Commit Graph

376 Commits

Author SHA1 Message Date
Linus Torvalds
29c395c77a Rework of the X86 irq stack handling:
The irq stack switching was moved out of the ASM entry code in course of
   the entry code consolidation. It ended up being suboptimal in various
   ways.
 
   - Make the stack switching inline so the stackpointer manipulation is not
     longer at an easy to find place.
 
   - Get rid of the unnecessary indirect call.
 
   - Avoid the double stack switching in interrupt return and reuse the
     interrupt stack for softirq handling.
 
   - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused
     about the stack pointer manipulation.
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Merge tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 irq entry updates from Thomas Gleixner:
 "The irq stack switching was moved out of the ASM entry code in course
  of the entry code consolidation. It ended up being suboptimal in
  various ways.

  This reworks the X86 irq stack handling:

   - Make the stack switching inline so the stackpointer manipulation is
     not longer at an easy to find place.

   - Get rid of the unnecessary indirect call.

   - Avoid the double stack switching in interrupt return and reuse the
     interrupt stack for softirq handling.

   - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got
     confused about the stack pointer manipulation"

* tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix stack-swizzle for FRAME_POINTER=y
  um: Enforce the usage of asm-generic/softirq_stack.h
  x86/softirq/64: Inline do_softirq_own_stack()
  softirq: Move do_softirq_own_stack() to generic asm header
  softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig
  x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
  x86/softirq: Remove indirection in do_softirq_own_stack()
  x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall
  x86/entry: Convert device interrupts to inline stack switching
  x86/entry: Convert system vectors to irq stack macro
  x86/irq: Provide macro for inlining irq stack switching
  x86/apic: Split out spurious handling code
  x86/irq/64: Adjust the per CPU irq stack pointer by 8
  x86/irq: Sanitize irq stack tracking
  x86/entry: Fix instrumentation annotation
2021-02-24 16:32:23 -08:00
Linus Torvalds
79db4d2293 clang-lto series for v5.12-rc1
- Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen)
 - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)
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Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang LTO updates from Kees Cook:
 "Clang Link Time Optimization.

  This is built on the work done preparing for LTO by arm64 folks,
  tracing folks, etc. This includes the core changes as well as the
  remaining pieces for arm64 (LTO has been the default build method on
  Android for about 3 years now, as it is the prerequisite for the
  Control Flow Integrity protections).

  While x86 LTO enablement is done, it depends on some pending objtool
  clean-ups. It's possible that I'll send a "part 2" pull request for
  LTO that includes x86 support.

  For merge log posterity, and as detailed in commit dc5723b02e
  ("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO
  build:

        make LLVM=1 LLVM_IAS=1 defconfig
        scripts/config -e LTO_CLANG_THIN
        make LLVM=1 LLVM_IAS=1

  (To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-"
  and "ARCH=arm64" to the "make" command lines.)

  Summary:

   - Clang LTO build infrastructure and arm64-specific enablement (Sami
     Tolvanen)

   - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)"

* tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
  arm64: allow LTO to be selected
  arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS
  arm64: vdso: disable LTO
  drivers/misc/lkdtm: disable LTO for rodata.o
  efi/libstub: disable LTO
  scripts/mod: disable LTO for empty.c
  modpost: lto: strip .lto from module names
  PCI: Fix PREL32 relocations for LTO
  init: lto: fix PREL32 relocations
  init: lto: ensure initcall ordering
  kbuild: lto: add a default list of used symbols
  kbuild: lto: merge module sections
  kbuild: lto: limit inlining
  kbuild: lto: fix module versioning
  kbuild: add support for Clang LTO
  tracing: move function tracer options to Kconfig
2021-02-23 09:28:51 -08:00
Linus Torvalds
0e63a5c6ba It has been a relatively quiet cycle in docsland.
- As promised, the minimum Sphinx version to build the docs is now 1.7,
    and we have dropped support for Python 2 entirely.  That allowed the
    removal of a bunch of compatibility code.
 
  - A set of treewide warning fixups from Mauro that I applied after it
    became clear nobody else was going to deal with them.
 
  - The automarkup mechanism can now create cross-references from relative
    paths to RST files.
 
  - More translations, typo fixes, and warning fixes.
 
 No conflicts with any other tree as far as I know.
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Merge tag 'docs-5.12' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It has been a relatively quiet cycle in docsland.

   - As promised, the minimum Sphinx version to build the docs is now
     1.7, and we have dropped support for Python 2 entirely. That
     allowed the removal of a bunch of compatibility code.

   - A set of treewide warning fixups from Mauro that I applied after it
     became clear nobody else was going to deal with them.

   - The automarkup mechanism can now create cross-references from
     relative paths to RST files.

   - More translations, typo fixes, and warning fixes"

* tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits)
  docs: kernel-hacking: be more civil
  docs: Remove the Microsoft rhetoric
  Documentation/admin-guide: kernel-parameters: Update nohlt section
  doc/admin-guide: fix spelling mistake: "perfomance" -> "performance"
  docs: Document cross-referencing using relative path
  docs: Enable usage of relative paths to docs on automarkup
  docs: thermal: fix spelling mistakes
  Documentation: admin-guide: Update kvm/xen config option
  docs: Make syscalls' helpers naming consistent
  coding-style.rst: Avoid comma statements
  Documentation: /proc/loadavg: add 3 more field descriptions
  Documentation/submitting-patches: Add blurb about backtraces in commit messages
  Docs: drop Python 2 support
  Move our minimum Sphinx version to 1.7
  Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams
  scripts/kernel-doc: add internal hyperlink to DOC: sections
  Update Documentation/admin-guide/sysctl/fs.rst
  docs: Update DTB format references
  docs: zh_CN: add iio index.rst translation
  docs/zh_CN: add iio ep93xx_adc.rst translation
  ...
2021-02-22 10:57:46 -08:00
Linus Torvalds
df24212a49 s390 updates for the 5.12 merge window
- Convert to using the generic entry infrastructure.
 
 - Add vdso time namespace support.
 
 - Switch s390 and alpha to 64-bit ino_t. As discussed here
   lkml.kernel.org/r/YCV7QiyoweJwvN+m@osiris
 
 - Get rid of expensive stck (store clock) usages where possible. Utilize
   cpu alternatives to patch stckf when supported.
 
 - Make tod_clock usage less error prone by converting it to a union and
   rework code which is using it.
 
 - Machine check handler fixes and cleanups.
 
 - Drop couple of minor inline asm optimizations to fix clang build.
 
 - Default configs changes notably to make libvirt happy.
 
 - Various changes to rework and improve qdio code.
 
 - Other small various fixes and improvements all over the code.
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Merge tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Convert to using the generic entry infrastructure.

 - Add vdso time namespace support.

 - Switch s390 and alpha to 64-bit ino_t. As discussed at

     https://lore.kernel.org/linux-mm/YCV7QiyoweJwvN+m@osiris/

 - Get rid of expensive stck (store clock) usages where possible.
   Utilize cpu alternatives to patch stckf when supported.

 - Make tod_clock usage less error prone by converting it to a union and
   rework code which is using it.

 - Machine check handler fixes and cleanups.

 - Drop couple of minor inline asm optimizations to fix clang build.

 - Default configs changes notably to make libvirt happy.

 - Various changes to rework and improve qdio code.

 - Other small various fixes and improvements all over the code.

* tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (68 commits)
  s390/qdio: remove 'merge_pending' mechanism
  s390/qdio: improve handling of PENDING buffers for QEBSM devices
  s390/qdio: rework q->qdio_error indication
  s390/qdio: inline qdio_kick_handler()
  s390/time: remove get_tod_clock_ext()
  s390/crypto: use store_tod_clock_ext()
  s390/hypfs: use store_tod_clock_ext()
  s390/debug: use union tod_clock
  s390/kvm: use union tod_clock
  s390/vdso: use union tod_clock
  s390/time: convert tod_clock_base to union
  s390/time: introduce new store_tod_clock_ext()
  s390/time: rename store_tod_clock_ext() and use union tod_clock
  s390/time: introduce union tod_clock
  s390,alpha: switch to 64-bit ino_t
  s390: split cleanup_sie
  s390: use r13 in cleanup_sie as temp register
  s390: fix kernel asce loading when sie is interrupted
  s390: add stack for machine check handler
  s390: use WRITE_ONCE when re-allocating async stack
  ...
2021-02-21 13:40:06 -08:00
Linus Torvalds
657bd90c93 Scheduler updates for v5.12:
[ NOTE: unfortunately this tree had to be freshly rebased today,
         it's a same-content tree of 82891be90f3c (-next published)
         merged with v5.11.
 
