user/sven/linux.git/lib/Kconfig.debug, branch v5.9.8

mm/page_alloc.c: fix freeing non-compound pages

2020-10-29T09:11:36Z

[ Upstream commit e320d3012d25b1fb5f3df4edb7bd44a1c362ec10 ] Here is a very rare race which leaks memory: Page P0 is allocated to the page cache. Page P1 is free. Thread A Thread B Thread C find_get_entry(): xas_load() returns P0 Removes P0 from page cache P0 finds its buddy P1 alloc_pages(GFP_KERNEL, 1) returns P0 P0 has refcount 1 page_cache_get_speculative(P0) P0 has refcount 2 __free_pages(P0) P0 has refcount 1 put_page(P0) P1 is not freed Fix this by freeing all the pages in __free_pages() that won't be freed by the call to put_page(). It's usually not a good idea to split a page, but this is a very unlikely scenario. Fixes: e286781d5f2e ("mm: speculative page references") Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Acked-by: Mike Rapoport Cc: Nick Piggin Cc: Hugh Dickins Cc: Peter Zijlstra Link: https://lkml.kernel.org/r/20200926213919.26642-1-willy@infradead.org Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

kcsan: kconfig: move to menu 'Generic Kernel Debugging Instruments'

2020-09-19T20:13:39Z

This moves the KCSAN kconfig items under menu 'Generic Kernel Debugging Instruments' where UBSAN resides. Signed-off-by: Changbin Du Signed-off-by: Andrew Morton Tested-by: Randy Dunlap Reviewed-by: Randy Dunlap Cc: Greg Kroah-Hartman Cc: Marco Elver Link: https://lkml.kernel.org/r/20200904152224.5570-1-changbin.du@gmail.com Signed-off-by: Linus Torvalds

lib/Kconfig.debug: fix typo in the help text of CONFIG_PANIC_TIMEOUT

2020-08-12T17:58:02Z

There exists duplicated "the" in the help text of CONFIG_PANIC_TIMEOUT, Remove it. Signed-off-by: Tiezhu Yang Signed-off-by: Andrew Morton Reviewed-by: Kees Cook Cc: Xuefeng Li Link: http://lkml.kernel.org/r/1591103358-32087-2-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Linus Torvalds

lib/test_bits.c: add tests of GENMASK

2020-08-12T17:58:00Z

Add tests of GENMASK and GENMASK_ULL. A few test cases that should fail compilation are provided under #ifdef TEST_GENMASK_FAILURES [rd.dunlap@gmail.com: add MODULE_LICENSE()] Link: http://lkml.kernel.org/r/dfc74524-0789-2827-4eff-476ddab65699@gmail.com [weiyongjun1@huawei.com: make some functions static] Link: http://lkml.kernel.org/r/20200702150336.4756-1-weiyongjun1@huawei.com Suggested-by: Andy Shevchenko Signed-off-by: Rikard Falkeborn Signed-off-by: Randy Dunlap Signed-off-by: Wei Yongjun Signed-off-by: Andrew Morton Reviewed-by: Andy Shevchenko Acked-by: William Breathitt Gray Cc: Emil Velikov Cc: Syed Nayyar Waris Cc: Andy Shevchenko Cc: Arnd Bergmann Cc: Geert Uytterhoeven Cc: Kees Cook Cc: Linus Walleij Cc: Masahiro Yamada Link: http://lkml.kernel.org/r/20200621054210.14804-2-rikard.falkeborn@gmail.com Link: http://lkml.kernel.org/r/20200608221823.35799-2-rikard.falkeborn@gmail.com Signed-off-by: Linus Torvalds

lib/: replace HTTP links with HTTPS ones

2020-08-12T17:58:00Z

Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Signed-off-by: Alexander A. Klimov Signed-off-by: Andrew Morton Acked-by: Coly Li [crc64.c] Link: http://lkml.kernel.org/r/20200726112154.16510-1-grandmaster@al2klimov.de Signed-off-by: Linus Torvalds

lib/Kconfig.debug: make TEST_LOCKUP depend on module

2020-08-12T17:58:00Z

Since test_lockup is a test module to generate lockups, it is better to limit TEST_LOCKUP to module (=m) or disabled (=n) because we can not use the module parameters when CONFIG_TEST_LOCKUP=y. Signed-off-by: Tiezhu Yang Signed-off-by: Andrew Morton Reviewed-by: Guenter Roeck Cc: Konstantin Khlebnikov Cc: Kees Cook Link: http://lkml.kernel.org/r/1595555407-29875-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Linus Torvalds

