Commit Graph

36224 Commits

Author SHA1 Message Date
Linus Torvalds 9819f682e4 A set of scheduler updates:
- Prevent PSI state corruption when schedule() races with cgroup move.  A
    recent commit combined two PSI callbacks to reduce the number of cgroup
    tree updates, but missed that schedule() can drop rq::lock for load
    balancing, which opens the race window for cgroup_move_task() which then
    observes half updated state. The fix is to solely use task::ps_flags
    instead of looking at the potentially mismatching scheduler state
 
  - Prevent an out-of-bounds access in uclamp caused bu a rounding division
    which can lead to an off-by-one error exceeding the buckets array size.
 
  - Prevent unfairness caused by missing load decay when a task is attached
    to a cfs runqueue. The old load of the task is attached to the runqueue
    and never removed. Fix it by enforcing the load update through the
    hierarchy for unthrottled run queue instances.
 
  - A documentation fix fot the 'sched_verbose' command line option
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Merge tag 'sched-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler updates:

   - Prevent PSI state corruption when schedule() races with cgroup
     move.

     A recent commit combined two PSI callbacks to reduce the number of
     cgroup tree updates, but missed that schedule() can drop rq::lock
     for load balancing, which opens the race window for
     cgroup_move_task() which then observes half updated state.

     The fix is to solely use task::ps_flags instead of looking at the
     potentially mismatching scheduler state

   - Prevent an out-of-bounds access in uclamp caused bu a rounding
     division which can lead to an off-by-one error exceeding the
     buckets array size.

   - Prevent unfairness caused by missing load decay when a task is
     attached to a cfs runqueue.

     The old load of the task was attached to the runqueue and never
     removed. Fix it by enforcing the load update through the hierarchy
     for unthrottled run queue instances.

   - A documentation fix fot the 'sched_verbose' command line option"

* tag 'sched-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix unfairness caused by missing load decay
  sched: Fix out-of-bound access in uclamp
  psi: Fix psi state corruption when schedule() races with cgroup move
  sched,doc: sched_debug_verbose cmdline should be sched_verbose
2021-05-09 13:14:34 -07:00
Linus Torvalds 732a27a089 A set of locking related fixes and updates:
- Two fixes for the futex syscall related to the timeout handling.
 
     FUTEX_LOCK_PI does not support the FUTEX_CLOCK_REALTIME bit and because
     it's not set the time namespace adjustment for clock MONOTONIC is
     applied wrongly.
 
     FUTEX_WAIT cannot support the FUTEX_CLOCK_REALTIME bit because its
     always a relative timeout.
 
   - Cleanups in the futex syscall entry points which became obvious when
     the two timeout handling bugs were fixed.
 
   - Cleanup of queued_write_lock_slowpath() as suggested by Linus
 
   - Fixup of the smp_call_function_single_async() prototype
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Merge tag 'locking-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "A set of locking related fixes and updates:

   - Two fixes for the futex syscall related to the timeout handling.

     FUTEX_LOCK_PI does not support the FUTEX_CLOCK_REALTIME bit and
     because it's not set the time namespace adjustment for clock
     MONOTONIC is applied wrongly.

     FUTEX_WAIT cannot support the FUTEX_CLOCK_REALTIME bit because its
     always a relative timeout.

   - Cleanups in the futex syscall entry points which became obvious
     when the two timeout handling bugs were fixed.

   - Cleanup of queued_write_lock_slowpath() as suggested by Linus

   - Fixup of the smp_call_function_single_async() prototype"

* tag 'locking-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Make syscall entry points less convoluted
  futex: Get rid of the val2 conditional dance
  futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI
  Revert 337f13046f ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op")
  locking/qrwlock: Cleanup queued_write_lock_slowpath()
  smp: Fix smp_call_function_single_async prototype
2021-05-09 13:07:03 -07:00
Linus Torvalds 0f979d815c Kbuild updates for v5.13 (2nd)
- 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
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Merge tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

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
  ...
2021-05-08 10:00:11 -07:00
Linus Torvalds fc858a5231 Networking fixes for 5.13-rc1, including fixes from bpf, can
and netfilter trees. Self-contained fixes, nothing risky.
 
 Current release - new code bugs:
 
  - dsa: ksz: fix a few bugs found by static-checker in the new driver
 
  - stmmac: fix frame preemption handshake not triggering after
            interface restart
 
 Previous releases - regressions:
 
  - make nla_strcmp handle more then one trailing null character
 
  - fix stack OOB reads while fragmenting IPv4 packets in openvswitch
    and net/sched
 
  - sctp: do asoc update earlier in sctp_sf_do_dupcook_a
 
  - sctp: delay auto_asconf init until binding the first addr
 
  - stmmac: clear receive all(RA) bit when promiscuous mode is off
 
  - can: mcp251x: fix resume from sleep before interface was brought up
 
 Previous releases - always broken:
 
  - bpf: fix leakage of uninitialized bpf stack under speculation
 
  - bpf: fix masking negation logic upon negative dst register
 
  - netfilter: don't assume that skb_header_pointer() will never fail
 
  - only allow init netns to set default tcp cong to a restricted algo
 
  - xsk: fix xp_aligned_validate_desc() when len == chunk_size to
         avoid false positive errors
 
  - ethtool: fix missing NLM_F_MULTI flag when dumping
 
  - can: m_can: m_can_tx_work_queue(): fix tx_skb race condition
 
  - sctp: fix a SCTP_MIB_CURRESTAB leak in sctp_sf_do_dupcook_b
 
  - bridge: fix NULL-deref caused by a races between assigning
            rx_handler_data and setting the IFF_BRIDGE_PORT bit
 
 Latecomer:
 
  - seg6: add counters support for SRv6 Behaviors
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.13-rc1, including fixes from bpf, can and
  netfilter trees. Self-contained fixes, nothing risky.

  Current release - new code bugs:

   - dsa: ksz: fix a few bugs found by static-checker in the new driver

   - stmmac: fix frame preemption handshake not triggering after
     interface restart

  Previous releases - regressions:

   - make nla_strcmp handle more then one trailing null character

   - fix stack OOB reads while fragmenting IPv4 packets in openvswitch
     and net/sched

   - sctp: do asoc update earlier in sctp_sf_do_dupcook_a

   - sctp: delay auto_asconf init until binding the first addr

   - stmmac: clear receive all(RA) bit when promiscuous mode is off

   - can: mcp251x: fix resume from sleep before interface was brought up

  Previous releases - always broken:

   - bpf: fix leakage of uninitialized bpf stack under speculation

   - bpf: fix masking negation logic upon negative dst register

   - netfilter: don't assume that skb_header_pointer() will never fail

   - only allow init netns to set default tcp cong to a restricted algo

   - xsk: fix xp_aligned_validate_desc() when len == chunk_size to avoid
     false positive errors

   - ethtool: fix missing NLM_F_MULTI flag when dumping

   - can: m_can: m_can_tx_work_queue(): fix tx_skb race condition

   - sctp: fix a SCTP_MIB_CURRESTAB leak in sctp_sf_do_dupcook_b

   - bridge: fix NULL-deref caused by a races between assigning
     rx_handler_data and setting the IFF_BRIDGE_PORT bit

  Latecomer:

   - seg6: add counters support for SRv6 Behaviors"

