Commit Graph

543 Commits

Author SHA1 Message Date
Linus Torvalds
c6439bfaab Deferred unwind changes for 6.17
This is the core infrastructure for the deferred unwinder that is required
 for sframes[1]. Several other patch series is based on this work although
 those patch series are not dependent on each other. In order to simplify the
 development, having this core series upstream will allow the other series to
 be worked on in parallel. The other series are:
 
 - The two patches to implement x86:
   https://lore.kernel.org/linux-trace-kernel/20250717004958.260781923@kernel.org/
   https://lore.kernel.org/linux-trace-kernel/20250717004958.432327787@kernel.org/
 
 - The s390 work:
   https://lore.kernel.org/linux-trace-kernel/20250710163522.3195293-1-jremus@linux.ibm.com/
 
 - The perf work:
   https://lore.kernel.org/linux-trace-kernel/20250718164119.089692174@kernel.org/
 
 - The ftrace work:
   https://lore.kernel.org/linux-trace-kernel/20250424192612.505622711@goodmis.org/
 
 - The sframe work:
   https://lore.kernel.org/linux-trace-kernel/20250717012848.927473176@kernel.org/
 
 And more is on the way.
 
 The core infrastructure adds the following in kernel APIs:
 
 - int unwind_user_faultable(struct unwind_stacktrace *trace);
 
     Performs a user space stack trace that may fault user pages in.
 
 - int unwind_deferred_init(struct unwind_work *work, unwind_callback_t func);
 
     Allows a tracer to register with the unwind deferred infrastructure.
 
 - int unwind_deferred_request(struct unwind_work *work, u64 *cookie);
 
     Used when a tracer request a deferred trace. Can be called from interrupt
     or NMI context.
 
 - void unwind_deferred_cancel(struct unwind_work *work);
 
     Called by a tracer to unregister from the deferred unwind infrastructure.
 
 - void unwind_deferred_task_exit(struct task_struct *task);
 
     Called by task exit code to flush any pending unwind requests.
 
 - void unwind_task_init(struct task_struct *task);
 
     Called by do_fork() to initialize the task struct for the deferred
     unwinder.
 
 - void unwind_task_free(struct task_struct *task);
 
     Called by do_exit() to free up any resources used by the deferred
     unwinder.
 
 None of the above is actually compiled unless an architecture enables it,
 which none currently do.
 
 [1] https://sourceware.org/binutils/wiki/sframe
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Merge tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull initial deferred unwind infrastructure from Steven Rostedt:
 "This is the core infrastructure for the deferred unwinder that is
  required for sframes[1]. Several other patch series are based on this
  work although those patch series are not dependent on each other. In
  order to simplify the development, having this core series upstream
  will allow the other series to be worked on in parallel. The other
  series are:

    - The two patches to implement x86 support [2] [3]

    - The s390 work [4]

    - The perf work [5]

    - The ftrace work [6]

    - The sframe work [7]

  And more is on the way.

  The core infrastructure adds the following in kernel APIs:

    - int unwind_user_faultable(struct unwind_stacktrace *trace);

        Performs a user space stack trace that may fault user pages in.

    - int unwind_deferred_init(struct unwind_work *work, unwind_callback_t func);

        Allows a tracer to register with the unwind deferred
        infrastructure.

    - int unwind_deferred_request(struct unwind_work *work, u64 *cookie);

        Used when a tracer request a deferred trace. Can be called from
        interrupt or NMI context.

    - void unwind_deferred_cancel(struct unwind_work *work);

        Called by a tracer to unregister from the deferred unwind
        infrastructure.

    - void unwind_deferred_task_exit(struct task_struct *task);

        Called by task exit code to flush any pending unwind requests.

    - void unwind_task_init(struct task_struct *task);

        Called by do_fork() to initialize the task struct for the
        deferred unwinder.

    - void unwind_task_free(struct task_struct *task);

        Called by do_exit() to free up any resources used by the
        deferred unwinder.

    None of the above is actually compiled unless an architecture enables it,
    which none currently do"

Link: https://sourceware.org/binutils/wiki/sframe [1]
Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.260781923@kernel.org/ [2]
Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.432327787@kernel.org/ [3]
Link: https://lore.kernel.org/linux-trace-kernel/20250710163522.3195293-1-jremus@linux.ibm.com/ [4]
Link: https://lore.kernel.org/linux-trace-kernel/20250718164119.089692174@kernel.org/ [5]
Link: https://lore.kernel.org/linux-trace-kernel/20250424192612.505622711@goodmis.org/ [6]
Link: https://lore.kernel.org/linux-trace-kernel/20250717012848.927473176@kernel.org/ [7]

* tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  unwind: Finish up unwind when a task exits
  unwind deferred: Use SRCU unwind_deferred_task_work()
  unwind: Add USED bit to only have one conditional on way back to user space
  unwind deferred: Add unwind_completed mask to stop spurious callbacks
  unwind deferred: Use bitmask to determine which callbacks to call
  unwind_user/deferred: Make unwind deferral requests NMI-safe
  unwind_user/deferred: Add deferred unwinding interface
  unwind_user/deferred: Add unwind cache
  unwind_user/deferred: Add unwind_user_faultable()
  unwind_user: Add user space unwinding API with frame pointer support
2025-08-01 09:46:24 -07:00
Linus Torvalds
04d29e3609 - Untangle the Retbleed from the ITS mitigation on Intel. Allow for ITS
to enable stuffing independently from Retbleed, do some cleanups to
   simplify and streamline the code
 
 - Simplify SRSO and make mitigation types selection more versatile
   depending on the Retbleed mitigation selection. Simplify code some
 
 - Add the second part of the attack vector controls which provide a lot
   friendlier user interface to the speculation mitigations than
   selecting each one by one as it is now.
 
   Instead, the selection of whole attack vectors which are relevant to
   the system in use can be done and protection against only those
   vectors is enabled, thus giving back some performance to the users
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Merge tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 CPU mitigation updates from Borislav Petkov:

 - Untangle the Retbleed from the ITS mitigation on Intel. Allow for ITS
   to enable stuffing independently from Retbleed, do some cleanups to
   simplify and streamline the code

 - Simplify SRSO and make mitigation types selection more versatile
   depending on the Retbleed mitigation selection. Simplify code some

 - Add the second part of the attack vector controls which provide a lot
   friendlier user interface to the speculation mitigations than
   selecting each one by one as it is now.

   Instead, the selection of whole attack vectors which are relevant to
   the system in use can be done and protection against only those
   vectors is enabled, thus giving back some performance to the users

* tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  x86/bugs: Print enabled attack vectors
  x86/bugs: Add attack vector controls for TSA
  x86/pti: Add attack vector controls for PTI
  x86/bugs: Add attack vector controls for ITS
  x86/bugs: Add attack vector controls for SRSO
  x86/bugs: Add attack vector controls for L1TF
  x86/bugs: Add attack vector controls for spectre_v2
  x86/bugs: Add attack vector controls for BHI
  x86/bugs: Add attack vector controls for spectre_v2_user
  x86/bugs: Add attack vector controls for retbleed
  x86/bugs: Add attack vector controls for spectre_v1
  x86/bugs: Add attack vector controls for GDS
  x86/bugs: Add attack vector controls for SRBDS
  x86/bugs: Add attack vector controls for RFDS
  x86/bugs: Add attack vector controls for MMIO
  x86/bugs: Add attack vector controls for TAA
  x86/bugs: Add attack vector controls for MDS
  x86/bugs: Define attack vectors relevant for each bug
  x86/Kconfig: Add arch attack vector support
  cpu: Define attack vectors
  ...
2025-07-29 16:34:45 -07:00
Linus Torvalds
78bb43e51b Updates for the generic entry code:
- Split the code into syscall and exception/interrupt parts to ease the
     conversion of ARM[64] to the generic entry infrastructure
 
   - Extend syscall user dispatching to support a single intercepted range
     instead of the default single non-intercepted range. That allows
     monitoring/analysis of a specific executable range, e.g. a library, and
     also provides flexibility for sandboxing scenarios.
 
   - Cleanup and extend the user dispatch selftest
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Merge tag 'core-entry-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull generic entry code updates from Thomas Gleixner:

 - Split the code into syscall and exception/interrupt parts to ease the
   conversion of ARM[64] to the generic entry infrastructure

 - Extend syscall user dispatching to support a single intercepted range
   instead of the default single non-intercepted range. That allows
   monitoring/analysis of a specific executable range, e.g. a library,
   and also provides flexibility for sandboxing scenarios

 - Cleanup and extend the user dispatch selftest

* tag 'core-entry-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Split generic entry into generic exception and syscall entry
  selftests: Add tests for PR_SYS_DISPATCH_INCLUSIVE_ON
  syscall_user_dispatch: Add PR_SYS_DISPATCH_INCLUSIVE_ON
  selftests: Fix errno checking in syscall_user_dispatch test
2025-07-29 15:14:29 -07:00
Josh Poimboeuf
71753c6ed2 unwind_user: Add user space unwinding API with frame pointer support
Introduce a generic API for unwinding user stacks.

In order to expand user space unwinding to be able to handle more complex
scenarios, such as deferred unwinding and reading user space information,
create a generic interface that all architectures can use that support the
various unwinding methods.

This is an alternative method for handling user space stack traces from
the simple stack_trace_save_user() API. This does not replace that
interface, but this interface will be used to expand the functionality of
user space stack walking.

None of the structures introduced will be exposed to user space tooling.

Support for frame pointer unwinding is added. For an architecture to
support frame pointer unwinding it needs to enable
CONFIG_HAVE_UNWIND_USER_FP and define ARCH_INIT_USER_FP_FRAME.

