The __user attribute is currently mainly used by sparse for type checking.
The attribute indicates whether a memory access is in user memory address
space or not. Such information is important during tracing kernel
internal functions or data structures as accessing user memory often
has different mechanisms compared to accessing kernel memory. For example,
the perf-probe needs explicit command line specification to indicate a
particular argument or string in user-space memory ([1], [2], [3]).
Currently, vmlinux BTF is available in kernel with many distributions.
If __user attribute information is available in vmlinux BTF, the explicit
user memory access information from users will not be necessary as
the kernel can figure it out by itself with vmlinux BTF.
Besides the above possible use for perf/probe, another use case is
for bpf verifier. Currently, for bpf BPF_PROG_TYPE_TRACING type of bpf
programs, users can write direct code like
p->m1->m2
and "p" could be a function parameter. Without __user information in BTF,
the verifier will assume p->m1 accessing kernel memory and will generate
normal loads. Let us say "p" actually tagged with __user in the source
code. In such cases, p->m1 is actually accessing user memory and direct
load is not right and may produce incorrect result. For such cases,
bpf_probe_read_user() will be the correct way to read p->m1.
To support encoding __user information in BTF, a new attribute
__attribute__((btf_type_tag("<arbitrary_string>")))
is implemented in clang ([4]). For example, if we have
#define __user __attribute__((btf_type_tag("user")))
during kernel compilation, the attribute "user" information will
be preserved in dwarf. After pahole converting dwarf to BTF, __user
information will be available in vmlinux BTF.
The following is an example with latest upstream clang (clang14) and
pahole 1.23:
[$ ~] cat test.c
#define __user __attribute__((btf_type_tag("user")))
int foo(int __user *arg) {
return *arg;
}
[$ ~] clang -O2 -g -c test.c
[$ ~] pahole -JV test.o
...
[1] INT int size=4 nr_bits=32 encoding=SIGNED
[2] TYPE_TAG user type_id=1
[3] PTR (anon) type_id=2
[4] FUNC_PROTO (anon) return=1 args=(3 arg)
[5] FUNC foo type_id=4
[$ ~]
You can see for the function argument "int __user *arg", its type is
described as
PTR -> TYPE_TAG(user) -> INT
The kernel can use this information for bpf verification or other
use cases.
Current btf_type_tag is only supported in clang (>= clang14) and
pahole (>= 1.23). gcc support is also proposed and under development ([5]).
[1] http://lkml.kernel.org/r/155789874562.26965.10836126971405890891.stgit@devnote2
[2] http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2
[3] http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2
[4] https://reviews.llvm.org/D111199
[5] https://lore.kernel.org/bpf/0cbeb2fb-1a18-f690-e360-24b1c90c2a91@fb.com/
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220127154600.652613-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Merge more updates from Andrew Morton:
"55 patches.
Subsystems affected by this patch series: percpu, procfs, sysctl,
misc, core-kernel, get_maintainer, lib, checkpatch, binfmt, nilfs2,
hfs, fat, adfs, panic, delayacct, kconfig, kcov, and ubsan"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (55 commits)
lib: remove redundant assignment to variable ret
ubsan: remove CONFIG_UBSAN_OBJECT_SIZE
kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR
lib/Kconfig.debug: make TEST_KMOD depend on PAGE_SIZE_LESS_THAN_256KB
btrfs: use generic Kconfig option for 256kB page size limit
arch/Kconfig: split PAGE_SIZE_LESS_THAN_256KB from PAGE_SIZE_LESS_THAN_64KB
configs: introduce debug.config for CI-like setup
delayacct: track delays from memory compact
Documentation/accounting/delay-accounting.rst: add thrashing page cache and direct compact
delayacct: cleanup flags in struct task_delay_info and functions use it
delayacct: fix incomplete disable operation when switch enable to disable
delayacct: support swapin delay accounting for swapping without blkio
panic: remove oops_id
panic: use error_report_end tracepoint on warnings
fs/adfs: remove unneeded variable make code cleaner
FAT: use io_schedule_timeout() instead of congestion_wait()
hfsplus: use struct_group_attr() for memcpy() region
nilfs2: remove redundant pointer sbufs
fs/binfmt_elf: use PT_LOAD p_align values for static PIE
const_structs.checkpatch: add frequently used ops structs
...
Until recent versions of GCC and Clang, it was not possible to disable
KCOV instrumentation via a function attribute. The relevant function
attribute was introduced in 540540d06e ("kcov: add
__no_sanitize_coverage to fix noinstr for all architectures").
x86 was the first architecture to want a working noinstr, and at the
time no compiler support for the attribute existed yet. Therefore,
commit 0f1441b44e ("objtool: Fix noinstr vs KCOV") introduced the
ability to NOP __sanitizer_cov_*() calls in .noinstr.text.
However, this doesn't work for other architectures like arm64 and s390
that want a working noinstr per ARCH_WANTS_NO_INSTR.