* tag 'net-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (73 commits)
  atm: firestream: Use fallthrough pseudo-keyword
  net: stmmac: Do not enable RX FIFO overflow interrupts
  mptcp: fix splat when closing unaccepted socket
  i40e: Remove LLDP frame filters
  i40e: Fix PHY type identifiers for 2.5G and 5G adapters
  i40e: fix the restart auto-negotiation after FEC modified
  i40e: Fix use-after-free in i40e_client_subtask()
  i40e: fix broken XDP support
  netfilter: nftables: avoid potential overflows on 32bit arches
  netfilter: nftables: avoid overflows in nft_hash_buckets()
  tcp: Specify cmsgbuf is user pointer for receive zerocopy.
  mlxsw: spectrum_mr: Update egress RIF list before route's action
  net: ipa: fix inter-EE IRQ register definitions
  can: m_can: m_can_tx_work_queue(): fix tx_skb race condition
  can: mcp251x: fix resume from sleep before interface was brought up
  can: mcp251xfd: mcp251xfd_probe(): add missing can_rx_offload_del() in error path
  can: mcp251xfd: mcp251xfd_probe(): fix an error pointer dereference in probe
  netfilter: nftables: Fix a memleak from userdata error path in new objects
  netfilter: remove BUG_ON() after skb_header_pointer()
  netfilter: nfnetlink_osf: Fix a missing skb_header_pointer() NULL check
  ...
2021-05-08 08:31:46 -07:00
Linus Torvalds a48b0872e6 Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton:
 "This is everything else from -mm for this merge window.

  90 patches.

  Subsystems affected by this patch series: mm (cleanups and slub),
  alpha, procfs, sysctl, misc, core-kernel, bitmap, lib, compat,
  checkpatch, epoll, isofs, nilfs2, hpfs, exit, fork, kexec, gcov,
  panic, delayacct, gdb, resource, selftests, async, initramfs, ipc,
  drivers/char, and spelling"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (90 commits)
  mm: fix typos in comments
  mm: fix typos in comments
  treewide: remove editor modelines and cruft
  ipc/sem.c: spelling fix
  fs: fat: fix spelling typo of values
  kernel/sys.c: fix typo
  kernel/up.c: fix typo
  kernel/user_namespace.c: fix typos
  kernel/umh.c: fix some spelling mistakes
  include/linux/pgtable.h: few spelling fixes
  mm/slab.c: fix spelling mistake "disired" -> "desired"
  scripts/spelling.txt: add "overflw"
  scripts/spelling.txt: Add "diabled" typo
  scripts/spelling.txt: add "overlfow"
  arm: print alloc free paths for address in registers
  mm/vmalloc: remove vwrite()
  mm: remove xlate_dev_kmem_ptr()
  drivers/char: remove /dev/kmem for good
  mm: fix some typos and code style problems
  ipc/sem.c: mundane typo fixes
  ...
2021-05-07 00:34:51 -07:00
Xiaofeng Cao 5afe69c2cc kernel/sys.c: fix typo
change 'infite'     to 'infinite'
change 'concurent'  to 'concurrent'
change 'memvers'    to 'members'
change 'decendants' to 'descendants'
change 'argumets'   to 'arguments'

Link: https://lkml.kernel.org/r/20210316112904.10661-1-cxfcosmos@gmail.com
Signed-off-by: Xiaofeng Cao <caoxiaofeng@yulong.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:34 -07:00
Bhaskar Chowdhury f0fffaff0b kernel/up.c: fix typo
s/condtions/conditions/

Link: https://lkml.kernel.org/r/20210317032732.3260835-1-unixbhaskar@gmail.com
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:34 -07:00
Xiaofeng Cao a12f4f85bc kernel/user_namespace.c: fix typos
change 'verifing' to 'verifying'
change 'certaint' to 'certain'
change 'approprpiate' to 'appropriate'

Link: https://lkml.kernel.org/r/20210317100129.12440-1-caoxiaofeng@yulong.com
Signed-off-by: Xiaofeng Cao <caoxiaofeng@yulong.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:34 -07:00
zhouchuangao 48207f7d41 kernel/umh.c: fix some spelling mistakes
Fix some spelling mistakes, and modify the order of the parameter comments
to be consistent with the order of the parameters passed to the function.

Link: https://lkml.kernel.org/r/1615636139-4076-1-git-send-email-zhouchuangao@vivo.com
Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:34 -07:00
David Hildenbrand bbcd53c960 drivers/char: remove /dev/kmem for good
Patch series "drivers/char: remove /dev/kmem for good".

Exploring /dev/kmem and /dev/mem in the context of memory hot(un)plug and
memory ballooning, I started questioning the existence of /dev/kmem.

Comparing it with the /proc/kcore implementation, it does not seem to be
able to deal with things like

a) Pages unmapped from the direct mapping (e.g., to be used by secretmem)
  -> kern_addr_valid(). virt_addr_valid() is not sufficient.

b) Special cases like gart aperture memory that is not to be touched
  -> mem_pfn_is_ram()

Unless I am missing something, it's at least broken in some cases and might
fault/crash the machine.

Looks like its existence has been questioned before in 2005 and 2010 [1],
after ~11 additional years, it might make sense to revive the discussion.

CONFIG_DEVKMEM is only enabled in a single defconfig (on purpose or by
mistake?).  All distributions disable it: in Ubuntu it has been disabled
for more than 10 years, in Debian since 2.6.31, in Fedora at least
starting with FC3, in RHEL starting with RHEL4, in SUSE starting from
15sp2, and OpenSUSE has it disabled as well.

1) /dev/kmem was popular for rootkits [2] before it got disabled
   basically everywhere. Ubuntu documents [3] "There is no modern user of
   /dev/kmem any more beyond attackers using it to load kernel rootkits.".
   RHEL documents in a BZ [5] "it served no practical purpose other than to
   serve as a potential security problem or to enable binary module drivers
   to access structures/functions they shouldn't be touching"

2) /proc/kcore is a decent interface to have a controlled way to read
   kernel memory for debugging puposes. (will need some extensions to
   deal with memory offlining/unplug, memory ballooning, and poisoned
   pages, though)

3) It might be useful for corner case debugging [1]. KDB/KGDB might be a
   better fit, especially, to write random memory; harder to shoot
   yourself into the foot.

4) "Kernel Memory Editor" [4] hasn't seen any updates since 2000 and seems
   to be incompatible with 64bit [1]. For educational purposes,
   /proc/kcore might be used to monitor value updates -- or older
   kernels can be used.

5) It's broken on arm64, and therefore, completely disabled there.

Looks like it's essentially unused and has been replaced by better
suited interfaces for individual tasks (/proc/kcore, KDB/KGDB). Let's
just remove it.

[1] https://lwn.net/Articles/147901/
[2] https://www.linuxjournal.com/article/10505
[3] https://wiki.ubuntu.com/Security/Features#A.2Fdev.2Fkmem_disabled
[4] https://sourceforge.net/projects/kme/
[5] https://bugzilla.redhat.com/show_bug.cgi?id=154796

Link: https://lkml.kernel.org/r/20210324102351.6932-1-david@redhat.com
Link: https://lkml.kernel.org/r/20210324102351.6932-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Alexander A. Klimov" <grandmaster@al2klimov.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Corentin Labbe <clabbe@baylibre.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Gregory Clement <gregory.clement@bootlin.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hillf Danton <hdanton@sina.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: James Troup <james.troup@canonical.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kairui Song <kasong@redhat.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: openrisc@lists.librecores.org
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Pavel Machek (CIP)" <pavel@denx.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: sparclinux@vger.kernel.org
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Theodore Dubois <tblodt@icloud.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: William Cohen <wcohen@redhat.com>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:34 -07:00
Rasmus Villemoes 17652f4240 modules: add CONFIG_MODPROBE_PATH
Allow the developer to specifiy the initial value of the modprobe_path[]
string.  This can be used to set it to the empty string initially, thus
effectively disabling request_module() during early boot until userspace
writes a new value via the /proc/sys/kernel/modprobe interface.  [1]

When building a custom kernel (often for an embedded target), it's normal
to build everything into the kernel that is needed for booting, and indeed
the initramfs often contains no modules at all, so every such
request_module() done before userspace init has mounted the real rootfs is
a waste of time.