         The main reason for the rebase was an authorship misattribution
         problem with a new commit, which we noticed in the last minute,
         and which we didn't want to be merged upstream. The offending
         commit was deep in the tree, and dependent commits had to be
         rebased as well. ]
 
 - Core scheduler updates:
 
   - Add CONFIG_PREEMPT_DYNAMIC: this in its current form adds the
     preempt=none/voluntary/full boot options (default: full),
     to allow distros to build a PREEMPT kernel but fall back to
     close to PREEMPT_VOLUNTARY (or PREEMPT_NONE) runtime scheduling
     behavior via a boot time selection.
 
     There's also the /debug/sched_debug switch to do this runtime.
 
     This feature is implemented via runtime patching (a new variant of static calls).
 
     The scope of the runtime patching can be best reviewed by looking
     at the sched_dynamic_update() function in kernel/sched/core.c.
 
     ( Note that the dynamic none/voluntary mode isn't 100% identical,
       for example preempt-RCU is available in all cases, plus the
       preempt count is maintained in all models, which has runtime
       overhead even with the code patching. )
 
     The PREEMPT_VOLUNTARY/PREEMPT_NONE models, used by the vast majority
     of distributions, are supposed to be unaffected.
 
   - Fix ignored rescheduling after rcu_eqs_enter(). This is a bug that
     was found via rcutorture triggering a hang. The bug is that
     rcu_idle_enter() may wake up a NOCB kthread, but this happens after
     the last generic need_resched() check. Some cpuidle drivers fix it
     by chance but many others don't.
 
     In true 2020 fashion the original bug fix has grown into a 5-patch
     scheduler/RCU fix series plus another 16 RCU patches to address
     the underlying issue of missed preemption events. These are the
     initial fixes that should fix current incarnations of the bug.
 
   - Clean up rbtree usage in the scheduler, by providing & using the following
     consistent set of rbtree APIs:
 
      partial-order; less() based:
        - rb_add(): add a new entry to the rbtree
        - rb_add_cached(): like rb_add(), but for a rb_root_cached
 
      total-order; cmp() based:
        - rb_find(): find an entry in an rbtree
        - rb_find_add(): find an entry, and add if not found
 
        - rb_find_first(): find the first (leftmost) matching entry
        - rb_next_match(): continue from rb_find_first()
        - rb_for_each(): iterate a sub-tree using the previous two
 
   - Improve the SMP/NUMA load-balancer: scan for an idle sibling in a single pass.
     This is a 4-commit series where each commit improves one aspect of the idle
     sibling scan logic.
 
   - Improve the cpufreq cooling driver by getting the effective CPU utilization
     metrics from the scheduler
 
   - Improve the fair scheduler's active load-balancing logic by reducing the number
     of active LB attempts & lengthen the load-balancing interval. This improves
     stress-ng mmapfork performance.
 
   - Fix CFS's estimated utilization (util_est) calculation bug that can result in
     too high utilization values
 
 - Misc updates & fixes:
 
    - Fix the HRTICK reprogramming & optimization feature
    - Fix SCHED_SOFTIRQ raising race & warning in the CPU offlining code
    - Reduce dl_add_task_root_domain() overhead
    - Fix uprobes refcount bug
    - Process pending softirqs in flush_smp_call_function_from_idle()
    - Clean up task priority related defines, remove *USER_*PRIO and
      USER_PRIO()
    - Simplify the sched_init_numa() deduplication sort
    - Documentation updates
    - Fix EAS bug in update_misfit_status(), which degraded the quality
      of energy-balancing
    - Smaller cleanups
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Core scheduler updates:

   - Add CONFIG_PREEMPT_DYNAMIC: this in its current form adds the
     preempt=none/voluntary/full boot options (default: full), to allow
     distros to build a PREEMPT kernel but fall back to close to
     PREEMPT_VOLUNTARY (or PREEMPT_NONE) runtime scheduling behavior via
     a boot time selection.

     There's also the /debug/sched_debug switch to do this runtime.

     This feature is implemented via runtime patching (a new variant of
     static calls).

     The scope of the runtime patching can be best reviewed by looking
     at the sched_dynamic_update() function in kernel/sched/core.c.

     ( Note that the dynamic none/voluntary mode isn't 100% identical,
       for example preempt-RCU is available in all cases, plus the
       preempt count is maintained in all models, which has runtime
       overhead even with the code patching. )

     The PREEMPT_VOLUNTARY/PREEMPT_NONE models, used by the vast
     majority of distributions, are supposed to be unaffected.

   - Fix ignored rescheduling after rcu_eqs_enter(). This is a bug that
     was found via rcutorture triggering a hang. The bug is that
     rcu_idle_enter() may wake up a NOCB kthread, but this happens after
     the last generic need_resched() check. Some cpuidle drivers fix it
     by chance but many others don't.

     In true 2020 fashion the original bug fix has grown into a 5-patch
     scheduler/RCU fix series plus another 16 RCU patches to address the
     underlying issue of missed preemption events. These are the initial
     fixes that should fix current incarnations of the bug.

   - Clean up rbtree usage in the scheduler, by providing & using the
     following consistent set of rbtree APIs:

       partial-order; less() based:
         - rb_add(): add a new entry to the rbtree
         - rb_add_cached(): like rb_add(), but for a rb_root_cached

       total-order; cmp() based:
         - rb_find(): find an entry in an rbtree
         - rb_find_add(): find an entry, and add if not found

         - rb_find_first(): find the first (leftmost) matching entry
         - rb_next_match(): continue from rb_find_first()
         - rb_for_each(): iterate a sub-tree using the previous two

   - Improve the SMP/NUMA load-balancer: scan for an idle sibling in a
     single pass. This is a 4-commit series where each commit improves
     one aspect of the idle sibling scan logic.

   - Improve the cpufreq cooling driver by getting the effective CPU
     utilization metrics from the scheduler

   - Improve the fair scheduler's active load-balancing logic by
     reducing the number of active LB attempts & lengthen the
     load-balancing interval. This improves stress-ng mmapfork
     performance.

   - Fix CFS's estimated utilization (util_est) calculation bug that can
     result in too high utilization values

  Misc updates & fixes:

   - Fix the HRTICK reprogramming & optimization feature

   - Fix SCHED_SOFTIRQ raising race & warning in the CPU offlining code

   - Reduce dl_add_task_root_domain() overhead

   - Fix uprobes refcount bug

   - Process pending softirqs in flush_smp_call_function_from_idle()

   - Clean up task priority related defines, remove *USER_*PRIO and
     USER_PRIO()

   - Simplify the sched_init_numa() deduplication sort

   - Documentation updates

   - Fix EAS bug in update_misfit_status(), which degraded the quality
     of energy-balancing

   - Smaller cleanups"

* tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
  sched,x86: Allow !PREEMPT_DYNAMIC
  entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point
  entry: Explicitly flush pending rcuog wakeup before last rescheduling point
  rcu/nocb: Trigger self-IPI on late deferred wake up before user resume
  rcu/nocb: Perform deferred wake up before last idle's need_resched() check
  rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers
  sched/features: Distinguish between NORMAL and DEADLINE hrtick
  sched/features: Fix hrtick reprogramming
  sched/deadline: Reduce rq lock contention in dl_add_task_root_domain()
  uprobes: (Re)add missing get_uprobe() in __find_uprobe()
  smp: Process pending softirqs in flush_smp_call_function_from_idle()
  sched: Harden PREEMPT_DYNAMIC
  static_call: Allow module use without exposing static_call_key
  sched: Add /debug/sched_preempt
  preempt/dynamic: Support dynamic preempt with preempt= boot option
  preempt/dynamic: Provide irqentry_exit_cond_resched() static call
  preempt/dynamic: Provide preempt_schedule[_notrace]() static calls
  preempt/dynamic: Provide cond_resched() and might_resched() static calls
  preempt: Introduce CONFIG_PREEMPT_DYNAMIC
  static_call: Provide DEFINE_STATIC_CALL_RET0()
  ...
2021-02-21 12:35:04 -08:00
Linus Torvalds
24880bef41 Remove oprofile and dcookies support
The "oprofile" user-space tools don't use the kernel OPROFILE support any more,
 and haven't in a long time. User-space has been converted to the perf
 interfaces.
 
 The dcookies stuff is only used by the oprofile code. Now that oprofile's
 support is getting removed from the kernel, there is no need for dcookies as
 well.
 
 Remove kernel's old oprofile and dcookies support.
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Merge tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux

Pull oprofile and dcookies removal from Viresh Kumar:
 "Remove oprofile and dcookies support

  The 'oprofile' user-space tools don't use the kernel OPROFILE support
  any more, and haven't in a long time. User-space has been converted to
  the perf interfaces.

  The dcookies stuff is only used by the oprofile code. Now that
  oprofile's support is getting removed from the kernel, there is no
  need for dcookies as well.

