kernel/linux.git/lib/Kconfig.debug, branch v5.4.224

random: remove ratelimiting for in-kernel unseeded randomness

2022-06-22T12:11:17+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

2021-09-26T12:07:10+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

kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

2020-10-01T11:17:10+00:00

[ Upstream commit 2cb80dbbbaba4f2f86f686c34cb79ea5cbfb0edb ] KUnit tests for initialized data behavior of proc_dointvec that is explicitly checked in the code. Includes basic parsing tests including int min/max overflow. Signed-off-by: Iurii Zaikin Signed-off-by: Brendan Higgins Reviewed-by: Greg Kroah-Hartman Reviewed-by: Logan Gunthorpe Acked-by: Luis Chamberlain Reviewed-by: Stephen Boyd Signed-off-by: Shuah Khan Signed-off-by: Sasha Levin

kbuild, btf: Fix dependencies for DEBUG_INFO_BTF

2020-04-23T08:36:18+00:00

commit 7d32e69310d67e6b04af04f26193f79dfc2f05c7 upstream. Currently turning on DEBUG_INFO_SPLIT when DEBUG_INFO_BTF is also enabled will produce invalid btf file, since gen_btf function in link-vmlinux.sh script doesn't handle *.dwo files. Enabling DEBUG_INFO_REDUCED will also produce invalid btf file, and using GCC_PLUGIN_RANDSTRUCT with BTF makes no sense. Fixes: e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux") Reported-by: Jann Horn Reported-by: Liu Yiding Signed-off-by: Slava Bacherikov Signed-off-by: Daniel Borkmann Reviewed-by: Kees Cook Acked-by: KP Singh Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200402204138.408021-1-slava@bacher09.org Signed-off-by: Greg Kroah-Hartman

kbuild: move headers_check rule to usr/include/Makefile

2020-03-05T15:43:47+00:00

commit 7ecaf069da52e472d393f03e79d721aabd724166 upstream. Currently, some sanity checks for uapi headers are done by scripts/headers_check.pl, which is wired up to the 'headers_check' target in the top Makefile. It is true compiling headers has better test coverage, but there are still several headers excluded from the compile test. I like to keep headers_check.pl for a while, but we can delete a lot of code by moving the build rule to usr/include/Makefile. Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

compiler: enable CONFIG_OPTIMIZE_INLINING forcibly

2019-09-26T00:51:40+00:00

Commit 9012d011660e ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING") allowed all architectures to enable this option. A couple of build errors were reported by randconfig, but all of them have been ironed out. Towards the goal of removing CONFIG_OPTIMIZE_INLINING entirely (and it will simplify the 'inline' macro in compiler_types.h), this commit changes it to always-on option. Going forward, the compiler will always be allowed to not inline functions marked 'inline'. This is not a problem for x86 since it has been long used by arch/x86/configs/{x86_64,i386}_defconfig. I am keeping the config option just in case any problem crops up for other architectures. The code clean-up will be done after confirming this is solid. Link: http://lkml.kernel.org/r/20190830034304.24259-1-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Acked-by: Nick Desaulniers Cc: Ingo Molnar Cc: Borislav Petkov Cc: Miguel Ojeda Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/kmemleak: increase the max mem pool to 1M

2019-09-24T22:54:07+00:00

There are some machines with slow disk and fast CPUs. When they are under memory pressure, it could take a long time to swap before the OOM kicks in to free up some memory. As the results, it needs a large mem pool for kmemleak or suffering from higher chance of a kmemleak metadata allocation failure. 524288 proves to be the good number for all architectures here. Increase the upper bound to 1M to leave some room for the future. Link: http://lkml.kernel.org/r/1565807572-26041-1-git-send-email-cai@lca.pw Signed-off-by: Qian Cai Acked-by: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: kmemleak: use the memory pool for early allocations

2019-09-24T22:54:07+00:00

Currently kmemleak uses a static early_log buffer to trace all memory allocation/freeing before the slab allocator is initialised. Such early log is replayed during kmemleak_init() to properly initialise the kmemleak metadata for objects allocated up that point. With a memory pool that does not rely on the slab allocator, it is possible to skip this early log entirely. In order to remove the early logging, consider kmemleak_enabled == 1 by default while the kmem_cache availability is checked directly on the object_cache and scan_area_cache variables. The RCU callback is only invoked after object_cache has been initialised as we wouldn't have any concurrent list traversal before this. In order to reduce the number of callbacks before kmemleak is fully initialised, move the kmemleak_init() call to mm_init(). [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: remove WARN_ON(), per Catalin] Link: http://lkml.kernel.org/r/20190812160642.52134-4-catalin.marinas@arm.com Signed-off-by: Catalin Marinas Cc: Matthew Wilcox Cc: Michal Hocko Cc: Qian Cai Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K

2019-09-24T22:54:07+00:00

The current default value (400) is too low on many systems (e.g. some ARM64 platform takes up 1000+ entries). syzbot uses 16000 as default value, and has proved to be enough on beefy configurations, so let's pick that value. This consumes more RAM on boot (each entry is 160 bytes, so in total ~2.5MB of RAM), but the memory would later be freed (early_log is __initdata). Link: http://lkml.kernel.org/r/20190730154027.101525-1-drinkcat@chromium.org Signed-off-by: Nicolas Boichat Suggested-by: Dmitry Vyukov Acked-by: Catalin Marinas Acked-by: Dmitry Vyukov Cc: Masahiro Yamada Cc: Kees Cook Cc: Petr Mladek Cc: Thomas Gleixner Cc: Tetsuo Handa Cc: Joe Lawrence Cc: Uladzislau Rezki Cc: Andy Shevchenko Cc: Stephen Rothwell Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES

2019-09-11T19:40:27+00:00

When CONFIG_MODULES is disabled, CONFIG_UNUSED_SYMBOLS is pointless, thus it should be invisible. Instead of adding "depends on MODULES", I moved it to the sub-menu "Enable loadable module support", which is a better fit. I put it close to TRIM_UNUSED_KSYMS because it depends on !UNUSED_SYMBOLS. Signed-off-by: Masahiro Yamada Signed-off-by: Jessica Yu