./Makefile: add debug option to enable function aligned on 32 bytes

2020-08-12T17:57:59Z

Recently 0day reported many strange performance changes (regression or improvement), in which there was no obvious relation between the culprit commit and the benchmark at the first look, and it causes people to doubt the test itself is wrong. Upon further check, many of these cases are caused by the change to the alignment of kernel text or data, as whole text/data of kernel are linked together, change in one domain may affect alignments of other domains. gcc has an option '-falign-functions=n' to force text aligned, and with that option enabled, some of those performance changes will be gone, like [1][2][3]. Add this option so that developers and 0day can easily find performance bump caused by text alignment change, as tracking these strange bump is quite time consuming. Though it can't help in other cases like data alignment changes like [4]. Following is some size data for v5.7 kernel built with a RHEL config used in 0day: text data bss dec filename 19738771 13292906 5554236 38585913 vmlinux.noalign 19758591 13297002 5529660 38585253 vmlinux.align32 Raw vmlinux size in bytes: v5.7 v5.7+align32 253950832 254018000 +0.02% Some benchmark data, most of them have no big change: * hackbench: [ -1.8%, +0.5%] * fsmark: [ -3.2%, +3.4%] # ext4/xfs/btrfs * kbuild: [ -2.0%, +0.9%] * will-it-scale: [ -0.5%, +1.8%] # mmap1/pagefault3 * netperf: - TCP_CRR [+16.6%, +97.4%] - TCP_RR [-18.5%, -1.8%] - TCP_STREAM [ -1.1%, +1.9%] [1] https://lore.kernel.org/lkml/20200114085637.GA29297@shao2-debian/ [2] https://lore.kernel.org/lkml/20200330011254.GA14393@feng-iot/ [3] https://lore.kernel.org/lkml/1d98d1f0-fe84-6df7-f5bd-f4cb2cdb7f45@intel.com/ [4] https://lore.kernel.org/lkml/20200205123216.GO12867@shao2-debian/ Signed-off-by: Feng Tang Signed-off-by: Andrew Morton Cc: Masahiro Yamada Cc: Michal Marek Cc: Andi Kleen Cc: Huang Ying Cc: Andy Shevchenko Link: http://lkml.kernel.org/r/1595475001-90945-1-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds

Merge tag 'driver-core-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2020-08-05T18:52:17Z

Pull driver core updates from Greg KH: "Here is the "big" set of changes to the driver core, and some drivers using the changes, for 5.9-rc1. "Biggest" thing in here is the device link exposure in sysfs, to help to tame the madness that is SoC device tree representations and driver interactions with it. Other stuff in here that is interesting is: - device probe log helper so that drivers can report problems in a unified way easier. - devres functions added - DEVICE_ATTR_ADMIN_* macro added to make it harder to write incorrect sysfs file permissions - documentation cleanups - ability for debugfs to be present in the kernel, yet not exposed to userspace. Needed for systems that want it enabled, but do not trust users, so they can still use some kernel functions that were otherwise disabled. - other minor fixes and cleanups The patches outside of drivers/base/ all have acks from the respective subsystem maintainers to go through this tree instead of theirs. All of these have been in linux-next with no reported issues" * tag 'driver-core-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (39 commits) drm/bridge: lvds-codec: simplify error handling drm/bridge/sii8620: fix resource acquisition error handling driver core: add deferring probe reason to devices_deferred property driver core: add device probe log helper driver core: Avoid binding drivers to dead devices Revert "test_firmware: Test platform fw loading on non-EFI systems" firmware_loader: EFI firmware loader must handle pre-allocated buffer selftest/firmware: Add selftest timeout in settings test_firmware: Test platform fw loading on non-EFI systems driver core: Change delimiter in devlink device's name to "--" debugfs: Add access restriction option tracefs: Remove unnecessary debug_fs checks. driver core: Fix probe_count imbalance in really_probe() kobject: remove unused KOBJ_MAX action driver core: Fix sleeping in invalid context during device link deletion driver core: Add waiting_for_supplier sysfs file for devices driver core: Add state_synced sysfs file for devices that support it driver core: Expose device link details in sysfs driver core: Drop mention of obsolete bus rwsem from kernel-doc debugfs: file: Remove unnecessary cast in kfree() ...

Merge tag 'x86-fpu-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-08-04T00:21:10Z

Pull x86 FPU selftest from Ingo Molnar: "Add the /sys/kernel/debug/selftest_helpers/test_fpu FPU self-test" * tag 'x86-fpu-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/fpu: Add an FPU selftest

Merge branch 'locking/nmi' into locking/core, to pick up completed topic branch

2020-08-03T11:00:27Z

Signed-off-by: Ingo Molnar