  Remove kernel's old oprofile and dcookies support"

* tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux:
  fs: Remove dcookies support
  drivers: Remove CONFIG_OPROFILE support
  arch: xtensa: Remove CONFIG_OPROFILE support
  arch: x86: Remove CONFIG_OPROFILE support
  arch: sparc: Remove CONFIG_OPROFILE support
  arch: sh: Remove CONFIG_OPROFILE support
  arch: s390: Remove CONFIG_OPROFILE support
  arch: powerpc: Remove oprofile
  arch: powerpc: Stop building and using oprofile
  arch: parisc: Remove CONFIG_OPROFILE support
  arch: mips: Remove CONFIG_OPROFILE support
  arch: microblaze: Remove CONFIG_OPROFILE support
  arch: ia64: Remove rest of perfmon support
  arch: ia64: Remove CONFIG_OPROFILE support
  arch: hexagon: Don't select HAVE_OPROFILE
  arch: arc: Remove CONFIG_OPROFILE support
  arch: arm: Remove CONFIG_OPROFILE support
  arch: alpha: Remove CONFIG_OPROFILE support
2021-02-21 10:40:34 -08:00
Linus Torvalds
591fd30eee Merge branch 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ELF compat updates from Al Viro:
 "Sanitizing ELF compat support, especially for triarch architectures:

   - X32 handling cleaned up

   - MIPS64 uses compat_binfmt_elf.c both for O32 and N32 now

   - Kconfig side of things regularized

  Eventually I hope to have compat_binfmt_elf.c killed, with both native
  and compat built from fs/binfmt_elf.c, with -DELF_BITS={64,32} passed
  by kbuild, but that's a separate story - not included here"

* 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  get rid of COMPAT_ELF_EXEC_PAGESIZE
  compat_binfmt_elf: don't bother with undef of ELF_ARCH
  Kconfig: regularize selection of CONFIG_BINFMT_ELF
  mips compat: switch to compat_binfmt_elf.c
  mips: don't bother with ELF_CORE_EFLAGS
  mips compat: don't bother with ELF_ET_DYN_BASE
  mips: KVM_GUEST makes no sense for 64bit builds...
  mips: kill unused definitions in binfmt_elf[on]32.c
  mips binfmt_elf*32.c: use elfcore-compat.h
  x32: make X32, !IA32_EMULATION setups able to execute x32 binaries
  [amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly
  elf_prstatus: collect the common part (everything before pr_reg) into a struct
  binfmt_elf: partially sanitize PRSTATUS_SIZE and SET_PR_FPVALID
2021-02-21 09:29:23 -08:00
Michal Hocko
6ef869e064 preempt: Introduce CONFIG_PREEMPT_DYNAMIC
Preemption mode selection is currently hardcoded on Kconfig choices.
Introduce a dedicated option to tune preemption flavour at boot time,

This will be only available on architectures efficiently supporting
static calls in order not to tempt with the feature against additional
overhead that might be prohibitive or undesirable.

CONFIG_PREEMPT_DYNAMIC is automatically selected by CONFIG_PREEMPT if
the architecture provides the necessary support (CONFIG_STATIC_CALL_INLINE,
CONFIG_GENERIC_ENTRY, and provide with __preempt_schedule_function() /
__preempt_schedule_notrace_function()).

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
[peterz: relax requirement to HAVE_STATIC_CALL]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210118141223.123667-5-frederic@kernel.org
2021-02-17 14:12:24 +01:00
Heiko Carstens
96c0a6a72d s390,alpha: switch to 64-bit ino_t
s390 and alpha are the only 64 bit architectures with a 32-bit ino_t.
Since this is quite unusual this causes bugs from time to time.

See e.g. commit ebce3eb2f7 ("ceph: fix inode number handling on
arches with 32-bit ino_t") for an example.

This (obviously) also prevents s390 and alpha to use 64-bit ino_t for
tmpfs. See commit b85a7a8bb5 ("tmpfs: disallow CONFIG_TMPFS_INODE64
on s390").

Therefore switch both s390 and alpha to 64-bit ino_t. This should only
have an effect on the ustat system call. To prevent ABI breakage
define struct ustat compatible to the old layout and change
sys_ustat() accordingly.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13 17:17:53 +01:00
Thomas Gleixner
cd1a41ceba softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig
To prepare for inlining do_softirq_own_stack() replace
__ARCH_HAS_DO_SOFTIRQ with a Kconfig switch and select it in the affected
architectures.

This allows in the next step to move the function prototype and the inline
stub into a seperate asm-generic header file which is required to avoid
include recursion.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210210002513.181713427@linutronix.de
2021-02-10 23:34:16 +01:00
Viresh Kumar
f8408264c7 drivers: Remove CONFIG_OPROFILE support
The "oprofile" user-space tools don't use the kernel OPROFILE support
any more, and haven't in a long time. User-space has been converted to
the perf interfaces.

Remove kernel's old oprofile support.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Robert Richter <rric@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org> #RCU
Acked-by: William Cohen <wcohen@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2021-01-29 10:06:24 +05:30
Lukas Bulwahn
ba1a297d78 arch/Kconfig: update a broken file reference
Commit adab66b71a ("Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"")
added the config HAVE_64BIT_ALIGNED_ACCESS back into arch/Kconfig with this
revert. In the meantime, commit c9b54d6f36 ("docs: move other kAPI
documents to core-api") changed ./Documentation/unaligned-memory-access.txt
to ./Documentation/core-api/unaligned-memory-access.rst.

Fortunately, ./scripts/documentation-file-ref-check detects this and warns
about this broken reference.

Update the file reference in arch/Kconfig.

Fixes: adab66b71a ("Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20210119095326.13896-1-lukas.bulwahn@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-21 14:06:00 -07:00
Sami Tolvanen
38e8918490 kbuild: lto: fix module versioning
With CONFIG_MODVERSIONS, version information is linked into each
compilation unit that exports symbols. With LTO, we cannot use this
method as all C code is compiled into LLVM bitcode instead. This
change collects symbol versions into .symversions files and merges
them in link-vmlinux.sh where they are all linked into vmlinux.o at
the same time.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-4-samitolvanen@google.com
2021-01-14 08:21:08 -08:00
Sami Tolvanen
dc5723b02e kbuild: add support for Clang LTO
This change adds build system support for Clang's Link Time
Optimization (LTO). With -flto, instead of ELF object files, Clang
produces LLVM bitcode, which is compiled into native code at link
time, allowing the final binary to be optimized globally. For more
details, see:

  https://llvm.org/docs/LinkTimeOptimization.html

The Kconfig option CONFIG_LTO_CLANG is implemented as a choice,
which defaults to LTO being disabled. To use LTO, the architecture
must select ARCH_SUPPORTS_LTO_CLANG and support:

  - compiling with Clang,
  - compiling all assembly code with Clang's integrated assembler,
  - and linking with LLD.

While using CONFIG_LTO_CLANG_FULL results in the best runtime
performance, the compilation is not scalable in time or
memory. CONFIG_LTO_CLANG_THIN enables ThinLTO, which allows
parallel optimization and faster incremental builds. ThinLTO is
used by default if the architecture also selects
ARCH_SUPPORTS_LTO_CLANG_THIN:

  https://clang.llvm.org/docs/ThinLTO.html

To enable LTO, LLVM tools must be used to handle bitcode files, by
passing LLVM=1 and LLVM_IAS=1 options to make:

  $ make LLVM=1 LLVM_IAS=1 defconfig
  $ scripts/config -e LTO_CLANG_THIN
  $ make LLVM=1 LLVM_IAS=1

To prepare for LTO support with other compilers, common parts are
gated behind the CONFIG_LTO option, and LTO can be disabled for
specific files by filtering out CC_FLAGS_LTO.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-3-samitolvanen@google.com
2021-01-14 08:21:08 -08:00
Al Viro
7facdc426f [amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly
To get rid of hardcoded size/offset in those macros we need to have
a definition of i386 variant of struct elf_prstatus.  However, we can't
do that in asm/compat.h - the types needed for that are not there and
adding an include of asm/user32.h into asm/compat.h would cause a lot
of mess.

That could be conveniently done in elfcore-compat.h, but currently there
is nowhere to put arch-dependent parts of it - no asm/elfcore-compat.h.
So we introduce a new file (asm/elfcore-compat.h, present on architectures
that have CONFIG_ARCH_HAS_ELFCORE_COMPAT set, currently only on x86),
have it pulled by linux/elfcore-compat.h and move the definitions there.

As a side benefit, we don't need to worry about accidental inclusion of
that file into binfmt_elf.c itself, so we don't need the dance with
COMPAT_PRSTATUS_SIZE, etc. - only fs/compat_binfmt_elf.c will see
that header.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-01-06 08:40:56 -05:00
Brian Gerst
2ca408d9c7 fanotify: Fix sys_fanotify_mark() on native x86-32
Commit

  121b32a58a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments")

converted native x86-32 which take 64-bit arguments to use the
compat handlers to allow conversion to passing args via pt_regs.
sys_fanotify_mark() was however missed, as it has a general compat
handler. Add a config option that will use the syscall wrapper that
takes the split args for native 32-bit.

