linux.git/lib/Kconfig.debug, branch v6.1.92

bpf, kconfig: Fix DEBUG_INFO_BTF_MODULES Kconfig definition

2024-05-17T09:55:56+00:00

[ Upstream commit 229087f6f1dc2d0c38feba805770f28529980ec0 ]

Turns out that due to CONFIG_DEBUG_INFO_BTF_MODULES not having an
explicitly specified "menu item name" in Kconfig, it's basically
impossible to turn it off (see [0]).

This patch fixes the issue by defining menu name for
CONFIG_DEBUG_INFO_BTF_MODULES, which makes it actually adjustable
and independent of CONFIG_DEBUG_INFO_BTF, in the sense that one can
have DEBUG_INFO_BTF=y and DEBUG_INFO_BTF_MODULES=n.

We still keep it as defaulting to Y, of course.

Fixes: 5f9ae91f7c0d ("kbuild: Build kernel module BTFs if BTF is enabled and pahole supports it")
Reported-by: Vincent Li 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/CAK3+h2xiFfzQ9UXf56nrRRP=p1+iUxGoEP5B+aq9MDT5jLXDSg@mail.gmail.com [0]
Link: https://lore.kernel.org/bpf/20240404220344.3879270-1-andrii@kernel.org
Signed-off-by: Sasha Levin

btf, scripts: Exclude Rust CUs with pahole

2024-01-20T10:50:10+00:00

commit c1177979af9c616661a126a80dd486ad0543b836 upstream.

Version 1.24 of pahole has the capability to exclude compilation units (CUs)
of specific languages [1] [2]. Rust, as of writing, is not currently supported
by pahole and if it's used with a build that has BTF debugging enabled it
results in malformed kernel and module binaries [3]. So it's better for pahole
to exclude Rust CUs until support for it arrives.

Co-developed-by: Eric Curtin 
Signed-off-by: Eric Curtin 
Signed-off-by: Martin Rodriguez Reboredo 
Signed-off-by: Daniel Borkmann 
Tested-by: Eric Curtin 
Reviewed-by: Neal Gompa 
Acked-by: Miguel Ojeda 
Acked-by: Arnaldo Carvalho de Melo 
Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=49358dfe2aaae4e90b072332c3e324019826783f [1]
Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=8ee363790b7437283c53090a85a9fec2f0b0fbc4 [2]
Link: https://github.com/Rust-for-Linux/linux/issues/735 [3]
Link: https://lore.kernel.org/bpf/20230111152050.559334-1-yakoyoku@gmail.com
Signed-off-by: Jiri Olsa 
Signed-off-by: Greg Kroah-Hartman

lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default

2023-10-25T10:03:02+00:00

commit cc6003916ed46d7a67d91ee32de0f9138047d55f upstream.

In workloads where this_cpu operations are frequently performed,
enabling DEBUG_PREEMPT may result in significant increase in
runtime overhead due to frequent invocation of
__this_cpu_preempt_check() function.

This can be demonstrated through benchmarks such as hackbench where this
configuration results in a 10% reduction in performance, primarily due to
the added overhead within memcg charging path.

Therefore, do not to enable DEBUG_PREEMPT by default and make users aware
of its potential impact on performance in some workloads.

hackbench-process-sockets
		      debug_preempt	 no_debug_preempt
Amean     1       0.4743 (   0.00%)      0.4295 *   9.45%*
Amean     4       1.4191 (   0.00%)      1.2650 *  10.86%*
Amean     7       2.2677 (   0.00%)      2.0094 *  11.39%*
Amean     12      3.6821 (   0.00%)      3.2115 *  12.78%*
Amean     21      6.6752 (   0.00%)      5.7956 *  13.18%*
Amean     30      9.6646 (   0.00%)      8.5197 *  11.85%*
Amean     48     15.3363 (   0.00%)     13.5559 *  11.61%*
Amean     79     24.8603 (   0.00%)     22.0597 *  11.27%*
Amean     96     30.1240 (   0.00%)     26.8073 *  11.01%*