By encoding the frame offsets in struct unwind_user_frame, much of this
code can also be reused for future unwinder implementations like sframe.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Link: https://lore.kernel.org/20250729182404.975790139@kernel.org
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Co-developed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/all/20250710164301.3094-2-mathieu.desnoyers@efficios.com/
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-29 14:46:07 -04:00
Kees Cook
57fbad15c2 stackleak: Rename STACKLEAK to KSTACK_ERASE
In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:

- Add the new top-level CONFIG_KSTACK_ERASE option which will be
  implemented either with the stackleak GCC plugin, or with the Clang
  stack depth callback support.
- Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE,
  but keep it for anything specific to the GCC plugin itself.
- Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named
  for what it does rather than what it protects against), but leave as
  many of the internals alone as possible to avoid even more churn.

While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS,
since that's the only place it is referenced from.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21 21:35:01 -07:00
David Kaplan
735e59204b x86/Kconfig: Add arch attack vector support
ARCH_HAS_CPU_ATTACK_VECTORS should be set for architectures which implement
the new attack-vector based controls for CPU mitigations.  If an arch does
not support attack-vector based controls then an attempt to use them
results in a warning.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250707183316.1349127-4-david.kaplan@amd.com
2025-07-11 17:56:40 +02:00
Jinjie Ruan
a70e9f647f entry: Split generic entry into generic exception and syscall entry
Currently CONFIG_GENERIC_ENTRY enables both the generic exception
entry logic and the generic syscall entry logic, which are otherwise
loosely coupled.

Introduce separate config options for these so that architectures can
select the two independently. This will make it easier for
architectures to migrate to generic entry code.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/20250213130007.1418890-2-ruanjinjie@huawei.com
Link: https://lore.kernel.org/all/20250624-generic-entry-split-v1-1-53d5ef4f94df@linaro.org

[Linus Walleij: rebase onto v6.16-rc1]
2025-06-30 19:52:55 +02:00
James Morse
bff70402d6 fs/resctrl: Add boiler plate for external resctrl code
Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL
for the common parts of the resctrl interface and make X86_CPU_RESCTRL
select this.

Adding an include of asm/resctrl.h to linux/resctrl.h allows the
/fs/resctrl files to switch over to using this header instead.

Co-developed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64
Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/20250515165855.31452-16-james.morse@arm.com
2025-05-16 11:05:40 +02:00
Linus Torvalds
f4d2ef4825 Kbuild updates for v6.15
- Improve performance in gendwarfksyms
 
  - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS
 
  - Support CONFIG_HEADERS_INSTALL for ARCH=um
 
  - Use more relative paths to sources files for better reproducibility
 
  - Support the loong64 Debian architecture
 
  - Add Kbuild bash completion
 
  - Introduce intermediate vmlinux.unstripped for architectures that need
    static relocations to be stripped from the final vmlinux
 
  - Fix versioning in Debian packages for -rc releases
 
  - Treat missing MODULE_DESCRIPTION() as an error
 
  - Convert Nios2 Makefiles to use the generic rule for built-in DTB
 
  - Add debuginfo support to the RPM package
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Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Improve performance in gendwarfksyms

 - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS

 - Support CONFIG_HEADERS_INSTALL for ARCH=um

 - Use more relative paths to sources files for better reproducibility

 - Support the loong64 Debian architecture

 - Add Kbuild bash completion

 - Introduce intermediate vmlinux.unstripped for architectures that need
   static relocations to be stripped from the final vmlinux

 - Fix versioning in Debian packages for -rc releases

 - Treat missing MODULE_DESCRIPTION() as an error

 - Convert Nios2 Makefiles to use the generic rule for built-in DTB

 - Add debuginfo support to the RPM package

* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
  kbuild: rpm-pkg: build a debuginfo RPM
  kconfig: merge_config: use an empty file as initfile
  nios2: migrate to the generic rule for built-in DTB
  rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
  kbuild: pacman-pkg: hardcode module installation path
  kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
  modpost: require a MODULE_DESCRIPTION()
  kbuild: make all file references relative to source root
  x86: drop unnecessary prefix map configuration
  kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
  kbuild: Add a help message for "headers"
  kbuild: deb-pkg: remove "version" variable in mkdebian
  kbuild: deb-pkg: fix versioning for -rc releases
  Documentation/kbuild: Fix indentation in modules.rst example
  x86: Get rid of Makefile.postlink
  kbuild: Create intermediate vmlinux build with relocations preserved
  kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
  kbuild: link-vmlinux.sh: Make output file name configurable
  kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
  Revert "kheaders: Ignore silly-rename files"
  ...
2025-04-05 15:46:50 -07:00
Ard Biesheuvel
9b400d1725 kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch specific tools
consume these static relocations in order to construct relocation tables
for KASLR.

The fact that vmlinux is created, consumed and subsequently updated goes
against the typical, declarative paradigm used by Make, which is based
on rules and dependencies. So as a first step towards cleaning this up,
introduce a Kconfig symbol to declare that the arch wants to consume the
static relocations emitted into vmlinux. This will be wired up further
in subsequent patches.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-17 00:29:50 +09:00
Thomas Weißschuh
365841e155 vdso: Add generic architecture-specific data storage
Some architectures need to expose architecture-specific data to the vDSO.

Enable the generic vDSO storage mechanism to both store and map this
data. Some architectures require more than a single page, like LoongArch,
so prepare for that usecase, too.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-7-13a4669dfc8c@linutronix.de
2025-02-21 09:54:01 +01:00
Greg Ungerer
e419ddeabe m68k: Use kernel's generic muldi3 libgcc function
Use the kernels own generic lib/muldi3.c implementation of muldi3 for
68K machines. Some 68K CPUs support 64bit multiplies so move the arch
specific umul_ppmm() macro into a header file that is included by
lib/muldi3.c. That way it can take advantage of the single instruction
when available.

There does not appear to be any existing mechanism for the generic
lib/muldi3.c code to pick up an external arch definition of umul_ppmm().
Create an arch specific libgcc.h that can optionally be included by
the system include/linux/libgcc.h to allow for this.

Somewhat oddly there is also a similar definition of umul_ppmm() in
the non-architecture code in lib/crypto/mpi/longlong.h for a wide range
or machines. Its presence ends up complicating the include setup and
means not being able to use something like compiler.h instead. Actually
there is a few other defines of umul_ppmm() macros spread around in
various architectures, but not directly usable for the m68k case.

Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/20231113133209.1367286-1-gerg@linux-m68k.org
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2024-12-09 13:29:17 +01:00
Linus Torvalds
6a34dfa15d Kbuild updates for v6.13
- Add generic support for built-in boot DTB files
 
  - Enable TAB cycling for dialog buttons in nconfig
 
  - Fix issues in streamline_config.pl
 
  - Refactor Kconfig
 
  - Add support for Clang's AutoFDO (Automatic Feedback-Directed
    Optimization)
 
  - Add support for Clang's Propeller, a profile-guided optimization.
 
  - Change the working directory to the external module directory for M=
    builds
 
  - Support building external modules in a separate output directory
 
  - Enable objtool for *.mod.o and additional kernel objects
 
  - Use lz4 instead of deprecated lz4c
 
  - Work around a performance issue with "git describe"
 
  - Refactor modpost
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Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add generic support for built-in boot DTB files

 - Enable TAB cycling for dialog buttons in nconfig

 - Fix issues in streamline_config.pl

 - Refactor Kconfig

 - Add support for Clang's AutoFDO (Automatic Feedback-Directed
   Optimization)

 - Add support for Clang's Propeller, a profile-guided optimization.

 - Change the working directory to the external module directory for M=
   builds

 - Support building external modules in a separate output directory

 - Enable objtool for *.mod.o and additional kernel objects

 - Use lz4 instead of deprecated lz4c

 - Work around a performance issue with "git describe"

 - Refactor modpost

* tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits)
  kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms
  gitignore: Don't ignore 'tags' directory
  kbuild: add dependency from vmlinux to resolve_btfids
  modpost: replace tdb_hash() with hash_str()
  kbuild: deb-pkg: add python3:native to build dependency
  genksyms: reduce indentation in export_symbol()
  modpost: improve error messages in device_id_check()
  modpost: rename alias symbol for MODULE_DEVICE_TABLE()
  modpost: rename variables in handle_moddevtable()
  modpost: move strstarts() to modpost.h
  modpost: convert do_usb_table() to a generic handler
  modpost: convert do_of_table() to a generic handler
  modpost: convert do_pnp_device_entry() to a generic handler
  modpost: convert do_pnp_card_entries() to a generic handler
  modpost: call module_alias_printf() from all do_*_entry() functions
  modpost: pass (struct module *) to do_*_entry() functions
  modpost: remove DEF_FIELD_ADDR_VAR() macro
  modpost: deduplicate MODULE_ALIAS() for all drivers
  modpost: introduce module_alias_printf() helper
  modpost: remove unnecessary check in do_acpi_entry()
  ...
2024-11-30 13:41:50 -08:00
Rong Xu
d5dc958361 kbuild: Add Propeller configuration for kernel build
Add the build support for using Clang's Propeller optimizer. Like
AutoFDO, Propeller uses hardware sampling to gather information
about the frequency of execution of different code paths within a
binary. This information is then used to guide the compiler's
optimization decisions, resulting in a more efficient binary.

The support requires a Clang compiler LLVM 19 or later, and the
create_llvm_prof tool
(https://github.com/google/autofdo/releases/tag/v0.30.1). This
commit is limited to x86 platforms that support PMU features
like LBR on Intel machines and AMD Zen3 BRS.

Here is an example workflow for building an AutoFDO+Propeller
optimized kernel:

1) Build the kernel on the host machine, with AutoFDO and Propeller
   build config
      CONFIG_AUTOFDO_CLANG=y
      CONFIG_PROPELLER_CLANG=y
   then
      $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<autofdo_profile>

“<autofdo_profile>” is the profile collected when doing a non-Propeller
AutoFDO build. This step builds a kernel that has the same optimization
level as AutoFDO, plus a metadata section that records basic block
information. This kernel image runs as fast as an AutoFDO optimized
kernel.