 [ bp: Fix typo in Kconfig help text. ]

Fixes: 121b32a58a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments")
Reported-by: Paweł Jasiak <pawel@jasiak.xyz>
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20201130223059.101286-1-brgerst@gmail.com
2020-12-28 11:58:59 +01:00
Andrey Konovalov
38dd767dae kasan: allow VMAP_STACK for HW_TAGS mode
Even though hardware tag-based mode currently doesn't support checking
vmalloc allocations, it doesn't use shadow memory and works with
VMAP_STACK as is. Change VMAP_STACK definition accordingly.

Link: https://lkml.kernel.org/r/ecdb2a1658ebd88eb276dee2493518ac0e82de41.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I3552cbc12321dec82cd7372676e9372a2eb452ac
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-22 12:55:08 -08:00
Linus Torvalds
09c0796adf Tracing updates for 5.11
The major update to this release is that there's a new arch config option called:
 CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it.
 All the ftrace callbacks now take a struct ftrace_regs instead of a struct
 pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then
 the ftrace_regs will have enough information to read the arguments of the
 function being traced, as well as access to the stack pointer. This way, if
 a user (like live kernel patching) only cares about the arguments, then it
 can avoid using the heavier weight "regs" callback, that puts in enough
 information in the struct ftrace_regs to simulate a breakpoint exception
 (needed for kprobes).
 
 New config option that audits the timestamps of the ftrace ring buffer at
 most every event recorded.  The "check_buffer()" calls will conflict with
 mainline, because I purposely added the check without including the fix that
 it caught, which is in mainline. Running a kernel built from the commit of
 the added check will trigger it.
 
 Ftrace recursion protection has been cleaned up to move the protection to
 the callback itself (this saves on an extra function call for those
 callbacks).
 
 Perf now handles its own RCU protection and does not depend on ftrace to do
 it for it (saving on that extra function call).
 
 New debug option to add "recursed_functions" file to tracefs that lists all
 the places that triggered the recursion protection of the function tracer.
 This will show where things need to be fixed as recursion slows down the
 function tracer.
 
 The eval enum mapping updates done at boot up are now offloaded to a work
 queue, as it caused a noticeable pause on slow embedded boards.
 
 Various clean ups and last minute fixes.
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Merge tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The major update to this release is that there's a new arch config
  option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS.

  Currently, only x86_64 enables it. All the ftrace callbacks now take a
  struct ftrace_regs instead of a struct pt_regs. If the architecture
  has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will
  have enough information to read the arguments of the function being
  traced, as well as access to the stack pointer.

  This way, if a user (like live kernel patching) only cares about the
  arguments, then it can avoid using the heavier weight "regs" callback,
  that puts in enough information in the struct ftrace_regs to simulate
  a breakpoint exception (needed for kprobes).

  A new config option that audits the timestamps of the ftrace ring
  buffer at most every event recorded.

  Ftrace recursion protection has been cleaned up to move the protection
  to the callback itself (this saves on an extra function call for those
  callbacks).

  Perf now handles its own RCU protection and does not depend on ftrace
  to do it for it (saving on that extra function call).

  New debug option to add "recursed_functions" file to tracefs that
  lists all the places that triggered the recursion protection of the
  function tracer. This will show where things need to be fixed as
  recursion slows down the function tracer.

  The eval enum mapping updates done at boot up are now offloaded to a
  work queue, as it caused a noticeable pause on slow embedded boards.

  Various clean ups and last minute fixes"

* tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  tracing: Offload eval map updates to a work queue
  Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
  ring-buffer: Add rb_check_bpage in __rb_allocate_pages
  ring-buffer: Fix two typos in comments
  tracing: Drop unneeded assignment in ring_buffer_resize()
  tracing: Disable ftrace selftests when any tracer is running
  seq_buf: Avoid type mismatch for seq_buf_init
  ring-buffer: Fix a typo in function description
  ring-buffer: Remove obsolete rb_event_is_commit()
  ring-buffer: Add test to validate the time stamp deltas
  ftrace/documentation: Fix RST C code blocks
  tracing: Clean up after filter logic rewriting
  tracing: Remove the useless value assignment in test_create_synth_event()
  livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
  ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default
  ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
  MAINTAINERS: assign ./fs/tracefs to TRACING
  tracing: Fix some typos in comments
  ftrace: Remove unused varible 'ret'
  ring-buffer: Add recording of ring buffer recursion into recursed_functions
  ...
2020-12-17 13:22:17 -08:00
Linus Torvalds
e994cc240a seccomp updates for v5.11-rc1
- Improve seccomp performance via constant-action bitmaps (YiFei Zhu & Kees Cook)
 
 - Fix bogus __user annotations (Jann Horn)
 
 - Add missed CONFIG for improved selftest coverage (Mickaël Salaün)
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Merge tag 'seccomp-v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp updates from Kees Cook:
 "The major change here is finally gaining seccomp constant-action
  bitmaps, which internally reduces the seccomp overhead for many
  real-world syscall filters to O(1), as discussed at Plumbers this
  year.

   - Improve seccomp performance via constant-action bitmaps (YiFei Zhu
     & Kees Cook)

   - Fix bogus __user annotations (Jann Horn)

   - Add missed CONFIG for improved selftest coverage (Mickaël Salaün)"

* tag 'seccomp-v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  selftests/seccomp: Update kernel config
  seccomp: Remove bogus __user annotations
  seccomp/cache: Report cache data through /proc/pid/seccomp_cache
  xtensa: Enable seccomp architecture tracking
  sh: Enable seccomp architecture tracking
  s390: Enable seccomp architecture tracking
  riscv: Enable seccomp architecture tracking
  powerpc: Enable seccomp architecture tracking
  parisc: Enable seccomp architecture tracking
  csky: Enable seccomp architecture tracking
  arm: Enable seccomp architecture tracking
  arm64: Enable seccomp architecture tracking
  selftests/seccomp: Compare bitmap vs filter overhead
  x86: Enable seccomp architecture tracking
  seccomp/cache: Add "emulator" to check if filter is constant allow
  seccomp/cache: Lookup syscall allowlist bitmap for fast path
2020-12-16 11:30:10 -08:00
Linus Torvalds
2cffa11e2a Generic interrupt and irqchips subsystem:
Core:
 
      - Consolidation and robustness changes for irq time accounting
 
      - Cleanup and consolidation of irq stats
 
      - Remove the fasteoi IPI flow which has been proved useless
 
      - Provide an interface for converting legacy interrupt mechanism into
        irqdomains
 
  Drivers:
 
      The rare event of not having completely new chip driver code, just new
      DT bindings and extensions of existing drivers to accomodate new
      variants!
 
      - Preliminary support for managed interrupts on platform devices
 
      - Correctly identify allocation of MSIs proxyied by another device
 
      - Generalise the Ocelot support to new SoCs
 
      - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation
 
      - Work around spurious interrupts on Qualcomm PDC
 
      - Random fixes and cleanups
 
 Thanks,
 
 	tglx
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Merge tag 'irq-core-2020-12-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Generic interrupt and irqchips subsystem updates. Unusually, there is
  not a single completely new irq chip driver, just new DT bindings and
  extensions of existing drivers to accomodate new variants!

  Core:

   - Consolidation and robustness changes for irq time accounting

   - Cleanup and consolidation of irq stats

   - Remove the fasteoi IPI flow which has been proved useless

   - Provide an interface for converting legacy interrupt mechanism into
     irqdomains

  Drivers:

   - Preliminary support for managed interrupts on platform devices

   - Correctly identify allocation of MSIs proxyied by another device

   - Generalise the Ocelot support to new SoCs

   - Improve GICv4.1 vcpu entry, matching the corresponding KVM
     optimisation

   - Work around spurious interrupts on Qualcomm PDC

   - Random fixes and cleanups"

* tag 'irq-core-2020-12-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
  irqchip/qcom-pdc: Fix phantom irq when changing between rising/falling
  driver core: platform: Add devm_platform_get_irqs_affinity()
  ACPI: Drop acpi_dev_irqresource_disabled()
  resource: Add irqresource_disabled()
  genirq/affinity: Add irq_update_affinity_desc()
  irqchip/gic-v3-its: Flag device allocation as proxied if behind a PCI bridge
  irqchip/gic-v3-its: Tag ITS device as shared if allocating for a proxy device
  platform-msi: Track shared domain allocation
  irqchip/ti-sci-intr: Fix freeing of irqs
  irqchip/ti-sci-inta: Fix printing of inta id on probe success
  drivers/irqchip: Remove EZChip NPS interrupt controller
  Revert "genirq: Add fasteoi IPI flow"
  irqchip/hip04: Make IPIs use handle_percpu_devid_irq()
  irqchip/bcm2836: Make IPIs use handle_percpu_devid_irq()
  irqchip/armada-370-xp: Make IPIs use handle_percpu_devid_irq()
  irqchip/gic, gic-v3: Make SGIs use handle_percpu_devid_irq()
  irqchip/ocelot: Add support for Jaguar2 platforms
  irqchip/ocelot: Add support for Serval platforms
  irqchip/ocelot: Add support for Luton platforms
  irqchip/ocelot: prepare to support more SoC
  ...
2020-12-15 15:03:31 -08:00
Linus Torvalds
ac73e3dc8a Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...
2020-12-15 12:53:37 -08:00
Mike Rapoport
5d6ad668f3 arch, mm: restore dependency of __kernel_map_pages() on DEBUG_PAGEALLOC
The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must
never fail.  With this assumption is wouldn't be safe to allow general
usage of this function.

