kernel/linux.git/lib/Kconfig.debug, branch v5.10.141

lockdep: Allow tuning tracing capacity constants.

2022-08-21T13:15:27+00:00

commit 5dc33592e95534dc8455ce3e9baaaf3dae0fff82 upstream. Since syzkaller continues various test cases until the kernel crashes, syzkaller tends to examine more locking dependencies than normal systems. As a result, syzbot is reporting that the fuzz testing was terminated due to hitting upper limits lockdep can track [1] [2] [3]. Since analysis via /proc/lockdep* did not show any obvious culprit [4] [5], we have no choice but allow tuning tracing capacity constants. [1] https://syzkaller.appspot.com/bug?id=3d97ba93fb3566000c1c59691ea427370d33ea1b [2] https://syzkaller.appspot.com/bug?id=381cb436fe60dc03d7fd2a092b46d7f09542a72a [3] https://syzkaller.appspot.com/bug?id=a588183ac34c1437fc0785e8f220e88282e5a29f [4] https://lkml.kernel.org/r/4b8f7a57-fa20-47bd-48a0-ae35d860f233@i-love.sakura.ne.jp [5] https://lkml.kernel.org/r/1c351187-253b-2d49-acaf-4563c63ae7d2@i-love.sakura.ne.jp References: https://lkml.kernel.org/r/1595640639-9310-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa Acked-by: Dmitry Vyukov Signed-off-by: Alexey Khoroshilov Signed-off-by: Greg Kroah-Hartman

random: remove ratelimiting for in-kernel unseeded randomness

2022-05-30T07:33:44+00:00

commit cc1e127bfa95b5fb2f9307e7168bf8b2b45b4c5e upstream. The CONFIG_WARN_ALL_UNSEEDED_RANDOM debug option controls whether the kernel warns about all unseeded randomness or just the first instance. There's some complicated rate limiting and comparison to the previous caller, such that even with CONFIG_WARN_ALL_UNSEEDED_RANDOM enabled, developers still don't see all the messages or even an accurate count of how many were missed. This is the result of basically parallel mechanisms aimed at accomplishing more or less the same thing, added at different points in random.c history, which sort of compete with the first-instance-only limiting we have now. It turns out, however, that nobody cares about the first unseeded randomness instance of in-kernel users. The same first user has been there for ages now, and nobody is doing anything about it. It isn't even clear that anybody _can_ do anything about it. Most places that can do something about it have switched over to using get_random_bytes_wait() or wait_for_random_bytes(), which is the right thing to do, but there is still much code that needs randomness sometimes during init, and as a geeneral rule, if you're not using one of the _wait functions or the readiness notifier callback, you're bound to be doing it wrong just based on that fact alone. So warning about this same first user that can't easily change is simply not an effective mechanism for anything at all. Users can't do anything about it, as the Kconfig text points out -- the problem isn't in userspace code -- and kernel developers don't or more often can't react to it. Instead, show the warning for all instances when CONFIG_WARN_ALL_UNSEEDED_RANDOM is set, so that developers can debug things need be, or if it isn't set, don't show a warning at all. At the same time, CONFIG_WARN_ALL_UNSEEDED_RANDOM now implies setting random.ratelimit_disable=1 on by default, since if you care about one you probably care about the other too. And we can clean up usage around the related urandom_warning ratelimiter as well (whose behavior isn't changing), so that it properly counts missed messages after the 10 message threshold is reached. Cc: Theodore Ts'o Cc: Dominik Brodowski Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH

2021-09-26T12:08:58+00:00

[ Upstream commit 6fe26259b4884b657cbc233fb9cdade9d704976e ] Commit 05a4a9527931 ("kernel/watchdog: split up config options") adds a new config HARDLOCKUP_DETECTOR, which selects the non-existing config HARDLOCKUP_DETECTOR_ARCH. Hence, ./scripts/checkkconfigsymbols.py warns: HARDLOCKUP_DETECTOR_ARCH Referencing files: lib/Kconfig.debug Simply drop selecting the non-existing HARDLOCKUP_DETECTOR_ARCH. Link: https://lkml.kernel.org/r/20210806115618.22088-1-lukas.bulwahn@gmail.com Fixes: 05a4a9527931 ("kernel/watchdog: split up config options") Signed-off-by: Lukas Bulwahn Cc: Nicholas Piggin Cc: Masahiro Yamada Cc: Babu Moger Cc: Don Zickus Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