2) Install the kernel on test/production machines.

3) Run the load tests. The '-c' option in perf specifies the sample
   event period. We suggest using a suitable prime number,
   like 500009, for this purpose.
   For Intel platforms:
      $ perf record -e BR_INST_RETIRED.NEAR_TAKEN:k -a -N -b -c <count> \
        -o <perf_file> -- <loadtest>
   For AMD platforms:
      The supported system are: Zen3 with BRS, or Zen4 with amd_lbr_v2
      # To see if Zen3 support LBR:
      $ cat proc/cpuinfo | grep " brs"
      # To see if Zen4 support LBR:
      $ cat proc/cpuinfo | grep amd_lbr_v2
      # If the result is yes, then collect the profile using:
      $ perf record --pfm-events RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a \
        -N -b -c <count> -o <perf_file> -- <loadtest>

4) (Optional) Download the raw perf file to the host machine.

5) Generate Propeller profile:
   $ create_llvm_prof --binary=<vmlinux> --profile=<perf_file> \
     --format=propeller --propeller_output_module_name \
     --out=<propeller_profile_prefix>_cc_profile.txt \
     --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt

   “create_llvm_prof” is the profile conversion tool, and a prebuilt
   binary for linux can be found on
   https://github.com/google/autofdo/releases/tag/v0.30.1 (can also build
   from source).

   "<propeller_profile_prefix>" can be something like
   "/home/user/dir/any_string".

   This command generates a pair of Propeller profiles:
   "<propeller_profile_prefix>_cc_profile.txt" and
   "<propeller_profile_prefix>_ld_profile.txt".

6) Rebuild the kernel using the AutoFDO and Propeller profile files.
      CONFIG_AUTOFDO_CLANG=y
      CONFIG_PROPELLER_CLANG=y
   and
      $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<autofdo_profile> \
        CLANG_PROPELLER_PROFILE_PREFIX=<propeller_profile_prefix>

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Stephane Eranian <eranian@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Linus Torvalds
42d9e8b7cc powerpc updates for 6.13
- Rework kfence support for the HPT MMU to work on systems with >= 16TB of RAM.
 
  - Remove the powerpc "maple" platform, used by the "Yellow Dog Powerstation".
 
  - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS,
    DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines.
 
  - Add support for running KVM nested guests on Power11.
 
  - Other small features, cleanups and fixes.
 
 Thanks to: Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa Shulyupin,
 David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert Uytterhoeven,
 Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard, Lukas Bulwahn, Madhavan
 Srinivasan, Markus Elfring, Michal Suchanek, Ming Lei, Mukesh Kumar Chaurasiya,
 Nathan Chancellor, Naveen N Rao, Nicholas Piggin, Nysal Jan K.A, Paulo Miguel
 Almeida, Pavithra Prakash, Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P
 Bappalige, Shen Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten
 Blum, Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun,
 zhang jiao.
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Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Rework kfence support for the HPT MMU to work on systems with >= 16TB
   of RAM.

 - Remove the powerpc "maple" platform, used by the "Yellow Dog
   Powerstation".

 - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS,
   DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines.

 - Add support for running KVM nested guests on Power11.

 - Other small features, cleanups and fixes.

Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa
Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert
Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard,
Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek,
Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao,
Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash,
Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen
Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum,
Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao.

* tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits)
  EDAC/powerpc: Remove PPC_MAPLE drivers
  powerpc/perf: Add per-task/process monitoring to vpa_pmu driver
  powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch
  docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu
  powerpc/perf: Add perf interface to expose vpa counters
  MAINTAINERS: powerpc: Mark Maddy as "M"
  powerpc/Makefile: Allow overriding CPP
  powerpc-km82xx.c: replace of_node_put() with __free
  ps3: Correct some typos in comments
  powerpc/kexec: Fix return of uninitialized variable
  macintosh: Use common error handling code in via_pmu_led_init()
  powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type()
  powerpc: remove dead config options for MPC85xx platform support
  powerpc/xive: Use cpumask_intersects()
  selftests/powerpc: Remove the path after initialization.
  powerpc/xmon: symbol lookup length fixed
  powerpc/ep8248e: Use %pa to format resource_size_t
  powerpc/ps3: Reorganize kerneldoc parameter names
  KVM: PPC: Book3S HV: Fix kmv -> kvm typo
  powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static
  ...
2024-11-23 10:44:31 -08:00
Linus Torvalds
5c00ff742b - The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection algorithm.
   This leads to improved memory savings.
 
 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
 
 	- "refine mas_mab_cp()"
 	- "Reduce the space to be cleared for maple_big_node"
 	- "maple_tree: simplify mas_push_node()"
 	- "Following cleanup after introduce mas_wr_store_type()"
 	- "refine storing null"
 
 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.
 
 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping code.
 
 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of shadow
   entries.
 
 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.
 
 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in the
   hugetlb code.
 
 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page into
   small pages.  Instead we replace the whole thing with a THP.  More
   consistent cleaner and potentiall saves a large number of pagefaults.
 
 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.
 
 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to do.
 
 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio size
   rather than as individual pages.  A 20% speedup was observed.
 
 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting.
 
 - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt
   removes the long-deprecated memcgv2 charge moving feature.
 
 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.
 
 - The series "x86/module: use large ROX pages for text allocations" from
   Mike Rapoport teaches x86 to use large pages for read-only-execute
   module text.
 
 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.
 
 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/.  A slow march towards shrinking
   struct page.
 
 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.
 
 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression.  It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.
 
 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests
   over to the KUnit framework.
 
 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a single
   VMA, rather than requiring that multiple VMAs be created for this.
   Improved efficiencies for userspace memory allocators are expected.
 
 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.
 
 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.
 
 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP from
   the kernel boot command line.
 
 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.
 
 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep is
   enabled.
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Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
2024-11-23 09:58:07 -08:00
Linus Torvalds
0352387523 First step of consolidating the VDSO data page handling:
The VDSO data page handling is architecture specific for historical
   reasons, but there is no real technical reason to do so.
 
   Aside of that VDSO data has become a dump ground for various mechanisms
   and fail to provide a clear separation of the functionalities.
 
   Clean this up by:
 
     * consolidating the VDSO page data by getting rid of architecture
       specific warts especially in x86 and PowerPC.
 
     * removing the last includes of header files which are pulling in other
       headers outside of the VDSO namespace.
 
     * seperating timekeeping and other VDSO data accordingly.
 
   Further consolidation of the VDSO page handling is done in subsequent
   changes scheduled for the next merge window.
 
   This also lays the ground for expanding the VDSO time getters for
   independent PTP clocks in a generic way without making every architecture
   add support seperately.
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Merge tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull vdso data page handling updates from Thomas Gleixner:
 "First steps of consolidating the VDSO data page handling.

  The VDSO data page handling is architecture specific for historical
  reasons, but there is no real technical reason to do so.

  Aside of that VDSO data has become a dump ground for various
  mechanisms and fail to provide a clear separation of the
  functionalities.

  Clean this up by:

   - consolidating the VDSO page data by getting rid of architecture
     specific warts especially in x86 and PowerPC.

   - removing the last includes of header files which are pulling in
     other headers outside of the VDSO namespace.

   - seperating timekeeping and other VDSO data accordingly.

  Further consolidation of the VDSO page handling is done in subsequent
  changes scheduled for the next merge window.

  This also lays the ground for expanding the VDSO time getters for
  independent PTP clocks in a generic way without making every
  architecture add support seperately"

* tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
  x86/vdso: Add missing brackets in switch case
  vdso: Rename struct arch_vdso_data to arch_vdso_time_data
  powerpc: Split systemcfg struct definitions out from vdso
  powerpc: Split systemcfg data out of vdso data page
  powerpc: Add kconfig option for the systemcfg page
  powerpc/pseries/lparcfg: Use num_possible_cpus() for potential processors
  powerpc/pseries/lparcfg: Fix printing of system_active_processors
  powerpc/procfs: Propagate error of remap_pfn_range()
  powerpc/vdso: Remove offset comment from 32bit vdso_arch_data
  x86/vdso: Split virtual clock pages into dedicated mapping
  x86/vdso: Delete vvar.h
  x86/vdso: Access vdso data without vvar.h
  x86/vdso: Move the rng offset to vsyscall.h
  x86/vdso: Access rng vdso data without vvar.h
  x86/vdso: Access timens vdso data without vvar.h
  x86/vdso: Allocate vvar page from C code
  x86/vdso: Access rng data from kernel without vvar
  x86/vdso: Place vdso_data at beginning of vvar page
  x86/vdso: Use __arch_get_vdso_data() to access vdso data
  x86/mm/mmap: Remove arch_vma_name()
  ...
2024-11-19 16:09:13 -08:00
Linus Torvalds
f41dac3efb Performance events changes for v6.13:
- Uprobes:
     - Add BPF session support (Jiri Olsa)
     - Switch to RCU Tasks Trace flavor for better performance (Andrii Nakryiko)
     - Massively increase uretprobe SMP scalability by SRCU-protecting
       the uretprobe lifetime (Andrii Nakryiko)
     - Kill xol_area->slot_count (Oleg Nesterov)
 
  - Core facilities:
     - Implement targeted high-frequency profiling by adding the ability
       for an event to "pause" or "resume" AUX area tracing (Adrian Hunter)
 
  - VM profiling/sampling:
     - Correct perf sampling with guest VMs (Colton Lewis)
 
  - New hardware support:
     - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)
 
