This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Remove the sentinel from ctl_table arrays. Reduce by one the values used
to compare the size of the adjusted arrays.
Signed-off-by: Joel Granados <j.granados@samsung.com>
Pull non-MM updates from Andrew Morton:
- Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min
heap optimizations".
- Kuan-Wei Chiu has also sped up the library sorting code in the series
"lib/sort: Optimize the number of swaps and comparisons".
- Alexey Gladkov has added the ability for code running within an IPC
namespace to alter its IPC and MQ limits. The series is "Allow to
change ipc/mq sysctls inside ipc namespace".
- Geert Uytterhoeven has contributed some dhrystone maintenance work in
the series "lib: dhry: miscellaneous cleanups".
- Ryusuke Konishi continues nilfs2 maintenance work in the series
"nilfs2: eliminate kmap and kmap_atomic calls"
"nilfs2: fix kernel bug at submit_bh_wbc()"
- Nathan Chancellor has updated our build tools requirements in the
series "Bump the minimum supported version of LLVM to 13.0.1".
- Muhammad Usama Anjum continues with the selftests maintenance work in
the series "selftests/mm: Improve run_vmtests.sh".
- Oleg Nesterov has done some maintenance work against the signal code
in the series "get_signal: minor cleanups and fix".
Plus the usual shower of singleton patches in various parts of the tree.
Please see the individual changelogs for details.
* tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
nilfs2: prevent kernel bug at submit_bh_wbc()
nilfs2: fix failure to detect DAT corruption in btree and direct mappings
ocfs2: enable ocfs2_listxattr for special files
ocfs2: remove SLAB_MEM_SPREAD flag usage
assoc_array: fix the return value in assoc_array_insert_mid_shortcut()
buildid: use kmap_local_page()
watchdog/core: remove sysctl handlers from public header
nilfs2: use div64_ul() instead of do_div()
mul_u64_u64_div_u64: increase precision by conditionally swapping a and b
kexec: copy only happens before uchunk goes to zero
get_signal: don't initialize ksig->info if SIGNAL_GROUP_EXIT/group_exec_task
get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig
get_signal: don't abuse ksig->info.si_signo and ksig->sig
const_structs.checkpatch: add device_type
Normalise "name (ad@dr)" MODULE_AUTHORs to "name <ad@dr>"
dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace()
list: leverage list_is_head() for list_entry_is_head()
nilfs2: MAINTAINERS: drop unreachable project mirror site
smp: make __smp_processor_id() 0-argument macro
fat: fix uninitialized field in nostale filehandles
...
For debugging kernel panics and other bugs, there is already an option of
panic_print to dump all tasks' call stacks. On today's large servers
running many containers, there could be thousands of tasks or more, and
this will print out huge amount of call stacks, taking a lot of time (for
serial console which is main target user case of panic_print).
And in many cases, only those several tasks being blocked are key for the
panic, so add an option to only dump blocked tasks' call stacks.
[akpm@linux-foundation.org: clarify documentation a little]
Link: https://lkml.kernel.org/r/20240202132042.3609657-1-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
with GCC 13.2.1 and W=1, there's compiling warning like this:
kernel/panic.c: In function `__warn':
kernel/panic.c:676:17: warning: function `__warn' might be a candidate for `gnu_printf' format attribute [-Wsuggest-attribute=format]
676 | vprintk(args->fmt, args->args);
| ^~~~~~~
The normal __printf(x,y) adding can't fix it. So add workaround which
disables -Wsuggest-attribute=format to mute it.
Link: https://lkml.kernel.org/r/20240107091641.579849-1-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If the kernel crashes in a context where printk() calls always
defer printing (such as in NMI or inside a printk_safe section)
then the final panic messages will be deferred to irq_work. But
if irq_work is not available, the messages will not get printed
unless explicitly flushed. The result is that the final
"end Kernel panic" banner does not get printed.
Add one final flush after the last printk() call to make sure
the final panic messages make it out as well.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-14-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
Commit:
5a5d7e9bad ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG")
amended warn_slowpath_fmt() to disable preemption until the WARN splat
has been emitted.
However the commit neglected to reenable preemption in the !fmt codepath,
i.e. when a WARN splat is emitted without additional format string.