At the time of 0f1441b44e, we didn't yet have ARCH_WANTS_NO_INSTR,
but now we can move the Kconfig dependency checks to the generic KCOV
option. KCOV will be available if:
- architecture does not care about noinstr, OR
- we have objtool support (like on x86), OR
- GCC is 12.0 or newer, OR
- Clang is 13.0 or newer.
Link: https://lkml.kernel.org/r/20211201152604.3984495-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit b05fbcc36b ("btrfs: disable build on platforms having page size
256K") disabled btrfs for configurations that used a 256kB page size.
However, it did not fully solve the problem because CONFIG_TEST_KMOD
selects CONFIG_BTRFS, which does not account for the dependency. This
results in a Kconfig warning and the failed BUILD_BUG_ON error
returning.
WARNING: unmet direct dependencies detected for BTRFS_FS
Depends on [n]: BLOCK [=y] && !PPC_256K_PAGES && !PAGE_SIZE_256KB [=y]
Selected by [m]:
- TEST_KMOD [=m] && RUNTIME_TESTING_MENU [=y] && m && MODULES [=y] && NETDEVICES [=y] && NET_CORE [=y] && INET [=y] && BLOCK [=y]
To resolve this, add CONFIG_PAGE_SIZE_LESS_THAN_256KB as a dependency of
CONFIG_TEST_KMOD so there is no more invalid configuration or build
errors.
Link: https://lkml.kernel.org/r/20211129230141.228085-4-nathan@kernel.org
Fixes: b05fbcc36b ("btrfs: disable build on platforms having page size 256K")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Borkmann says:
====================
bpf 2021-12-08
We've added 12 non-merge commits during the last 22 day(s) which contain
a total of 29 files changed, 659 insertions(+), 80 deletions(-).
The main changes are:
1) Fix an off-by-two error in packet range markings and also add a batch of
new tests for coverage of these corner cases, from Maxim Mikityanskiy.
2) Fix a compilation issue on MIPS JIT for R10000 CPUs, from Johan Almbladh.
3) Fix two functional regressions and a build warning related to BTF kfunc
for modules, from Kumar Kartikeya Dwivedi.
4) Fix outdated code and docs regarding BPF's migrate_disable() use on non-
PREEMPT_RT kernels, from Sebastian Andrzej Siewior.
5) Add missing includes in order to be able to detangle cgroup vs bpf header
dependencies, from Jakub Kicinski.
6) Fix regression in BPF sockmap tests caused by missing detachment of progs
from sockets when they are removed from the map, from John Fastabend.
7) Fix a missing "no previous prototype" warning in x86 JIT caused by BPF
dispatcher, from Björn Töpel.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Add selftests to cover packet access corner cases
bpf: Fix the off-by-two error in range markings
treewide: Add missing includes masked by cgroup -> bpf dependency
tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets
bpf: Fix bpf_check_mod_kfunc_call for built-in modules
bpf: Make CONFIG_DEBUG_INFO_BTF depend upon CONFIG_BPF_SYSCALL
mips, bpf: Fix reference to non-existing Kconfig symbol
bpf: Make sure bpf_disable_instrumentation() is safe vs preemption.
Documentation/locking/locktypes: Update migrate_disable() bits.
bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap
bpf, sockmap: Attach map progs to psock early for feature probes
bpf, x86: Fix "no previous prototype" warning
====================
Link: https://lore.kernel.org/r/20211208155125.11826-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net device are refcounted. Over the years we had numerous bugs
caused by imbalanced dev_hold() and dev_put() calls.
The general idea is to be able to precisely pair each decrement with
a corresponding prior increment. Both share a cookie, basically
a pointer to private data storing stack traces.
This patch adds dev_hold_track() and dev_put_track().
To use these helpers, each data structure owning a refcount
should also use a "netdevice_tracker" to pair the hold and put.
netdevice_tracker dev_tracker;
...
dev_hold_track(dev, &dev_tracker, GFP_ATOMIC);
...
dev_put_track(dev, &dev_tracker);
Whenever a leak happens, we will get precise stack traces
of the point dev_hold_track() happened, at device dismantle phase.
We will also get a stack trace if too many dev_put_track() for the same
netdevice_tracker are attempted.
This is guarded by CONFIG_NET_DEV_REFCNT_TRACKER option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vinicius Costa Gomes reported [0] that build fails when
CONFIG_DEBUG_INFO_BTF is enabled and CONFIG_BPF_SYSCALL is disabled.
This leads to btf.c not being compiled, and then no symbol being present
in vmlinux for the declarations in btf.h. Since BTF is not useful
without enabling BPF subsystem, disallow this combination.
However, theoretically disabling both now could still fail, as the
symbol for kfunc_btf_id_list variables is not available. This isn't a
problem as the compiler usually optimizes the whole register/unregister
call, but at lower optimization levels it can fail the build in linking
stage.
Fix that by adding dummy variables so that modules taking address of
them still work, but the whole thing is a noop.
[0]: https://lore.kernel.org/bpf/20211110205418.332403-1-vinicius.gomes@intel.com
Fixes: 14f267d95f ("bpf: btf: Introduce helpers for dynamic BTF set registration")
Reported-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211122144742.477787-2-memxor@gmail.com
PA-RISC uses a much bigger frame size for functions than other
architectures. So increase it to 2048 for 32- and 64-bit kernels.