  - Misc fixes and enhancements:
     - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
     - x86/amd: Warn only on new bits set (Breno Leitao)
     - x86/amd/uncore: Avoid a false positive warning about snprintf
                       truncation in amd_uncore_umc_ctx_init (Jean Delvare)
     - uprobes: Re-order struct uprobe_task to save some space (Christophe JAILLET)
     - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
     - x86/rapl: Clean up cpumask and hotplug (Kan Liang)
     - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg Nesterov)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "Uprobes:
    - Add BPF session support (Jiri Olsa)
    - Switch to RCU Tasks Trace flavor for better performance (Andrii
      Nakryiko)
    - Massively increase uretprobe SMP scalability by SRCU-protecting
      the uretprobe lifetime (Andrii Nakryiko)
    - Kill xol_area->slot_count (Oleg Nesterov)

  Core facilities:
    - Implement targeted high-frequency profiling by adding the ability
      for an event to "pause" or "resume" AUX area tracing (Adrian
      Hunter)

  VM profiling/sampling:
    - Correct perf sampling with guest VMs (Colton Lewis)

  New hardware support:
    - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)

  Misc fixes and enhancements:
    - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
    - x86/amd: Warn only on new bits set (Breno Leitao)
    - x86/amd/uncore: Avoid a false positive warning about snprintf
      truncation in amd_uncore_umc_ctx_init (Jean Delvare)
    - uprobes: Re-order struct uprobe_task to save some space
      (Christophe JAILLET)
    - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
    - x86/rapl: Clean up cpumask and hotplug (Kan Liang)
    - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg
      Nesterov)"

* tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  perf/core: Correct perf sampling with guest VMs
  perf/x86: Refactor misc flag assignments
  perf/powerpc: Use perf_arch_instruction_pointer()
  perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()
  perf/arm: Drop unused functions
  uprobes: Re-order struct uprobe_task to save some space
  perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init
  perf/x86/intel: Do not enable large PEBS for events with aux actions or aux sampling
  perf/x86/intel/pt: Add support for pause / resume
  perf/core: Add aux_pause, aux_resume, aux_start_paused
  perf/x86/intel/pt: Fix buffer full but size is 0 case
  uprobes: SRCU-protect uretprobe lifetime (with timeout)
  uprobes: allow put_uprobe() from non-sleepable softirq context
  perf/x86/rapl: Clean up cpumask and hotplug
  perf/x86/rapl: Move the pmu allocation out of CPU hotplug
  uprobe: Add support for session consumer
  uprobe: Add data pointer to consumer handlers
  perf/x86/amd: Warn only on new bits set
  uprobes: fold xol_take_insn_slot() into xol_get_insn_slot()
  uprobes: kill xol_area->slot_count
  ...
2024-11-19 13:34:06 -08:00
Mike Rapoport (Microsoft)
2e45474ab1 execmem: add support for cache of large ROX pages
Using large pages to map text areas reduces iTLB pressure and improves
performance.

Extend execmem_alloc() with an ability to use huge pages with ROX
permissions as a cache for smaller allocations.

To populate the cache, a writable large page is allocated from vmalloc
with VM_ALLOW_HUGE_VMAP, filled with invalid instructions and then
remapped as ROX.

The direct map alias of that large page is exculded from the direct map.

Portions of that large page are handed out to execmem_alloc() callers
without any changes to the permissions.

When the memory is freed with execmem_free() it is invalidated again so
that it won't contain stale instructions.

An architecture has to implement execmem_fill_trapping_insns() callback
and select ARCH_HAS_EXECMEM_ROX configuration option to be able to use the
ROX cache.

The cache is enabled on per-range basis when an architecture sets
EXECMEM_ROX_CACHE flag in definition of an execmem_range.

Link: https://lkml.kernel.org/r/20241023162711.2579610-8-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops <kdevops@lists.linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:16 -08:00
Rong Xu
315ad8780a kbuild: Add AutoFDO support for Clang build
Add the build support for using Clang's AutoFDO. Building the kernel
with AutoFDO does not reduce the optimization level from the
compiler. AutoFDO uses hardware sampling to gather information about
the frequency of execution of different code paths within a binary.
This information is then used to guide the compiler's optimization
decisions, resulting in a more efficient binary. Experiments
showed that the kernel can improve up to 10% in latency.

The support requires a Clang compiler after LLVM 17. This submission
is limited to x86 platforms that support PMU features like LBR on
Intel machines and AMD Zen3 BRS. Support for SPE on ARM 1,
 and BRBE on ARM 1 is part of planned future work.

Here is an example workflow for AutoFDO kernel:

1) Build the kernel on the host machine with LLVM enabled, for example,
       $ make menuconfig LLVM=1
    Turn on AutoFDO build config:
      CONFIG_AUTOFDO_CLANG=y
    With a configuration that has LLVM enabled, use the following
    command:
       scripts/config -e AUTOFDO_CLANG
    After getting the config, build with
      $ make LLVM=1

2) Install the kernel on the test machine.

3) Run the load tests. The '-c' option in perf specifies the sample
   event period. We suggest     using a suitable prime number,
   like 500009, for this purpose.
   For Intel platforms:
      $ perf record -e BR_INST_RETIRED.NEAR_TAKEN:k -a -N -b -c <count> \
        -o <perf_file> -- <loadtest>
   For AMD platforms:
      The supported system are: Zen3 with BRS, or Zen4 with amd_lbr_v2
     For Zen3:
      $ cat proc/cpuinfo | grep " brs"
      For Zen4:
      $ cat proc/cpuinfo | grep amd_lbr_v2
      $ perf record --pfm-events RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a \
        -N -b -c <count> -o <perf_file> -- <loadtest>

4) (Optional) Download the raw perf file to the host machine.

5) To generate an AutoFDO profile, two offline tools are available:
   create_llvm_prof and llvm_profgen. The create_llvm_prof tool is part
   of the AutoFDO project and can be found on GitHub
   (https://github.com/google/autofdo), version v0.30.1 or later. The
   llvm_profgen tool is included in the LLVM compiler itself. It's
   important to note that the version of llvm_profgen doesn't need to
   match the version of Clang. It needs to be the LLVM 19 release or
   later, or from the LLVM trunk.
      $ llvm-profgen --kernel --binary=<vmlinux> --perfdata=<perf_file> \
        -o <profile_file>
   or
      $ create_llvm_prof --binary=<vmlinux> --profile=<perf_file> \
        --format=extbinary --out=<profile_file>

   Note that multiple AutoFDO profile files can be merged into one via:
      $ llvm-profdata merge -o <profile_file>  <profile_1> ... <profile_n>

6) Rebuild the kernel using the AutoFDO profile file with the same config
   as step 1, (Note CONFIG_AUTOFDO_CLANG needs to be enabled):
      $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<profile_file>

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Stephane Eranian <eranian@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Tested-by: Peter Jung <ptr1337@cachyos.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-06 22:41:09 +09:00
Nam Cao
a812eee0b6 vdso: Rename struct arch_vdso_data to arch_vdso_time_data
The struct arch_vdso_data is only about vdso time data. So rename it to
arch_vdso_time_data to make it obvious.
Non time-related data will be migrated out of these structs soon.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-28-b64f0842d512@linutronix.de
2024-11-02 12:37:36 +01:00
Naveen N Rao
1198c9c689 kbuild: Add generic hook for architectures to use before the final vmlinux link
On powerpc, we would like to be able to make a pass on vmlinux.o and
generate a new object file to be linked into vmlinux. Add a generic pass
in Makefile.vmlinux that architectures can use for this purpose.

Architectures need to select CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX and must
provide arch/<arch>/tools/Makefile with .arch.vmlinux.o target, which
will be invoked prior to the final vmlinux link step.

Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-12-hbathini@linux.ibm.com
2024-10-31 11:00:54 +11:00
Alice Ryhl
2313ab74c3 cfi: tweak llvm version for HAVE_CFI_ICALL_NORMALIZE_INTEGERS
The llvm fix [1] did not make it for 19.0.0, but ended up getting
backported to llvm 19.1.3 [2]. Thus, fix the version requirement to
correctly specify which versions have the bug.

Link: https://github.com/llvm/llvm-project/pull/104826 [1]
Link: https://github.com/llvm/llvm-project/pull/113938 [2]
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202410281414.c351044e-oliver.sang@intel.com
Fixes: 8b8ca9c25f ("cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20241030-cfi-icall-1913-v1-1-ab8a26e13733@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-31 00:41:37 +01:00
Alice Ryhl
8b8ca9c25f cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS
The HAVE_CFI_ICALL_NORMALIZE_INTEGERS option has some tricky conditions
when KASAN or GCOV are turned on, as in that case we need some clang and
rustc fixes [1][2] to avoid boot failures. The intent with the current
setup is that you should be able to override the check and turn on the
option if your clang/rustc has the fix. However, this override does not
work in practice. Thus, use the new RUSTC_LLVM_VERSION to correctly
implement the check for whether the fix is available.

Additionally, remove KASAN_HW_TAGS from the list of incompatible
options. The CFI_ICALL_NORMALIZE_INTEGERS option is incompatible with
KASAN because LLVM will emit some constructors when using KASAN that are
assigned incorrect CFI tags. These constructors are emitted due to use
of -fsanitize=kernel-address or -fsanitize=kernel-hwaddress that are
respectively passed when KASAN_GENERIC or KASAN_SW_TAGS are enabled.
However, the KASAN_HW_TAGS option relies on hardware support for MTE
instead and does not pass either flag. (Note also that KASAN_HW_TAGS
does not `select CONSTRUCTORS`.)

Link: https://github.com/llvm/llvm-project/pull/104826 [1]
Link: https://github.com/rust-lang/rust/pull/129373 [2]
Fixes: 4c66f8307a ("cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20241010-icall-detect-vers-v1-2-8f114956aa88@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-13 22:23:13 +02:00
Andrii Nakryiko
87195a1ee3 uprobes: switch to RCU Tasks Trace flavor for better performance
This patch switches uprobes SRCU usage to RCU Tasks Trace flavor, which
is optimized for more lightweight and quick readers (at the expense of
slower writers, which for uprobes is a fine tradeof) and has better
performance and scalability with number of CPUs.

