linux-stable.git/arch/mips, branch v5.13.2 Linux kernel stable tree MIPS: Fix PKMAP with 32-bit MIPS huge page support 2021-07-14T15:07:25+00:00 Wei Li liwei391@huawei.com 2021-06-29T14:14:20+00:00 466654d21be1bb74ba41706895209a5dc0b11a31 [ Upstream commit cf02ce742f09188272bcc8b0e62d789eb671fc4c ] When 32-bit MIPS huge page support is enabled, we halve the number of pointers a PTE page holds, making its last half go to waste. Correspondingly, we should halve the number of kmap entries, as we just initialized only a single pte table for that in pagetable_init(). Fixes: 35476311e529 ("MIPS: Add partial 32-bit huge page support") Signed-off-by: Wei Li <liwei391@huawei.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit cf02ce742f09188272bcc8b0e62d789eb671fc4c ]

When 32-bit MIPS huge page support is enabled, we halve the number of
pointers a PTE page holds, making its last half go to waste.
Correspondingly, we should halve the number of kmap entries, as we just
initialized only a single pte table for that in pagetable_init().

Fixes: 35476311e529 ("MIPS: Add partial 32-bit huge page support")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
sched/core: Initialize the idle task with preemption disabled 2021-07-14T15:06:21+00:00 Valentin Schneider valentin.schneider@arm.com 2021-05-12T09:46:36+00:00 24c79a7e54ccfa29fb8cbf7ed8d1e48ff1ec6e3d [ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ]

As pointed out by commit

  de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

  @begone@
  @@

  -preempt_disable();
  ...
  cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Revert "MIPS: make userspace mapping young by default" 2021-06-05T15:58:11+00:00 Thomas Bogendoerfer tsbogend@alpha.franken.de 2021-06-05T03:01:08+00:00 50c25ee97cf6ab011542167ab590c17012cea4ed This reverts commit f685a533a7fab35c5d069dcd663f59c8e4171a75. The MIPS cache flush logic needs to know whether the mapping was already established to decide how to flush caches. This is done by checking the valid bit in the PTE. The commit above breaks this logic by setting the valid in the PTE in new mappings, which causes kernel crashes. Link: https://lkml.kernel.org/r/20210526094335.92948-1-tsbogend@alpha.franken.de Fixes: f685a533a7f ("MIPS: make userspace mapping young by default") Reported-by: Zhou Yanjie <zhouyanjie@wanyeetech.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huang Pei <huangpei@loongson.cn> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This reverts commit f685a533a7fab35c5d069dcd663f59c8e4171a75.

The MIPS cache flush logic needs to know whether the mapping was already
established to decide how to flush caches.  This is done by checking the
valid bit in the PTE.  The commit above breaks this logic by setting the
valid in the PTE in new mappings, which causes kernel crashes.

Link: https://lkml.kernel.org/r/20210526094335.92948-1-tsbogend@alpha.franken.de
Fixes: f685a533a7f ("MIPS: make userspace mapping young by default")
Reported-by: Zhou Yanjie <zhouyanjie@wanyeetech.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huang Pei <huangpei@loongson.cn>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'mips-fixes_5.13_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux 2021-05-28T18:24:13+00:00 Linus Torvalds torvalds@linux-foundation.org 2021-05-28T18:24:13+00:00 afdd14704d7eb4d7634cb7ba8d117066fed44282 Pull MIPS fixes from Thomas Bogendoerfer: - fix function/preempt trace hangs - a few build fixes * tag 'mips-fixes_5.13_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER MIPS: ralink: export rt_sysc_membase for rt2880_wdt.c MIPS: launch.h: add include guard to prevent build errors MIPS: alchemy: xxs1500: add gpio-au1000.h header file 
Pull MIPS fixes from Thomas Bogendoerfer:

 - fix function/preempt trace hangs

 - a few build fixes

* tag 'mips-fixes_5.13_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER
  MIPS: ralink: export rt_sysc_membase for rt2880_wdt.c
  MIPS: launch.h: add include guard to prevent build errors
  MIPS: alchemy: xxs1500: add gpio-au1000.h header file
MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER 2021-05-25T13:33:17+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2021-05-15T11:02:01+00:00 78cf0eb926cb1abeff2106bae67752e032fe5f3e When update the latest mainline kernel with the following three configs, the kernel hangs during startup: (1) CONFIG_FUNCTION_GRAPH_TRACER=y (2) CONFIG_PREEMPT_TRACER=y (3) CONFIG_FTRACE_STARTUP_TEST=y When update the latest mainline kernel with the above two configs (1) and (2), the kernel starts normally, but it still hangs when execute the following command: echo "function_graph" > /sys/kernel/debug/tracing/current_tracer Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences with function_graph tracer at the first glance. I use ejtag to find out the epc address is related with preempt_enable() in the file arch/mips/lib/mips-atomic.c, because function tracing can trace the preempt_{enable,disable} calls that are traced, replace them with preempt_{enable,disable}_notrace to prevent function tracing from going into an infinite loop, and then it can fix the kernel hang issue. By the way, it seems that this commit is a complement and improvement of commit f93a1a00f2bd ("MIPS: Fix crash that occurs when function tracing is enabled"). Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
When update the latest mainline kernel with the following three configs,
the kernel hangs during startup:

(1) CONFIG_FUNCTION_GRAPH_TRACER=y
(2) CONFIG_PREEMPT_TRACER=y
(3) CONFIG_FTRACE_STARTUP_TEST=y

When update the latest mainline kernel with the above two configs (1)
and (2), the kernel starts normally, but it still hangs when execute
the following command:

echo "function_graph" > /sys/kernel/debug/tracing/current_tracer

Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs
disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences
with function_graph tracer at the first glance.

I use ejtag to find out the epc address is related with preempt_enable()
in the file arch/mips/lib/mips-atomic.c, because function tracing can
trace the preempt_{enable,disable} calls that are traced, replace them
with preempt_{enable,disable}_notrace to prevent function tracing from
going into an infinite loop, and then it can fix the kernel hang issue.

By the way, it seems that this commit is a complement and improvement of
commit f93a1a00f2bd ("MIPS: Fix crash that occurs when function tracing
is enabled").

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
MIPS: ralink: export rt_sysc_membase for rt2880_wdt.c 2021-05-25T13:22:04+00:00 Randy Dunlap rdunlap@infradead.org 2021-05-17T00:54:17+00:00 fef532ea0cd871afab7d9a7b6e9da99ac2c24371 rt2880_wdt.c uses (well, attempts to use) rt_sysc_membase. However, when this watchdog driver is built as a loadable module, there is a build error since the rt_sysc_membase symbol is not exported. Export it to quell the build error. ERROR: modpost: "rt_sysc_membase" [drivers/watchdog/rt2880_wdt.ko] undefined! Fixes: 473cf939ff34 ("watchdog: add ralink watchdog driver") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: John Crispin <john@phrozen.org> Cc: linux-mips@vger.kernel.org Cc: linux-watchdog@vger.kernel.org Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
rt2880_wdt.c uses (well, attempts to use) rt_sysc_membase. However,
when this watchdog driver is built as a loadable module, there is a
build error since the rt_sysc_membase symbol is not exported.
Export it to quell the build error.

ERROR: modpost: "rt_sysc_membase" [drivers/watchdog/rt2880_wdt.ko] undefined!

Fixes: 473cf939ff34 ("watchdog: add ralink watchdog driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: John Crispin <john@phrozen.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-watchdog@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
MIPS: launch.h: add include guard to prevent build errors 2021-05-25T13:18:59+00:00 Randy Dunlap rdunlap@infradead.org 2021-05-21T05:13:43+00:00 6855adc2c5d9dff08be9e6e01deb319738b28780 arch/mips/include/asm/mips-boards/launch.h needs an include guard to prevent it from being #included more than once. Prevents these build errors: In file included from ../arch/mips/mti-malta/malta-amon.c:16: ../arch/mips/include/asm/mips-boards/launch.h:8:8: error: redefinition of 'struct cpulaunch' 8 | struct cpulaunch { | ^~~~~~~~~ In file included from ../arch/mips/include/asm/mips-cps.h:13, from ../arch/mips/include/asm/smp-ops.h:16, from ../arch/mips/include/asm/smp.h:21, from ../include/linux/smp.h:114, from ../arch/mips/mti-malta/malta-amon.c:12: ../arch/mips/include/asm/mips-boards/launch.h:8:8: note: originally defined here 8 | struct cpulaunch { | ^~~~~~~~~ make[3]: [../scripts/Makefile.build:273: arch/mips/mti-malta/malta-amon.o] Error 1 (ignored) Fixes: 6decd1aad15f ("MIPS: add support for buggy MT7621S core detection") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: linux-mips@vger.kernel.org Cc: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com> Reviewed-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
arch/mips/include/asm/mips-boards/launch.h needs an include guard
to prevent it from being #included more than once.
Prevents these build errors:

In file included from ../arch/mips/mti-malta/malta-amon.c:16:
../arch/mips/include/asm/mips-boards/launch.h:8:8: error: redefinition of 'struct cpulaunch'
    8 | struct cpulaunch {
      |        ^~~~~~~~~
In file included from ../arch/mips/include/asm/mips-cps.h:13,
                 from ../arch/mips/include/asm/smp-ops.h:16,
                 from ../arch/mips/include/asm/smp.h:21,
                 from ../include/linux/smp.h:114,
                 from ../arch/mips/mti-malta/malta-amon.c:12:
../arch/mips/include/asm/mips-boards/launch.h:8:8: note: originally defined here
    8 | struct cpulaunch {
      |        ^~~~~~~~~
make[3]: [../scripts/Makefile.build:273: arch/mips/mti-malta/malta-amon.o] Error 1 (ignored)

Fixes: 6decd1aad15f ("MIPS: add support for buggy MT7621S core detection")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org
Cc: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Reviewed-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
MIPS: alchemy: xxs1500: add gpio-au1000.h header file 2021-05-25T13:16:23+00:00 Randy Dunlap rdunlap@infradead.org 2021-05-17T00:01:08+00:00 ff4cff962a7eedc73e54b5096693da7f86c61346 board-xxs1500.c references 2 functions without declaring them, so add the header file to placate the build. ../arch/mips/alchemy/board-xxs1500.c: In function 'board_setup': ../arch/mips/alchemy/board-xxs1500.c:56:2: error: implicit declaration of function 'alchemy_gpio1_input_enable' [-Werror=implicit-function-declaration] 56 | alchemy_gpio1_input_enable(); ../arch/mips/alchemy/board-xxs1500.c:57:2: error: implicit declaration of function 'alchemy_gpio2_enable'; did you mean 'alchemy_uart_enable'? [-Werror=implicit-function-declaration] 57 | alchemy_gpio2_enable(); Fixes: 8e026910fcd4 ("MIPS: Alchemy: merge GPR/MTX-1/XXS1500 board code into single files") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: linux-mips@vger.kernel.org Cc: Manuel Lauss <manuel.lauss@googlemail.com> Cc: Ralf Baechle <ralf@linux-mips.org> Acked-by: Manuel Lauss <manuel.lauss@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
board-xxs1500.c references 2 functions without declaring them, so add
the header file to placate the build.

../arch/mips/alchemy/board-xxs1500.c: In function 'board_setup':
../arch/mips/alchemy/board-xxs1500.c:56:2: error: implicit declaration of function 'alchemy_gpio1_input_enable' [-Werror=implicit-function-declaration]
   56 |  alchemy_gpio1_input_enable();
../arch/mips/alchemy/board-xxs1500.c:57:2: error: implicit declaration of function 'alchemy_gpio2_enable'; did you mean 'alchemy_uart_enable'? [-Werror=implicit-function-declaration]
   57 |  alchemy_gpio2_enable();

Fixes: 8e026910fcd4 ("MIPS: Alchemy: merge GPR/MTX-1/XXS1500 board code into single files")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
quota: Disable quotactl_path syscall 2021-05-17T12:39:56+00:00 Jan Kara jack@suse.cz 2021-05-17T12:39:56+00:00 5b9fedb31e476693c90d8ee040e7d4c51b3e7cc4 In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up new quotactl_path syscall. However some people in LWN discussion have objected that the path based syscall is missing dirfd and flags argument which is mostly standard for contemporary path based syscalls. Indeed they have a point and after a discussion with Christian Brauner and Sascha Hauer I've decided to disable the syscall for now and update its API. Since there is no userspace currently using that syscall and it hasn't been released in any major release, we should be fine. CC: Christian Brauner <christian.brauner@ubuntu.com> CC: Sascha Hauer <s.hauer@pengutronix.de> Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein Signed-off-by: Jan Kara <jack@suse.cz> 
In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up
new quotactl_path syscall. However some people in LWN discussion have
objected that the path based syscall is missing dirfd and flags argument
which is mostly standard for contemporary path based syscalls. Indeed
they have a point and after a discussion with Christian Brauner and
Sascha Hauer I've decided to disable the syscall for now and update its
API. Since there is no userspace currently using that syscall and it
hasn't been released in any major release, we should be fine.

