Commit Graph

1277 Commits

Author SHA1 Message Date
Linus Torvalds
fd8c09ad0d Merge tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Support multiple hook locations for maint scripts of Debian package

 - Remove 'cpio' from the build tool requirement

 - Introduce gendwarfksyms tool, which computes CRCs for export symbols
   based on the DWARF information

 - Support CONFIG_MODVERSIONS for Rust

 - Resolve all conflicts in the genksyms parser

 - Fix several syntax errors in genksyms

* tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (64 commits)
  kbuild: fix Clang LTO with CONFIG_OBJTOOL=n
  kbuild: Strip runtime const RELA sections correctly
  kconfig: fix memory leak in sym_warn_unmet_dep()
  kconfig: fix file name in warnings when loading KCONFIG_DEFCONFIG_LIST
  genksyms: fix syntax error for attribute before init-declarator
  genksyms: fix syntax error for builtin (u)int*x*_t types
  genksyms: fix syntax error for attribute after 'union'
  genksyms: fix syntax error for attribute after 'struct'
  genksyms: fix syntax error for attribute after abstact_declarator
  genksyms: fix syntax error for attribute before nested_declarator
  genksyms: fix syntax error for attribute before abstract_declarator
  genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier
  genksyms: record attributes consistently for init-declarator
  genksyms: restrict direct-declarator to take one parameter-type-list
  genksyms: restrict direct-abstract-declarator to take one parameter-type-list
  genksyms: remove Makefile hack
  genksyms: fix last 3 shift/reduce conflicts
  genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts
  genksyms: reduce type_qualifier directly to decl_specifier
  genksyms: rename cvar_qualifier to type_qualifier
  ...
2025-01-31 12:07:07 -08:00
Linus Torvalds
7d6e5b5258 Merge tag 'drm-next-2025-01-27' of https://gitlab.freedesktop.org/drm/kernel
Pull drm fixes from Simona Vetter:
 "cgroup:
   - fix Koncfig fallout from new dmem controller

  Driver Changes:
   - v3d NULL pointer regression fix in fence signalling race
   - virtio: uaf in dma_buf free path
   - xlnx: fix kerneldoc
   - bochs: fix double-free on driver removal
   - zynqmp: add missing locking to DP bridge driver
   - amdgpu fixes all over:
       - documentation, display, sriov, various hw block drivers
       - use drm/sched helper
       - mark some debug module options as unsafe
       - amdkfd: mark some debug module options as unsafe, trap handler
         updates, fix partial migration handling

  DRM core:
   - fix fbdev Kconfig select rules, improve tiled-based display
     support"

* tag 'drm-next-2025-01-27' of https://gitlab.freedesktop.org/drm/kernel: (40 commits)
  drm/amd/display: Optimize cursor position updates
  drm/amd/display: Add hubp cache reset when powergating
  drm/amd/amdgpu: Enable scratch data dump for mes 12
  drm/amd: Clarify kdoc for amdgpu.gttsize
  drm/amd/amdgpu: Prevent null pointer dereference in GPU bandwidth calculation
  drm/amd/display: Fix error pointers in amdgpu_dm_crtc_mem_type_changed
  drm/amdgpu: fix ring timeout issue in gfx10 sr-iov environment
  drm/amd/pm: Fix smu v13.0.6 caps initialization
  drm/amd/pm: Refactor SMU 13.0.6 SDMA reset firmware version checks
  revert "drm/amdgpu/pm: add definition PPSMC_MSG_ResetSDMA2"
  revert "drm/amdgpu/pm: Implement SDMA queue reset for different asic"
  drm/amd/pm: Add capability flags for SMU v13.0.6
  drm/amd/display: fix SUBVP DC_DEBUG_MASK documentation
  drm/amd/display: fix CEC DC_DEBUG_MASK documentation
  drm/amdgpu: fix the PCIe lanes reporting in the INFO IOCTL
  drm/amdgpu: cache gpu pcie link width
  drm/amd/display: mark static functions noinline_for_stack
  drm/amdkfd: Clear MODE.VSKIP in gfx9 trap handler
  drm/amdgpu: Refine ip detection log message
  drm/amdgpu: Add handler for SDMA context empty
  ...
2025-01-27 17:17:16 -08:00
Linus Torvalds
e3610441d1 Merge tag 'rust-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Finish the move to custom FFI integer types started in the previous
     cycle and finally map 'long' to 'isize' and 'char' to 'u8'. Do a
     few cleanups on top thanks to that.