Similarly to baseline vs SRCU, we've benchmarked SRCU-based
implementation vs RCU Tasks Trace implementation.

SRCU
====
uprobe-nop      ( 1 cpus):    3.276 ± 0.005M/s  (  3.276M/s/cpu)
uprobe-nop      ( 2 cpus):    4.125 ± 0.002M/s  (  2.063M/s/cpu)
uprobe-nop      ( 4 cpus):    7.713 ± 0.002M/s  (  1.928M/s/cpu)
uprobe-nop      ( 8 cpus):    8.097 ± 0.006M/s  (  1.012M/s/cpu)
uprobe-nop      (16 cpus):    6.501 ± 0.056M/s  (  0.406M/s/cpu)
uprobe-nop      (32 cpus):    4.398 ± 0.084M/s  (  0.137M/s/cpu)
uprobe-nop      (64 cpus):    6.452 ± 0.000M/s  (  0.101M/s/cpu)

uretprobe-nop   ( 1 cpus):    2.055 ± 0.001M/s  (  2.055M/s/cpu)
uretprobe-nop   ( 2 cpus):    2.677 ± 0.000M/s  (  1.339M/s/cpu)
uretprobe-nop   ( 4 cpus):    4.561 ± 0.003M/s  (  1.140M/s/cpu)
uretprobe-nop   ( 8 cpus):    5.291 ± 0.002M/s  (  0.661M/s/cpu)
uretprobe-nop   (16 cpus):    5.065 ± 0.019M/s  (  0.317M/s/cpu)
uretprobe-nop   (32 cpus):    3.622 ± 0.003M/s  (  0.113M/s/cpu)
uretprobe-nop   (64 cpus):    3.723 ± 0.002M/s  (  0.058M/s/cpu)

RCU Tasks Trace
===============
uprobe-nop      ( 1 cpus):    3.396 ± 0.002M/s  (  3.396M/s/cpu)
uprobe-nop      ( 2 cpus):    4.271 ± 0.006M/s  (  2.135M/s/cpu)
uprobe-nop      ( 4 cpus):    8.499 ± 0.015M/s  (  2.125M/s/cpu)
uprobe-nop      ( 8 cpus):   10.355 ± 0.028M/s  (  1.294M/s/cpu)
uprobe-nop      (16 cpus):    7.615 ± 0.099M/s  (  0.476M/s/cpu)
uprobe-nop      (32 cpus):    4.430 ± 0.007M/s  (  0.138M/s/cpu)
uprobe-nop      (64 cpus):    6.887 ± 0.020M/s  (  0.108M/s/cpu)

uretprobe-nop   ( 1 cpus):    2.174 ± 0.001M/s  (  2.174M/s/cpu)
uretprobe-nop   ( 2 cpus):    2.853 ± 0.001M/s  (  1.426M/s/cpu)
uretprobe-nop   ( 4 cpus):    4.913 ± 0.002M/s  (  1.228M/s/cpu)
uretprobe-nop   ( 8 cpus):    5.883 ± 0.002M/s  (  0.735M/s/cpu)
uretprobe-nop   (16 cpus):    5.147 ± 0.001M/s  (  0.322M/s/cpu)
uretprobe-nop   (32 cpus):    3.738 ± 0.008M/s  (  0.117M/s/cpu)
uretprobe-nop   (64 cpus):    4.397 ± 0.002M/s  (  0.069M/s/cpu)

Peak throughput for uprobes increases from 8 mln/s to 10.3 mln/s
(+28%!), and for uretprobes from 5.3 mln/s to 5.8 mln/s (+11%), as we
have more work to do on uretprobes side.

Even single-thread (no contention) performance is slightly better: 3.276
mln/s to 3.396 mln/s (+3.5%) for uprobes, and 2.055 mln/s to 2.174 mln/s
(+5.8%) for uretprobes.

We also select TASKS_TRACE_RCU for UPROBES in Kconfig due to the new
dependency.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20240910174312.3646590-1-andrii@kernel.org
2024-10-07 09:28:42 +02:00
Alice Ryhl
4c66f8307a cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig
There is a bug in the LLVM implementation of KASAN and GCOV that makes
these options incompatible with the CFI_ICALL_NORMALIZE_INTEGERS option.

The bug has already been fixed in llvm/clang [1] and rustc [2]. However,
Kconfig currently has no way to gate features on the LLVM version inside
rustc, so we cannot write down a precise `depends on` clause in this
case. Instead, a `def_bool` option is defined for whether
CFI_ICALL_NORMALIZE_INTEGERS is available, and its default value is set
to false when GCOV or KASAN are turned on. End users using a patched
clang/rustc can turn on the HAVE_CFI_ICALL_NORMALIZE_INTEGERS option
directly to override this.

An alternative solution is to inspect a binary created by clang or rustc
to see whether the faulty CFI tags are in the binary. This would be a
precise check, but it would involve hard-coding the *hashed* version of
the CFI tag. This is because there's no way to get clang or rustc to
output the unhased version of the CFI tag. Relying on the precise
hashing algorithm using by CFI seems too fragile, so I have not pursued
this option. Besides, this kind of hack is exactly what lead to the LLVM
bug in the first place.

If the CFI_ICALL_NORMALIZE_INTEGERS option is used without CONFIG_RUST,
then we actually can perform a precise check today: just compare the
clang version number. This works since clang and llvm are always updated
in lockstep. However, encoding this in Kconfig would give the
HAVE_CFI_ICALL_NORMALIZE_INTEGERS option a dependency on CONFIG_RUST,
which is not possible as the reverse dependency already exists.

HAVE_CFI_ICALL_NORMALIZE_INTEGERS is defined to be a `def_bool` instead
of `bool` to avoid asking end users whether they want to turn on the
option. Turning it on explicitly is something only experts should do, so
making it hard to do so is not an issue.

I added a `depends on CFI_CLANG` clause to the new Kconfig option. I'm
not sure whether that makes sense or not, but it doesn't seem to make a
big difference.

In a future kernel release, I would like to add a Kconfig option similar
to CLANG_VERSION/RUSTC_VERSION for inspecting the version of the LLVM
inside rustc. Once that feature lands, this logic will be replaced with
a precise version check. This check is not being introduced here to
avoid introducing a new _VERSION constant in a fix.

Link: https://github.com/llvm/llvm-project/pull/104826 [1]
Link: https://github.com/rust-lang/rust/pull/129373 [2]
Fixes: ce4a262098 ("cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202409231044.4f064459-oliver.sang@intel.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-26 21:27:27 +02:00
Linus Torvalds
5701725692 Rust changes for v6.12
Toolchain and infrastructure:
 
  - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up objtool
    warnings), teach objtool about 'noreturn' Rust symbols and mimic
    '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we should be
    objtool-warning-free, so enable it to run for all Rust object files.
 
  - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.
 
  - Support 'RUSTC_VERSION', including re-config and re-build on change.
 
  - Split helpers file into several files in a folder, to avoid conflicts
    in it. Eventually those files will be moved to the right places with
    the new build system. In addition, remove the need to manually export
    the symbols defined there, reusing existing machinery for that.
 
  - Relax restriction on configurations with Rust + GCC plugins to just
    the RANDSTRUCT plugin.
 
 'kernel' crate:
 
  - New 'list' module: doubly-linked linked list for use with reference
    counted values, which is heavily used by the upcoming Rust Binder.
    This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
    unique for the given ID), 'AtomicTracker' (tracks whether a 'ListArc'
    exists using an atomic), 'ListLinks' (the prev/next pointers for an
    item in a linked list), 'List' (the linked list itself), 'Iter' (an
    iterator over a 'List'), 'Cursor' (a cursor into a 'List' that allows
    to remove elements), 'ListArcField' (a field exclusively owned by a
    'ListArc'), as well as support for heterogeneous lists.
 
  - New 'rbtree' module: red-black tree abstractions used by the upcoming
    Rust Binder. This includes 'RBTree' (the red-black tree itself),
    'RBTreeNode' (a node), 'RBTreeNodeReservation' (a memory reservation
    for a node), 'Iter' and 'IterMut' (immutable and mutable iterators),
    'Cursor' (bidirectional cursor that allows to remove elements), as
    well as an entry API similar to the Rust standard library one.
 
  - 'init' module: add 'write_[pin_]init' methods and the 'InPlaceWrite'
    trait. Add the 'assert_pinned!' macro.
 
  - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
    introducing an associated type in the trait.
 
  - 'alloc' module: add 'drop_contents' method to 'BoxExt'.
 
  - 'types' module: implement the 'ForeignOwnable' trait for
    'Pin<Box<T>>' and improve the trait's documentation. In addition,
    add the 'into_raw' method to the 'ARef' type.
 
  - 'error' module: in preparation for the upcoming Rust support for
    32-bit architectures, like arm, locally allow Clippy lint for those.
 
 Documentation:
 
  - https://rust.docs.kernel.org has been announced, so link to it.
 
  - Enable rustdoc's "jump to definition" feature, making its output a
    bit closer to the experience in a cross-referencer.
 
  - Debian Testing now also provides recent Rust releases (outside of
    the freeze period), so add it to the list.
 
 MAINTAINERS:
 
  - Trevor is joining as reviewer of the "RUST" entry.
 
 And a few other small bits.
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Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up
     objtool warnings), teach objtool about 'noreturn' Rust symbols and
     mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we
     should be objtool-warning-free, so enable it to run for all Rust
     object files.

   - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.

   - Support 'RUSTC_VERSION', including re-config and re-build on
     change.

   - Split helpers file into several files in a folder, to avoid
     conflicts in it. Eventually those files will be moved to the right
     places with the new build system. In addition, remove the need to
     manually export the symbols defined there, reusing existing
     machinery for that.

   - Relax restriction on configurations with Rust + GCC plugins to just
     the RANDSTRUCT plugin.

