linux-stable.git/lib, branch v6.8.7

lib: checksum: hide unused expected_csum_ipv6_magic[]

2024-04-17T09:23:28+00:00

[ Upstream commit e9d47b7b31563a6524b9f64ea70ed0289cc4d9c4 ]

When CONFIG_NET is disabled, an extra warning shows up for this
unused variable:

lib/checksum_kunit.c:218:18: error: 'expected_csum_ipv6_magic' defined but not used [-Werror=unused-const-variable=]

Replace the #ifdef with an IS_ENABLED() check that makes the compiler's
dead-code-elimination take care of the link failure.

Fixes: f24a70106dc1 ("lib: checksum: Fix build with CONFIG_NET=n")
Suggested-by: Christophe Leroy 
Acked-by: Palmer Dabbelt 
Acked-by: Jakub Kicinski 
Signed-off-by: Arnd Bergmann 
Reviewed-by: Simon Horman 
Tested-by: Simon Horman  # build-tested
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

dump_stack: Do not get cpu_sync for panic CPU

2024-04-13T11:09:58+00:00

[ Upstream commit 7412dc6d55eed6b76180e40ac3601412ebde29bd ]

dump_stack() is called in panic(). If for some reason another CPU
is holding the printk_cpu_sync and is unable to release it, the
panic CPU will be unable to continue and print the stacktrace.

Since non-panic CPUs are not allowed to store new printk messages
anyway, there is no need to synchronize the stacktrace output in
a panic situation.

For the panic CPU, do not get the printk_cpu_sync because it is
not needed and avoids a potential deadlock scenario in panic().

Link: https://lore.kernel.org/lkml/ZcIGKU8sxti38Kok@alley
Signed-off-by: John Ogness 
Reviewed-by: Petr Mladek 
Link: https://lore.kernel.org/r/20240207134103.1357162-15-john.ogness@linutronix.de
Signed-off-by: Petr Mladek 
Signed-off-by: Sasha Levin

stackdepot: rename pool_index to pool_index_plus_1

2024-04-10T14:38:14+00:00

[ Upstream commit a6c1d9cb9a68bfa4512248419c4f4d880d19fe90 ]

Commit 3ee34eabac2a ("lib/stackdepot: fix first entry having a 0-handle")
changed the meaning of the pool_index field to mean "the pool index plus
1".  This made the code accessing this field less self-documenting, as
well as causing debuggers such as drgn to not be able to easily remain
compatible with both old and new kernels, because they typically do that
by testing for presence of the new field.  Because stackdepot is a
debugging tool, we should make sure that it is debugger friendly.
Therefore, give the field a different name to improve readability as well
as enabling debugger backwards compatibility.

This is needed in 6.9, which would otherwise become an odd release with
the new semantics and old name so debuggers wouldn't recognize the new
semantics there.

Fixes: 3ee34eabac2a ("lib/stackdepot: fix first entry having a 0-handle")
Link: https://lkml.kernel.org/r/20240402001500.53533-1-pcc@google.com
Link: https://linux-review.googlesource.com/id/Ib3e70c36c1d230dd0a118dc22649b33e768b9f88
Signed-off-by: Peter Collingbourne 
Acked-by: Vlastimil Babka 
Reviewed-by: Alexander Potapenko 
Acked-by: Marco Elver 
Acked-by: Oscar Salvador 
Cc: Andrey Konovalov 
Cc: Michal Hocko 
Cc: Omar Sandoval 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

lib/stackdepot: move stack_record struct definition into the header

2024-04-10T14:38:14+00:00

[ Upstream commit 8151c7a35d8bd8a12e93538ef7963ea209b6ab41 ]

In order to move the heavy lifting into page_owner code, this one needs to
have access to the stack_record structure, which right now sits in
lib/stackdepot.c.  Move it to the stackdepot.h header so page_owner can
access stack_record's struct fields.

Link: https://lkml.kernel.org/r/20240215215907.20121-3-osalvador@suse.de
Signed-off-by: Oscar Salvador 
Reviewed-by: Marco Elver 
Reviewed-by: Vlastimil Babka 
Acked-by: Andrey Konovalov 
Cc: Alexander Potapenko 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Stable-dep-of: a6c1d9cb9a68 ("stackdepot: rename pool_index to pool_index_plus_1")
Signed-off-by: Sasha Levin

pci_iounmap(): Fix MMIO mapping leak

2024-04-03T13:32:02+00:00

[ Upstream commit 7626913652cc786c238e2dd7d8740b17d41b2637 ]

The #ifdef ARCH_HAS_GENERIC_IOPORT_MAP accidentally also guards iounmap(),
which means MMIO mappings are leaked.