   - Start to use 'derive(CoercePointee)' on Rust >= 1.84.0.

     This is a major milestone on the path to build the kernel using
     only stable Rust features. In particular, previously we were using
     the unstable features 'coerce_unsized', 'dispatch_from_dyn' and
     'unsize', and now we will use the new 'derive_coerce_pointee' one,
     which is on track to stabilization. This new feature is a macro
     that essentially expands into code that internally uses the
     unstable features that we were using before, without having to
     expose those.

     With it, stable Rust users, including the kernel, will be able to
     build custom smart pointers that work with trait objects, e.g.:

         fn f(p: &Arc<dyn Display>) {
             pr_info!("{p}\n");
         }

         let a: Arc<dyn Display> = Arc::new(42i32, GFP_KERNEL)?;
         let b: Arc<dyn Display> = Arc::new("hello there", GFP_KERNEL)?;

         f(&a); // Prints "42".
         f(&b); // Prints "hello there".

     Together with the 'arbitrary_self_types' feature that we started
     using in the previous cycle, using our custom smart pointers like
     'Arc' will eventually only rely in stable Rust.

   - Introduce 'PROCMACROLDFLAGS' environment variable to allow to link
     Rust proc macros using different flags than those used for linking
     Rust host programs (e.g. when 'rustc' uses a different C library
     than the host programs' one), which Android needs.

   - Help kernel builds under macOS with Rust enabled by accomodating
     other naming conventions for dynamic libraries (i.e. '.so' vs.
     '.dylib') which are used for Rust procedural macros. The actual
     support for macOS (i.e. the rest of the pieces needed) is provided
     out-of-tree by others, following the policy used for other parts of
     the kernel by Kbuild.

   - Run Clippy for 'rusttest' code too and clean the bits it spotted.

   - Provide Clippy with the minimum supported Rust version to improve
     the suggestions it gives.

   - Document 'bindgen' 0.71.0 regression.

  'kernel' crate:

   - 'build_error!': move users of the hidden function to the documented
     macro, prevent such uses in the future by moving the function
     elsewhere and add the macro to the prelude.

   - 'types' module: add improved version of 'ForeignOwnable::borrow_mut'
     (which was removed in the past since it was problematic); change
     'ForeignOwnable' pointer type to '*mut'.

   - 'alloc' module: implement 'Display' for 'Box' and align the 'Debug'
     implementation to it; add example (doctest) for 'ArrayLayout::new()'

   - 'sync' module: document 'PhantomData' in 'Arc'; use
     'NonNull::new_unchecked' in 'ForeignOwnable for Arc' impl.

   - 'uaccess' module: accept 'Vec's with different allocators in
     'UserSliceReader::read_all'.

   - 'workqueue' module: enable run-testing a couple more doctests.

   - 'error' module: simplify 'from_errno()'.

   - 'block' module: fix formatting in code documentation (a lint to catch
     these is being implemented).

   - Avoid 'unwrap()'s in doctests, which also improves the examples by
     showing how kernel code is supposed to be written.

   - Avoid 'as' casts with 'cast{,_mut}' calls which are a bit safer.

  And a few other cleanups"

* tag 'rust-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (32 commits)
  kbuild: rust: add PROCMACROLDFLAGS
  rust: uaccess: generalize userSliceReader to support any Vec
  rust: kernel: add improved version of `ForeignOwnable::borrow_mut`
  rust: kernel: reorder `ForeignOwnable` items
  rust: kernel: change `ForeignOwnable` pointer to mut
  rust: arc: split unsafe block, add missing comment
  rust: types: avoid `as` casts
  rust: arc: use `NonNull::new_unchecked`
  rust: use derive(CoercePointee) on rustc >= 1.84.0
  rust: alloc: add doctest for `ArrayLayout::new()`
  rust: init: update `stack_try_pin_init` examples
  rust: error: import `kernel`'s `LayoutError` instead of `core`'s
  rust: str: replace unwraps with question mark operators
  rust: page: remove unnecessary helper function from doctest
  rust: rbtree: remove unwrap in asserts
  rust: init: replace unwraps with question mark operators
  rust: use host dylib naming convention to support macOS
  rust: add `build_error!` to the prelude
  rust: kernel: move `build_error` hidden function to prevent mistakes
  rust: use the `build_error!` macro, not the hidden function
  ...
2025-01-21 17:48:03 -08:00
Sami Tolvanen
ac61506bf2 rust: Use gendwarfksyms + extended modversions for CONFIG_MODVERSIONS
Previously, two things stopped Rust from using MODVERSIONS:
1. Rust symbols are occasionally too long to be represented in the
   original versions table
2. Rust types cannot be properly hashed by the existing genksyms
   approach because:
	* Looking up type definitions in Rust is more complex than C
	* Type layout is potentially dependent on the compiler in Rust,
	  not just the source type declaration.