Moreover, some architectures that implement __kernel_map_pages() have this
function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap
pages when page allocation debugging is disabled at runtime.

As all the users of __kernel_map_pages() were converted to use
debug_pagealloc_map_pages() it is safe to make it available only when
DEBUG_PAGEALLOC is set.

Link: https://lkml.kernel.org/r/20201109192128.960-4-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:43 -08:00
Mike Rapoport
4f5b0c1789 arm, arm64: move free_unused_memmap() to generic mm
ARM and ARM64 free unused parts of the memory map just before the
initialization of the page allocator. To allow holes in the memory map both
architectures overload pfn_valid() and define HAVE_ARCH_PFN_VALID.

Allowing holes in the memory map for FLATMEM may be useful for small
machines, such as ARC and m68k and will enable those architectures to cease
using DISCONTIGMEM and still support more than one memory bank.

Move the functions that free unused memory map to generic mm and enable
them in case HAVE_ARCH_PFN_VALID=y.

Link: https://lkml.kernel.org/r/20201101170454.9567-10-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:42 -08:00
Kalesh Singh
c49dd34018 mm: speedup mremap on 1GB or larger regions
Android needs to move large memory regions for garbage collection.  The GC
requires moving physical pages of multi-gigabyte heap using mremap.
During this move, the application threads have to be paused for
correctness.  It is critical to keep this pause as short as possible to
avoid jitters during user interaction.

Optimize mremap for >= 1GB-sized regions by moving at the PUD/PGD level if
the source and destination addresses are PUD-aligned.  For
CONFIG_PGTABLE_LEVELS == 3, moving at the PUD level in effect moves PGD
entries, since the PUD entry is “folded back” onto the PGD entry.  Add
HAVE_MOVE_PUD so that architectures where moving at the PUD level isn't
supported/tested can turn this off by not selecting the config.

Link: https://lkml.kernel.org/r/20201014005320.2233162-4-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Hassan Naveed <hnaveed@wavecomp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jia He <justin.he@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:40 -08:00
Colin Ian King
a86ecfa6a8 arch/Kconfig: fix spelling mistakes
There are a few spelling mistakes in the Kconfig comments and help text.
Fix these.

Link: https://lkml.kernel.org/r/20201207155004.171962-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.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>
2020-12-15 12:13:37 -08:00
Linus Torvalds
1ac0884d54 A set of updates for entry/exit handling:
- More generalization of entry/exit functionality
 
  - The consolidation work to reclaim TIF flags on x86 and also for non-x86
    specific TIF flags which are solely relevant for syscall related work
    and have been moved into their own storage space. The x86 specific part
    had to be merged in to avoid a major conflict.
 
  - The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
    delivery mode of task work and results in an impressive performance
    improvement for io_uring. The non-x86 consolidation of this is going to
    come seperate via Jens.
 
  - The selective syscall redirection facility which provides a clean and
    efficient way to support the non-Linux syscalls of WINE by catching them
    at syscall entry and redirecting them to the user space emulation. This
    can be utilized for other purposes as well and has been designed
    carefully to avoid overhead for the regular fastpath. This includes the
    core changes and the x86 support code.
 
  - Simplification of the context tracking entry/exit handling for the users
    of the generic entry code which guarantee the proper ordering and
    protection.
 
  - Preparatory changes to make the generic entry code accomodate S390
    specific requirements which are mostly related to their syscall restart
    mechanism.
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Merge tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core entry/exit updates from Thomas Gleixner:
 "A set of updates for entry/exit handling:

   - More generalization of entry/exit functionality

   - The consolidation work to reclaim TIF flags on x86 and also for
     non-x86 specific TIF flags which are solely relevant for syscall
     related work and have been moved into their own storage space. The
     x86 specific part had to be merged in to avoid a major conflict.

   - The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
     delivery mode of task work and results in an impressive performance
     improvement for io_uring. The non-x86 consolidation of this is
     going to come seperate via Jens.

   - The selective syscall redirection facility which provides a clean
     and efficient way to support the non-Linux syscalls of WINE by
     catching them at syscall entry and redirecting them to the user
     space emulation. This can be utilized for other purposes as well
     and has been designed carefully to avoid overhead for the regular
     fastpath. This includes the core changes and the x86 support code.

   - Simplification of the context tracking entry/exit handling for the
     users of the generic entry code which guarantee the proper ordering
     and protection.

   - Preparatory changes to make the generic entry code accomodate S390
     specific requirements which are mostly related to their syscall
     restart mechanism"

* tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  entry: Add syscall_exit_to_user_mode_work()
  entry: Add exit_to_user_mode() wrapper
  entry_Add_enter_from_user_mode_wrapper
  entry: Rename exit_to_user_mode()
  entry: Rename enter_from_user_mode()
  docs: Document Syscall User Dispatch
  selftests: Add benchmark for syscall user dispatch
  selftests: Add kselftest for syscall user dispatch
  entry: Support Syscall User Dispatch on common syscall entry
  kernel: Implement selective syscall userspace redirection
  signal: Expose SYS_USER_DISPATCH si_code type
  x86: vdso: Expose sigreturn address on vdso to the kernel
  MAINTAINERS: Add entry for common entry code
  entry: Fix boot for !CONFIG_GENERIC_ENTRY
  x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK
  context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs
  sched: Detect call to schedule from critical entry code
  context_tracking: Don't implement exception_enter/exit() on CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK
  context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK
  x86: Reclaim unused x86 TI flags
  ...
2020-12-14 17:13:53 -08:00
Steven Rostedt (VMware)
adab66b71a Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
It was believed that metag was the only architecture that required the ring
buffer to keep 8 byte words aligned on 8 byte architectures, and with its
removal, it was assumed that the ring buffer code did not need to handle
this case. It appears that sparc64 also requires this.

The following was reported on a sparc64 boot up:

   kernel: futex hash table entries: 65536 (order: 9, 4194304 bytes, linear)
   kernel: Running postponed tracer tests:
   kernel: Testing tracer function:
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: PASSED

Need to put back the 64BIT aligned code for the ring buffer.

Link: https://lore.kernel.org/r/CADxRZqzXQRYgKc=y-KV=S_yHL+Y8Ay2mh5ezeZUnpRvg+syWKw@mail.gmail.com

Cc: stable@vger.kernel.org
Fixes: 86b3de60a0 ("ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS")
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14 12:33:51 -05:00
Frederic Weisbecker
2b91ec9f55 s390/vtime: Use the generic IRQ entry accounting
s390 has its own version of IRQ entry accounting because it doesn't
account the idle time the same way the other architectures do. Only
the actual idle sleep time is accounted as idle time, the rest of the
idle task execution is accounted as system time.

Make the generic IRQ entry accounting aware of architectures that have
their own way of accounting idle time and convert s390 to use it.

This prepares s390 to get involved in further consolidations of IRQ
time accounting.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-3-frederic@kernel.org
2020-12-02 20:20:04 +01:00
Nathan Chancellor
59612b24f7 kbuild: Hoist '--orphan-handling' into Kconfig
Currently, '--orphan-handling=warn' is spread out across four different
architectures in their respective Makefiles, which makes it a little
unruly to deal with in case it needs to be disabled for a specific
linker version (in this case, ld.lld 10.0.1).

To make it easier to control this, hoist this warning into Kconfig and
the main Makefile so that disabling it is simpler, as the warning will
only be enabled in a couple places (main Makefile and a couple of
compressed boot folders that blow away LDFLAGS_vmlinx) and making it
conditional is easier due to Kconfig syntax. One small additional
benefit of this is saving a call to ld-option on incremental builds
because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN.

To keep the list of supported architectures the same, introduce
CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to
gain this automatically after all of the sections are specified and size
asserted. A special thanks to Kees Cook for the help text on this
config.