This fixes e.g. a warning in lib/xxhash.c.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Merge misc updates from Andrew Morton:
"257 patches.
Subsystems affected by this patch series: scripts, ocfs2, vfs, and
mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
cleanups, kfence, and damon)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
mm/damon: remove return value from before_terminate callback
mm/damon: fix a few spelling mistakes in comments and a pr_debug message
mm/damon: simplify stop mechanism
Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
Docs/admin-guide/mm/damon/start: simplify the content
Docs/admin-guide/mm/damon/start: fix a wrong link
Docs/admin-guide/mm/damon/start: fix wrong example commands
mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
mm/damon: remove unnecessary variable initialization
Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
selftests/damon: support watermarks
mm/damon/dbgfs: support watermarks
mm/damon/schemes: activate schemes based on a watermarks mechanism
tools/selftests/damon: update for regions prioritization of schemes
mm/damon/dbgfs: support prioritization weights
mm/damon/vaddr,paddr: support pageout prioritization
mm/damon/schemes: prioritize regions within the quotas
mm/damon/selftests: support schemes quotas
mm/damon/dbgfs: support quotas of schemes
...
Pull tracing updates from Steven Rostedt:
- kprobes: Restructured stack unwinder to show properly on x86 when a
stack dump happens from a kretprobe callback.
- Fix to bootconfig parsing
- Have tracefs allow owner and group permissions by default (only
denying others). There's been pressure to allow non root to tracefs
in a controlled fashion, and using groups is probably the safest.
- Bootconfig memory managament updates.
- Bootconfig clean up to have the tools directory be less dependent on
changes in the kernel tree.
- Allow perf to be traced by function tracer.
- Rewrite of function graph tracer to be a callback from the function
tracer instead of having its own trampoline (this change will happen
on an arch by arch basis, and currently only x86_64 implements it).
- Allow multiple direct trampolines (bpf hooks to functions) be batched
together in one synchronization.
- Allow histogram triggers to add variables that can perform
calculations against the event's fields.
- Use the linker to determine architecture callbacks from the ftrace
trampoline to allow for proper parameter prototypes and prevent
warnings from the compiler.
- Extend histogram triggers to key off of variables.
- Have trace recursion use bit magic to determine preempt context over
if branches.
- Have trace recursion disable preemption as all use cases do anyway.
- Added testing for verification of tracing utilities.
- Various small clean ups and fixes.
* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
tracing/histogram: Fix semicolon.cocci warnings
tracing/histogram: Fix documentation inline emphasis warning
tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
tracing: Show size of requested perf buffer
bootconfig: Initialize ret in xbc_parse_tree()
ftrace: do CPU checking after preemption disabled
ftrace: disable preemption when recursion locked
tracing/histogram: Document expression arithmetic and constants
tracing/histogram: Optimize division by a power of 2
tracing/histogram: Covert expr to const if both operands are constants
tracing/histogram: Simplify handling of .sym-offset in expressions
tracing: Fix operator precedence for hist triggers expression
tracing: Add division and multiplication support for hist triggers
tracing: Add support for creating hist trigger variables from literal
selftests/ftrace: Stop tracing while reading the trace file by default
MAINTAINERS: Update KPROBES and TRACING entries
test_kprobes: Move it from kernel/ to lib/
docs, kprobes: Remove invalid URL and add new reference
samples/kretprobes: Fix return value if register_kretprobe() failed
lib/bootconfig: Fix the xbc_get_info kerneldoc
...
Pull overflow updates from Kees Cook:
"The end goal of the current buffer overflow detection work[0] is to
gain full compile-time and run-time coverage of all detectable buffer
overflows seen via array indexing or memcpy(), memmove(), and
memset(). The str*() family of functions already have full coverage.
While much of the work for these changes have been on-going for many
releases (i.e. 0-element and 1-element array replacements, as well as
avoiding false positives and fixing discovered overflows[1]), this
series contains the foundational elements of several related buffer
overflow detection improvements by providing new common helpers and
FORTIFY_SOURCE changes needed to gain the introspection required for
compiler visibility into array sizes. Also included are a handful of
already Acked instances using the helpers (or related clean-ups), with
many more waiting at the ready to be taken via subsystem-specific
trees[2].
The new helpers are:
- struct_group() for gaining struct member range introspection
- memset_after() and memset_startat() for clearing to the end of
structures
- DECLARE_FLEX_ARRAY() for using flex arrays in unions or alone in
structs
Also included is the beginning of the refactoring of FORTIFY_SOURCE to
support memcpy() introspection, fix missing and regressed coverage
under GCC, and to prepare to fix the currently broken Clang support.
Finishing this work is part of the larger series[0], but depends on
all the false positives and buffer overflow bug fixes to have landed
already and those that depend on this series to land.
As part of the FORTIFY_SOURCE refactoring, a set of both a
compile-time and run-time tests are added for FORTIFY_SOURCE and the
mem*()-family functions respectively. The compile time tests have
found a legitimate (though corner-case) bug[6] already.