  'kernel' crate:

   - New 'list' module: doubly-linked linked list for use with reference
     counted values, which is heavily used by the upcoming Rust Binder.

     This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
     unique for the given ID), 'AtomicTracker' (tracks whether a
     'ListArc' exists using an atomic), 'ListLinks' (the prev/next
     pointers for an item in a linked list), 'List' (the linked list
     itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor
     into a 'List' that allows to remove elements), 'ListArcField' (a
     field exclusively owned by a 'ListArc'), as well as support for
     heterogeneous lists.

   - New 'rbtree' module: red-black tree abstractions used by the
     upcoming Rust Binder.

     This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a
     node), 'RBTreeNodeReservation' (a memory reservation for a node),
     'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor'
     (bidirectional cursor that allows to remove elements), as well as
     an entry API similar to the Rust standard library one.

   - 'init' module: add 'write_[pin_]init' methods and the
     'InPlaceWrite' trait. Add the 'assert_pinned!' macro.

   - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
     introducing an associated type in the trait.

   - 'alloc' module: add 'drop_contents' method to 'BoxExt'.

   - 'types' module: implement the 'ForeignOwnable' trait for
     'Pin<Box<T>>' and improve the trait's documentation. In addition,
     add the 'into_raw' method to the 'ARef' type.

   - 'error' module: in preparation for the upcoming Rust support for
     32-bit architectures, like arm, locally allow Clippy lint for
     those.

  Documentation:

   - https://rust.docs.kernel.org has been announced, so link to it.

   - Enable rustdoc's "jump to definition" feature, making its output a
     bit closer to the experience in a cross-referencer.

   - Debian Testing now also provides recent Rust releases (outside of
     the freeze period), so add it to the list.

  MAINTAINERS:

   - Trevor is joining as reviewer of the "RUST" entry.

  And a few other small bits"

* tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits)
  kasan: rust: Add KASAN smoke test via UAF
  kbuild: rust: Enable KASAN support
  rust: kasan: Rust does not support KHWASAN
  kbuild: rust: Define probing macros for rustc
  kasan: simplify and clarify Makefile
  rust: cfi: add support for CFI_CLANG with Rust
  cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
  rust: support for shadow call stack sanitizer
  docs: rust: include other expressions in conditional compilation section
  kbuild: rust: replace proc macros dependency on `core.o` with the version text
  kbuild: rust: rebuild if the version text changes
  kbuild: rust: re-run Kconfig if the version text changes
  kbuild: rust: add `CONFIG_RUSTC_VERSION`
  rust: avoid `box_uninit_write` feature
  MAINTAINERS: add Trevor Gross as Rust reviewer
  rust: rbtree: add `RBTree::entry`
  rust: rbtree: add cursor
  rust: rbtree: add mutable iterator
  rust: rbtree: add iterator
  rust: rbtree: add red-black tree implementation backed by the C version
  ...
2024-09-25 10:25:40 -07:00
Linus Torvalds
726e2d0cf2 dma-mapping updates for linux 6.12
- support DMA zones for arm64 systems where memory starts at > 4GB
    (Baruch Siach, Catalin Marinas)
  - support direct calls into dma-iommu and thus obsolete dma_map_ops for
    many common configurations (Leon Romanovsky)
  - add DMA-API tracing (Sean Anderson)
  - remove the not very useful return value from various dma_set_* APIs
    (Christoph Hellwig)
  - misc cleanups and minor optimizations (Chen Y, Yosry Ahmed,
    Christoph Hellwig)
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Merge tag 'dma-mapping-6.12-2024-09-19' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - support DMA zones for arm64 systems where memory starts at > 4GB
   (Baruch Siach, Catalin Marinas)

 - support direct calls into dma-iommu and thus obsolete dma_map_ops for
   many common configurations (Leon Romanovsky)

 - add DMA-API tracing (Sean Anderson)

 - remove the not very useful return value from various dma_set_* APIs
   (Christoph Hellwig)

 - misc cleanups and minor optimizations (Chen Y, Yosry Ahmed, Christoph
   Hellwig)

* tag 'dma-mapping-6.12-2024-09-19' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: reflow dma_supported
  dma-mapping: reliably inform about DMA support for IOMMU
  dma-mapping: add tracing for dma-mapping API calls
  dma-mapping: use IOMMU DMA calls for common alloc/free page calls
  dma-direct: optimize page freeing when it is not addressable
  dma-mapping: clearly mark DMA ops as an architecture feature
  vdpa_sim: don't select DMA_OPS
  arm64: mm: keep low RAM dma zone
  dma-mapping: don't return errors from dma_set_max_seg_size
  dma-mapping: don't return errors from dma_set_seg_boundary
  dma-mapping: don't return errors from dma_set_min_align_mask
  scsi: check that busses support the DMA API before setting dma parameters
  arm64: mm: fix DMA zone when dma-ranges is missing
  dma-mapping: direct calls for dma-iommu
  dma-mapping: call ->unmap_page and ->unmap_sg unconditionally
  arm64: support DMA zone above 4GB
  dma-mapping: replace zone_dma_bits by zone_dma_limit
  dma-mapping: use bit masking to check VM_DMA_COHERENT
2024-09-19 11:12:49 +02:00
Alice Ryhl
ce4a262098 cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
Introduce a Kconfig option for enabling the experimental option to
normalize integer types. This ensures that integer types of the same
size and signedness are considered compatible by the Control Flow
Integrity sanitizer.

The security impact of this flag is minimal. When Sami Tolvanen looked
into it, he found that integer normalization reduced the number of
unique type hashes in the kernel by ~1%, which is acceptable.

This option exists for compatibility with Rust, as C and Rust do not
have the same set of integer types. There are cases where C has two
different integer types of the same size and signedness, but Rust only
has one integer type of that size and signedness. When Rust calls into
C functions using such types in their signature, this results in CFI
failures. One example is 'unsigned long long' and 'unsigned long' which
are both 64-bit on LP64 targets, so on those targets this flag will give
both types the same CFI tag.

This flag changes the ABI heavily. It is not applied automatically when
CONFIG_RUST is turned on to make sure that the CONFIG_RUST option does
not change the ABI of C code. For example, some build may need to make
other changes atomically with toggling this flag. Having it be a
separate option makes it possible to first turn on normalized integer
tags, and then later turn on CONFIG_RUST.

Similarly, when turning on CONFIG_RUST in a build, you may need a few
attempts where the RUST=y commit gets reverted a few times. It is
inconvenient if reverting RUST=y also requires reverting the changes you
made to support normalized integer tags.

To avoid having this flag impact builds that don't care about this, the
next patch in this series will make CONFIG_RUST turn on this option
using `select` rather than `depends on`.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Acked-by: Kees Cook <kees@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240801-kcfi-v2-1-c93caed3d121@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-13 00:43:55 +02:00
Christoph Hellwig
de6c85bf91 dma-mapping: clearly mark DMA ops as an architecture feature
DMA ops are a helper for architectures and not for drivers to override
the DMA implementation.

Unfortunately driver authors keep ignoring this.  Make the fact more
clear by renaming the symbol to ARCH_HAS_DMA_OPS and having the two drivers
overriding their dma_ops depend on that.  These drivers should probably be
marked broken, but we can give them a bit of a grace period for that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> # for IPU6
Acked-by: Robin Murphy <robin.murphy@arm.com>
2024-09-04 07:08:51 +03:00
Valentin Schneider
d65d411c92 treewide: context_tracking: Rename CONTEXT_* into CT_STATE_*
Context tracking state related symbols currently use a mix of the
CONTEXT_ (e.g. CONTEXT_KERNEL) and CT_SATE_ (e.g. CT_STATE_MASK) prefixes.

Clean up the naming and make the ctx_state enum use the CT_STATE_ prefix.

Suggested-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
2024-07-29 07:33:10 +05:30
Linus Torvalds
14d7c92f8d Revert "mm: mmap: allow for the maximum number of bits for randomizing mmap_base by default"
This reverts commit 3afb76a66b.

This was a wrongheaded workaround for an issue that had already been
fixed much better by commit 4ef9ad19e1 ("mm: huge_memory: don't force
huge page alignment on 32 bit").

Asking users questions at kernel compile time that they can't make sense
of is not a viable strategy.  And the fact that even the kernel VM
maintainers apparently didn't catch that this "fix" is not a fix any
more pretty much proves the point that people can't be expected to
understand the implications of the question.

It may well be the case that we could improve things further, and that
__thp_get_unmapped_area() should take the mapping randomization into
account even for 64-bit kernels.  Maybe we should not be so eager to use
THP mappings.

But in no case should this be a kernel config option.

Cc: Rafael Aquini <aquini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-17 12:57:03 -07:00
Rafael Aquini
3afb76a66b mm: mmap: allow for the maximum number of bits for randomizing mmap_base by default
An ASLR regression was noticed [1] and tracked down to file-mapped areas
being backed by THP in recent kernels.  The 21-bit alignment constraint
for such mappings reduces the entropy for randomizing the placement of
64-bit library mappings and breaks ASLR completely for 32-bit libraries.

The reported issue is easily addressed by increasing vm.mmap_rnd_bits and
vm.mmap_rnd_compat_bits.  This patch just provides a simple way to set
ARCH_MMAP_RND_BITS and ARCH_MMAP_RND_COMPAT_BITS to their maximum values
allowed by the architecture at build time.

[1] https://zolutal.github.io/aslrnt/

[akpm@linux-foundation.org: default to `y' if 32-bit, per Rafael]
Link: https://lkml.kernel.org/r/20240606180622.102099-1-aquini@redhat.com
Fixes: 1854bc6e24 ("mm/readahead: Align file mappings for non-DAX")
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-15 10:43:06 -07:00
Samuel Holland
6cbd1d6d36 arch: add ARCH_HAS_KERNEL_FPU_SUPPORT
Several architectures provide an API to enable the FPU and run
floating-point SIMD code in kernel space.  However, the function names,
header locations, and semantics are inconsistent across architectures, and
FPU support may be gated behind other Kconfig options.

provide a standard way for architectures to declare that kernel space
FPU support is available. Architectures selecting this option must
implement what is currently the most common API (kernel_fpu_begin() and
kernel_fpu_end(), plus a new function kernel_fpu_available()) and
provide the appropriate CFLAGS for compiling floating-point C code.