CONFIG_EXTENDED_MODVERSIONS addresses the first point, and
CONFIG_GENDWARFKSYMS the second. If Rust wants to use MODVERSIONS, allow
it to do so by selecting both features.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Co-developed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-18 08:51:48 +09:00
Geert Uytterhoeven
bea6afc1bf cgroup/rdma: Drop bogus PAGE_COUNTER select
When adding the Device memory controller (DMEM), "select PAGE_COUNTER"
was added to CGROUP_RDMA, presumably instead of CGROUP_DMEM.
While commit e33b51499a ("cgroup/dmem: Select PAGE_COUNTER") added
the missing select to CGROUP_DMEM, the bogus select is still there.
Remove it.

Fixes: b168ed458d ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Closes: https://lore.kernel.org/CAMuHMdUmPfahsnZwx2iB5yfh8rjjW25LNcnYujNBgcKotUXBNg@mail.gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b4d462f038a2f895f30ae759928397c8183f6f7e.1737020925.git.geert+renesas@glider.be
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2025-01-17 13:48:57 +01:00
Maxime Ripard
e33b51499a cgroup/dmem: Select PAGE_COUNTER
The dmem cgroup the page counting API implemented behing the
PAGE_COUNTER kconfig option. However, it doesn't select it, resulting in
potential build breakages. Select PAGE_COUNTER.

Fixes: b168ed458d ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501111330.3VuUx8vf-lkp@intel.com/
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20250113092608.1349287-1-mripard@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2025-01-15 09:45:20 +01:00
Xiangfei Ding
47cb6bf786 rust: use derive(CoercePointee) on rustc >= 1.84.0
The `kernel` crate relies on both `coerce_unsized` and `dispatch_from_dyn`
unstable features.

Alice Ryhl has proposed [1] the introduction of the unstable macro
`SmartPointer` to reduce such dependence, along with a RFC patch [2].
Since Rust 1.81.0 this macro, later renamed to `CoercePointee` in
Rust 1.84.0 [3], has been fully implemented with the naming discussion
resolved.

This feature is now on track to stabilization in the language.
In order to do so, we shall start using this macro in the `kernel` crate
to prove the functionality and utility of the macro as the justification
of its stabilization.

This patch makes this switch in such a way that the crate remains
backward compatible with older Rust compiler versions,
via the new Kconfig option `RUSTC_HAS_COERCE_POINTEE`.

A minimal demonstration example is added to the
`samples/rust/rust_print_main.rs` module.

Link: https://rust-lang.github.io/rfcs/3621-derive-smart-pointer.html [1]
Link: https://lore.kernel.org/all/20240823-derive-smart-pointer-v1-1-53769cd37239@google.com/ [2]
Link: https://github.com/rust-lang/rust/pull/131284 [3]
Signed-off-by: Xiangfei Ding <dingxiangfei2009@gmail.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241203205050.679106-2-dingxiangfei2009@gmail.com
[ Fixed version to 1.84. Renamed option to `RUSTC_HAS_COERCE_POINTEE`
  to match `CC_HAS_*` ones. Moved up new config option, closer to the
  `CC_HAS_*` ones. Simplified Kconfig line. Fixed typos and slightly
  reworded example and commit. Added Link to PR. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-13 23:45:30 +01:00
Miguel Ojeda
c23d1f7e15 rust: document bindgen 0.71.0 regression
`bindgen` 0.71.0 regressed [1] on the "`--version` requires header"
issue which appeared in 0.69.0 first [2] and was fixed in 0.69.1. It
has been fixed again in 0.71.1 [3].