Link: https://lkml.kernel.org/r/20230121033942.350387-1-42.hyeyoo@gmail.com
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: Roman Gushchin 
Acked-by: Mel Gorman 
Acked-by: Davidlohr Bueso 
Cc: Ben Segall 
Cc: Christoph Lameter 
Cc: Daniel Bristot de Oliveira 
Cc: David Rientjes 
Cc: Dennis Zhou 
Cc: Dietmar Eggemann 
Cc: Ingo Molnar 
Cc: Johannes Weiner 
Cc: Joonsoo Kim 
Cc: Juri Lelli 
Cc: Matthew Wilcox 
Cc: Muchun Song 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: Shakeel Butt 
Cc: Steven Rostedt (Google) 
Cc: Tejun Heo 
Cc: Valentin Schneider 
Cc: Vincent Guittot 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Cc: Luiz Capitulino 
Signed-off-by: Greg Kroah-Hartman

test_kprobes: Fix implicit declaration error of test_kprobes

2023-01-07T10:11:55+00:00

commit 63a4dc0a0bb0e9bfeb2c88ccda81abdde4cdd6b8 upstream.

If KPROBES_SANITY_TEST and ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled, but
STACKTRACE is not set. Build failed as below:

lib/test_kprobes.c: In function ‘stacktrace_return_handler’:
lib/test_kprobes.c:228:8: error: implicit declaration of function ‘stack_trace_save’; did you mean ‘stacktrace_driver’? [-Werror=implicit-function-declaration]
  ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0);
        ^~~~~~~~~~~~~~~~
        stacktrace_driver
cc1: all warnings being treated as errors
scripts/Makefile.build:250: recipe for target 'lib/test_kprobes.o' failed
make[2]: *** [lib/test_kprobes.o] Error 1

To fix this error, Select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled.

Link: https://lore.kernel.org/all/20221121030620.63181-1-hucool.lihua@huawei.com/

Fixes: 1f6d3a8f5e39 ("kprobes: Add a test case for stacktrace from kretprobe handler")
Cc: stable@vger.kernel.org
Signed-off-by: Li Hua 
Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'mm-hotfixes-stable-2022-12-02' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-12-02T21:39:38+00:00

Pull misc hotfixes from Andrew Morton:
 "15 hotfixes,  11 marked cc:stable.

  Only three or four of the latter address post-6.0 issues, which is
  hopefully a sign that things are converging"

* tag 'mm-hotfixes-stable-2022-12-02' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  revert "kbuild: fix -Wimplicit-function-declaration in license_is_gpl_compatible"
  Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled
  drm/amdgpu: temporarily disable broken Clang builds due to blown stack-frame
  mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths
  mm/khugepaged: fix GUP-fast interaction by sending IPI
  mm/khugepaged: take the right locks for page table retraction
  mm: migrate: fix THP's mapcount on isolation
  mm: introduce arch_has_hw_nonleaf_pmd_young()
  mm: add dummy pmd_young() for architectures not having it
  mm/damon/sysfs: fix wrong empty schemes assumption under online tuning in damon_sysfs_set_schemes()
  tools/vm/slabinfo-gnuplot: use "grep -E" instead of "egrep"
  nilfs2: fix NULL pointer dereference in nilfs_palloc_commit_free_entry()
  hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing
  madvise: use zap_page_range_single for madvise dontneed
  mm: replace VM_WARN_ON to pr_warn if the node is offline with __GFP_THISNODE

error-injection: Add prompt for function error injection

2022-12-01T21:14:21+00:00

The config to be able to inject error codes into any function annotated
with ALLOW_ERROR_INJECTION() is enabled when FUNCTION_ERROR_INJECTION is
enabled.  But unfortunately, this is always enabled on x86 when KPROBES
is enabled, and there's no way to turn it off.

As kprobes is useful for observability of the kernel, it is useful to
have it enabled in production environments.  But error injection should
be avoided.  Add a prompt to the config to allow it to be disabled even
when kprobes is enabled, and get rid of the "def_bool y".

This is a kernel debug feature (it's in Kconfig.debug), and should have
never been something enabled by default.