Link: https://lkml.kernel.org/r/20240329072441.591471-2-samuel.holland@sifive.com
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian König <christian.koenig@amd.com> 
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: WANG Xuerui <git@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-19 14:36:17 -07:00
Mike Rapoport (IBM)
7582b7be16 kprobes: remove dependency on CONFIG_MODULES
kprobes depended on CONFIG_MODULES because it has to allocate memory for
code.

Since code allocations are now implemented with execmem, kprobes can be
enabled in non-modular kernels.

Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside
modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the
dependency of CONFIG_KPROBES on CONFIG_MODULES.

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
[mcgrof: rebase in light of NEED_TASKS_RCU ]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14 00:35:06 -07:00
Mike Rapoport (IBM)
223b5e57d0 mm/execmem, arch: convert remaining overrides of module_alloc to execmem
Extend execmem parameters to accommodate more complex overrides of
module_alloc() by architectures.

This includes specification of a fallback range required by arm, arm64
and powerpc, EXECMEM_MODULE_DATA type required by powerpc, support for
allocation of KASAN shadow required by s390 and x86 and support for
late initialization of execmem required by arm64.

The core implementation of execmem_alloc() takes care of suppressing
warnings when the initial allocation fails but there is a fallback range
defined.

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Tested-by: Liviu Dudau <liviu@dudau.co.uk>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14 00:31:43 -07:00
Linus Torvalds
92f74f7f40 execve updates for 6.10-rc1
- Provide knob to change (previously fixed) coredump NOTES size (Allen Pais)
 
 - Add sched_prepare_exec tracepoint (Marco Elver)
 
 - Make /proc/$pid/auxv work under binfmt_elf_fdpic (Max Filippov)
 
 - Convert ARCH_HAVE_EXTRA_ELF_NOTES to proper Kconfig (Vignesh Balasubramanian)
 
 - Leave a gap between .bss and brk
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Merge tag 'execve-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve updates from Kees Cook:

 - Provide knob to change (previously fixed) coredump NOTES size
   (Allen Pais)

 - Add sched_prepare_exec tracepoint (Marco Elver)

 - Make /proc/$pid/auxv work under binfmt_elf_fdpic (Max Filippov)

 - Convert ARCH_HAVE_EXTRA_ELF_NOTES to proper Kconfig (Vignesh
   Balasubramanian)

 - Leave a gap between .bss and brk

* tag 'execve-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  fs/coredump: Enable dynamic configuration of max file note size
  binfmt_elf_fdpic: fix /proc/<pid>/auxv
  binfmt_elf: Leave a gap between .bss and brk
  Replace macro "ARCH_HAVE_EXTRA_ELF_NOTES" with kconfig
  tracing: Add sched_prepare_exec tracepoint
2024-05-13 14:01:33 -07:00
Linus Torvalds
2e57d1d606 sparc32,parisc,csky: Provide one-byte and two-byte cmpxchg() support
This series provides native one-byte and two-byte cmpxchg() support
 for sparc32 and parisc, courtesy of Al Viro.  This support is provided
 by the same hashed-array-of-locks technique used for the other atomic
 operations provided for these two platforms.
 
 This series also provides emulated one-byte cmpxchg() support for csky
 using a new cmpxchg_emu_u8() function that uses a four-byte cmpxchg()
 to emulate the one-byte variant.
 
 Similar patches for emulation of one-byte cmpxchg() for arc, sh, and
 xtensa have not yet received maintainer acks, so they are slated for
 the v6.11 merge window.
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Merge tag 'cmpxchg.2024.05.11a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull cmpxchg updates from Paul McKenney:
 "Provide one-byte and two-byte cmpxchg() support on sparc32, parisc,
  and csky

  This provides native one-byte and two-byte cmpxchg() support for
  sparc32 and parisc, courtesy of Al Viro. This support is provided by
  the same hashed-array-of-locks technique used for the other atomic
  operations provided for these two platforms.

  There is also emulated one-byte cmpxchg() support for csky using a new
  cmpxchg_emu_u8() function that uses a four-byte cmpxchg() to emulate
  the one-byte variant.

  Similar patches for emulation of one-byte cmpxchg() for arc, sh, and
  xtensa have not yet received maintainer acks, so they are slated for
  the v6.11 merge window"

* tag 'cmpxchg.2024.05.11a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  csky: Emulate one-byte cmpxchg
  lib: Add one-byte emulation function
  parisc: add u16 support to cmpxchg()
  parisc: add missing export of __cmpxchg_u8()
  parisc: unify implementations of __cmpxchg_u{8,32,64}
  parisc: __cmpxchg_u32(): lift conversion into the callers
  sparc32: add __cmpxchg_u{8,16}() and teach __cmpxchg() to handle those sizes
  sparc32: unify __cmpxchg_u{32,64}
  sparc32: make the first argument of __cmpxchg_u64() volatile u64 *
  sparc32: make __cmpxchg_u32() return u32
2024-05-13 10:05:39 -07:00
Linus Torvalds
c0b9620bc3 RCU pull request for v6.10
This pull request contains the following branches:
 
 fixes.2024.04.15a: Fix a lockdep complain for lazy-preemptible kernel,
 remove redundant BH disable for TINY_RCU, remove redundant READ_ONCE()
 in tree.c, fix false positives KCSAN splat and fix buffer overflow in
 the print_cpu_stall_info().
 
 misc.2024.04.12a: Misc updates related to bpf, tracing and update the
 MAINTAINERS file.
 
 rcu-sync-normal-improve.2024.04.15a: An improvement of a normal
 synchronize_rcu() call in terms of latency. It maintains a separate
 track for sync. users only. This approach bypasses per-cpu nocb-lists
 thus sync-users do not depend on nocb-list length and how fast regular
 callbacks are processed.
 
 rcu-tasks.2024.04.15a: RCU tasks, switch tasks RCU grace periods to
 sleep at TASK_IDLE priority, fix some comments, add some diagnostic
 warning to the exit_tasks_rcu_start() and fix a buffer overflow in
 the show_rcu_tasks_trace_gp_kthread().
 
 rcutorture.2024.04.15a: Increase memory to guest OS, fix a Tasks
 Rude RCU testing, some updates for TREE09, dump mode information
 to debug GP kthread state, remove redundant READ_ONCE(), fix some
 comments about RCU_TORTURE_PIPE_LEN and pipe_count, remove some
 redundant pointer initialization, fix a hung splat task by when
 the rcutorture tests start to exit, fix invalid context warning,
 add '--do-kvfree' parameter to torture test and use slow register
 unregister callbacks only for rcutype test.
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Merge tag 'rcu.next.v6.10' of https://github.com/urezki/linux

Pull RCU updates from Uladzislau Rezki:

 - Fix a lockdep complain for lazy-preemptible kernel, remove redundant
   BH disable for TINY_RCU, remove redundant READ_ONCE() in tree.c, fix
   false positives KCSAN splat and fix buffer overflow in the
   print_cpu_stall_info().

 - Misc updates related to bpf, tracing and update the MAINTAINERS file.

 - An improvement of a normal synchronize_rcu() call in terms of
   latency. It maintains a separate track for sync. users only. This
   approach bypasses per-cpu nocb-lists thus sync-users do not depend on
   nocb-list length and how fast regular callbacks are processed.

 - RCU tasks: switch tasks RCU grace periods to sleep at TASK_IDLE
   priority, fix some comments, add some diagnostic warning to the
   exit_tasks_rcu_start() and fix a buffer overflow in the
   show_rcu_tasks_trace_gp_kthread().

 - RCU torture: Increase memory to guest OS, fix a Tasks Rude RCU
   testing, some updates for TREE09, dump mode information to debug GP
   kthread state, remove redundant READ_ONCE(), fix some comments about
   RCU_TORTURE_PIPE_LEN and pipe_count, remove some redundant pointer
   initialization, fix a hung splat task by when the rcutorture tests
   start to exit, fix invalid context warning, add '--do-kvfree'
   parameter to torture test and use slow register unregister callbacks
   only for rcutype test.

* tag 'rcu.next.v6.10' of https://github.com/urezki/linux: (48 commits)
  rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test
  torture: Scale --do-kvfree test time
  rcutorture: Fix invalid context warning when enable srcu barrier testing
  rcutorture: Make stall-tasks directly exit when rcutorture tests end
  rcutorture: Removing redundant function pointer initialization
  rcutorture: Make rcutorture support print rcu-tasks gp state
  rcutorture: Use the gp_kthread_dbg operation specified by cur_ops
  rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading
  rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment
  rcutorture: Remove extraneous rcu_torture_pipe_update_one() READ_ONCE()
  rcu: Allocate WQ with WQ_MEM_RECLAIM bit set
  rcu: Support direct wake-up of synchronize_rcu() users
  rcu: Add a trace event for synchronize_rcu_normal()
  rcu: Reduce synchronize_rcu() latency
  rcu: Fix buffer overflow in print_cpu_stall_info()
  rcu: Mollify sparse with RCU guard
  rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow
  rcu-tasks: Fix the comments for tasks_rcu_exit_srcu_stall_timer
  rcu-tasks: Replace exit_tasks_rcu_start() initialization with WARN_ON_ONCE()
  rcu: Remove redundant CONFIG_PROVE_RCU #if condition
  ...
2024-05-13 09:49:06 -07:00
Sean Christopherson
fe42754b94 cpu: Re-enable CPU mitigations by default for !X86 architectures
Rename x86's to CPU_MITIGATIONS, define it in generic code, and force it
on for all architectures exception x86.  A recent commit to turn
mitigations off by default if SPECULATION_MITIGATIONS=n kinda sorta
missed that "cpu_mitigations" is completely generic, whereas
SPECULATION_MITIGATIONS is x86-specific.