Please note that the appearance of "panic" and "BUG" in the
FORTIFY_SOURCE refactoring are the result of relocating existing code,
and no new use of those code-paths are expected nor desired.
Finally, there are two tree-wide conversions for 0-element arrays and
flexible array unions to gain sane compiler introspection coverage
that result in no known object code differences.
After this series (and the changes that have now landed via netdev and
usb), we are very close to finally being able to build with
-Warray-bounds and -Wzero-length-bounds.
However, due corner cases in GCC[3] and Clang[4], I have not included
the last two patches that turn on these options, as I don't want to
introduce any known warnings to the build. Hopefully these can be
solved soon"
Link: https://lore.kernel.org/lkml/20210818060533.3569517-1-keescook@chromium.org/ [0]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=FORTIFY_SOURCE [1]
Link: https://lore.kernel.org/lkml/202108220107.3E26FE6C9C@keescook/ [2]
Link: https://lore.kernel.org/lkml/3ab153ec-2798-da4c-f7b1-81b0ac8b0c5b@roeck-us.net/ [3]
Link: https://bugs.llvm.org/show_bug.cgi?id=51682 [4]
Link: https://lore.kernel.org/lkml/202109051257.29B29745C0@keescook/ [5]
Link: https://lore.kernel.org/lkml/20211020200039.170424-1-keescook@chromium.org/ [6]
* tag 'overflow-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (30 commits)
fortify: strlen: Avoid shadowing previous locals
compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer
treewide: Replace 0-element memcpy() destinations with flexible arrays
treewide: Replace open-coded flex arrays in unions
stddef: Introduce DECLARE_FLEX_ARRAY() helper
btrfs: Use memset_startat() to clear end of struct
string.h: Introduce memset_startat() for wiping trailing members and padding
xfrm: Use memset_after() to clear padding
string.h: Introduce memset_after() for wiping trailing members/padding
lib: Introduce CONFIG_MEMCPY_KUNIT_TEST
fortify: Add compile-time FORTIFY_SOURCE tests
fortify: Allow strlen() and strnlen() to pass compile-time known lengths
fortify: Prepare to improve strnlen() and strlen() warnings
fortify: Fix dropped strcpy() compile-time write overflow check
fortify: Explicitly disable Clang support
fortify: Move remaining fortify helpers into fortify-string.h
lib/string: Move helper functions out of string.c
compiler_types.h: Remove __compiletime_object_size()
cm4000_cs: Use struct_group() to zero struct cm4000_dev region
can: flexcan: Use struct_group() to zero struct flexcan_regs regions
...
This converts the kprobes testcases to use the kunit framework.
It adds a dependency on CONFIG_KUNIT, and the output will change
to TAP:
TAP version 14
1..1
# Subtest: kprobes_test
1..4
random: crng init done
ok 1 - test_kprobe
ok 2 - test_kprobes
ok 3 - test_kretprobe
ok 4 - test_kretprobes
ok 1 - kprobes_test
Note that the kprobes testcases are no longer run immediately after
kprobes initialization, but as a late initcall when kunit is
initialized. kprobes itself is initialized with an early initcall,
so the order is still correct.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Before changing anything about memcpy(), memmove(), and memset(), add
run-time tests to check basic behaviors for any regressions.
Signed-off-by: Kees Cook <keescook@chromium.org>
Normally objtool will now follow indirect calls; there is no need.
However, this becomes a problem with noinstr validation; if there's an
indirect call from noinstr code, we very much need to know it is to
another noinstr function. Luckily there aren't many indirect calls in
entry code with the obvious exception of paravirt. As such, noinstr
validation didn't work with paravirt kernels.
In order to track pv_ops[] call targets, objtool reads the static
pv_ops[] tables as well as direct assignments to the pv_ops[] array,
provided the compiler makes them a single instruction like:
bf87: 48 c7 05 00 00 00 00 00 00 00 00 movq $0x0,0x0(%rip)
bf92 <xen_init_spinlocks+0x5f>
bf8a: R_X86_64_PC32 pv_ops+0x268
There are, as of yet, no warnings for when this goes wrong :/
Using the functions found with the above means, all pv_ops[] calls are
now subject to noinstr validation.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095149.118815755@infradead.org
Merge more updates from Andrew Morton:
"147 patches, based on 7d2a07b769.
Subsystems affected by this patch series: mm (memory-hotplug, rmap,
ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
selftests, ipc, and scripts"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
scripts: check_extable: fix typo in user error message
mm/workingset: correct kernel-doc notations
ipc: replace costly bailout check in sysvipc_find_ipc()
selftests/memfd: remove unused variable
Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
configs: remove the obsolete CONFIG_INPUT_POLLDEV
prctl: allow to setup brk for et_dyn executables
pid: cleanup the stale comment mentioning pidmap_init().
kernel/fork.c: unexport get_{mm,task}_exe_file
coredump: fix memleak in dump_vma_snapshot()
fs/coredump.c: log if a core dump is aborted due to changed file permissions
nilfs2: use refcount_dec_and_lock() to fix potential UAF
nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
nilfs2: fix NULL pointer in nilfs_##name##_attr_release
nilfs2: fix memory leak in nilfs_sysfs_create_device_group
trap: cleanup trap_init()
init: move usermodehelper_enable() to populate_rootfs()
...