CC: Christian Brauner <christian.brauner@ubuntu.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein
Signed-off-by: Jan Kara <jack@suse.cz>
Merge tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 2021-05-08T17:00:11+00:00 Linus Torvalds torvalds@linux-foundation.org 2021-05-08T17:00:11+00:00 0f979d815cd52084b99e9f6b367e79488850df2e Pull more Kbuild updates from Masahiro Yamada: - Convert sh and sparc to use generic shell scripts to generate the syscall headers - refactor .gitignore files - Update kernel/config_data.gz only when the content of the .config is really changed, which avoids the unneeded re-link of vmlinux - move "remove stale files" workarounds to scripts/remove-stale-files - suppress unused-but-set-variable warnings by default for Clang as well - fix locale setting LANG=C to LC_ALL=C - improve 'make distclean' - always keep intermediate objects from scripts/link-vmlinux.sh - move IF_ENABLED out of <linux/kconfig.h> to make it self-contained - misc cleanups * tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits) linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h> kbuild: Don't remove link-vmlinux temporary files on exit/signal kbuild: remove the unneeded comments for external module builds kbuild: make distclean remove tag files in sub-directories kbuild: make distclean work against $(objtree) instead of $(srctree) kbuild: refactor modname-multi by using suffix-search kbuild: refactor fdtoverlay rule kbuild: parameterize the .o part of suffix-search arch: use cross_compiling to check whether it is a cross build or not kbuild: remove ARCH=sh64 support from top Makefile .gitignore: prefix local generated files with a slash kbuild: replace LANG=C with LC_ALL=C Makefile: Move -Wno-unused-but-set-variable out of GCC only block kbuild: add a script to remove stale generated files kbuild: update config_data.gz only when the content of .config is changed .gitignore: ignore only top-level modules.builtin .gitignore: move tags and TAGS close to other tag files kernel/.gitgnore: remove stale timeconst.h and hz.bc usr/include: refactor .gitignore genksyms: fix stale comment ... 
Pull more Kbuild updates from Masahiro Yamada:

 - Convert sh and sparc to use generic shell scripts to generate the
   syscall headers

 - refactor .gitignore files

 - Update kernel/config_data.gz only when the content of the .config
   is really changed, which avoids the unneeded re-link of vmlinux

 - move "remove stale files" workarounds to scripts/remove-stale-files

 - suppress unused-but-set-variable warnings by default for Clang
   as well

 - fix locale setting LANG=C to LC_ALL=C

 - improve 'make distclean'

 - always keep intermediate objects from scripts/link-vmlinux.sh

 - move IF_ENABLED out of <linux/kconfig.h> to make it self-contained

 - misc cleanups

* tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
  linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h>
  kbuild: Don't remove link-vmlinux temporary files on exit/signal
  kbuild: remove the unneeded comments for external module builds
  kbuild: make distclean remove tag files in sub-directories
  kbuild: make distclean work against $(objtree) instead of $(srctree)
  kbuild: refactor modname-multi by using suffix-search
  kbuild: refactor fdtoverlay rule
  kbuild: parameterize the .o part of suffix-search
  arch: use cross_compiling to check whether it is a cross build or not
  kbuild: remove ARCH=sh64 support from top Makefile
  .gitignore: prefix local generated files with a slash
  kbuild: replace LANG=C with LC_ALL=C
  Makefile: Move -Wno-unused-but-set-variable out of GCC only block
  kbuild: add a script to remove stale generated files
  kbuild: update config_data.gz only when the content of .config is changed
  .gitignore: ignore only top-level modules.builtin
  .gitignore: move tags and TAGS close to other tag files
  kernel/.gitgnore: remove stale timeconst.h and hz.bc
  usr/include: refactor .gitignore
  genksyms: fix stale comment
  ...