Link: https://github.com/ClangBuiltLinux/linux/issues/1187
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-01 22:45:36 +09:00
YiFei Zhu
0d8315dddd seccomp/cache: Report cache data through /proc/pid/seccomp_cache
Currently the kernel does not provide an infrastructure to translate
architecture numbers to a human-readable name. Translating syscall
numbers to syscall names is possible through FTRACE_SYSCALL
infrastructure but it does not provide support for compat syscalls.

This will create a file for each PID as /proc/pid/seccomp_cache.
The file will be empty when no seccomp filters are loaded, or be
in the format of:
<arch name> <decimal syscall number> <ALLOW | FILTER>
where ALLOW means the cache is guaranteed to allow the syscall,
and filter means the cache will pass the syscall to the BPF filter.

For the docker default profile on x86_64 it looks like:
x86_64 0 ALLOW
x86_64 1 ALLOW
x86_64 2 ALLOW
x86_64 3 ALLOW
[...]
x86_64 132 ALLOW
x86_64 133 ALLOW
x86_64 134 FILTER
x86_64 135 FILTER
x86_64 136 FILTER
x86_64 137 ALLOW
x86_64 138 ALLOW
x86_64 139 FILTER
x86_64 140 ALLOW
x86_64 141 ALLOW
[...]

This file is guarded by CONFIG_SECCOMP_CACHE_DEBUG with a default
of N because I think certain users of seccomp might not want the
application to know which syscalls are definitely usable. For
the same reason, it is also guarded by CAP_SYS_ADMIN.

Suggested-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/lkml/CAG48ez3Ofqp4crXGksLmZY6=fGrF_tWyUCg7PBkAetvbbOPeOA@mail.gmail.com/
Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/94e663fa53136f5a11f432c661794d1ee7060779.1605101222.git.yifeifz2@illinois.edu
2020-11-20 11:16:35 -08:00
Frederic Weisbecker
83c2da2e60 context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK
Historically, context tracking had to deal with fragile entry code path,
ie: before user_exit() is called and after user_enter() is called, in
case some of those spots would call schedule() or use RCU. On such
cases, the site had to be protected between exception_enter() and
exception_exit() that save the context tracking state in the task stack.

Such sleepable fragile code path had many different origins: tracing,
exceptions, early or late calls to context tracking on syscalls...

Aside of that not being pretty, saving the context tracking state on
the task stack forces us to run context tracking on all CPUs, including
housekeepers, and prevents us to completely shutdown nohz_full at
runtime on a CPU in the future as context tracking and its overhead
would still need to run system wide.

Now thanks to the extensive efforts to sanitize x86 entry code, those
conditions have been removed and we can now get rid of these workarounds
in this architecture.

Create a Kconfig feature to express this achievement.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201117151637.259084-2-frederic@kernel.org
2020-11-19 11:25:41 +01:00
Linus Torvalds
f56e65dff6 Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull initial set_fs() removal from Al Viro:
 "Christoph's set_fs base series + fixups"

* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Allow a NULL pos pointer to __kernel_read
  fs: Allow a NULL pos pointer to __kernel_write
  powerpc: remove address space overrides using set_fs()
  powerpc: use non-set_fs based maccess routines
  x86: remove address space overrides using set_fs()
  x86: make TASK_SIZE_MAX usable from assembly code
  x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h
  lkdtm: remove set_fs-based tests
  test_bitmap: remove user bitmap tests
  uaccess: add infrastructure for kernel builds with set_fs()
  fs: don't allow splice read/write without explicit ops
  fs: don't allow kernel reads and writes without iter ops
  sysctl: Convert to iter interfaces
  proc: add a read_iter method to proc proc_ops
  proc: cleanup the compat vs no compat file ops
  proc: remove a level of indentation in proc_get_inode
2020-10-22 09:59:21 -07:00
Linus Torvalds
96685f8666 powerpc updates for 5.10
- A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM & selecting it for
    powerpc, as well as a related fix for sparc.
 
  - Remove support for PowerPC 601.
 
  - Some fixes for watchpoints & addition of a new ptrace flag for detecting ISA
    v3.1 (Power10) watchpoint features.
 
  - A fix for kernels using 4K pages and the hash MMU on bare metal Power9
    systems with > 16TB of RAM, or RAM on the 2nd node.
 
  - A basic idle driver for shallow stop states on Power10.
 
  - Tweaks to our sched domains code to better inform the scheduler about the
    hardware topology on Power9/10, where two SMT4 cores can be presented by
    firmware as an SMT8 core.
 
  - A series doing further reworks & cleanups of our EEH code.
 
  - Addition of a filter for RTAS (firmware) calls done via sys_rtas(), to
    prevent root from overwriting kernel memory.
 
  - Other smaller features, fixes & cleanups.
 
 Thanks to:
   Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Athira Rajeev, Biwen
   Li, Cameron Berkenpas, Cédric Le Goater, Christophe Leroy, Christoph Hellwig,
   Colin Ian King, Daniel Axtens, David Dai, Finn Thain, Frederic Barrat, Gautham
   R. Shenoy, Greg Kurz, Gustavo Romero, Ira Weiny, Jason Yan, Joel Stanley,
   Jordan Niethe, Kajol Jain, Konrad Rzeszutek Wilk, Laurent Dufour, Leonardo
   Bras, Liu Shixin, Luca Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar,
   Nathan Lynch, Nicholas Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver
   O'Halloran, Pedro Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai,
   Qinglang Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott
   Cheloha, Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt,
   Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain,
   Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang
   Yingliang, zhengbin.
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Merge tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM & selecting
   it for powerpc, as well as a related fix for sparc.

 - Remove support for PowerPC 601.

 - Some fixes for watchpoints & addition of a new ptrace flag for
   detecting ISA v3.1 (Power10) watchpoint features.

 - A fix for kernels using 4K pages and the hash MMU on bare metal
   Power9 systems with > 16TB of RAM, or RAM on the 2nd node.

 - A basic idle driver for shallow stop states on Power10.

 - Tweaks to our sched domains code to better inform the scheduler about
   the hardware topology on Power9/10, where two SMT4 cores can be
   presented by firmware as an SMT8 core.

 - A series doing further reworks & cleanups of our EEH code.

 - Addition of a filter for RTAS (firmware) calls done via sys_rtas(),
   to prevent root from overwriting kernel memory.

 - Other smaller features, fixes & cleanups.

Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Athira Rajeev, Biwen Li, Cameron Berkenpas, Cédric Le Goater, Christophe
Leroy, Christoph Hellwig, Colin Ian King, Daniel Axtens, David Dai, Finn
Thain, Frederic Barrat, Gautham R. Shenoy, Greg Kurz, Gustavo Romero,
Ira Weiny, Jason Yan, Joel Stanley, Jordan Niethe, Kajol Jain, Konrad
Rzeszutek Wilk, Laurent Dufour, Leonardo Bras, Liu Shixin, Luca
Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar, Nathan Lynch, Nicholas
Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Pedro
Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai, Qinglang
Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott Cheloha,
Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt,
Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain,
Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang
Yingliang, zhengbin.

* tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (228 commits)
  Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed"
  selftests/powerpc: Fix eeh-basic.sh exit codes
  cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier
  powerpc/time: Make get_tb() common to PPC32 and PPC64
  powerpc/time: Make get_tbl() common to PPC32 and PPC64
  powerpc/time: Remove get_tbu()
  powerpc/time: Avoid using get_tbl() and get_tbu() internally
  powerpc/time: Make mftb() common to PPC32 and PPC64
  powerpc/time: Rename mftbl() to mftb()
  powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S
  powerpc/32s: Rename head_32.S to head_book3s_32.S
  powerpc/32s: Setup the early hash table at all time.
  powerpc/time: Remove ifdef in get_dec() and set_dec()
  powerpc: Remove get_tb_or_rtc()
  powerpc: Remove __USE_RTC()
  powerpc: Tidy up a bit after removal of PowerPC 601.
  powerpc: Remove support for PowerPC 601
  powerpc: Remove PowerPC 601
  powerpc: Drop SYNC_601() ISYNC_601() and SYNC()
  powerpc: Remove CONFIG_PPC601_SYNC_FIX
  ...
2020-10-16 12:21:15 -07:00
Linus Torvalds
8b05418b25 seccomp updates for v5.10-rc1
- heavily refactor seccomp selftests (and clone3 selftests dependency) to
   fix powerpc (Kees Cook, Thadeu Lima de Souza Cascardo)
 - fix style issue in selftests (Zou Wei)
 - upgrade "unknown action" from KILL_THREAD to KILL_PROCESS (Rich Felker)
 - replace task_pt_regs(current) with current_pt_regs() (Denis Efremov)
 - fix corner-case race in USER_NOTIF (Jann Horn)
 - make CONFIG_SECCOMP no longer per-arch (YiFei Zhu)
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Merge tag 'seccomp-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp updates from Kees Cook:
 "The bulk of the changes are with the seccomp selftests to accommodate
  some powerpc-specific behavioral characteristics. Additional cleanups,
  fixes, and improvements are also included:

   - heavily refactor seccomp selftests (and clone3 selftests
     dependency) to fix powerpc (Kees Cook, Thadeu Lima de Souza
     Cascardo)

   - fix style issue in selftests (Zou Wei)

   - upgrade "unknown action" from KILL_THREAD to KILL_PROCESS (Rich
     Felker)

   - replace task_pt_regs(current) with current_pt_regs() (Denis
     Efremov)

   - fix corner-case race in USER_NOTIF (Jann Horn)

   - make CONFIG_SECCOMP no longer per-arch (YiFei Zhu)"

* tag 'seccomp-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits)
  seccomp: Make duplicate listener detection non-racy
  seccomp: Move config option SECCOMP to arch/Kconfig
  selftests/clone3: Avoid OS-defined clone_args
  selftests/seccomp: powerpc: Set syscall return during ptrace syscall exit
  selftests/seccomp: Allow syscall nr and ret value to be set separately
  selftests/seccomp: Record syscall during ptrace entry
  selftests/seccomp: powerpc: Fix seccomp return value testing
  selftests/seccomp: Remove SYSCALL_NUM_RET_SHARE_REG in favor of SYSCALL_RET_SET
  selftests/seccomp: Avoid redundant register flushes
  selftests/seccomp: Convert REGSET calls into ARCH_GETREG/ARCH_SETREG
  selftests/seccomp: Convert HAVE_GETREG into ARCH_GETREG/ARCH_SETREG
  selftests/seccomp: Remove syscall setting #ifdefs
  selftests/seccomp: mips: Remove O32-specific macro
  selftests/seccomp: arm64: Define SYSCALL_NUM_SET macro
  selftests/seccomp: arm: Define SYSCALL_NUM_SET macro
  selftests/seccomp: mips: Define SYSCALL_NUM_SET macro
  selftests/seccomp: Provide generic syscall setting macro
  selftests/seccomp: Refactor arch register macros to avoid xtensa special case
  selftests/seccomp: Use __NR_mknodat instead of __NR_mknod
  selftests/seccomp: Use bitwise instead of arithmetic operator for flags
  ...
2020-10-13 16:33:43 -07:00
YiFei Zhu
282a181b1a seccomp: Move config option SECCOMP to arch/Kconfig
In order to make adding configurable features into seccomp easier,
it's better to have the options at one single location, considering
especially that the bulk of seccomp code is arch-independent. An quick
look also show that many SECCOMP descriptions are outdated; they talk
about /proc rather than prctl.

As a result of moving the config option and keeping it default on,
architectures arm, arm64, csky, riscv, sh, and xtensa did not have SECCOMP
on by default prior to this and SECCOMP will be default in this change.

Architectures microblaze, mips, powerpc, s390, sh, and sparc have an
outdated depend on PROC_FS and this dependency is removed in this change.

Suggested-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/lkml/CAG48ez1YWz9cnp08UZgeieYRhHdqh-ch7aNwc4JRBnGyrmgfMg@mail.gmail.com/
Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
[kees: added HAVE_ARCH_SECCOMP help text, tweaked wording]
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/9ede6ef35c847e58d61e476c6a39540520066613.1600951211.git.yifeifz2@illinois.edu
2020-10-08 13:17:47 -07:00
Nicholas Piggin
d53c3dfb23 mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
Reading and modifying current->mm and current->active_mm and switching
mm should be done with irqs off, to prevent races seeing an intermediate
state.

This is similar to commit 38cf307c1f ("mm: fix kthread_use_mm() vs TLB
invalidate"). At exec-time when the new mm is activated, the old one
should usually be single-threaded and no longer used, unless something
else is holding an mm_users reference (which may be possible).

Absent other mm_users, there is also a race with preemption and lazy tlb
switching. Consider the kernel_execve case where the current thread is
using a lazy tlb active mm:

  call_usermodehelper()
    kernel_execve()
      old_mm = current->mm;
      active_mm = current->active_mm;
      *** preempt *** -------------------->  schedule()
                                               prev->active_mm = NULL;
                                               mmdrop(prev active_mm);
                                             ...
                      <--------------------  schedule()
      current->mm = mm;
      current->active_mm = mm;
      if (!old_mm)
          mmdrop(active_mm);

If we switch back to the kernel thread from a different mm, there is a
double free of the old active_mm, and a missing free of the new one.

Closing this race only requires interrupts to be disabled while ->mm
and ->active_mm are being switched, but the TLB problem requires also
holding interrupts off over activate_mm. Unfortunately not all archs
can do that yet, e.g., arm defers the switch if irqs are disabled and
expects finish_arch_post_lock_switch() to be called to complete the
flush; um takes a blocking lock in activate_mm().

So as a first step, disable interrupts across the mm/active_mm updates
to close the lazy tlb preempt race, and provide an arch option to
extend that to activate_mm which allows architectures doing IPI based
TLB shootdowns to close the second race.

This is a bit ugly, but in the interest of fixing the bug and backporting
before all architectures are converted this is a compromise.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914045219.3736466-2-npiggin@gmail.com
2020-09-16 12:24:31 +10:00
Christoph Hellwig
5e6e9852d6 uaccess: add infrastructure for kernel builds with set_fs()
Add a CONFIG_SET_FS option that is selected by architecturess that
implement set_fs, which is all of them initially.  If the option is not
set stubs for routines related to overriding the address space are
provided so that architectures can start to opt out of providing set_fs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-08 22:21:32 -04:00
Peter Zijlstra
f03c412915 static_call: Add simple self-test for static calls
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200818135804.922581202@infradead.org
2020-09-01 09:58:05 +02:00
Josh Poimboeuf
9183c3f9ed static_call: Add inline static call infrastructure
Add infrastructure for an arch-specific CONFIG_HAVE_STATIC_CALL_INLINE
option, which is a faster version of CONFIG_HAVE_STATIC_CALL.  At
runtime, the static call sites are patched directly, rather than using
the out-of-line trampolines.

Compared to out-of-line static calls, the performance benefits are more
modest, but still measurable.  Steven Rostedt did some tracepoint
measurements:

  https://lkml.kernel.org/r/20181126155405.72b4f718@gandalf.local.home

This code is heavily inspired by the jump label code (aka "static
jumps"), as some of the concepts are very similar.

For more details, see the comments in include/linux/static_call.h.

[peterz: simplified interface; merged trampolines]

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135804.684334440@infradead.org
2020-09-01 09:58:04 +02:00
Josh Poimboeuf
115284d89a static_call: Add basic static call infrastructure
Static calls are a replacement for global function pointers.  They use
code patching to allow direct calls to be used instead of indirect
calls.  They give the flexibility of function pointers, but with
improved performance.  This is especially important for cases where
retpolines would otherwise be used, as retpolines can significantly
impact performance.

The concept and code are an extension of previous work done by Ard
Biesheuvel and Steven Rostedt:

  https://lkml.kernel.org/r/20181005081333.15018-1-ard.biesheuvel@linaro.org
  https://lkml.kernel.org/r/20181006015110.653946300@goodmis.org

There are two implementations, depending on arch support:

 1) out-of-line: patched trampolines (CONFIG_HAVE_STATIC_CALL)
 2) basic function pointers

For more details, see the comments in include/linux/static_call.h.

[peterz: simplified interface]

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135804.623259796@infradead.org
2020-09-01 09:58:04 +02:00
Linus Torvalds
b923f1247b A set oftimekeeping/VDSO updates:
- Preparatory work to allow S390 to switch over to the generic VDSO
    implementation.
 
    S390 requires that the VDSO data pointer is handed in to the counter
    read function when time namespace support is enabled. Adding the pointer
    is a NOOP for all other architectures because the compiler is supposed
    to optimize that out when it is unused in the architecture specific
    inline. The change also solved a similar problem for MIPS which
    fortunately has time namespaces not yet enabled.
 
    S390 needs to update clock related VDSO data independent of the
    timekeeping updates. This was solved so far with yet another sequence
    counter in the S390 implementation. A better solution is to utilize the
    already existing VDSO sequence count for this. The core code now exposes
    helper functions which allow to serialize against the timekeeper code
    and against concurrent readers.
 
    S390 needs extra data for their clock readout function. The initial
    common VDSO data structure did not provide a way to add that. It now has
    an embedded architecture specific struct embedded which defaults to an
    empty struct.
 
    Doing this now avoids tree dependencies and conflicts post rc1 and
    allows all other architectures which work on generic VDSO support to
    work from a common upstream base.
 
  - A trivial comment fix.
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Merge tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timekeeping updates from Thomas Gleixner:
 "A set of timekeeping/VDSO updates:

   - Preparatory work to allow S390 to switch over to the generic VDSO
     implementation.