This follows up commit ebd09577be ("lib/test: convert
lib/test_list_sort.c to use KUnit").
Converting this test to KUnit makes the test a bit shorter, standardizes
how it reports pass/fail, and adds an easier way to run the test [1].
Like ebd09577be, this leaves the file and Kconfig option name the same,
but slightly changes their dependencies (needs CONFIG_KUNIT).
[1] Can be run via
$ ./tools/testing/kunit/kunit.py run --kunitconfig /dev/stdin <<EOF
CONFIG_KUNIT=y
CONFIG_TEST_SORT=y
EOF
[11:30:27] Starting KUnit Kernel ...
[11:30:30] ============================================================
[11:30:30] ======== [PASSED] lib_sort ========
[11:30:30] [PASSED] test_sort
[11:30:30] ============================================================
[11:30:30] Testing complete. 1 tests run. 0 failed. 0 crashed. 0 skipped.
[11:30:30] Elapsed time: 37.032s total, 0.001s configuring, 34.090s building, 0.000s running
Note: this is the time it took after a `make mrproper`.
With an incremental rebuild, this looks more like:
[11:38:58] Elapsed time: 6.444s total, 0.001s configuring, 3.416s building, 0.000s running
Since the test has no dependencies, it can also be run (with some other
tests) with just:
$ ./tools/testing/kunit/kunit.py run
Link: https://lkml.kernel.org/r/20210715232441.1380885-1-dlatypov@google.com
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Cc: Pravin Shedge <pravin.shedge4linux@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull Kbuild updates from Masahiro Yamada:
- Add -s option (strict mode) to merge_config.sh to make it fail when
any symbol is redefined.
- Show a warning if a different compiler is used for building external
modules.
- Infer --target from ARCH for CC=clang to let you cross-compile the
kernel without CROSS_COMPILE.
- Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
- Add <linux/stdarg.h> to the kernel source instead of borrowing
<stdarg.h> from the compiler.
- Add Nick Desaulniers as a Kbuild reviewer.
- Drop stale cc-option tests.
- Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
to handle symbols in inline assembly.
- Show a warning if 'FORCE' is missing for if_changed rules.
- Various cleanups
* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
kbuild: redo fake deps at include/ksym/*.h
kbuild: clean up objtool_args slightly
modpost: get the *.mod file path more simply
checkkconfigsymbols.py: Fix the '--ignore' option
kbuild: merge vmlinux_link() between ARCH=um and other architectures
kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
kbuild: remove stale *.symversions
kbuild: remove unused quiet_cmd_update_lto_symversions
gen_compile_commands: extract compiler command from a series of commands
x86: remove cc-option-yn test for -mtune=
arc: replace cc-option-yn uses with cc-option
s390: replace cc-option-yn uses with cc-option
ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
sparc: move the install rule to arch/sparc/Makefile
security: remove unneeded subdir-$(CONFIG_...)
kbuild: sh: remove unused install script
kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
kbuild: Switch to 'f' variants of integrated assembler flag
kbuild: Shuffle blank line to improve comment meaning
...
cc-option, cc-option-yn, and cc-disable-warning all invoke the compiler
during build time, and can slow down the build when these checks become
stale for our supported compilers, whose minimally supported versions
increases over time. See Documentation/process/changes.rst for the
current supported minimal versions (GCC 4.9+, clang 10.0.1+). Compiler
version support for these flags may be verified on godbolt.org.
The following flags are GCC only and supported since at least GCC 4.9.
Remove cc-option and cc-disable-warning tests.
* -fno-tree-loop-im
* -Wno-maybe-uninitialized
* -fno-reorder-blocks
* -fno-ipa-cp-clone
* -fno-partial-inlining
* -femit-struct-debug-baseonly
* -fno-inline-functions-called-once
* -fconserve-stack
The following flags are supported by all supported versions of GCC and
Clang. Remove their cc-option, cc-option-yn, and cc-disable-warning tests.
* -fno-delete-null-pointer-checks
* -fno-var-tracking
* -Wno-array-bounds
The following configs are made dependent on GCC, since they use GCC
specific flags.
* READABLE_ASM
* DEBUG_SECTION_MISMATCH
-mfentry was not supported by s390-linux-gnu-gcc until gcc-9+, add a
comment.
--param=allow-store-data-races=0 was renamed to -fno-allow-store-data-races
in the GCC 10 release; add a comment.
-Wmaybe-uninitialized (GCC specific) was being added for CONFIG_GCOV,
then again unconditionally; add it only once.
Also, base RETPOLINE_CFLAGS and RETPOLINE_VDSO_CFLAGS on CONFIC_CC_IS_*
then remove cc-option tests for Clang.