This is particularly useful when combined with the previous patch, which
made the initramfs unpacking asynchronous - for that to work, it had to
make any usermodehelper call wait for the unpacking to finish before
attempting to invoke the userspace helper.  By eliminating all such
(known-to-be-futile) calls of usermodehelper, the initramfs unpacking and
the {device,late}_initcalls can proceed in parallel for much longer.

For a relatively slow ppc board I'm working on, the two patches combined
lead to 0.2s faster boot - but more importantly, the fact that the
initramfs unpacking proceeds completely in the background while devices
get probed means I get to handle the gpio watchdog in time without getting
reset.

[1] __request_module() already has an early -ENOENT return when
modprobe_path is the empty string.

Link: https://lkml.kernel.org/r/20210313212528.2956377-3-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
Rasmus Villemoes e7cb072eb9 init/initramfs.c: do unpacking asynchronously
Patch series "background initramfs unpacking, and CONFIG_MODPROBE_PATH", v3.

These two patches are independent, but better-together.

The second is a rather trivial patch that simply allows the developer to
change "/sbin/modprobe" to something else - e.g.  the empty string, so
that all request_module() during early boot return -ENOENT early, without
even spawning a usermode helper, needlessly synchronizing with the
initramfs unpacking.

The first patch delegates decompressing the initramfs to a worker thread,
allowing do_initcalls() in main.c to proceed to the device_ and late_
initcalls without waiting for that decompression (and populating of
rootfs) to finish.  Obviously, some of those later calls may rely on the
initramfs being available, so I've added synchronization points in the
firmware loader and usermodehelper paths - there might be other places
that would need this, but so far no one has been able to think of any
places I have missed.

There's not much to win if most of the functionality needed during boot is
only available as modules.  But systems with a custom-made .config and
initramfs can boot faster, partly due to utilizing more than one cpu
earlier, partly by avoiding known-futile modprobe calls (which would still
trigger synchronization with the initramfs unpacking, thus eliminating
most of the first benefit).

This patch (of 2):

Most of the boot process doesn't actually need anything from the
initramfs, until of course PID1 is to be executed.  So instead of doing
the decompressing and populating of the initramfs synchronously in
populate_rootfs() itself, push that off to a worker thread.

This is primarily motivated by an embedded ppc target, where unpacking
even the rather modest sized initramfs takes 0.6 seconds, which is long
enough that the external watchdog becomes unhappy that it doesn't get
attention soon enough.  By doing the initramfs decompression in a worker
thread, we get to do the device_initcalls and hence start petting the
watchdog much sooner.

Normal desktops might benefit as well.  On my mostly stock Ubuntu kernel,
my initramfs is a 26M xz-compressed blob, decompressing to around 126M.
That takes almost two seconds:

[    0.201454] Trying to unpack rootfs image as initramfs...
[    1.976633] Freeing initrd memory: 29416K

Before this patch, these lines occur consecutively in dmesg.  With this
patch, the timestamps on these two lines is roughly the same as above, but
with 172 lines inbetween - so more than one cpu has been kept busy doing
work that would otherwise only happen after the populate_rootfs()
finished.

Should one of the initcalls done after rootfs_initcall time (i.e., device_
and late_ initcalls) need something from the initramfs (say, a kernel
module or a firmware blob), it will simply wait for the initramfs
unpacking to be done before proceeding, which should in theory make this
completely safe.

But if some driver pokes around in the filesystem directly and not via one
of the official kernel interfaces (i.e.  request_firmware*(),
call_usermodehelper*) that theory may not hold - also, I certainly might
have missed a spot when sprinkling wait_for_initramfs().  So there is an
escape hatch in the form of an initramfs_async= command line parameter.

Link: https://lkml.kernel.org/r/20210313212528.2956377-1-linux@rasmusvillemoes.dk
Link: https://lkml.kernel.org/r/20210313212528.2956377-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
Rasmus Villemoes a065c0faac kernel/async.c: remove async_unregister_domain()
No callers in the tree.

Link: https://lkml.kernel.org/r/20210309151723.1907838-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
Rasmus Villemoes 07416af11d kernel/async.c: stop guarding pr_debug() statements
It's currently nigh impossible to get these pr_debug()s to print
something.  Being guarded by initcall_debug means one has to enable tons
of other debug output during boot, and the system_state condition further
means it's impossible to get them when loading modules later.

Also, the compiler can't know that these global conditions do not change,
so there are W=2 warnings

kernel/async.c:125:9: warning: `calltime' may be used uninitialized in this function [-Wmaybe-uninitialized]
kernel/async.c:300:9: warning: `starttime' may be used uninitialized in this function [-Wmaybe-uninitialized]

Make it possible, for a DYNAMIC_DEBUG kernel, to get these to print their
messages by booting with appropriate 'dyndbg="file async.c +p"' command
line argument.  For a non-DYNAMIC_DEBUG kernel, pr_debug() compiles to
nothing.

This does cost doing an unconditional ktime_get() for the starttime value,
but the corresponding ktime_get for the end time can be elided by
factoring it into a function which only gets called if the printk()
arguments end up being evaluated.

Link: https://lkml.kernel.org/r/20210309151723.1907838-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
Alistair Popple 56fd94919b kernel/resource: fix locking in request_free_mem_region
request_free_mem_region() is used to find an empty range of physical
addresses for hotplugging ZONE_DEVICE memory.  It does this by iterating
over the range of possible addresses using region_intersects() to see if
the range is free before calling request_mem_region() to allocate the
region.

However the resource_lock is dropped between these two calls meaning by
the time request_mem_region() is called in request_free_mem_region()
another thread may have already reserved the requested region.  This
results in unexpected failures and a message in the kernel log from
hitting this condition:

        /*
         * mm/hmm.c reserves physical addresses which then
         * become unavailable to other users.  Conflicts are
         * not expected.  Warn to aid debugging if encountered.
         */
        if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
                pr_warn("Unaddressable device %s %pR conflicts with %pR",
                        conflict->name, conflict, res);

These unexpected failures can be corrected by holding resource_lock across
the two calls.  This also requires memory allocation to be performed prior
to taking the lock.

Link: https://lkml.kernel.org/r/20210419070109.4780-3-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Muchun Song <smuchun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
Alistair Popple 63cdafe0af kernel/resource: refactor __request_region to allow external locking
Refactor the portion of __request_region() done whilst holding the
resource_lock into a separate function to allow callers to hold the lock.

Link: https://lkml.kernel.org/r/20210419070109.4780-2-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Muchun Song <smuchun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
Alistair Popple d486ccb252 kernel/resource: allow region_intersects users to hold resource_lock
Introduce a version of region_intersects() that can be called with the
resource_lock already held.

This will be used in a future fix to __request_free_mem_region().