Rename x86's SPECULATIVE_MITIGATIONS instead of keeping both and have it
select CPU_MITIGATIONS, as having two configs for the same thing is
unnecessary and confusing.  This will also allow x86 to use the knob to
manage mitigations that aren't strictly related to speculative
execution.

Use another Kconfig to communicate to common code that CPU_MITIGATIONS
is already defined instead of having x86's menu depend on the common
CPU_MITIGATIONS.  This allows keeping a single point of contact for all
of x86's mitigations, and it's not clear that other architectures *want*
to allow disabling mitigations at compile-time.

Fixes: f337a6a21e ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n")
Closes: https://lkml.kernel.org/r/20240413115324.53303a68%40canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240420000556.2645001-2-seanjc@google.com
2024-04-25 15:47:35 +02:00
Vignesh Balasubramanian
a9c3475dd6 Replace macro "ARCH_HAVE_EXTRA_ELF_NOTES" with kconfig
"ARCH_HAVE_EXTRA_ELF_NOTES" enables an extra note section in the
core dump. Kconfig variable is preferred over ARCH_HAVE_* macro.

Co-developed-by: Jini Susan George <jinisusan.george@amd.com>
Signed-off-by: Jini Susan George <jinisusan.george@amd.com>
Signed-off-by: Vignesh Balasubramanian <vigbalas@amd.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20240412062138.1132841-2-vigbalas@amd.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-04-15 11:02:51 -07:00
Linus Torvalds
d5cf50dafc Kconfig: add some hidden tabs on purpose
Commit d96c36004e ("tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig
entry") removed a hidden tab because it apparently showed breakage in
some third-party kernel config parsing tool.

It wasn't clear what tool it was, but let's make sure it gets fixed.
Because if you can't parse tabs as whitespace, you should not be parsing
the kernel Kconfig files.

In fact, let's make such breakage more obvious than some esoteric ftrace
record size option.  If you can't parse tabs, you can't have page sizes.

Yes, tab-vs-space confusion is sadly a traditional Unix thing, and
'make' is famous for being broken in this regard.  But no, that does not
mean that it's ok.

I'd add more random tabs to our Kconfig files, but I don't want to make
things uglier than necessary.  But it *might* bbe necessary if it turns
out we see more of this kind of silly tooling.

Fixes: d96c36004e ("tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry")
Link: https://lore.kernel.org/lkml/CAHk-=wj-hLLN_t_m5OL4dXLaxvXKy_axuoJYXif7iczbfgAevQ@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-04-12 10:05:10 -07:00
Paul E. McKenney
a88d970c8b lib: Add one-byte emulation function
Architectures are required to provide four-byte cmpxchg() and 64-bit
architectures are additionally required to provide eight-byte cmpxchg().
However, there are cases where one-byte cmpxchg() would be extremely
useful.  Therefore, provide cmpxchg_emu_u8() that emulates one-byte
cmpxchg() in terms of four-byte cmpxchg().

Note that this emulations is fully ordered, and can (for example) cause
one-byte cmpxchg_relaxed() to incur the overhead of full ordering.
If this causes problems for a given architecture, that architecture is
free to provide its own lighter-weight primitives.

[ paulmck: Apply Marco Elver feedback. ]
[ paulmck: Apply kernel test robot feedback. ]
[ paulmck: Drop two-byte support per Arnd Bergmann feedback. ]

Link: https://lore.kernel.org/all/0733eb10-5e7a-4450-9b8a-527b97c842ff@paulmck-laptop/

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <linux-arch@vger.kernel.org>
2024-04-09 22:06:00 -07:00
Paul E. McKenney
900da4d2a5 arch: Select new NEED_TASKS_RCU Kconfig option
Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does
"select TASKS_RCU if PREEMPTION".  This works, but requires any change in
this enablement logic to be replicated across all such "select" clauses.
A new NEED_TASKS_RCU Kconfig option has been created to allow this
enablement logic to be in one place in kernel/rcu/Kconfig.

Therefore, select the new NEED_TASKS_RCU Kconfig option instead of the
old TASKS_RCU option.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09 15:13:05 +02:00
Linus Torvalds
b71871395c hardening fixes for v6.9-rc1
- CONFIG_MEMCPY_SLOW_KUNIT_TEST is no longer needed (Guenter Roeck)
 
 - Fix needless UTF-8 character in arch/Kconfig (Liu Song)
 
 - Improve __counted_by warning message in LKDTM (Nathan Chancellor)
 
 - Refactor DEFINE_FLEX() for default use of __counted_by
 
 - Disable signed integer overflow sanitizer on GCC < 8
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Merge tag 'hardening-v6.9-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull more hardening updates from Kees Cook:

 - CONFIG_MEMCPY_SLOW_KUNIT_TEST is no longer needed (Guenter Roeck)

 - Fix needless UTF-8 character in arch/Kconfig (Liu Song)

 - Improve __counted_by warning message in LKDTM (Nathan Chancellor)

 - Refactor DEFINE_FLEX() for default use of __counted_by

 - Disable signed integer overflow sanitizer on GCC < 8

* tag 'hardening-v6.9-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lkdtm/bugs: Improve warning message for compilers without counted_by support
  overflow: Change DEFINE_FLEX to take __counted_by member
  Revert "kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST"
  arch/Kconfig: eliminate needless UTF-8 character in Kconfig help
  ubsan: Disable signed integer overflow sanitizer on GCC < 8
2024-03-23 08:43:21 -07:00
Linus Torvalds
1d35aae78f Kbuild updates for v6.9
- Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)
 
  - Use more threads when building Debian packages in parallel
 
  - Fix warnings shown during the RPM kernel package uninstallation
 
  - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
    Makefile
 
  - Support GCC's -fmin-function-alignment flag
 
  - Fix a null pointer dereference bug in modpost
 
  - Add the DTB support to the RPM package
 
  - Various fixes and cleanups in Kconfig
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Merge tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)

 - Use more threads when building Debian packages in parallel

 - Fix warnings shown during the RPM kernel package uninstallation

 - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
   Makefile

 - Support GCC's -fmin-function-alignment flag

 - Fix a null pointer dereference bug in modpost

 - Add the DTB support to the RPM package

 - Various fixes and cleanups in Kconfig

* tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits)
  kconfig: tests: test dependency after shuffling choices
  kconfig: tests: add a test for randconfig with dependent choices
  kconfig: tests: support KCONFIG_SEED for the randconfig runner
  kbuild: rpm-pkg: add dtb files in kernel rpm
  kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig()
  kconfig: check prompt for choice while parsing
  kconfig: lxdialog: remove unused dialog colors
  kconfig: lxdialog: fix button color for blackbg theme
  modpost: fix null pointer dereference
  kbuild: remove GCC's default -Wpacked-bitfield-compat flag
  kbuild: unexport abs_srctree and abs_objtree
  kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1
  kconfig: remove named choice support
  kconfig: use linked list in get_symbol_str() to iterate over menus
  kconfig: link menus to a symbol
  kbuild: fix inconsistent indentation in top Makefile
  kbuild: Use -fmin-function-alignment when available
  alpha: merge two entries for CONFIG_ALPHA_GAMMA
  alpha: merge two entries for CONFIG_ALPHA_EV4
  kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj)
  ...
2024-03-21 14:41:00 -07:00
Liu Song
c4ca2276f1 arch/Kconfig: eliminate needless UTF-8 character in Kconfig help
Use "find ./linux/* | grep Kconfig | xargs file | grep UTF", can find
files with utf-8 encoded characters, these files will display garbled
characters in menuconfig, except for characters with special meanings
that cannot be modified, modify the characters with obvious errors to
eliminate the wrong display under meunconfig.

Signed-off-by: Liu Song <liusong@linux.alibaba.com>
Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/lkml/1659435153-119538-1-git-send-email-liusong@linux.alibaba.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-03-18 11:24:15 -07:00
Arnd Bergmann
ba89f9c8cc arch: consolidate existing CONFIG_PAGE_SIZE_*KB definitions
These four architectures define the same Kconfig symbols for configuring
the page size. Move the logic into a common place where it can be shared
with all other architectures.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-03-06 19:28:26 +01:00
Petr Pavlu
5270316c9f kbuild: Use -fmin-function-alignment when available
GCC recently added option -fmin-function-alignment, which should appear
in GCC 14. Unlike -falign-functions, this option causes all functions to
be aligned at the specified value, including the cold ones.

In particular, when an arm64 kernel is built with
DYNAMIC_FTRACE_WITH_CALL_OPS=y, the 8-byte function alignment is
required for correct functionality. This was done by -falign-functions=8
and having workarounds in the kernel to force the compiler to follow
this alignment. The new -fmin-function-alignment option directly
guarantees it.

Detect availability of -fmin-function-alignment and use it instead of
-falign-functions when present. Introduce CC_HAS_SANE_FUNCTION_ALIGNMENT
and enable __cold to work as expected when it is set.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-02-25 18:04:26 +09:00
Samuel Holland
6f9dc684ca scs: add CONFIG_MMU dependency for vfree_atomic()
The shadow call stack implementation fails to build without CONFIG_MMU:

  ld.lld: error: undefined symbol: vfree_atomic
  >>> referenced by scs.c
  >>>               kernel/scs.o:(scs_free) in archive vmlinux.a

Link: https://lkml.kernel.org/r/20240122175204.2371009-1-samuel.holland@sifive.com
Fixes: a2abe7cbd8 ("scs: switch to vmapped shadow stacks")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-25 23:52:21 -08:00