Thus document it so that, when we upgrade the minimum past 0.69.0 in the
future, we do not forget that we cannot remove the workaround until we
arrive at 0.71.1 at least.

Link: https://github.com/rust-lang/rust-bindgen/issues/3039 [1]
Link: https://github.com/rust-lang/rust-bindgen/issues/2677 [2]
Link: https://github.com/rust-lang/rust-bindgen/blob/main/CHANGELOG.md#v0711-2024-12-09 [3]
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241209212544.1977065-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-10 00:17:00 +01:00
Maarten Lankhorst
b168ed458d kernel/cgroup: Add "dmem" memory accounting cgroup
This code is based on the RDMA and misc cgroup initially, but now
uses page_counter. It uses the same min/low/max semantics as the memory
cgroup as a result.

There's a small mismatch as TTM uses u64, and page_counter long pages.
In practice it's not a problem. 32-bits systems don't really come with
>=4GB cards and as long as we're consistently wrong with units, it's
fine. The device page size may not be in the same units as kernel page
size, and each region might also have a different page size (VRAM vs GART
for example).

The interface is simple:
- Call dmem_cgroup_register_region()
- Use dmem_cgroup_try_charge to check if you can allocate a chunk of memory,
  use dmem_cgroup__uncharge when freeing it. This may return an error code,
  or -EAGAIN when the cgroup limit is reached. In that case a reference
  to the limiting pool is returned.
- The limiting cs can be used as compare function for
  dmem_cgroup_state_evict_valuable.
- After having evicted enough, drop reference to limiting cs with
  dmem_cgroup_pool_state_put.

This API allows you to limit device resources with cgroups.
You can see the supported cards in /sys/fs/cgroup/dmem.capacity
You need to echo +dmem to cgroup.subtree_control, and then you can
partition device memory.

Co-developed-by: Friedrich Vock <friedrich.vock@gmx.de>
Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de>
Co-developed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20241204143112.1250983-1-dev@lankhorst.se
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2025-01-06 17:24:38 +01:00
Linus Torvalds
f5f4745a7f Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...
2024-11-25 16:09:48 -08:00
Linus Torvalds
36843bfbf7 Merge tag 'hardening-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:

 - Disable __counted_by in Clang < 19.1.3 (Jan Hendrik Farr)

 - string_helpers: Silence output truncation warning (Bartosz
   Golaszewski)

 - compiler.h: Avoid needing BUILD_BUG_ON_ZERO() (Philipp Reisner)

 - MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be}
   (Thorsten Blum)

* tag 'hardening-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Compiler Attributes: disable __counted_by for clang < 19.1.3
  compiler.h: Fix undefined BUILD_BUG_ON_ZERO()
  lib: string_helpers: silence snprintf() output truncation warning
  MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be}
2024-11-25 15:22:35 -08:00
Linus Torvalds
06afb0f361 Merge tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:

 - Addition of faultable tracepoints

   There's a tracepoint attached to both a system call entry and exit.
   This location is known to allow page faults. The tracepoints are
   called under an rcu_read_lock() which does not allow faults that can
   sleep. This limits the ability of tracepoint handlers to page fault
   in user space system call parameters. Now these tracepoints have been
   made "faultable", allowing the callbacks to fault in user space
   parameters and record them.

   Note, only the infrastructure has been implemented. The consumers
   (perf, ftrace, BPF) now need to have their code modified to allow
   faults.

 - Fix up of BPF code for the tracepoint faultable logic

 - Update tracepoints to use the new static branch API

 - Remove trace_*_rcuidle() variants and the SRCU protection they used

 - Remove unused TRACE_EVENT_FL_FILTERED logic

 - Replace strncpy() with strscpy() and memcpy()

 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()

 - Fix perf events to not duplicate samples when tracing is enabled

 - Replace atomic64_add_return(1, counter) with
   atomic64_inc_return(counter)

 - Make stack trace buffer 4K instead of PAGE_SIZE

 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used

 - Get the true return address for function tracer when function graph
   tracer is also running.

   When function_graph trace is running along with function tracer, the
   parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.