net: kcov: don't select SKB_EXTENSIONS when there is no NET

2021-09-12T06:58:26+00:00

commit 85ce50d337d10a6fd328fa70b0a15543bf5c0f64 upstream. Fix kconfig warning when CONFIG_NET is not set/enabled: WARNING: unmet direct dependencies detected for SKB_EXTENSIONS Depends on [n]: NET [=n] Selected by [y]: - KCOV [=y] && ARCH_HAS_KCOV [=y] && (CC_HAS_SANCOV_TRACE_PC [=y] || GCC_PLUGINS [=n]) Fixes: 6370cc3bbd8a ("net: add kcov handle to skb extensions") Signed-off-by: Randy Dunlap Cc: Aleksandr Nogikh Cc: Willem de Bruijn Link: https://lore.kernel.org/r/20201110175746.11437-1-rdunlap@infradead.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: add kcov handle to skb extensions

2021-07-28T12:35:33+00:00

[ Upstream commit 6370cc3bbd8a0f9bf975b013781243ab147876c6 ] Remote KCOV coverage collection enables coverage-guided fuzzing of the code that is not reachable during normal system call execution. It is especially helpful for fuzzing networking subsystems, where it is common to perform packet handling in separate work queues even for the packets that originated directly from the user space. Enable coverage-guided frame injection by adding kcov remote handle to skb extensions. Default initialization in __alloc_skb and __build_skb_around ensures that no socket buffer that was generated during a system call will be missed. Code that is of interest and that performs packet processing should be annotated with kcov_remote_start()/kcov_remote_stop(). An alternative approach is to determine kcov_handle solely on the basis of the device/interface that received the specific socket buffer. However, in this case it would be impossible to distinguish between packets that originated during normal background network processes or were intentionally injected from the user space. Signed-off-by: Aleksandr Nogikh Acked-by: Willem de Bruijn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

locking/lockdep: Reduce LOCKDEP dependency list

2021-07-14T14:56:05+00:00

[ Upstream commit b8e00abe7d9fe21dd13609e2e3a707e38902b105 ] Some arches (um, sparc64, riscv, xtensa) cause a Kconfig warning for LOCKDEP. These arch-es select LOCKDEP_SUPPORT but they are not listed as one of the arch-es that LOCKDEP depends on. Since (16) arch-es define the Kconfig symbol LOCKDEP_SUPPORT if they intend to have LOCKDEP support, replace the awkward list of arch-es that LOCKDEP depends on with the LOCKDEP_SUPPORT symbol. But wait. LOCKDEP_SUPPORT is included in LOCK_DEBUGGING_SUPPORT, which is already a dependency here, so LOCKDEP_SUPPORT is redundant and not needed. That leaves the FRAME_POINTER dependency, but it is part of an expression like this: depends on (A && B) && (FRAME_POINTER || B') where B' is a dependency of B so if B is true then B' is true and the value of FRAME_POINTER does not matter. Thus we can also delete the FRAME_POINTER dependency. Fixes this kconfig warning: (for um, sparc64, riscv, xtensa) WARNING: unmet direct dependencies detected for LOCKDEP Depends on [n]: DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] && (FRAME_POINTER [=n] || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86) Selected by [y]: - PROVE_LOCKING [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] - LOCK_STAT [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] - DEBUG_LOCK_ALLOC [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] Fixes: 7d37cb2c912d ("lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS") Signed-off-by: Randy Dunlap Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Link: https://lkml.kernel.org/r/20210524224150.8009-1-rdunlap@infradead.org Signed-off-by: Sasha Levin

lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS

2021-04-21T11:00:54+00:00

[ Upstream commit 7d37cb2c912dc5c25ffac784a4f9b98c06c6bd08 ] When LATENCYTOP, LOCKDEP, or FAULT_INJECTION_STACKTRACE_FILTER is enabled and ARCH_WANT_FRAME_POINTERS is disabled, Kbuild gives a warning such as: WARNING: unmet direct dependencies detected for FRAME_POINTER Depends on [n]: DEBUG_KERNEL [=y] && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS [=n] || MCOUNT [=n] Selected by [y]: - LATENCYTOP [=y] && DEBUG_KERNEL [=y] && STACKTRACE_SUPPORT [=y] && PROC_FS [=y] && !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 Depending on ARCH_WANT_FRAME_POINTERS causes a recursive dependency error. ARCH_WANT_FRAME_POINTERS is to be selected by the architecture, and is not supposed to be overridden by other config options. Link: https://lkml.kernel.org/r/20210329165329.27994-1-julianbraha@gmail.com Signed-off-by: Julian Braha Cc: Andreas Schwab Cc: Geert Uytterhoeven Cc: Necip Fazil Yildiran Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

docs: Kconfig/Makefile: add a check for broken ABI files

2020-10-30T12:08:07+00:00

The files under Documentation/ABI should follow the syntax as defined at Documentation/ABI/README. Allow checking if they're following the syntax by running the ABI parser script on COMPILE_TEST. With that, when there's a problem with a file under Documentation/ABI, it would produce a warning like: Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#14: What '/sys/bus/pci/devices//aer_stats/aer_rootport_total_err_cor' doesn't have a description Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#21: What '/sys/bus/pci/devices//aer_stats/aer_rootport_total_err_fatal' doesn't have a description Acked-by: Jonathan Corbet Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/57a38de85cb4b548857207cf1fc1bf1ee08613c9.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-10-22T20:13:57+00:00

Pull Kbuild updates from Masahiro Yamada: - Support 'make compile_commands.json' to generate the compilation database more easily, avoiding stale entries - Support 'make clang-analyzer' and 'make clang-tidy' for static checks using clang-tidy - Preprocess scripts/modules.lds.S to allow CONFIG options in the module linker script - Drop cc-option tests from compiler flags supported by our minimal GCC/Clang versions - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y - Use sha1 build id for both BFD linker and LLD - Improve deb-pkg for reproducible builds and rootless builds - Remove stale, useless scripts/namespace.pl - Turn -Wreturn-type warning into error - Fix build error of deb-pkg when CONFIG_MODULES=n - Replace 'hostname' command with more portable 'uname -n' - Various Makefile cleanups * tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: Use uname for LINUX_COMPILE_HOST detection kbuild: Only add -fno-var-tracking-assignments for old GCC versions kbuild: remove leftover comment for filechk utility treewide: remove DISABLE_LTO kbuild: deb-pkg: clean up package name variables kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n kbuild: enforce -Werror=return-type scripts: remove namespace.pl builddeb: Add support for all required debian/rules targets builddeb: Enable rootless builds builddeb: Pass -n to gzip for reproducible packages kbuild: split the build log of kallsyms kbuild: explicitly specify the build id style scripts/setlocalversion: make git describe output more reliable kbuild: remove cc-option test of -Werror=date-time kbuild: remove cc-option test of -fno-stack-check kbuild: remove cc-option test of -fno-strict-overflow kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan kbuild: do not create built-in objects for external module builds ...

Merge tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2020-10-18T21:45:59+00:00

Pull more Kunit updates from Shuah Khan: - add Kunit to kernel_init() and remove KUnit from init calls entirely. This addresses the concern that Kunit would not work correctly during late init phase. - add a linker section where KUnit can put references to its test suites. This is the first step in transitioning to dispatching all KUnit tests from a centralized executor rather than having each as its own separate late_initcall. - add a centralized executor to dispatch tests rather than relying on late_initcall to schedule each test suite separately. Centralized execution is for built-in tests only; modules will execute tests when loaded. - convert bitfield test to use KUnit framework - Documentation updates for naming guidelines and how kunit_test_suite() works. - add test plan to KUnit TAP format * tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE lib: kunit: add bitfield test conversion to KUnit Documentation: kunit: add a brief blurb about kunit_test_suite kunit: test: add test plan to KUnit TAP format init: main: add KUnit to kernel init kunit: test: create a single centralized executor for all tests vmlinux.lds.h: add linker section for KUnit test suites Documentation: kunit: Add naming guidelines