Cc: stable@vger.kernel.org
Fixes: 540adea3809f6 ("error-injection: Separate error-injection from kprobe")
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Linus Torvalds

Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled

2022-11-30T22:49:42+00:00

When enabled, KASAN enlarges function's stack-frames.  Pushing quite a few
over the current threshold.  This can mainly be seen on 32-bit
architectures where the present limit (when !GCC) is a lowly 1024-Bytes.

Link: https://lkml.kernel.org/r/20221125120750.3537134-3-lee@kernel.org
Signed-off-by: Lee Jones 
Acked-by: Arnd Bergmann 
Cc: Alex Deucher 
Cc: "Christian König" 
Cc: Daniel Vetter 
Cc: David Airlie 
Cc: Harry Wentland 
Cc: Leo Li 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: "Pan, Xinhui" 
Cc: Rodrigo Siqueira 
Cc: Thomas Zimmermann 
Cc: Tom Rix 
Cc: 
Signed-off-by: Andrew Morton

test_kprobes: fix implicit declaration error of test_kprobes

2022-11-23T02:50:45+00:00

If KPROBES_SANITY_TEST and ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled, but
STACKTRACE is not set. Build failed as below:

lib/test_kprobes.c: In function `stacktrace_return_handler':
lib/test_kprobes.c:228:8: error: implicit declaration of function `stack_trace_save'; did you mean `stacktrace_driver'? [-Werror=implicit-function-declaration]
  ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0);
        ^~~~~~~~~~~~~~~~
        stacktrace_driver
cc1: all warnings being treated as errors
scripts/Makefile.build:250: recipe for target 'lib/test_kprobes.o' failed
make[2]: *** [lib/test_kprobes.o] Error 1

To fix this error, Select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled.

Link: https://lkml.kernel.org/r/20221121030620.63181-1-hucool.lihua@huawei.com
Fixes: 1f6d3a8f5e39 ("kprobes: Add a test case for stacktrace from kretprobe handler")
Signed-off-by: Li Hua 
Acked-by: Masami Hiramatsu (Google) 
Cc: Steven Rostedt (VMware) 
Signed-off-by: Andrew Morton

Kconfig.debug: ensure early check for KMSAN in CONFIG_KMSAN_WARN

2022-11-08T23:57:24+00:00

As pointed out by Masahiro Yamada, Kconfig picks up the first default
entry which has true 'if' condition.  Hence, the previously added check
for KMSAN was never used, because it followed the checks for 64BIT and
!64BIT.

Put KMSAN check before others to ensure it is always applied.

Link: https://lkml.kernel.org/r/20221102110611.1085175-3-glider@google.com
Link: https://github.com/google/kmsan/issues/89
Link: https://lore.kernel.org/linux-mm/20221024212144.2852069-3-glider@google.com/
Fixes: 921757bc9b61 ("Kconfig.debug: disable CONFIG_FRAME_WARN for KMSAN by default")
Signed-off-by: Alexander Potapenko 
Cc: Kees Cook 
Cc: Masahiro Yamada 
Cc: Nick Desaulniers 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Dmitry Vyukov 
Cc: Ingo Molnar 
Cc: Marco Elver 
Cc: Peter Zijlstra (Intel) 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton

maple_tree: reorganize testing to restore module testing

2022-11-08T23:57:22+00:00

Along the development cycle, the testing code support for module/in-kernel
compiles was removed.  Restore this functionality by moving any internal
API tests to the userspace side, as well as threading tests.  Fix the
lockdep issues and add a way to reduce memory usage so the tests can
complete with KASAN + memleak detection.  Make the tests work on 32 bit
hosts where possible and detect 32 bit hosts in the radix test suite.

[akpm@linux-foundation.org: fix module export]
[akpm@linux-foundation.org: fix it some more]
[liam.howlett@oracle.com: fix compile warnings on 32bit build in check_find()]
  Link: https://lkml.kernel.org/r/20221107203816.1260327-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20221028180415.3074673-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Signed-off-by: Andrew Morton