Move the guard so we call iounmap() for MMIO mappings.

Fixes: 316e8d79a095 ("pci_iounmap'2: Electric Boogaloo: try to make sense of it all")
Link: https://lore.kernel.org/r/20240131090023.12331-2-pstanner@redhat.com
Reported-by: Danilo Krummrich 
Suggested-by: Arnd Bergmann 
Signed-off-by: Philipp Stanner 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Arnd Bergmann 
Cc:  # v5.15+
Signed-off-by: Sasha Levin

lib/stackdepot: off by one in depot_fetch_stack()

2024-03-26T22:17:17+00:00

[ Upstream commit dc24559472a682eb124e869cb110e7a2fd857322 ]

The stack_pools[] array has DEPOT_MAX_POOLS.  The "pools_num" tracks the
number of pools which are initialized.  See depot_init_pool() for more
details.

If pool_index == pools_num_cached, this will read one element beyond what
we want.  If not all the pools are initialized, then the pool will be
NULL, triggering a WARN(), and if they are all initialized it will read
one element beyond the end of the array.

Link: https://lkml.kernel.org/r/361ac881-60b7-471f-91e5-5bf8fe8042b2@moroto.mountain
Fixes: b29d31885814 ("lib/stackdepot: store free stack records in a freelist")
Signed-off-by: Dan Carpenter 
Cc: Alexander Potapenko 
Cc: Andrey Konovalov 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

lib/stackdepot: fix first entry having a 0-handle

2024-03-26T22:17:16+00:00

[ Upstream commit 3ee34eabac2abb6b1b6fcdebffe18870719ad000 ]

Patch series "page_owner: print stacks and their outstanding allocations",
v10.

page_owner is a great debug functionality tool that lets us know about all
pages that have been allocated/freed and their specific stacktrace.  This
comes very handy when debugging memory leaks, since with some scripting we
can see the outstanding allocations, which might point to a memory leak.

In my experience, that is one of the most useful cases, but it can get
really tedious to screen through all pages and try to reconstruct the
stack <-> allocated/freed relationship, becoming most of the time a
daunting and slow process when we have tons of allocation/free operations.

This patchset aims to ease that by adding a new functionality into
page_owner.  This functionality creates a new directory called
'page_owner_stacks' under 'sys/kernel//debug' with a read-only file called
'show_stacks', which prints out all the stacks followed by their
outstanding number of allocations (being that the times the stacktrace has
allocated but not freed yet).  This gives us a clear and a quick overview
of stacks <-> allocated/free.

We take advantage of the new refcount_f field that stack_record struct
gained, and increment/decrement the stack refcount on every
__set_page_owner() (alloc operation) and __reset_page_owner (free
operation) call.

Unfortunately, we cannot use the new stackdepot api STACK_DEPOT_FLAG_GET
because it does not fulfill page_owner needs, meaning we would have to
special case things, at which point makes more sense for page_owner to do
its own {dec,inc}rementing of the stacks.  E.g: Using
STACK_DEPOT_FLAG_PUT, once the refcount reaches 0, such stack gets
evicted, so page_owner would lose information.

This patchset also creates a new file called 'set_threshold' within
'page_owner_stacks' directory, and by writing a value to it, the stacks
which refcount is below such value will be filtered out.

A PoC can be found below:

 # cat /sys/kernel/debug/page_owner_stacks/show_stacks > page_owner_full_stacks.txt
 # head -40 page_owner_full_stacks.txt
  prep_new_page+0xa9/0x120
  get_page_from_freelist+0x801/0x2210
  __alloc_pages+0x18b/0x350
  alloc_pages_mpol+0x91/0x1f0
  folio_alloc+0x14/0x50
  filemap_alloc_folio+0xb2/0x100
  page_cache_ra_unbounded+0x96/0x180
  filemap_get_pages+0xfd/0x590
  filemap_read+0xcc/0x330
  blkdev_read_iter+0xb8/0x150
  vfs_read+0x285/0x320
  ksys_read+0xa5/0xe0
  do_syscall_64+0x80/0x160
  entry_SYSCALL_64_after_hwframe+0x6e/0x76
 stack_count: 521

  prep_new_page+0xa9/0x120
  get_page_from_freelist+0x801/0x2210
  __alloc_pages+0x18b/0x350
  alloc_pages_mpol+0x91/0x1f0
  folio_alloc+0x14/0x50
  filemap_alloc_folio+0xb2/0x100
  __filemap_get_folio+0x14a/0x490
  ext4_write_begin+0xbd/0x4b0 [ext4]
  generic_perform_write+0xc1/0x1e0
  ext4_buffered_write_iter+0x68/0xe0 [ext4]
  ext4_file_write_iter+0x70/0x740 [ext4]
  vfs_write+0x33d/0x420
  ksys_write+0xa5/0xe0
  do_syscall_64+0x80/0x160
  entry_SYSCALL_64_after_hwframe+0x6e/0x76
 stack_count: 4609
...
...