     S390 requires that the VDSO data pointer is handed in to the
     counter read function when time namespace support is enabled.
     Adding the pointer is a NOOP for all other architectures because
     the compiler is supposed to optimize that out when it is unused in
     the architecture specific inline. The change also solved a similar
     problem for MIPS which fortunately has time namespaces not yet
     enabled.

     S390 needs to update clock related VDSO data independent of the
     timekeeping updates. This was solved so far with yet another
     sequence counter in the S390 implementation. A better solution is
     to utilize the already existing VDSO sequence count for this. The
     core code now exposes helper functions which allow to serialize
     against the timekeeper code and against concurrent readers.

     S390 needs extra data for their clock readout function. The initial
     common VDSO data structure did not provide a way to add that. It
     now has an embedded architecture specific struct embedded which
     defaults to an empty struct.

     Doing this now avoids tree dependencies and conflicts post rc1 and
     allows all other architectures which work on generic VDSO support
     to work from a common upstream base.

   - A trivial comment fix"

* tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Delete repeated words in comments
  lib/vdso: Allow to add architecture-specific vdso data
  timekeeping/vsyscall: Provide vdso_update_begin/end()
  vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()
2020-08-14 14:26:08 -07:00
Linus Torvalds
fc80c51fd4 Kbuild updates for v5.9
- run the checker (e.g. sparse) after the compiler
 
  - remove unneeded cc-option tests for old compiler flags
 
  - fix tar-pkg to install dtbs
 
  - introduce ccflags-remove-y and asflags-remove-y syntax
 
  - allow to trace functions in sub-directories of lib/
 
  - introduce hostprogs-always-y and userprogs-always-y syntax
 
  - various Makefile cleanups
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Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - run the checker (e.g. sparse) after the compiler

 - remove unneeded cc-option tests for old compiler flags

 - fix tar-pkg to install dtbs

 - introduce ccflags-remove-y and asflags-remove-y syntax

 - allow to trace functions in sub-directories of lib/

 - introduce hostprogs-always-y and userprogs-always-y syntax

 - various Makefile cleanups

* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
  kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
  kbuild: introduce hostprogs-always-y and userprogs-always-y
  kbuild: sort hostprogs before passing it to ifneq
  kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
  kbuild: Replace HTTP links with HTTPS ones
  kbuild: trace functions in subdirectories of lib/
  kbuild: introduce ccflags-remove-y and asflags-remove-y
  kbuild: do not export LDFLAGS_vmlinux
  kbuild: always create directories of targets
  powerpc/boot: add DTB to 'targets'
  kbuild: buildtar: add dtbs support
  kbuild: remove cc-option test of -ffreestanding
  kbuild: remove cc-option test of -fno-stack-protector
  Revert "kbuild: Create directory for target DTB"
  kbuild: run the checker after the compiler
2020-08-09 14:10:26 -07:00
Sven Schnelle
d60d7de3e1 lib/vdso: Allow to add architecture-specific vdso data
The initial assumption that all VDSO related data can be completely generic
does not hold. S390 needs architecture specific storage to access the clock
steering information.

Add struct arch_vdso_data to the vdso data struct. For architectures which
do not need extra data this defaults to an empty struct. Architectures
which require it, enable CONFIG_ARCH_HAS_VDSO_DATA and provide their
specific struct in asm/vdso/data.h.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200804150124.41692-2-svens@linux.ibm.com
2020-08-06 10:57:30 +02:00
Linus Torvalds
2324d50d05 It's been a busy cycle for documentation - hopefully the busiest for a
while to come.  Changes include:
 
  - Some new Chinese translations
 
  - Progress on the battle against double words words and non-HTTPS URLs
 
  - Some block-mq documentation
 
  - More RST conversions from Mauro.  At this point, that task is
    essentially complete, so we shouldn't see this kind of churn again for a
    while.  Unless we decide to switch to asciidoc or something...:)
 
  - Lots of typo fixes, warning fixes, and more.
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Merge tag 'docs-5.9' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It's been a busy cycle for documentation - hopefully the busiest for a
  while to come. Changes include:

   - Some new Chinese translations

   - Progress on the battle against double words words and non-HTTPS
     URLs

   - Some block-mq documentation

   - More RST conversions from Mauro. At this point, that task is
     essentially complete, so we shouldn't see this kind of churn again
     for a while. Unless we decide to switch to asciidoc or
     something...:)

   - Lots of typo fixes, warning fixes, and more"

* tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits)
  scripts/kernel-doc: optionally treat warnings as errors
  docs: ia64: correct typo
  mailmap: add entry for <alobakin@marvell.com>
  doc/zh_CN: add cpu-load Chinese version
  Documentation/admin-guide: tainted-kernels: fix spelling mistake
  MAINTAINERS: adjust kprobes.rst entry to new location
  devices.txt: document rfkill allocation
  PCI: correct flag name
  docs: filesystems: vfs: correct flag name
  docs: filesystems: vfs: correct sync_mode flag names
  docs: path-lookup: markup fixes for emphasis
  docs: path-lookup: more markup fixes
  docs: path-lookup: fix HTML entity mojibake
  CREDITS: Replace HTTP links with HTTPS ones
  docs: process: Add an example for creating a fixes tag
  doc/zh_CN: add Chinese translation prefer section
  doc/zh_CN: add clearing-warn-once Chinese version
  doc/zh_CN: add admin-guide index
  doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label
  futex: MAINTAINERS: Re-add selftests directory
  ...
2020-08-04 22:47:54 -07:00
Linus Torvalds
3f0d6ecdf1 Generic implementation of common syscall, interrupt and exception
entry/exit functionality based on the recent X86 effort to ensure
 correctness of entry/exit vs. RCU and instrumentation.
 
 As this functionality and the required entry/exit sequences are not
 architecture specific, sharing them allows other architectures to benefit
 instead of copying the same code over and over again.
 
 This branch was kept standalone to allow others to work on it. The
 conversion of x86 comes in a seperate pull request which obviously is based
 on this branch.
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Merge tag 'core-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull generic kernel entry/exit code from Thomas Gleixner:
 "Generic implementation of common syscall, interrupt and exception
  entry/exit functionality based on the recent X86 effort to ensure
  correctness of entry/exit vs RCU and instrumentation.

  As this functionality and the required entry/exit sequences are not
  architecture specific, sharing them allows other architectures to
  benefit instead of copying the same code over and over again.

  This branch was kept standalone to allow others to work on it. The
  conversion of x86 comes in a seperate pull request which obviously is
  based on this branch"

* tag 'core-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Correct __secure_computing() stub
  entry: Correct 'noinstr' attributes
  entry: Provide infrastructure for work before transitioning to guest mode
  entry: Provide generic interrupt entry/exit code
  entry: Provide generic syscall exit function
  entry: Provide generic syscall entry functionality
  seccomp: Provide stub for __secure_computing()
2020-08-04 21:00:11 -07:00
Thomas Gleixner
142781e108 entry: Provide generic syscall entry functionality
On syscall entry certain work needs to be done:

   - Establish state (lockdep, context tracking, tracing)
   - Conditional work (ptrace, seccomp, audit...)

This code is needlessly duplicated and  different in all
architectures.

Provide a generic version based on the x86 implementation which has all the
RCU and instrumentation bits right.

As interrupt/exception entry from user space needs parts of the same
functionality, provide a function for this as well.

syscall_enter_from_user_mode() and irqentry_enter_from_user_mode() must be
called right after the low level ASM entry. The calling code must be
non-instrumentable. After the functions returns state is correct and the
subsequent functions can be instrumented.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200722220519.513463269@linutronix.de
2020-07-24 14:59:03 +02:00
Masahiro Yamada
893ab00439 kbuild: remove cc-option test of -fno-stack-protector
Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.

No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.

GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)

Get rid of cc-option from -fno-stack-protector.

Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.

Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-07-07 11:13:10 +09:00
Christian Brauner
140c8180eb
arch: remove HAVE_COPY_THREAD_TLS
All architectures support copy_thread_tls() now, so remove the legacy
copy_thread() function and the HAVE_COPY_THREAD_TLS config option. Everyone
uses the same process creation calling convention based on
copy_thread_tls() and struct kernel_clone_args. This will make it easier to
maintain the core process creation code under kernel/, simplifies the
callpaths and makes the identical for all architectures.

Cc: linux-arch@vger.kernel.org
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Greentime Hu <green.hu@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-04 23:41:37 +02:00
Mauro Carvalho Chehab
c9b54d6f36 docs: move other kAPI documents to core-api
There are a number of random documents that seem to be
describing some aspects of the core-api. Move them to such
directory, adding them at the core-api/index.rst file.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/86d979ed183adb76af93a92f20189bccf97f0055.1592918949.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-26 11:33:42 -06:00
Masahiro Yamada
a7f7f6248d treewide: replace '---help---' in Kconfig files with 'help'
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 01:57:21 +09:00