[akpm@linux-foundation.org: make __region_intersects static]

Link: https://lkml.kernel.org/r/20210419070109.4780-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Muchun Song <smuchun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
David Hildenbrand 97523a4edb kernel/resource: remove first_lvl / siblings_only logic
All functions that search for IORESOURCE_SYSTEM_RAM or IORESOURCE_MEM
resources now properly consider the whole resource tree, not just the
first level.  Let's drop the unused first_lvl / siblings_only logic.

Remove documentation that indicates that some functions behave differently,
all consider the full resource tree now.

Link: https://lkml.kernel.org/r/20210325115326.7826-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
David Hildenbrand 3c9c797534 kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources
It used to be true that we can have system RAM (IORESOURCE_SYSTEM_RAM |
IORESOURCE_BUSY) only on the first level in the resource tree.  However,
this is no longer holds for driver-managed system RAM (i.e., added via
dax/kmem and virtio-mem), which gets added on lower levels, for example,
inside device containers.

IORESOURCE_SYSTEM_RAM is defined as IORESOURCE_MEM | IORESOURCE_SYSRAM and
just a special type of IORESOURCE_MEM.

The function walk_mem_res() only considers the first level and is used in
arch/x86/mm/ioremap.c:__ioremap_check_mem() only.  We currently fail to
identify System RAM added by dax/kmem and virtio-mem as
"IORES_MAP_SYSTEM_RAM", for example, allowing for remapping of such
"normal RAM" in __ioremap_caller().

Let's find all IORESOURCE_MEM | IORESOURCE_BUSY resources, making the
function behave similar to walk_system_ram_res().

Link: https://lkml.kernel.org/r/20210325115326.7826-3-david@redhat.com
Fixes: ebf71552bb ("virtio-mem: Add parent resource for all added "System RAM"")
Fixes: c221c0b030 ("device-dax: "Hotplug" persistent memory for use like normal RAM")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
David Hildenbrand 97f61c8f44 kernel/resource: make walk_system_ram_res() find all busy IORESOURCE_SYSTEM_RAM resources
Patch series "kernel/resource: make walk_system_ram_res() and walk_mem_res() search the whole tree", v2.

Playing with kdump+virtio-mem I noticed that kexec_file_load() does not
consider System RAM added via dax/kmem and virtio-mem when preparing the
elf header for kdump.  Looking into the details, the logic used in
walk_system_ram_res() and walk_mem_res() seems to be outdated.

walk_system_ram_range() already does the right thing, let's change
walk_system_ram_res() and walk_mem_res(), and clean up.

Loading a kdump kernel via "kexec -p -s" ...  will result in the kdump
kernel to also dump dax/kmem and virtio-mem added System RAM now.

Note: kexec-tools on x86-64 also have to be updated to consider this
memory in the kexec_load() case when processing /proc/iomem.

This patch (of 3):

It used to be true that we can have system RAM (IORESOURCE_SYSTEM_RAM |
IORESOURCE_BUSY) only on the first level in the resource tree.  However,
this is no longer holds for driver-managed system RAM (i.e., added via
dax/kmem and virtio-mem), which gets added on lower levels, for example,
inside device containers.

We have two users of walk_system_ram_res(), which currently only
consideres the first level:

a) kernel/kexec_file.c:kexec_walk_resources() -- We properly skip
   IORESOURCE_SYSRAM_DRIVER_MANAGED resources via
   locate_mem_hole_callback(), so even after this change, we won't be
   placing kexec images onto dax/kmem and virtio-mem added memory.  No
   change.

b) arch/x86/kernel/crash.c:fill_up_crash_elf_data() -- we're currently
   not adding relevant ranges to the crash elf header, resulting in them
   not getting dumped via kdump.

This change fixes loading a crashkernel via kexec_file_load() and
including dax/kmem and virtio-mem added System RAM in the crashdump on
x86-64.  Note that e.g,, arm64 relies on memblock data and, therefore,
always considers all added System RAM already.

Let's find all IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY resources, making
the function behave like walk_system_ram_range().

Link: https://lkml.kernel.org/r/20210325115326.7826-1-david@redhat.com
Link: https://lkml.kernel.org/r/20210325115326.7826-2-david@redhat.com
Fixes: ebf71552bb ("virtio-mem: Add parent resource for all added "System RAM"")
Fixes: c221c0b030 ("device-dax: "Hotplug" persistent memory for use like normal RAM")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:33 -07:00
Nick Desaulniers 9b472e85d0 gcov: clang: drop support for clang-10 and older
LLVM changed the expected function signatures for llvm_gcda_start_file()
and llvm_gcda_emit_function() in the clang-11 release.  Drop the older
implementations and require folks to upgrade their compiler if they're
interested in GCOV support.

Link: https://reviews.llvm.org/rGcdd683b516d147925212724b09ec6fb792a40041
Link: https://reviews.llvm.org/rG13a633b438b6500ecad9e4f936ebadf3411d0f44
Link: https://lkml.kernel.org/r/20210312224132.3413602-3-ndesaulniers@google.com
Link: https://lkml.kernel.org/r/20210413183113.2977432-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Cc: Prasad Sodagudi <psodagud@quicinc.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00
Johannes Berg 1391efa952 gcov: use kvmalloc()
Using vmalloc() in gcov is really quite wasteful, many of the objects
allocated are really small (e.g.  I've seen 24 bytes.) Use kvmalloc() to
automatically pick the better of kmalloc() or vmalloc() depending on the
size.

[johannes.berg@intel.com: fix clang-11+ build]
  Link: https://lkml.kernel.org/r/20210412214210.6e1ecca9cdc5.I24459763acf0591d5e6b31c7e3a59890d802f79c@changeid

Link: https://lkml.kernel.org/r/20210315235453.799e7a9d627d.I741d0db096c6f312910f7f1bcdfde0fda20801a4@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00
Johannes Berg 3180c44fe1 gcov: simplify buffer allocation
Use just a single vmalloc() with struct_size() instead of a separate
kmalloc() for the iter struct.

Link: https://lkml.kernel.org/r/20210315235453.b6de4a92096e.Iac40a5166589cefbff8449e466bd1b38ea7a17af@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00
Johannes Berg 7a1d55b987 gcov: combine common code
There's a lot of duplicated code between gcc and clang implementations,
move it over to fs.c to simplify the code, there's no reason to believe
that for small data like this one would not just implement the simple
convert_to_gcda() function.

Link: https://lkml.kernel.org/r/20210315235453.e3fbb86e99a0.I08a3ee6dbe47ea3e8024956083f162884a958e40@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00
Pavel Tatashin b2075dbb15 kexec: dump kmessage before machine_kexec
kmsg_dump(KMSG_DUMP_SHUTDOWN) is called before machine_restart(),
machine_halt(), and machine_power_off().  The only one that is missing
is machine_kexec().

The dmesg output that it contains can be used to study the shutdown
performance of both kernel and systemd during kexec reboot.

Here is example of dmesg data collected after kexec:

  root@dplat-cp22:~# cat /sys/fs/pstore/dmesg-ramoops-0 | tail
  ...
  [   70.914592] psci: CPU3 killed (polled 0 ms)
  [   70.915705] CPU4: shutdown
  [   70.916643] psci: CPU4 killed (polled 4 ms)
  [   70.917715] CPU5: shutdown
  [   70.918725] psci: CPU5 killed (polled 0 ms)
  [   70.919704] CPU6: shutdown
  [   70.920726] psci: CPU6 killed (polled 4 ms)
  [   70.921642] CPU7: shutdown
  [   70.922650] psci: CPU7 killed (polled 0 ms)

Link: https://lkml.kernel.org/r/20210319192326.146000-2-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00
Jia-Ju Bai 31d82c2c78 kernel: kexec_file: fix error return code of kexec_calculate_store_digests()
When vzalloc() returns NULL to sha_regions, no error return code of
kexec_calculate_store_digests() is assigned.  To fix this bug, ret is
assigned with -ENOMEM in this case.