One consequence is that users may see more splats than intended. E.g. a
WARN splat emitted in a work item results in at least two extra splats:
BUG: workqueue leaked lock or atomic
(emitted by process_one_work())
BUG: scheduling while atomic
(emitted by worker_thread() -> schedule())
Ironically the point of the commit was to *avoid* extra splats. ;)
Fix it.
Fixes: 5a5d7e9bad ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/3ec48fde01e4ee6505f77908ba351bad200ae3d1.1694763684.git.lukas@wunner.de
In order to avoid WARN/BUG from generating nested or even recursive
warnings, force rcu_is_watching() true during
WARN/lockdep_rcu_suspicious().
Notably things like unwinding the stack can trigger rcu_dereference()
warnings, which then triggers more unwinding which then triggers more
warnings etc..
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230126151323.408156109@infradead.org
Pull kernel hardening fixes from Kees Cook:
- Fix CFI failure with KASAN (Sami Tolvanen)
- Fix LKDTM + CFI under GCC 7 and 8 (Kristina Martsenko)
- Limit CONFIG_ZERO_CALL_USED_REGS to Clang > 15.0.6 (Nathan
Chancellor)
- Ignore "contents" argument in LoadPin's LSM hook handling
- Fix paste-o in /sys/kernel/warn_count API docs
- Use READ_ONCE() consistently for oops/warn limit reading
* tag 'hardening-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
cfi: Fix CFI failure with KASAN
exit: Use READ_ONCE() for all oops/warn limit reads
security: Restrict CONFIG_ZERO_CALL_USED_REGS to gcc or clang > 15.0.6
lkdtm: cfi: Make PAC test work with GCC 7 and 8
docs: Fix path paste-o for /sys/kernel/warn_count
LoadPin: Ignore the "contents" argument of the LSM hooks
Pull kernel hardening updates from Kees Cook:
- Convert flexible array members, fix -Wstringop-overflow warnings, and
fix KCFI function type mismatches that went ignored by maintainers
(Gustavo A. R. Silva, Nathan Chancellor, Kees Cook)
- Remove the remaining side-effect users of ksize() by converting
dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add
more __alloc_size attributes, and introduce full testing of all
allocator functions. Finally remove the ksize() side-effect so that
each allocation-aware checker can finally behave without exceptions
- Introduce oops_limit (default 10,000) and warn_limit (default off) to
provide greater granularity of control for panic_on_oops and
panic_on_warn (Jann Horn, Kees Cook)
- Introduce overflows_type() and castable_to_type() helpers for cleaner
overflow checking
- Improve code generation for strscpy() and update str*() kern-doc
- Convert strscpy and sigphash tests to KUnit, and expand memcpy tests
- Always use a non-NULL argument for prepare_kernel_cred()
- Disable structleak plugin in FORTIFY KUnit test (Anders Roxell)
- Adjust orphan linker section checking to respect CONFIG_WERROR (Xin
Li)
- Make sure siginfo is cleared for forced SIGKILL (haifeng.xu)
- Fix um vs FORTIFY warnings for always-NULL arguments
* tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits)
ksmbd: replace one-element arrays with flexible-array members
hpet: Replace one-element array with flexible-array member
um: virt-pci: Avoid GCC non-NULL warning
signal: Initialize the info in ksignal
lib: fortify_kunit: build without structleak plugin
panic: Expose "warn_count" to sysfs
panic: Introduce warn_limit
panic: Consolidate open-coded panic_on_warn checks
exit: Allow oops_limit to be disabled
exit: Expose "oops_count" to sysfs
exit: Put an upper limit on how often we can oops
panic: Separate sysctl logic from CONFIG_SMP
mm/pgtable: Fix multiple -Wstringop-overflow warnings
mm: Make ksize() a reporting-only function
kunit/fortify: Validate __alloc_size attribute results
drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid()
drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid()
driver core: Add __alloc_size hint to devm allocators
overflow: Introduce overflows_type() and castable_to_type()
coredump: Proactively round up to kmalloc bucket size
...
console_unblank() does this too (called in both places right after),
and with a lot more confidence inspiring approach to locking.