Link: https://github.com/ClangBuiltLinux/linux/issues/1436
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull parisc architecture updates from Helge Deller:
- Fix a kernel crash when a signal is delivered to bad userspace stack
- Fix fall-through warnings in math-emu code
- Increase size of gcc stack frame check
- Switch coding from 'pci_' to 'dma_' API
- Make struct parisc_driver::remove() return void
- Some parisc related Makefile changes
- Minor cleanups, e.g. change to octal permissions, fix macro
collisions, fix PMD_ORDER collision, replace spaces with tabs
* tag 'for-5.15/parisc' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: math-emu: Fix fall-through warnings
parisc: fix crash with signals and alloca
parisc: Fix compile failure when building 64-bit kernel natively
parisc: ccio-dma.c: Added tab instead of spaces
parisc/parport_gsc: switch from 'pci_' to 'dma_' API
parisc: move core-y in arch/parisc/Makefile to arch/parisc/Kbuild
parisc: switch from 'pci_' to 'dma_' API
parisc: Make struct parisc_driver::remove() return void
parisc: remove unused arch/parisc/boot/install.sh and its phony target
parisc: Rename PMD_ORDER to PMD_TABLE_ORDER
parisc: math-emu: Avoid "fmt" macro collision
parisc: Increase size of gcc stack frame check
parisc: Replace symbolic permissions with octal permissions
Pull nfsd updates from Chuck Lever:
"New features:
- Support for server-side disconnect injection via debugfs
- Protocol definitions for new RPC_AUTH_TLS authentication flavor
Performance improvements:
- Reduce page allocator traffic in the NFSD splice read actor
- Reduce CPU utilization in svcrdma's Send completion handler
Notable bug fixes:
- Stabilize lockd operation when re-exporting NFS mounts
- Fix the use of %.*s in NFSD tracepoints
- Fix /proc/sys/fs/nfs/nsm_use_hostnames"
* tag 'nfsd-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (31 commits)
nfsd: fix crash on LOCKT on reexported NFSv3
nfs: don't allow reexport reclaims
lockd: don't attempt blocking locks on nfs reexports
nfs: don't atempt blocking locks on nfs reexports
Keep read and write fds with each nlm_file
lockd: update nlm_lookup_file reexport comment
nlm: minor refactoring
nlm: minor nlm_lookup_file argument change
lockd: lockd server-side shouldn't set fl_ops
SUNRPC: Add documentation for the fail_sunrpc/ directory
SUNRPC: Server-side disconnect injection
SUNRPC: Move client-side disconnect injection
SUNRPC: Add a /sys/kernel/debug/fail_sunrpc/ directory
svcrdma: xpt_bc_xprt is already clear in __svc_rdma_free()
nfsd4: Fix forced-expiry locking
rpc: fix gss_svc_init cleanup on failure
SUNRPC: Add RPC_AUTH_TLS protocol numbers
lockd: change the proc_handler for nsm_use_hostnames
sysctl: introduce new proc handler proc_dobool
SUNRPC: Fix a NULL pointer deref in trace_svc_stats_latency()
...
parisc uses much bigger frames than other architectures, so increase the
stack frame check value to avoid compiler warnings.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Helge Deller <deller@gmx.de>
This directory will contain a set of administrative controls for
enabling error injection for kernel RPC consumers.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
STRING_SELFTEST is presented in the "Library routines" menu. Move it in
Kernel hacking > Kernel Testing and Coverage > Runtime Testing together
with other similar tests found in lib/
--- Runtime Testing
<*> Test functions located in the hexdump module at runtime
<*> Test string functions (NEW)
<*> Test functions located in the string_helpers module at runtime
<*> Test strscpy*() family of functions at runtime
<*> Test kstrto*() family of functions at runtime
<*> Test printf() family of functions at runtime
<*> Test scanf() family of functions at runtime
Link: https://lkml.kernel.org/r/20210719185158.190371-1-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit dbbee9d5cd ("mm/page_alloc: convert per-cpu list protection to
local_lock") folded in a workaround patch for pahole that was unable to
deal with zero-sized percpu structures.
A superior workaround is achieved with commit a0b8200d06 ("kbuild:
skip per-CPU BTF generation for pahole v1.18-v1.21").
This patch reverts the dummy field and the pahole version check.
Fixes: dbbee9d5cd ("mm/page_alloc: convert per-cpu list protection to local_lock")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull Kbuild updates from Masahiro Yamada:
- Increase the -falign-functions alignment for the debug option.
- Remove ugly libelf checks from the top Makefile.
- Make the silent build (-s) more silent.
- Re-compile the kernel if KBUILD_BUILD_TIMESTAMP is specified.