Link: https://lkml.kernel.org/r/20210309083904.24321-1-baijiaju1990@gmail.com
Fixes: a43cac0d9d ("kexec: split kexec_file syscall code to kexec_file.c")
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00
Joe LeVeque a119b4e518 kexec: Add kexec reboot string
The purpose is to notify the kernel module for fast reboot.

Upstream a patch from the SONiC network operating system [1].

[1]: https://github.com/Azure/sonic-linux-kernel/pull/46

Link: https://lkml.kernel.org/r/20210304124626.13927-1-pmenzel@molgen.mpg.de
Signed-off-by: Joe LeVeque <jolevequ@microsoft.com>
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Guohan Lu <lguohan@gmail.com>
Cc: Joe LeVeque <jolevequ@microsoft.com>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00
Xiaofeng Cao a8ca6b1388 kernel/fork.c: fix typos
change 'ancestoral' to 'ancestral'
change 'reuseable' to 'reusable'
delete 'do' grammatically

Link: https://lkml.kernel.org/r/20210317082031.11692-1-caoxiaofeng@yulong.com
Signed-off-by: Xiaofeng Cao <caoxiaofeng@yulong.com>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:13 -07:00
Rolf Eike Beer a689539938 kernel/fork.c: simplify copy_mm()
All this can happen without a single goto.

Link: https://lkml.kernel.org/r/2072685.XptgVkyDqn@devpool47
Signed-off-by: Rolf Eike Beer <eb@emlix.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:13 -07:00
Jim Newsome 5449162ac0 do_wait: make PIDTYPE_PID case O(1) instead of O(n)
Add a special-case when waiting on a pid (via waitpid, waitid, wait4, etc)
to avoid doing an O(n) scan of children and tracees, and instead do an
O(1) lookup.  This improves performance when waiting on a pid from a
thread group with many children and/or tracees.

Time to fork and then call waitpid on the child, from a task that already
has N children [1]:

N    | Before  | After
-----|---------|------
1    | 74 us   | 74 us
20   | 72 us   | 75 us
100  | 83 us   | 77 us
500  | 99 us   | 74 us
1000 | 179 us  | 75 us
5000 | 804 us  | 79 us
8000 | 1268 us | 78 us

[1]: https://lkml.org/lkml/2021/3/12/1567

This can make a substantial performance improvement for applications with
a thread that has many children or tracees and frequently needs to wait on
them.  Tools that use ptrace to intercept syscalls for a large number of
processes are likely to fall into this category.  In particular this patch
was developed while building a ptrace-based second generation of the
Shadow emulator [2], for which it allows us to avoid quadratic scaling
(without having to use a workaround that introduces a ~40% performance
penalty) [3].  Other examples of tools that fall into this category which
this patch may help include User Mode Linux [4] and DetTrace [5].

[2]: https://shadow.github.io/
[3]: https://github.com/shadow/shadow/issues/1134#issuecomment-798992292
[4]: https://en.wikipedia.org/wiki/User-mode_Linux
[5]: https://github.com/dettrace/dettrace

Link: https://lkml.kernel.org/r/20210314231544.9379-1-jnewsome@torproject.org
Signed-off-by: James Newsome <jnewsome@torproject.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Christian Brauner <christian@brauner.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:13 -07:00
Rasmus Villemoes 32c93976ac kernel/cred.c: make init_groups static
init_groups is declared in both cred.h and init_task.h, but it is not
actually referenced anywhere outside of cred.c where it is defined.  So
make it static and remove the declarations.

Link: https://lkml.kernel.org/r/20210310220102.2484201-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:11 -07:00
Rasmus Villemoes 8ba9d40b6b kernel/async.c: fix pr_debug statement
An async_func_t returns void - any errors encountered it has to stash
somewhere for consumers to discover later.

Link: https://lkml.kernel.org/r/20210226124355.2503524-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:11 -07:00
Thomas Gleixner 51cf94d168 futex: Make syscall entry points less convoluted
The futex and the compat syscall entry points do pretty much the same
except for the timespec data types and the corresponding copy from
user function.

Split out the rest into inline functions and share the functionality.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210422194705.244476369@linutronix.de
2021-05-06 20:19:04 +02:00
Thomas Gleixner b097d5ed33 futex: Get rid of the val2 conditional dance
There is no point in checking which FUTEX operand treats the utime pointer
as 'val2' argument because that argument to do_futex() is only used by
exactly these operands.

So just handing it in unconditionally is not making any difference, but
removes a lot of pointless gunk.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210422194705.125957049@linutronix.de
2021-05-06 20:19:04 +02:00
Thomas Gleixner cdf78db407 futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI
FUTEX_LOCK_PI does not require to have the FUTEX_CLOCK_REALTIME bit set
because it has been using CLOCK_REALTIME based absolute timeouts
forever. Due to that, the time namespace adjustment which is applied when
FUTEX_CLOCK_REALTIME is not set, will wrongly take place for FUTEX_LOCK_PI
and wreckage the timeout.

Exclude it from that procedure.

Fixes: c2f7d08ccc ("futex: Adjust absolute futex timeouts with per time namespace offset")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210422194704.984540159@linutronix.de
2021-05-06 20:12:40 +02:00
Thomas Gleixner 4fbf5d6837 Revert 337f13046f ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op")
The FUTEX_WAIT operand has historically a relative timeout which means that
the clock id is irrelevant as relative timeouts on CLOCK_REALTIME are not
subject to wall clock changes and therefore are mapped by the kernel to
CLOCK_MONOTONIC for simplicity.

If a caller would set FUTEX_CLOCK_REALTIME for FUTEX_WAIT the timeout is
still treated relative vs. CLOCK_MONOTONIC and then the wait arms that
timeout based on CLOCK_REALTIME which is broken and obviously has never
been used or even tested.

Reject any attempt to use FUTEX_CLOCK_REALTIME with FUTEX_WAIT again.

The desired functionality can be achieved with FUTEX_WAIT_BITSET and a
FUTEX_BITSET_MATCH_ANY argument.

Fixes: 337f13046f ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210422194704.834797921@linutronix.de
2021-05-06 20:12:40 +02:00
Linus Torvalds 7ec901b6fa tracing: Fix probes written to the set_ftrace_filter file
Now that there's a library that accesses the tracefs file system,
 (libtracefs), the way the files are interacted with is slightly
 different than the command line. For instance, the write() system
 call is used directly instead of an echo. This exposes some old bugs.
 
 If a probe is written to "set_ftrace_filter" without any white space
 after it, it will be ignored. This is because the write expects
 that a string written to it that does not end with white spaces thinks
 there is more to come. But if the file is closed, the release function
 needs to finish it. The "set_ftrace_filter" release function handles
 the filter part of the "set_ftrace_filter" file, but did not handle
 the probe part.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCYJP4OBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6quzjAQCoFQXkJtYhwlMk0dTxclrsQlm0t93H
 pHwJA9Zyxe25UgD8D/rpG/wtHaSSuP6omEDbqvshpNdszqKb0Nt+UM116QU=
 =niJ6
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fix probes written to the set_ftrace_filter file

  Now that there's a library that accesses the tracefs file system
  (libtracefs), the way the files are interacted with is slightly
  different than the command line. For instance, the write() system call
  is used directly instead of an echo. This exposes some old bugs.