Reconstructing this story is very strange:
In b61312d353 ("oops handling: ensure that any oops is flushed to
the mtdoops console") it is claimed that a printk(" "); flushed out
the console buffer, which was removed in e3e8a75d2a ("[PATCH]
Extract and use wake_up_klogd()"). In todays kernels this is done way
earlier in console_flush_on_panic with some really nasty tricks. I
didn't bother to fully reconstruct this all, least because the call to
bust_spinlock(0); gets moved every few years, depending upon how the
wind blows (or well, who screamed loudest about the various issue each
call site caused).
Before that commit the only calls to console_unblank() where in s390
arch code.
The other side here is the console->unblank callback, which was
introduced in 2.1.31 for the vt driver. Which predates the
console_unblank() function by a lot, which was added (without users)
in 2.4.14.3. So pretty much impossible to guess at any motivation
here. Also afaict the vt driver is the only (and always was the only)
console driver implementing the unblank callback, so no idea why a
call to console_unblank() was added for the mtdooops driver - the
action actually flushing out the console buffers is done from
console_unlock() only.
Note that as prep for the s390 users the locking was adjusted in
2.5.22 (I couldn't figure out how to properly reference the BK commit
from the historical git trees) from a normal semaphore to a trylock.
Note that a copy of the direct unblank_screen() call was added to
panic() in c7c3f05e34 ("panic: avoid deadlocks in re-entrant console
drivers"), which partially inlined the bust_spinlocks(0); call.
Long story short, I have no idea why the direct call to unblank_screen
survived for so long (the infrastructure to do it properly existed for
years), nor why it wasn't removed when the console_unblank() call was
finally added. But it makes a ton more sense to finally do that than
not - it's just better encapsulation to go through the console
functions instead of doing a direct call, so let's dare. Plus it
really does not make much sense to call the only unblank
implementation there is twice, once without, and once with appropriate
locking.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
Cc: Yangxi Xiang <xyangxi5@gmail.com>
Cc: nick black <dankamongmen@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Marco Elver <elver@google.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: David Gow <davidgow@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20220830145004.430545-1-daniel.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull KUnit updates from Shuah Khan:
"This consists of several fixes and an important feature to discourage
running KUnit tests on production systems. Running tests on a
production system could leave the system in a bad state.
Summary:
- Add a new taint type, TAINT_TEST to signal that a test has been
run.
This should discourage people from running these tests on
production systems, and to make it easier to tell if tests have
been run accidentally (by loading the wrong configuration, etc)
- Several documentation and tool enhancements and fixes"
* tag 'linux-kselftest-kunit-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
Documentation: KUnit: Fix example with compilation error
Documentation: kunit: Add CLI args for kunit_tool
kcsan: test: Add a .kunitconfig to run KCSAN tests
kunit: executor: Fix a memory leak on failure in kunit_filter_tests
clk: explicitly disable CONFIG_UML_PCI_OVER_VIRTIO in .kunitconfig
mmc: sdhci-of-aspeed: test: Use kunit_test_suite() macro
nitro_enclaves: test: Use kunit_test_suite() macro
thunderbolt: test: Use kunit_test_suite() macro
kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suites
kunit: unify module and builtin suite definitions
selftest: Taint kernel when test module loaded
module: panic: Taint the kernel when selftest modules load
Documentation: kunit: fix example run_kunit func to allow spaces in args
Documentation: kunit: Cleanup run_wrapper, fix x-ref
kunit: test.h: fix a kernel-doc markup
kunit: tool: Enable virtio/PCI by default on UML
kunit: tool: make --kunitconfig repeatable, blindly concat
kunit: add coverage_uml.config to enable GCOV on UML
kunit: tool: refactor internal kconfig handling, allow overriding
kunit: tool: introduce --qemu_args
...
Most in-kernel tests (such as KUnit tests) are not supposed to run on
production systems: they may do deliberately illegal things to trigger
errors, and have security implications (for example, KUnit assertions
will often deliberately leak kernel addresses).
Add a new taint type, TAINT_TEST to signal that a test has been run.
This will be printed as 'N' (originally for kuNit, as every other
sensible letter was taken.)
This should discourage people from running these tests on production
systems, and to make it easier to tell if tests have been run
accidentally (by loading the wrong configuration, etc.)
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