 - Remove (un)regfunc pointers out of tracepoint structure

 - Added last minute bug fix for setting pending modules in stack
   function filter.

     echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter

   Would cause a kernel NULL dereference.

 - Minor clean ups

* tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  ftrace: Fix regression with module command in stack_trace_filter
  tracing: Fix function name for trampoline
  ftrace: Get the true parent ip for function tracer
  tracing: Remove redundant check on field->field in histograms
  bpf: ensure RCU Tasks Trace GP for sleepable raw tracepoint BPF links
  bpf: decouple BPF link/attach hook and BPF program sleepable semantics
  bpf: put bpf_link's program when link is safe to be deallocated
  tracing: Replace strncpy() with strscpy() when copying comm
  tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL
  tracing: Fix syscall tracepoint use-after-free
  tracing: Introduce tracepoint_is_faultable()
  tracing: Introduce tracepoint extended structure
  tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
  tracing: Replace multiple deprecated strncpy with memcpy
  tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
  tracing: Use atomic64_inc_return() in trace_clock_counter()
  trace/trace_event_perf: remove duplicate samples on the first tracepoint event
  tracing/bpf: Add might_fault check to syscall probes
  tracing/perf: Add might_fault check to syscall probes
  tracing/ftrace: Add might_fault check to syscall probes
  ...
2024-11-22 13:27:01 -08:00
Jan Hendrik Farr
f06e108a3d Compiler Attributes: disable __counted_by for clang < 19.1.3
This patch disables __counted_by for clang versions < 19.1.3 because
of the two issues listed below. It does this by introducing
CONFIG_CC_HAS_COUNTED_BY.

1. clang < 19.1.2 has a bug that can lead to __bdos returning 0:
https://github.com/llvm/llvm-project/pull/110497

2. clang < 19.1.3 has a bug that can lead to __bdos being off by 4:
https://github.com/llvm/llvm-project/pull/112636

Fixes: c8248faf3c ("Compiler Attributes: counted_by: Adjust name and identifier expansion")
Cc: stable@vger.kernel.org # 6.6.x: 16c31dd7fd: Compiler Attributes: counted_by: bump min gcc version
Cc: stable@vger.kernel.org # 6.6.x: 2993eb7a8d: Compiler Attributes: counted_by: fixup clang URL
Cc: stable@vger.kernel.org # 6.6.x: 231dc3f0c9: lkdtm/bugs: Improve warning message for compilers without counted_by support
Cc: stable@vger.kernel.org # 6.6.x
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20240913164630.GA4091534@thelio-3990X/
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202409260949.a1254989-oliver.sang@intel.com
Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Jan Hendrik Farr <kernel@jfarr.cc>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc
Signed-off-by: Kees Cook <kees@kernel.org>
2024-11-19 08:48:27 -08:00
Kuan-Wei Chiu
bf9850f6ea lib/Makefile: make union-find compilation conditional on CONFIG_CPUSETS
Currently, cpuset is the only user of the union-find implementation. 
Compiling union-find in all configurations unnecessarily increases the
code size when building the kernel without cgroup support.  Modify the
build system to compile union-find only when CONFIG_CPUSETS is enabled.

Link: https://lore.kernel.org/lkml/1ccd6411-5002-4574-bb8e-3e64bba6a757@redhat.com/
Link: https://lkml.kernel.org/r/20241011141214.87096-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Waiman Long <llong@redhat.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Xavier <xavier_qy@163.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 17:12:32 -08:00
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
Gary Guo
af0121c2d3 kbuild: rust: add CONFIG_RUSTC_LLVM_VERSION
Each version of Rust supports a range of LLVM versions. There are cases where
we want to gate a config on the LLVM version instead of the Rust version.
Normalized cfi integer tags are one example [1].

The invocation of rustc-version is being moved from init/Kconfig to
scripts/Kconfig.include for consistency with cc-version.

Link: https://lore.kernel.org/all/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com/ [1]
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20241011114040.3900487-1-gary@garyguo.net
[ Added missing `-llvm` to the Usage documentation. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-13 22:22:28 +02:00
Mathieu Desnoyers
a363d27cdb tracing: Allow system call tracepoints to handle page faults
Use Tasks Trace RCU to protect iteration of system call enter/exit
tracepoint probes to allow those probes to handle page faults.

