linux-stable.git/arch/alpha, branch v5.13.2

sched/core: Initialize the idle task with preemption disabled

2021-07-14T15:06:21+00:00

[ 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 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Signed-off-by: Sasha Levin

quota: Disable quotactl_path syscall

2021-05-17T12:39:56+00:00

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 
CC: Sascha Hauer 
Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein
Signed-off-by: Jan Kara

Merge branch 'akpm' (patches from Andrew)

2021-05-07T07:34:51+00:00

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 : (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
  ...

mm: remove xlate_dev_kmem_ptr()

2021-05-07T07:26:34+00:00

Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr()
leftovers.

Link: https://lkml.kernel.org/r/20210324102351.6932-3-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Geert Uytterhoeven 
Acked-by: Michal Hocko 
Cc: Linus Torvalds 
Cc: Greg Kroah-Hartman 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Russell King 
Cc: Brian Cain 
Cc: Geert Uytterhoeven 
Cc: Thomas Bogendoerfer 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: "David S. Miller" 
Cc: Arnd Bergmann 
Cc: David Hildenbrand 
Cc: Krzysztof Kozlowski 
Cc: Mikulas Patocka 
Cc: Luc Van Oostenryck 
Cc: Mike Rapoport 
Cc: Palmer Dabbelt 
Cc: Luis Chamberlain 
Cc: Greentime Hu 
Cc: Sebastian Andrzej Siewior 
Cc: Randy Dunlap 
Cc: Jiaxun Yang 
Cc: "Peter Zijlstra (Intel)" 
Cc: Christophe Leroy 
Cc: Gerald Schaefer 
Cc: Niklas Schnelle 
Cc: Pierre Morel 
Cc: Ingo Molnar 
Cc: Kuninori Morimoto 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

alpha: csum_partial_copy.c: add function prototypes from

2021-05-07T02:24:11+00:00

Fix "no previous prototype" W=1 warnings from the kernel test robot:

  arch/alpha/lib/csum_partial_copy.c:349:1: error: no previous prototype for 'csum_and_copy_from_user' [-Werror=missing-prototypes]
  349 | csum_and_copy_from_user(const void __user *src, void *dst, int len)
      | ^~~~~~~~~~~~~~~~~~~~~~~
  arch/alpha/lib/csum_partial_copy.c:358:1: error: no previous prototype for 'csum_partial_copy_nocheck' [-Werror=missing-prototypes]
  358 | csum_partial_copy_nocheck(const void *src, void *dst, int len)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~

Link: https://lkml.kernel.org/r/20210425235749.19113-1-rdunlap@infradead.org
Fixes: 808b49da54e6 ("alpha: turn csum_partial_copy_from_user() into csum_and_copy_from_user()")
Signed-off-by: Randy Dunlap 
Reported-by: kernel test robot 
Cc: Al Viro 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

alpha: eliminate old-style function definitions

2021-05-07T02:24:11+00:00

'make ARCH=alpha W=1' reports a couple of old-style function
definitions with missing parameter list, so fix those.

  arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_base':
  arch/alpha/kernel/pc873xx.c:16:21: warning: old-style function definition [-Wold-style-definition]
   16 | unsigned int __init pc873xx_get_base()

  arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_model':
  arch/alpha/kernel/pc873xx.c:21:14: warning: old-style function definition [-Wold-style-definition]
   21 | char *__init pc873xx_get_model()

Link: https://lkml.kernel.org/r/20210421061312.30097-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2021-05-02T01:50:44+00:00

Pull Landlock LSM from James Morris:
 "Add Landlock, a new LSM from Mickaël Salaün.

  Briefly, Landlock provides for unprivileged application sandboxing.

  From Mickaël's cover letter:
    "The goal of Landlock is to enable to restrict ambient rights (e.g.
     global filesystem access) for a set of processes. Because Landlock
     is a stackable LSM [1], it makes possible to create safe security
     sandboxes as new security layers in addition to the existing
     system-wide access-controls. This kind of sandbox is expected to
     help mitigate the security impact of bugs or unexpected/malicious
     behaviors in user-space applications. Landlock empowers any
     process, including unprivileged ones, to securely restrict
     themselves.

     Landlock is inspired by seccomp-bpf but instead of filtering
     syscalls and their raw arguments, a Landlock rule can restrict the
     use of kernel objects like file hierarchies, according to the
     kernel semantic. Landlock also takes inspiration from other OS
     sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD
     Pledge/Unveil.

