linux-stable.git/kernel/power/snapshot.c, branch linux-5.15.y

PM: hibernate: Clean up sync_read handling in snapshot_write_next()

2023-11-28T16:56:29+00:00

commit d08970df1980476f27936e24d452550f3e9e92e1 upstream.

In snapshot_write_next(), sync_read is set and unset in three different
spots unnecessiarly. As a result there is a subtle bug where the first
page after the meta data has been loaded unconditionally sets sync_read
to 0. If this first PFN was actually a highmem page, then the returned
buffer will be the global "buffer," and the page needs to be loaded
synchronously.

That is, I'm not sure we can always assume the following to be safe:

	handle->buffer = get_buffer(&orig_bm, &ca);
	handle->sync_read = 0;

Because get_buffer() can call get_highmem_page_buffer() which can
return 'buffer'.

The easiest way to address this is just set sync_read before
snapshot_write_next() returns if handle->buffer == buffer.

Signed-off-by: Brian Geffon 
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable 
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM: hibernate: Use __get_safe_page() rather than touching the list

2023-11-28T16:56:29+00:00

commit f0c7183008b41e92fa676406d87f18773724b48b upstream.

We found at least one situation where the safe pages list was empty and
get_buffer() would gladly try to use a NULL pointer.

Signed-off-by: Brian Geffon 
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM: hibernate: Fix mistake in kerneldoc comment

2022-12-31T12:14:01+00:00

[ Upstream commit 6e5d7300cbe7c3541bc31f16db3e9266e6027b4b ]

The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:

max_size = (count - (size + PAGES_FOR_IO)) / 2
	    - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);

but the one in the kerneldoc comment of the function is different and
incorrect.

Fixes: ddeb64870810 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers")
Signed-off-by: xiongxin 
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: hibernate: Remove register_nosave_region_late()

2022-02-16T11:56:15+00:00

[ Upstream commit 33569ef3c754a82010f266b7b938a66a3ccf90a4 ]

It is an unused wrapper forcing kmalloc allocation for registering
nosave regions. Also, rename __register_nosave_region() to
register_nosave_region() now that there is no need for disambiguation.

Signed-off-by: Amadeusz Sławiński 
Reviewed-by: Cezary Rojewski 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: hibernate: remove leading spaces before tabs

2021-06-11T16:52:05+00:00

 1) Run the following command to find and remove the leading spaces
    before tabs:
    $ find kernel/power/ -type f | xargs sed -r -i 's/^[ ]+\t/\t/'
 2) Manually check and correct if necessary

Signed-off-by: Zhen Lei 
Signed-off-by: Rafael J. Wysocki

PM: hibernate: fix spelling mistakes

2021-05-24T14:17:07+00:00

Fix some spelling mistakes in comments:

corresonds ==> corresponds
alocated ==> allocated
unitialized ==> uninitialized
Deompression ==> Decompression

Signed-off-by: Zhen Lei 
Signed-off-by: Rafael J. Wysocki

PM: sleep: fix typos in comments

2021-04-08T17:37:21+00:00

Change "occured" to "occurred" in kernel/power/autosleep.c.

Change "consiting" to "consisting" in kernel/power/snapshot.c.

Change "avaiable" to "available" in kernel/power/swap.c.

No functionality changed.

Signed-off-by: Lu Jialin 
Signed-off-by: Rafael J. Wysocki

kernel/power: allow hibernation with page_poison sanity checking

2020-12-15T20:13:46+00:00

Page poisoning used to be incompatible with hibernation, as the state of
poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION
forces CONFIG_PAGE_POISONING_NO_SANITY.  For the same reason, the
poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable
hibernation.  The latter restriction was removed by commit 1ad1410f632d
("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and
similarly for init_on_free by commit 18451f9f9e58 ("PM: hibernate: fix
crashes with init_on_free=1") by making sure free pages are cleared after
resume.

We can use the same mechanism to instead poison free pages with
PAGE_POISON after resume.  This covers both zero and 0xAA patterns.  Thus
we can remove the Kconfig restriction that disables page poison sanity
checking when hibernation is enabled.

Link: https://lkml.kernel.org/r/20201113104033.22907-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka 
Acked-by: Rafael J. Wysocki 	[hibernation]
Reviewed-by: David Hildenbrand 
Cc: Mike Rapoport 
Cc: Alexander Potapenko 
Cc: Kees Cook 
Cc: Laura Abbott 
Cc: Mateusz Nosek 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

PM: hibernate: make direct map manipulations more explicit

2020-12-15T20:13:43+00:00

When DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP is enabled a page may be
not present in the direct map and has to be explicitly mapped before it
could be copied.

Introduce hibernate_map_page() and hibernation_unmap_page() that will
explicitly use set_direct_map_{default,invalid}_noflush() for
ARCH_HAS_SET_DIRECT_MAP case and debug_pagealloc_{map,unmap}_pages() for
DEBUG_PAGEALLOC case.

The remapping of the pages in safe_copy_page() presumes that it only
changes protection bits in an existing PTE and so it is safe to ignore
return value of set_direct_map_{default,invalid}_noflush().

Still, add a pr_warn() so that future changes in set_memory APIs will not
silently break hibernation.

Link: https://lkml.kernel.org/r/20201109192128.960-3-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Acked-by: Rafael J. Wysocki 
Reviewed-by: David Hildenbrand 
Acked-by: Kirill A. Shutemov 
Acked-by: Vlastimil Babka 
Cc: Albert Ou 
Cc: Andy Lutomirski 
Cc: Benjamin Herrenschmidt 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Christian Borntraeger 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: David Rientjes 
Cc: "David S. Miller" 
Cc: "Edgecombe, Rick P" 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Joonsoo Kim 
Cc: Len Brown 
Cc: Michael Ellerman 
Cc: Palmer Dabbelt 
Cc: Paul Mackerras 
Cc: Paul Walmsley 
Cc: Pavel Machek 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: "Rafael J. Wysocki" 
Cc: Thomas Gleixner 
Cc: Vasily Gorbik 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/: fix repeated words in comments

2020-10-16T18:11:19+00:00

Fix multiple occurrences of duplicated words in kernel/.

Fix one typo/spello on the same line as a duplicate word.  Change one
instance of "the the" to "that the".  Otherwise just drop one of the
repeated words.

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Link: https://lkml.kernel.org/r/98202fa6-8919-ef63-9efe-c0fad5ca7af1@infradead.org
Signed-off-by: Linus Torvalds