In preparation for this change, all tracers registering to system call
enter/exit tracepoints should expect those to be called with preemption
enabled.

This allows tracers to fault-in userspace system call arguments such as
path strings within their probe callbacks.

Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes <joel@joelfernandes.org>
Link: https://lore.kernel.org/20241009010718.2050182-6-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 17:08:03 -04:00
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
Alice Ryhl
93e34a0b5c rust: KASAN+RETHUNK requires rustc 1.83.0
When enabling both KASAN and RETHUNK, objtool emits the following
warnings:

    rust/core.o: warning: objtool: asan.module_ctor+0x13: 'naked' return found in MITIGATION_RETHUNK build
    rust/core.o: warning: objtool: asan.module_dtor+0x13: 'naked' return found in MITIGATION_RETHUNK build

This is caused by the -Zfunction-return=thunk-extern flag in rustc not
informing LLVM about the mitigation at the module level (it does so at
the function level only currently, which covers most cases, but both
are required), which means that the KASAN functions asan.module_ctor
and asan.module_dtor are generated without the rethunk mitigation.

The other mitigations that we enabled for Rust (SLS, RETPOLINE) do not
have the same bug, as they're being applied through the target-feature
functionality instead.

This is being fixed for rustc 1.83.0, so update Kconfig to reject this
configuration on older compilers.

Link: https://github.com/rust-lang/rust/pull/130824
Fixes: d7868550d5 ("x86/rust: support MITIGATION_RETHUNK")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Closes: https://lore.kernel.org/all/CANiq72myZL4_poCMuNFevtpYYc0V0embjSuKb7y=C+m3vVA_8g@mail.gmail.com/
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240926093849.1192264-1-aliceryhl@google.com
[ Reworded to add the details mentioned in the list. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-26 21:27:27 +02:00
Miguel Ojeda
af6017b6a3 rust: cfi: fix patchable-function-entry starting version
The `-Zpatchable-function-entry` flag is available since Rust
1.81.0, not Rust 1.80.0, i.e. commit ac7595fdb1ee ("Support for -Z
patchable-function-entry") in upstream Rust.

Fixes: ca627e6365 ("rust: cfi: add support for CFI_CLANG with Rust")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/20240925141944.277936-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-26 21:27:27 +02:00
Linus Torvalds
5701725692 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
88264981f2 Merge tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext support from Tejun Heo:
 "This implements a new scheduler class called ‘ext_sched_class’, or
  sched_ext, which allows scheduling policies to be implemented as BPF
  programs.

  The goals of this are:

   - Ease of experimentation and exploration: Enabling rapid iteration
     of new scheduling policies.

   - Customization: Building application-specific schedulers which
     implement policies that are not applicable to general-purpose
     schedulers.

   - Rapid scheduler deployments: Non-disruptive swap outs of scheduling
     policies in production environments"

See individual commits for more documentation, but also the cover letter
for the latest series:

Link: https://lore.kernel.org/all/20240618212056.2833381-1-tj@kernel.org/

* tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (110 commits)
  sched: Move update_other_load_avgs() to kernel/sched/pelt.c
  sched_ext: Don't trigger ops.quiescent/runnable() on migrations
  sched_ext: Synchronize bypass state changes with rq lock
  scx_qmap: Implement highpri boosting
  sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()
  sched_ext: Compact struct bpf_iter_scx_dsq_kern
  sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq()
  sched_ext: Move consume_local_task() upward
  sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq()
  sched_ext: Reorder args for consume_local/remote_task()
  sched_ext: Restructure dispatch_to_local_dsq()
  sched_ext: Fix processs_ddsp_deferred_locals() by unifying DTL_INVALID handling
  sched_ext: Make find_dsq_for_dispatch() handle SCX_DSQ_LOCAL_ON
  sched_ext: Refactor consume_remote_task()
  sched_ext: Rename scx_kfunc_set_sleepable to unlocked and relocate
  sched_ext: Add missing static to scx_dump_data
  sched_ext: Add missing static to scx_has_op[]
  sched_ext: Temporarily work around pick_task_scx() being called without balance_scx()
  sched_ext: Add a cgroup scheduler which uses flattened hierarchy
  sched_ext: Add cgroup support
  ...
2024-09-21 09:44:57 -07:00
Linus Torvalds
7856a56541 Merge tag 'mm-nonmm-stable-2024-09-21-07-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
 "Many singleton patches - please see the various changelogs for
  details.