     In this current form, Landlock misses some access-control features.
     This enables to minimize this patch series and ease review. This
     series still addresses multiple use cases, especially with the
     combined use of seccomp-bpf: applications with built-in sandboxing,
     init systems, security sandbox tools and security-oriented APIs [2]"

  The cover letter and v34 posting is here:

      https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/

  See also:

      https://landlock.io/

  This code has had extensive design discussion and review over several
  years"

Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1]
Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2]

* tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  landlock: Enable user space to infer supported features
  landlock: Add user and kernel documentation
  samples/landlock: Add a sandbox manager example
  selftests/landlock: Add user space tests
  landlock: Add syscall implementations
  arch: Wire up Landlock syscalls
  fs,security: Add sb_delete hook
  landlock: Support filesystem access-control
  LSM: Infrastructure management of the superblock
  landlock: Add ptrace restrictions
  landlock: Set up the security framework and manage credentials
  landlock: Add ruleset and domain management
  landlock: Add object management

mm: move mem_init_print_info() into mm_init()

2021-04-30T18:20:42+00:00

mem_init_print_info() is called in mem_init() on each architecture, and
pass NULL argument, so using void argument and move it into mm_init().

Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Acked-by: Dave Hansen 	[x86]
Reviewed-by: Christophe Leroy 	[powerpc]
Acked-by: David Hildenbrand 
Tested-by: Anatoly Pugachev 	[sparc64]
Acked-by: Russell King 	[arm]
Acked-by: Mike Rapoport 
Cc: Catalin Marinas 
Cc: Richard Henderson 
Cc: Guo Ren 
Cc: Yoshinori Sato 
Cc: Huacai Chen 
Cc: Jonas Bonn 
Cc: Palmer Dabbelt 
Cc: Heiko Carstens 
Cc: "David S. Miller" 
Cc: "Peter Zijlstra" 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2021-04-29T21:24:39+00:00

Pull Kbuild updates from Masahiro Yamada:

 - Evaluate $(call cc-option,...) etc. only for build targets

 - Add CONFIG_VMLINUX_MAP to generate .map file when linking vmlinux

 - Remove unnecessary --gcc-toolchains Clang flag because the --prefix
   flag finds the toolchains

 - Do not pass Clang's --prefix flag when using the integrated as

 - Check the assembler version in Kconfig time

 - Add new CONFIG options, AS_VERSION, AS_IS_GNU, AS_IS_LLVM to clean up
   some dependencies in Kconfig

 - Fix invalid Module.symvers creation when building only modules
   without vmlinux

 - Fix false-positive modpost warnings when CONFIG_TRIM_UNUSED_KSYMS is
   set, but there is no module to build

 - Refactor module installation Makefile

 - Support zstd for module compression

 - Convert alpha and ia64 to use generic shell scripts to generate the
   syscall headers

 - Add a new elfnote to indicate if the kernel was built with LTO, which
   will be used by pahole

 - Flatten the directory structure under include/config/ so CONFIG
   options and filenames match

 - Change the deb source package name from linux-$(KERNELRELEASE) to
   linux-upstream

* tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (42 commits)
  kbuild: Add $(KBUILD_HOSTLDFLAGS) to 'has_libelf' test
  kbuild: deb-pkg: change the source package name to linux-upstream
  tools: do not include scripts/Kbuild.include
  kbuild: redo fake deps at include/config/*.h
  kbuild: remove TMPO from try-run
  MAINTAINERS: add pattern for dummy-tools
  kbuild: add an elfnote for whether vmlinux is built with lto
  ia64: syscalls: switch to generic syscallhdr.sh
  ia64: syscalls: switch to generic syscalltbl.sh
  alpha: syscalls: switch to generic syscallhdr.sh
  alpha: syscalls: switch to generic syscalltbl.sh
  sysctl: use min() helper for namecmp()
  kbuild: add support for zstd compressed modules
  kbuild: remove CONFIG_MODULE_COMPRESS
  kbuild: merge scripts/Makefile.modsign to scripts/Makefile.modinst
  kbuild: move module strip/compression code into scripts/Makefile.modinst
  kbuild: refactor scripts/Makefile.modinst
  kbuild: rename extmod-prefix to extmod_prefix
  kbuild: check module name conflict for external modules as well
  kbuild: show the target directory for depmod log
  ...

alpha: syscalls: switch to generic syscallhdr.sh

2021-04-24T20:25:32+00:00

Many architectures duplicate similar shell scripts.

This commit converts alpha to use scripts/syscallhdr.sh.

Signed-off-by: Masahiro Yamada