  If a probe is written to "set_ftrace_filter" without any white space
  after it, it will be ignored. This is because the write expects that a
  string written to it that does not end with white spaces thinks there
  is more to come. But if the file is closed, the release function needs
  to finish it. The "set_ftrace_filter" release function handles the
  filter part of the "set_ftrace_filter" file, but did not handle the
  probe part"

* tag 'trace-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Handle commands when closing set_ftrace_filter file
2021-05-06 10:03:38 -07:00
Waiman Long 28ce0e70ec locking/qrwlock: Cleanup queued_write_lock_slowpath()
Make the code more readable by replacing the atomic_cmpxchg_acquire()
by an equivalent atomic_try_cmpxchg_acquire() and change atomic_add()
to atomic_or().

For architectures that use qrwlock, I do not find one that has an
atomic_add() defined but not an atomic_or().  I guess it should be fine
by changing atomic_add() to atomic_or().

Note that the previous use of atomic_add() isn't wrong as only one
writer that is the wait_lock owner can set the waiting flag and the
flag will be cleared later on when acquiring the write lock.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20210426185017.19815-1-longman@redhat.com
2021-05-06 15:33:49 +02:00
Arnd Bergmann 1139aeb1c5 smp: Fix smp_call_function_single_async prototype
As of commit 966a967116 ("smp: Avoid using two cache lines for struct
call_single_data"), the smp code prefers 32-byte aligned call_single_data
objects for performance reasons, but the block layer includes an instance
of this structure in the main 'struct request' that is more senstive
to size than to performance here, see 4ccafe0320 ("block: unalign
call_single_data in struct request").

The result is a violation of the calling conventions that clang correctly
points out:

block/blk-mq.c:630:39: warning: passing 8-byte aligned argument to 32-byte aligned parameter 2 of 'smp_call_function_single_async' may result in an unaligned pointer access [-Walign-mismatch]
                smp_call_function_single_async(cpu, &rq->csd);

It does seem that the usage of the call_single_data without cache line
alignment should still be allowed by the smp code, so just change the
function prototype so it accepts both, but leave the default alignment
unchanged for the other users. This seems better to me than adding
a local hack to shut up an otherwise correct warning in the caller.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lkml.kernel.org/r/20210505211300.3174456-1-arnd@kernel.org
2021-05-06 15:33:49 +02:00
Odin Ugedal 0258bdfaff sched/fair: Fix unfairness caused by missing load decay
This fixes an issue where old load on a cfs_rq is not properly decayed,
resulting in strange behavior where fairness can decrease drastically.
Real workloads with equally weighted control groups have ended up
getting a respective 99% and 1%(!!) of cpu time.

When an idle task is attached to a cfs_rq by attaching a pid to a cgroup,
the old load of the task is attached to the new cfs_rq and sched_entity by
attach_entity_cfs_rq. If the task is then moved to another cpu (and
therefore cfs_rq) before being enqueued/woken up, the load will be moved
to cfs_rq->removed from the sched_entity. Such a move will happen when
enforcing a cpuset on the task (eg. via a cgroup) that force it to move.

The load will however not be removed from the task_group itself, making
it look like there is a constant load on that cfs_rq. This causes the
vruntime of tasks on other sibling cfs_rq's to increase faster than they
are supposed to; causing severe fairness issues. If no other task is
started on the given cfs_rq, and due to the cpuset it would not happen,
this load would never be properly unloaded. With this patch the load
will be properly removed inside update_blocked_averages. This also
applies to tasks moved to the fair scheduling class and moved to another
cpu, and this path will also fix that. For fork, the entity is queued
right away, so this problem does not affect that.

This applies to cases where the new process is the first in the cfs_rq,
issue introduced 3d30544f02 ("sched/fair: Apply more PELT fixes"), and
when there has previously been load on the cgroup but the cgroup was
removed from the leaflist due to having null PELT load, indroduced
in 039ae8bcf7 ("sched/fair: Fix O(nr_cgroups) in the load balancing
path").

For a simple cgroup hierarchy (as seen below) with two equally weighted
groups, that in theory should get 50/50 of cpu time each, it often leads
to a load of 60/40 or 70/30.

parent/
  cg-1/
    cpu.weight: 100
    cpuset.cpus: 1
  cg-2/
    cpu.weight: 100
    cpuset.cpus: 1

If the hierarchy is deeper (as seen below), while keeping cg-1 and cg-2
equally weighted, they should still get a 50/50 balance of cpu time.
This however sometimes results in a balance of 10/90 or 1/99(!!) between
the task groups.

$ ps u -C stress
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root       18568  1.1  0.0   3684   100 pts/12   R+   13:36   0:00 stress --cpu 1
root       18580 99.3  0.0   3684   100 pts/12   R+   13:36   0:09 stress --cpu 1

parent/
  cg-1/
    cpu.weight: 100
    sub-group/
      cpu.weight: 1
      cpuset.cpus: 1
  cg-2/
    cpu.weight: 100
    sub-group/
      cpu.weight: 10000
      cpuset.cpus: 1

This can be reproduced by attaching an idle process to a cgroup and
moving it to a given cpuset before it wakes up. The issue is evident in
many (if not most) container runtimes, and has been reproduced
with both crun and runc (and therefore docker and all its "derivatives"),
and with both cgroup v1 and v2.

Fixes: 3d30544f02 ("sched/fair: Apply more PELT fixes")
Fixes: 039ae8bcf7 ("sched/fair: Fix O(nr_cgroups) in the load balancing path")
Signed-off-by: Odin Ugedal <odin@uged.al>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210501141950.23622-2-odin@uged.al
2021-05-06 15:33:27 +02:00
Quentin Perret 6d2f8909a5 sched: Fix out-of-bound access in uclamp
Util-clamp places tasks in different buckets based on their clamp values
for performance reasons. However, the size of buckets is currently
computed using a rounding division, which can lead to an off-by-one
error in some configurations.

For instance, with 20 buckets, the bucket size will be 1024/20=51. A
task with a clamp of 1024 will be mapped to bucket id 1024/51=20. Sadly,
correct indexes are in range [0,19], hence leading to an out of bound
memory access.

Clamp the bucket id to fix the issue.

Fixes: 69842cba9a ("sched/uclamp: Add CPU's clamp buckets refcounting")
Suggested-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lkml.kernel.org/r/20210430151412.160913-1-qperret@google.com
2021-05-06 15:33:26 +02:00
Johannes Weiner d583d360a6 psi: Fix psi state corruption when schedule() races with cgroup move
4117cebf1a ("psi: Optimize task switch inside shared cgroups")
introduced a race condition that corrupts internal psi state. This
manifests as kernel warnings, sometimes followed by bogusly high IO
pressure:

  psi: task underflow! cpu=1 t=2 tasks=[0 0 0 0] clear=c set=0
  (schedule() decreasing RUNNING and ONCPU, both of which are 0)

  psi: incosistent task state! task=2412744:systemd cpu=17 psi_flags=e clear=3 set=0
  (cgroup_move_task() clearing MEMSTALL and IOWAIT, but task is MEMSTALL | RUNNING | ONCPU)

What the offending commit does is batch the two psi callbacks in
schedule() to reduce the number of cgroup tree updates. When prev is
deactivated and removed from the runqueue, nothing is done in psi at
first; when the task switch completes, TSK_RUNNING and TSK_IOWAIT are
updated along with TSK_ONCPU.