  Quite a lot of nilfs2 work this time around.

  Notable patch series in this pull request are:

   - "mul_u64_u64_div_u64: new implementation" by Nicolas Pitre, with
     assistance from Uwe Kleine-König. Reimplement mul_u64_u64_div_u64()
     to provide (much) more accurate results. The current implementation
     was causing Uwe some issues in the PWM drivers.

   - "xz: Updates to license, filters, and compression options" from
     Lasse Collin. Miscellaneous maintenance and kinor feature work to
     the xz decompressor.

   - "Fix some GDB command error and add some GDB commands" from
     Kuan-Ying Lee. Fixes and enhancements to the gdb scripts.

   - "treewide: add missing MODULE_DESCRIPTION() macros" from Jeff
     Johnson. Adds lots of MODULE_DESCRIPTIONs, thus fixing lots of
     warnings about this.

   - "nilfs2: add support for some common ioctls" from Ryusuke Konishi.
     Adds various commonly-available ioctls to nilfs2.

   - "This series fixes a number of formatting issues in kernel doc
     comments" from Ryusuke Konishi does that.

   - "nilfs2: prevent unexpected ENOENT propagation" from Ryusuke
     Konishi. Fix issues where -ENOENT was being unintentionally and
     inappropriately returned to userspace.

   - "nilfs2: assorted cleanups" from Huang Xiaojia.

   - "nilfs2: fix potential issues with empty b-tree nodes" from Ryusuke
     Konishi fixes some issues which can occur on corrupted nilfs2
     filesystems.

   - "scripts/decode_stacktrace.sh: improve error reporting and
     usability" from Luca Ceresoli does those things"

* tag 'mm-nonmm-stable-2024-09-21-07-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (103 commits)
  list: test: increase coverage of list_test_list_replace*()
  list: test: fix tests for list_cut_position()
  proc: use __auto_type more
  treewide: correct the typo 'retun'
  ocfs2: cleanup return value and mlog in ocfs2_global_read_info()
  nilfs2: remove duplicate 'unlikely()' usage
  nilfs2: fix potential oob read in nilfs_btree_check_delete()
  nilfs2: determine empty node blocks as corrupted
  nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
  user_namespace: use kmemdup_array() instead of kmemdup() for multiple allocation
  tools/mm: rm thp_swap_allocator_test when make clean
  squashfs: fix percpu address space issues in decompressor_multi_percpu.c
  lib: glob.c: added null check for character class
  nilfs2: refactor nilfs_segctor_thread()
  nilfs2: use kthread_create and kthread_stop for the log writer thread
  nilfs2: remove sc_timer_task
  nilfs2: do not repair reserved inode bitmap in nilfs_new_inode()
  nilfs2: eliminate the shared counter and spinlock for i_generation
  nilfs2: separate inode type information from i_state field
  nilfs2: use the BITS_PER_LONG macro
  ...
2024-09-21 08:20:50 -07:00
Linus Torvalds
617a814f14 Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Linus Torvalds
78567e2bc7 Merge tag 'cgroup-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:

 - cpuset isolation improvements

 - cpuset cgroup1 support is split into its own file behind the new
   config option CONFIG_CPUSET_V1. This makes it the second controller
   which makes cgroup1 support optional after memcg

 - Handling of unavailable v1 controller handling improved during
   cgroup1 mount operations

 - union_find applied to cpuset. It makes code simpler and more
   efficient

 - Reduce spurious events in pids.events

 - Cleanups and other misc changes

 - Contains a merge of cgroup/for-6.11-fixes to receive cpuset fixes
   that further changes build upon