- Various script cleanups
* tag 'kbuild-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (27 commits)
scripts: add generic syscallnr.sh
scripts: check duplicated syscall number in syscall table
sparc: syscalls: use pattern rules to generate syscall headers
parisc: syscalls: use pattern rules to generate syscall headers
nds32: add arch/nds32/boot/.gitignore
kbuild: mkcompile_h: consider timestamp if KBUILD_BUILD_TIMESTAMP is set
kbuild: modpost: Explicitly warn about unprototyped symbols
kbuild: remove trailing slashes from $(KBUILD_EXTMOD)
kconfig.h: explain IS_MODULE(), IS_ENABLED()
kconfig: constify long_opts
scripts/setlocalversion: simplify the short version part
scripts/setlocalversion: factor out 12-chars hash construction
scripts/setlocalversion: add more comments to -dirty flag detection
scripts/setlocalversion: remove workaround for old make-kpkg
scripts/setlocalversion: remove mercurial, svn and git-svn supports
kbuild: clean up ${quiet} checks in shell scripts
kbuild: sink stdout from cmd for silent build
init: use $(call cmd,) for generating include/generated/compile.h
kbuild: merge scripts/mkmakefile to top Makefile
sh: move core-y in arch/sh/Makefile to arch/sh/Kbuild
...
Add the running kernel's build ID[1] to the stacktrace information header.
This makes it simpler for developers to locate the vmlinux with full
debuginfo for a particular kernel stacktrace. Combined with
scripts/decode_stracktrace.sh, a developer can download the correct
vmlinux from a debuginfod[2] server and find the exact file and line
number for the functions plus offsets in a stacktrace.
This is especially useful for pstore crash debugging where the kernel
crashes are recorded in the pstore logs and the recovery kernel is
different or the debuginfo doesn't exist on the device due to space
concerns (the data can be large and a security concern). The stacktrace
can be analyzed after the crash by using the build ID to find the matching
vmlinux and understand where in the function something went wrong.
Example stacktrace from lkdtm:
WARNING: CPU: 4 PID: 3255 at drivers/misc/lkdtm/bugs.c:83 lkdtm_WARNING+0x28/0x30 [lkdtm]
Modules linked in: lkdtm rfcomm algif_hash algif_skcipher af_alg xt_cgroup uinput xt_MASQUERADE
CPU: 4 PID: 3255 Comm: bash Not tainted 5.11 #3 aa23f7a1231c229de205662d5a9e0d4c580f19a1
Hardware name: Google Lazor (rev3+) with KB Backlight (DT)
pstate: 00400009 (nzcv daif +PAN -UAO -TCO BTYPE=--)
pc : lkdtm_WARNING+0x28/0x30 [lkdtm]
The hex string aa23f7a1231c229de205662d5a9e0d4c580f19a1 is the build ID,
following the kernel version number. Put it all behind a config option,
STACKTRACE_BUILD_ID, so that kernel developers can remove this
information if they decide it is too much.
Link: https://lkml.kernel.org/r/20210511003845.2429846-5-swboyd@chromium.org
Link: https://fedoraproject.org/wiki/Releases/FeatureBuildId [1]
Link: https://sourceware.org/elfutils/Debuginfod.html [2]
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Evan Green <evgreen@chromium.org>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull KUnit update from Shuah Khan:
"Fixes and features:
- add support for skipped tests
- introduce kunit_kmalloc_array/kunit_kcalloc() helpers
- add gnu_printf specifiers
- add kunit_shutdown
- add unit test for filtering suites by names
- convert lib/test_list_sort.c to use KUnit
- code organization moving default config to tools/testing/kunit
- refactor of internal parser input handling
- cleanups and updates to documentation
- code cleanup related to casts"
* tag 'linux-kselftest-kunit-fixes-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
kunit: add unit test for filtering suites by names
kasan: test: make use of kunit_skip()
kunit: test: Add example tests which are always skipped
kunit: tool: Support skipped tests in kunit_tool
kunit: Support skipped tests
thunderbolt: test: Reinstate a few casts of bitfields
kunit: tool: internal refactor of parser input handling
lib/test: convert lib/test_list_sort.c to use KUnit
kunit: introduce kunit_kmalloc_array/kunit_kcalloc() helpers
kunit: Remove the unused all_tests.config
kunit: Move default config from arch/um -> tools/testing/kunit
kunit: arch/um/configs: Enable KUNIT_ALL_TESTS by default
kunit: Add gnu_printf specifiers
lib/cmdline_kunit: Remove a cast which are no-longer required
kernel/sysctl-test: Remove some casts which are no-longer required
thunderbolt: test: Remove some casts which are no longer required
mmc: sdhci-of-aspeed: Remove some unnecessary casts from KUnit tests
iio: Remove a cast in iio-test-format which is no longer required
device property: Remove some casts in property-entry-test
Documentation: kunit: Clean up some string casts in examples
...
Merge more updates from Andrew Morton:
"190 patches.
Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
signals, exec, kcov, selftests, compress/decompress, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
ipc/util.c: use binary search for max_idx
ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
ipc: use kmalloc for msg_queue and shmid_kernel
ipc sem: use kvmalloc for sem_undo allocation
lib/decompressors: remove set but not used variabled 'level'
selftests/vm/pkeys: exercise x86 XSAVE init state
selftests/vm/pkeys: refill shadow register after implicit kernel write
selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
kcov: add __no_sanitize_coverage to fix noinstr for all architectures
exec: remove checks in __register_bimfmt()
x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
hfsplus: report create_date to kstat.btime
hfsplus: remove unnecessary oom message
nilfs2: remove redundant continue statement in a while-loop
kprobes: remove duplicated strong free_insn_page in x86 and s390
init: print out unknown kernel parameters
checkpatch: do not complain about positive return values starting with EPOLL
checkpatch: improve the indented label test
checkpatch: scripts/spdxcheck.py now requires python3
...