However, the deactivation and the task switch inside schedule() aren't
atomic: pick_next_task() may drop the rq lock for load balancing. When
this happens, cgroup_move_task() can run after the task has been
physically dequeued, but the psi updates are still pending. Since it
looks at the task's scheduler state, it doesn't move everything to the
new cgroup that the task switch that follows is about to clear from
it. cgroup_move_task() will leak the TSK_RUNNING count in the old
cgroup, and psi_sched_switch() will underflow it in the new cgroup.

A similar thing can happen for iowait. TSK_IOWAIT is usually set when
a p->in_iowait task is dequeued, but again this update is deferred to
the switch. cgroup_move_task() can see an unqueued p->in_iowait task
and move a non-existent TSK_IOWAIT. This results in the inconsistent
task state warning, as well as a counter underflow that will result in
permanent IO ghost pressure being reported.

Fix this bug by making cgroup_move_task() use task->psi_flags instead
of looking at the potentially mismatching scheduler state.

[ We used the scheduler state historically in order to not rely on
  task->psi_flags for anything but debugging. But that ship has sailed
  anyway, and this is simpler and more robust.

  We previously already batched TSK_ONCPU clearing with the
  TSK_RUNNING update inside the deactivation call from schedule(). But
  that ordering was safe and didn't result in TSK_ONCPU corruption:
  unlike most places in the scheduler, cgroup_move_task() only checked
  task_current() and handled TSK_ONCPU if the task was still queued. ]

Fixes: 4117cebf1a ("psi: Optimize task switch inside shared cgroups")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210503174917.38579-1-hannes@cmpxchg.org
2021-05-06 15:33:26 +02:00
Linus Torvalds 8404c9fbc8 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "The remainder of the main mm/ queue.

  143 patches.

  Subsystems affected by this patch series (all mm): pagecache, hugetlb,
  userfaultfd, vmscan, compaction, migration, cma, ksm, vmstat, mmap,
  kconfig, util, memory-hotplug, zswap, zsmalloc, highmem, cleanups, and
  kfence"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (143 commits)
  kfence: use power-efficient work queue to run delayed work
  kfence: maximize allocation wait timeout duration
  kfence: await for allocation using wait_event
  kfence: zero guard page after out-of-bounds access
  mm/process_vm_access.c: remove duplicate include
  mm/mempool: minor coding style tweaks
  mm/highmem.c: fix coding style issue
  btrfs: use memzero_page() instead of open coded kmap pattern
  iov_iter: lift memzero_page() to highmem.h
  mm/zsmalloc: use BUG_ON instead of if condition followed by BUG.
  mm/zswap.c: switch from strlcpy to strscpy
  arm64/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
  x86/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
  mm,memory_hotplug: add kernel boot option to enable memmap_on_memory
  acpi,memhotplug: enable MHP_MEMMAP_ON_MEMORY when supported
  mm,memory_hotplug: allocate memmap from the added memory range
  mm,memory_hotplug: factor out adjusting present pages into adjust_present_page_count()
  mm,memory_hotplug: relax fully spanned sections check
  drivers/base/memory: introduce memory_block_{online,offline}
  mm/memory_hotplug: remove broken locking of zone PCP structures during hot remove
  ...
2021-05-05 13:50:15 -07:00
Linus Torvalds 5d6a1b84e0 gpio updates for v5.13
- new driver for the Realtek Otto GPIO controller
 - ACPI support for gpio-mpc8xxx
 - edge event support for gpio-sch (+ Kconfig fixes)
 - Kconfig improvements in gpio-ich
 - fixes to older issues in gpio-mockup
 - ACPI quirk for ignoring EC wakeups on Dell Venue 10 Pro 5055
 - improve the GPIO aggregator code by using more generic interfaces instead of
   reimplementing them in the driver
 - convert the DT bindings for gpio-74x164 to yaml
 - documentation improvements
 - a slew of other minor fixes and improvements to GPIO drivers
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Merge tag 'gpio-updates-for-v5.13-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:

 - new driver for the Realtek Otto GPIO controller

 - ACPI support for gpio-mpc8xxx

 - edge event support for gpio-sch (+ Kconfig fixes)

 - Kconfig improvements in gpio-ich

 - fixes to older issues in gpio-mockup

 - ACPI quirk for ignoring EC wakeups on Dell Venue 10 Pro 5055

 - improve the GPIO aggregator code by using more generic interfaces
   instead of reimplementing them in the driver

 - convert the DT bindings for gpio-74x164 to yaml

 - documentation improvements

 - a slew of other minor fixes and improvements to GPIO drivers

* tag 'gpio-updates-for-v5.13-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (34 commits)
  dt-bindings: gpio: add YAML description for rockchip,gpio-bank
  gpio: mxs: remove useless function
  dt-bindings: gpio: fairchild,74hc595: Convert to json-schema
  gpio: it87: remove unused code
  gpio: 104-dio-48e: Fix coding style issues
  gpio: mpc8xxx: Add ACPI support
  gpio: ich: Switch to be dependent on LPC_ICH
  gpio: sch: Drop MFD_CORE selection
  gpio: sch: depends on LPC_SCH
  gpiolib: acpi: Add quirk to ignore EC wakeups on Dell Venue 10 Pro 5055
  gpio: sch: Hook into ACPI GPE handler to catch GPIO edge events
  gpio: sch: Add edge event support
  gpio: aggregator: Replace custom get_arg() with a generic next_arg()
  lib/cmdline: Export next_arg() for being used in modules
  gpio: omap: Use device_get_match_data() helper
  gpio: Add Realtek Otto GPIO support
  dt-bindings: gpio: Binding for Realtek Otto GPIO
  docs: kernel-parameters: Add gpio_mockup_named_lines
  docs: kernel-parameters: Move gpio-mockup for alphabetic order
  lib: bitmap: provide devm_bitmap_alloc() and devm_bitmap_zalloc()
  ...
2021-05-05 12:39:29 -07:00
Pintu Kumar ef49843841 mm/compaction: remove unused variable sysctl_compact_memory
The sysctl_compact_memory is mostly unused in mm/compaction.c It just
acts as a place holder for sysctl to store .data.

But the .data itself is not needed here.

So we can get ride of this variable completely and make .data as NULL.
This will also eliminate the extern declaration from header file.  No
functionality is broken or changed this way.

Link: https://lkml.kernel.org/r/1614852224-14671-1-git-send-email-pintu@codeaurora.org
Signed-off-by: Pintu Kumar <pintu@codeaurora.org>
Signed-off-by: Pintu Agarwal <pintu.ping@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05 11:27:24 -07:00
Steven Rostedt (VMware) 8c9af478c0 ftrace: Handle commands when closing set_ftrace_filter file
# echo switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter

will cause switch_mm to stop tracing by the traceoff command.

 # echo -n switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter

does nothing.

The reason is that the parsing in the write function only processes
commands if it finished parsing (there is white space written after the
command). That's to handle:

 write(fd, "switch_mm:", 10);
 write(fd, "traceoff", 8);

cases, where the command is broken over multiple writes.

The problem is if the file descriptor is closed, then the write call is
not processed, and the command needs to be processed in the release code.
The release code can handle matching of functions, but does not handle
commands.