 # echo 5000 > /sys/kernel/debug/page_owner_stacks/set_threshold
 # cat /sys/kernel/debug/page_owner_stacks/show_stacks > page_owner_full_stacks_5000.txt
 # head -40 page_owner_full_stacks_5000.txt
  prep_new_page+0xa9/0x120
  get_page_from_freelist+0x801/0x2210
  __alloc_pages+0x18b/0x350
  alloc_pages_mpol+0x91/0x1f0
  folio_alloc+0x14/0x50
  filemap_alloc_folio+0xb2/0x100
  __filemap_get_folio+0x14a/0x490
  ext4_write_begin+0xbd/0x4b0 [ext4]
  generic_perform_write+0xc1/0x1e0
  ext4_buffered_write_iter+0x68/0xe0 [ext4]
  ext4_file_write_iter+0x70/0x740 [ext4]
  vfs_write+0x33d/0x420
  ksys_pwrite64+0x75/0x90
  do_syscall_64+0x80/0x160
  entry_SYSCALL_64_after_hwframe+0x6e/0x76
 stack_count: 6781

  prep_new_page+0xa9/0x120
  get_page_from_freelist+0x801/0x2210
  __alloc_pages+0x18b/0x350
  pcpu_populate_chunk+0xec/0x350
  pcpu_balance_workfn+0x2d1/0x4a0
  process_scheduled_works+0x84/0x380
  worker_thread+0x12a/0x2a0
  kthread+0xe3/0x110
  ret_from_fork+0x30/0x50
  ret_from_fork_asm+0x1b/0x30
 stack_count: 8641

This patch (of 7):

The very first entry of stack_record gets a handle of 0, but this is wrong
because stackdepot treats a 0-handle as a non-valid one.  E.g: See the
check in stack_depot_fetch()

Fix this by adding and offset of 1.

This bug has been lurking since the very beginning of stackdepot, but no
one really cared as it seems.  Because of that I am not adding a Fixes
tag.

Link: https://lkml.kernel.org/r/20240215215907.20121-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20240215215907.20121-2-osalvador@suse.de
Co-developed-by: Marco Elver 
Signed-off-by: Marco Elver 
Signed-off-by: Oscar Salvador 
Acked-by: Vlastimil Babka 
Acked-by: Andrey Konovalov 
Cc: Alexander Potapenko 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Stable-dep-of: dc24559472a6 ("lib/stackdepot: off by one in depot_fetch_stack()")
Signed-off-by: Sasha Levin

net: blackhole_dev: fix build warning for ethh set but not used

2024-03-26T22:16:38+00:00

[ Upstream commit 843a8851e89e2e85db04caaf88d8554818319047 ]

lib/test_blackhole_dev.c sets a variable that is never read, causing
this following building warning:

	lib/test_blackhole_dev.c:32:17: warning: variable 'ethh' set but not used [-Wunused-but-set-variable]

Remove the variable struct ethhdr *ethh, which is unused.

Fixes: 509e56b37cc3 ("blackhole_dev: add a selftest")
Signed-off-by: Breno Leitao 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

lib: memcpy_kunit: Fix an invalid format specifier in an assertion msg

2024-03-26T22:16:28+00:00

[ Upstream commit 0a549ed22c3c7cc6da5c5f5918efd019944489a5 ]

The 'i' passed as an assertion message is a size_t, so should use '%zu',
not '%d'.

This was found by annotating the _MSG() variants of KUnit's assertions
to let gcc validate the format strings.

Fixes: bb95ebbe89a7 ("lib: Introduce CONFIG_MEMCPY_KUNIT_TEST")
Signed-off-by: David Gow 
Tested-by: Guenter Roeck 
Reviewed-by: Justin Stitt 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

lib/cmdline: Fix an invalid format specifier in an assertion msg

2024-03-26T22:16:28+00:00

[ Upstream commit d2733a026fc7247ba42d7a8e1b737cf14bf1df21 ]

The correct format specifier for p - n (both p and n are pointers) is
%td, as the type should be ptrdiff_t.

This was discovered by annotating KUnit assertion macros with gcc's
printf specifier, but note that gcc incorrectly suggested a %d or %ld
specifier (depending on the pointer size of the architecture being
built).

Fixes: 0ea09083116d ("lib/cmdline: Allow get_options() to take 0 to validate the input")
Signed-off-by: David Gow 
Tested-by: Guenter Roeck 
Reviewed-by: Daniel Latypov 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin