into hugepage counterpart.
- revert commit 24be7468 completely

Signed-off-by: Naoya Horiguchi <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Larry Woodman <[email protected]>
Cc: Lee Schermerhorn <[email protected]>
Acked-by: Fengguang Wu <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>

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hugetlb: fix infinite loop in get_futex_key() when backed by huge pages

If a futex key happens to be located within a huge page mapped
MAP_PRIVATE, get_futex_key() can go into an infinite loop waiti

hugetlb: fix infinite loop in get_futex_key() when backed by huge pages

If a futex key happens to be located within a huge page mapped
MAP_PRIVATE, get_futex_key() can go into an infinite loop waiting for a
page->mapping that will never exist.

See https://bugzilla.redhat.com/show_bug.cgi?id=552257 for more details
about the problem.

This patch makes page->mapping a poisoned value that includes
PAGE_MAPPING_ANON mapped MAP_PRIVATE. This is enough for futex to
continue but because of PAGE_MAPPING_ANON, the poisoned value is not
dereferenced or used by futex. No other part of the VM should be
dereferencing the page->mapping of a hugetlbfs page as its page cache is
not on the LRU.

This patch fixes the problem with the test case described in the bugzilla.

[[email protected]: mel cant spel]
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: Darren Hart <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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core, x86: make LIST_POISON less deadly

The list macros use LIST_POISON1 and LIST_POISON2 as undereferencable
pointers in order to trap erronous use of freed list_heads. Unfortunately
userspace can

core, x86: make LIST_POISON less deadly

The list macros use LIST_POISON1 and LIST_POISON2 as undereferencable
pointers in order to trap erronous use of freed list_heads. Unfortunately
userspace can arrange for those pointers to actually be dereferencable,
potentially turning an oops to an expolit.

To avoid this allow architectures (currently x86_64 only) to override
the default values for these pointers with truly-undereferencable values.
This is easy on x86_64 as the virtual address space is large and contains
areas that cannot be mapped.

Other 64-bit architectures will likely find similar unmapped ranges.

[ingo: switch to 0xdead000000000000 as the unmapped area]
[ingo: add comments, cleanup]
[jaswinder: eliminate sparse warnings]

Acked-by: Linus Torvalds <[email protected]>
Signed-off-by: Jaswinder Singh Rajput <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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