Cc: stable@vger.kernel.org
Fixes: eda1e32855 ("tracing: handle broken names in ftrace filter")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-05-05 10:38:24 -04:00
Linus Torvalds 74d6790cda Merge branch 'stable/for-linus-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "Christoph Hellwig has taken a cleaver and trimmed off the not-needed
  code and nicely folded duplicate code in the generic framework.

  This lays the groundwork for more work to add extra DMA-backend-ish in
  the future. Along with that some bug-fixes to make this a nice working
  package"

* 'stable/for-linus-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: don't override user specified size in swiotlb_adjust_size
  swiotlb: Fix the type of index
  swiotlb: Make SWIOTLB_NO_FORCE perform no allocation
  ARM: Qualify enabling of swiotlb_init()
  swiotlb: remove swiotlb_nr_tbl
  swiotlb: dynamically allocate io_tlb_default_mem
  swiotlb: move global variables into a new io_tlb_mem structure
  xen-swiotlb: remove the unused size argument from xen_swiotlb_fixup
  xen-swiotlb: split xen_swiotlb_init
  swiotlb: lift the double initialization protection from xen-swiotlb
  xen-swiotlb: remove xen_io_tlb_start and xen_io_tlb_nslabs
  xen-swiotlb: remove xen_set_nslabs
  xen-swiotlb: use io_tlb_end in xen_swiotlb_dma_supported
  xen-swiotlb: use is_swiotlb_buffer in is_xen_swiotlb_buffer
  swiotlb: split swiotlb_tbl_sync_single
  swiotlb: move orig addr and size validation into swiotlb_bounce
  swiotlb: remove the alloc_size parameter to swiotlb_tbl_unmap_single
  powerpc/svm: stop using io_tlb_start
2021-05-04 10:58:49 -07:00
Linus Torvalds 954b720705 dma-mapping updates for Linux 5.13:
- add a new dma_alloc_noncontiguous API (me, Ricardo Ribalda)
  - fix a copyright noice (Hao Fang)
  - add an unlikely annotation to dma_mapping_error (Heiner Kallweit)
  - remove a pointless empty line (Wang Qing)
  - add support for multi-pages map/unmap bencharking (Xiang Chen)
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Merge tag 'dma-mapping-5.13' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - add a new dma_alloc_noncontiguous API (me, Ricardo Ribalda)

 - fix a copyright notice (Hao Fang)

 - add an unlikely annotation to dma_mapping_error (Heiner Kallweit)

 - remove a pointless empty line (Wang Qing)

 - add support for multi-pages map/unmap bencharking (Xiang Chen)

* tag 'dma-mapping-5.13' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: add unlikely hint to error path in dma_mapping_error
  dma-mapping: benchmark: Add support for multi-pages map/unmap
  dma-mapping: benchmark: use the correct HiSilicon copyright
  dma-mapping: remove a pointless empty line in dma_alloc_coherent
  media: uvcvideo: Use dma_alloc_noncontiguous API
  dma-iommu: implement ->alloc_noncontiguous
  dma-iommu: refactor iommu_dma_alloc_remap
  dma-mapping: add a dma_alloc_noncontiguous API
  dma-mapping: refactor dma_{alloc,free}_pages
  dma-mapping: add a dma_mmap_pages helper
2021-05-04 10:52:09 -07:00
Linus Torvalds 9b1f61d5d7 tracing updates for 5.13
New feature:
 
  The "func-no-repeats" option in tracefs/options directory. When set
  the function tracer will detect if the current function being traced
  is the same as the previous one, and instead of recording it, it will
  keep track of the number of times that the function is repeated in a row.
  And when another function is recorded, it will write a new event that
  shows the function that repeated, the number of times it repeated and
  the time stamp of when the last repeated function occurred.
 
 Enhancements:
 
  In order to implement the above "func-no-repeats" option, the ring
  buffer timestamp can now give the accurate timestamp of the event
  as it is being recorded, instead of having to record an absolute
  timestamp for all events. This helps the histogram code which no longer
  needs to waste ring buffer space.
 
  New validation logic to make sure all trace events that access
  dereferenced pointers do so in a safe way, and will warn otherwise.
 
 Fixes:
 
  No longer limit the PIDs of tasks that are recorded for "saved_cmdlines"
  to PID_MAX_DEFAULT (32768), as systemd now allows for a much larger
  range. This caused the mapping of PIDs to the task names to be dropped
  for all tasks with a PID greater than 32768.
 
  Change trace_clock_global() to never block. This caused a deadlock.
 
 Clean ups:
 
  Typos, prototype fixes, and removing of duplicate or unused code.
 
  Better management of ftrace_page allocations.
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Merge tag 'trace-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New feature:

   - A new "func-no-repeats" option in tracefs/options directory.

     When set the function tracer will detect if the current function
     being traced is the same as the previous one, and instead of
     recording it, it will keep track of the number of times that the
     function is repeated in a row. And when another function is
     recorded, it will write a new event that shows the function that
     repeated, the number of times it repeated and the time stamp of
     when the last repeated function occurred.

  Enhancements:

   - In order to implement the above "func-no-repeats" option, the ring
     buffer timestamp can now give the accurate timestamp of the event
     as it is being recorded, instead of having to record an absolute
     timestamp for all events. This helps the histogram code which no
     longer needs to waste ring buffer space.

   - New validation logic to make sure all trace events that access
     dereferenced pointers do so in a safe way, and will warn otherwise.

  Fixes:

   - No longer limit the PIDs of tasks that are recorded for
     "saved_cmdlines" to PID_MAX_DEFAULT (32768), as systemd now allows
     for a much larger range. This caused the mapping of PIDs to the
     task names to be dropped for all tasks with a PID greater than
     32768.

   - Change trace_clock_global() to never block. This caused a deadlock.

  Clean ups:

   - Typos, prototype fixes, and removing of duplicate or unused code.

   - Better management of ftrace_page allocations"

* tag 'trace-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (32 commits)
  tracing: Restructure trace_clock_global() to never block
  tracing: Map all PIDs to command lines
  ftrace: Reuse the output of the function tracer for func_repeats
  tracing: Add "func_no_repeats" option for function tracing
  tracing: Unify the logic for function tracing options
  tracing: Add method for recording "func_repeats" events
  tracing: Add "last_func_repeats" to struct trace_array
  tracing: Define new ftrace event "func_repeats"
  tracing: Define static void trace_print_time()
  ftrace: Simplify the calculation of page number for ftrace_page->records some more
  ftrace: Store the order of pages allocated in ftrace_page
  tracing: Remove unused argument from "ring_buffer_time_stamp()
  tracing: Remove duplicate struct declaration in trace_events.h
  tracing: Update create_system_filter() kernel-doc comment
  tracing: A minor cleanup for create_system_filter()
  kernel: trace: Mundane typo fixes in the file trace_events_filter.c
  tracing: Fix various typos in comments
  scripts/recordmcount.pl: Make vim and emacs indent the same
  scripts/recordmcount.pl: Make indent spacing consistent
  tracing: Add a verifier to check string pointers for trace events
  ...
2021-05-03 11:19:54 -07:00
Linus Torvalds 23806a3e96 Merge branch 'work.file' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull receive_fd update from Al Viro:
 "Cleanup of receive_fd mess"

* 'work.file' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: split receive_fd_replace from __receive_fd
2021-05-03 11:05:28 -07:00