Merge misc updates from Andrew Morton:
"191 patches.
Subsystems affected by this patch series: kthread, ia64, scripts,
ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
pagealloc, and memory-failure)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits)
mm,hwpoison: make get_hwpoison_page() call get_any_page()
mm,hwpoison: send SIGBUS with error virutal address
mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
docs: remove description of DISCONTIGMEM
arch, mm: remove stale mentions of DISCONIGMEM
mm: remove CONFIG_DISCONTIGMEM
m68k: remove support for DISCONTIGMEM
arc: remove support for DISCONTIGMEM
arc: update comment about HIGHMEM implementation
alpha: remove DISCONTIGMEM and NUMA
mm/page_alloc: move free_the_page
mm/page_alloc: fix counting of managed_pages
mm/page_alloc: improve memmap_pages dbg msg
mm: drop SECTION_SHIFT in code comments
mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
mm/page_alloc: scale the number of pages that are batch freed
...
Pull timer updates from Thomas Gleixner:
"Time and clocksource/clockevent related updates:
Core changes:
- Infrastructure to support per CPU "broadcast" devices for per CPU
clockevent devices which stop in deep idle states. This allows us
to utilize the more efficient architected timer on certain ARM SoCs
for normal operation instead of permanentely using the slow to
access SoC specific clockevent device.
- Print the name of the broadcast/wakeup device in /proc/timer_list
- Make the clocksource watchdog more robust against delays between
reading the current active clocksource and the watchdog
clocksource. Such delays can be caused by NMIs, SMIs and vCPU
preemption.
Handle this by reading the watchdog clocksource twice, i.e. before
and after reading the current active clocksource. In case that the
two watchdog reads shows an excessive time delta, the read sequence
is repeated up to 3 times.
- Improve the debug output and add a test module for the watchdog
mechanism.
- Reimplementation of the venerable time64_to_tm() function with a
faster and significantly smaller version. Straight from the source,
i.e. the author of the related research paper contributed this!
Driver changes:
- No new drivers, not even new device tree bindings!
- Fixes, improvements and cleanups and all over the place"
* tag 'timers-core-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
time/kunit: Add missing MODULE_LICENSE()
time: Improve performance of time64_to_tm()
clockevents: Use list_move() instead of list_del()/list_add()
clocksource: Print deviation in nanoseconds when a clocksource becomes unstable
clocksource: Provide kernel module to test clocksource watchdog
clocksource: Reduce clocksource-skew threshold
clocksource: Limit number of CPUs checked for clock synchronization
clocksource: Check per-CPU clock synchronization when marked unstable
clocksource: Retry clock read if long delays detected
clockevents: Add missing parameter documentation
clocksource/drivers/timer-ti-dm: Drop unnecessary restore
clocksource/arm_arch_timer: Improve Allwinner A64 timer workaround
clocksource/drivers/arm_global_timer: Remove duplicated argument in arm_global_timer
clocksource/drivers/arm_global_timer: Make symbol 'gt_clk_rate_change_nb' static
arm: zynq: don't disable CONFIG_ARM_GLOBAL_TIMER due to CONFIG_CPU_FREQ anymore
clocksource/drivers/arm_global_timer: Implement rate compensation whenever source clock changes
clocksource/drivers/ingenic: Rename unreasonable array names
clocksource/drivers/timer-ti-dm: Save and restore timer TIOCP_CFG
clocksource/drivers/mediatek: Ack and disable interrupts on suspend
clocksource/drivers/samsung_pwm: Constify source IO memory
...
Pull printk updates from Petr Mladek:
- Add %pt[RT]s modifier to vsprintf(). It overrides ISO 8601 separator
by using ' ' (space). It produces "YYYY-mm-dd HH:MM:SS" instead of
"YYYY-mm-ddTHH:MM:SS".
- Correctly parse long row of numbers by sscanf() when using the field
width. Add extensive sscanf() selftest.
- Generalize re-entrant CPU lock that has already been used to
serialize dump_stack() output. It is part of the ongoing printk
rework. It will allow to remove the obsoleted printk_safe buffers and
introduce atomic consoles.
- Some code clean up and sparse warning fixes.
* tag 'printk-for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: fix cpu lock ordering
lib/dump_stack: move cpu lock to printk.c
printk: Remove trailing semicolon in macros
random32: Fix implicit truncation warning in prandom_seed_state()
lib: test_scanf: Remove pointless use of type_min() with unsigned types
selftests: lib: Add wrapper script for test_scanf
lib: test_scanf: Add tests for sscanf number conversion
lib: vsprintf: Fix handling of number field widths in vsscanf
lib: vsprintf: scanf: Negative number must have field width > 1
usb: host: xhci-tegra: Switch to use %ptTs
nilfs2: Switch to use %ptTs
kdb: Switch to use %ptTs
lib/vsprintf: Allow to override ISO 8601 date and time separator