* tag 'cgroup-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (34 commits)
  cgroup: Do not report unavailable v1 controllers in /proc/cgroups
  cgroup: Disallow mounting v1 hierarchies without controller implementation
  cgroup/cpuset: Expose cpuset filesystem with cpuset v1 only
  cgroup/cpuset: Move cpu.h include to cpuset-internal.h
  cgroup/cpuset: add sefltest for cpuset v1
  cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1
  cgroup/cpuset: rename functions shared between v1 and v2
  cgroup/cpuset: move v1 interfaces to cpuset-v1.c
  cgroup/cpuset: move validate_change_legacy to cpuset-v1.c
  cgroup/cpuset: move legacy hotplug update to cpuset-v1.c
  cgroup/cpuset: add callback_lock helper
  cgroup/cpuset: move memory_spread to cpuset-v1.c
  cgroup/cpuset: move relax_domain_level to cpuset-v1.c
  cgroup/cpuset: move memory_pressure to cpuset-v1.c
  cgroup/cpuset: move common code to cpuset-internal.h
  cgroup/cpuset: introduce cpuset-v1.c
  selftest/cgroup: Make test_cpuset_prs.sh deal with pre-isolated CPUs
  cgroup/cpuset: Account for boot time isolated CPUs
  cgroup/cpuset: remove use_parent_ecpus of cpuset
  cgroup/cpuset: remove fetch_xcpus
  ...
2024-09-18 06:39:03 +02:00
Matthew Maurer
f64e2f3a66 rust: kasan: Rust does not support KHWASAN
Rust does not yet have support for software tags. Prevent RUST from
being selected if KASAN_SW_TAGS is enabled.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20240820194910.187826-3-mmaurer@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-16 18:04:37 +02:00
Matthew Maurer
ca627e6365 rust: cfi: add support for CFI_CLANG with Rust
Make it possible to use the Control Flow Integrity (CFI) sanitizer when
Rust is enabled. Enabling CFI with Rust requires that CFI is configured
to normalize integer types so that all integer types of the same size
and signedness are compatible under CFI.

Rust and C use the same LLVM backend for code generation, so Rust KCFI
is compatible with the KCFI used in the kernel for C. In the case of
FineIBT, CFI also depends on -Zpatchable-function-entry for rewriting
the function prologue, so we set that flag for Rust as well. The flag
for FineIBT requires rustc 1.80.0 or later, so include a Kconfig
requirement for that.

Enabling Rust will select CFI_ICALL_NORMALIZE_INTEGERS because the flag
is required to use Rust with CFI. Using select rather than `depends on`
avoids the case where Rust is not visible in menuconfig due to
CFI_ICALL_NORMALIZE_INTEGERS not being enabled. One disadvantage of
select is that RUST must `depends on` all of the things that
CFI_ICALL_NORMALIZE_INTEGERS depends on to avoid invalid configurations.

Alice has been using KCFI on her phone for several months, so it is
reasonably well tested on arm64.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
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-v2-2-c93caed3d121@google.com
[ Replaced `!FINEIBT` requirement with `!CALL_PADDING` to prevent
  a build error on older Rust compilers. Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-16 17:29:58 +02:00
Alice Ryhl
d077242d68 rust: support for shadow call stack sanitizer
Add all of the flags that are needed to support the shadow call stack
(SCS) sanitizer with Rust, and updates Kconfig to allow only
configurations that work.

The -Zfixed-x18 flag is required to use SCS on arm64, and requires rustc
version 1.80.0 or greater. This restriction is reflected in Kconfig.

When CONFIG_DYNAMIC_SCS is enabled, the build will be configured to
include unwind tables in the build artifacts. Dynamic SCS uses the
unwind tables at boot to find all places that need to be patched. The
-Cforce-unwind-tables=y flag ensures that unwind tables are available
for Rust code.

In non-dynamic mode, the -Zsanitizer=shadow-call-stack flag is what
enables the SCS sanitizer. Using this flag requires rustc version 1.82.0
or greater on the targets used by Rust in the kernel. This restriction
is reflected in Kconfig.

It is possible to avoid the requirement of rustc 1.80.0 by using
-Ctarget-feature=+reserve-x18 instead of -Zfixed-x18. However, this flag
emits a warning during the build, so this patch does not add support for
using it and instead requires 1.80.0 or greater.

The dependency is placed on `select HAVE_RUST` to avoid a situation
where enabling Rust silently turns off the sanitizer. Instead, turning
on the sanitizer results in Rust being disabled. We generally do not
want changes to CONFIG_RUST to result in any mitigations being changed
or turned off.

At the time of writing, rustc 1.82.0 only exists via the nightly release
channel. There is a chance that the -Zsanitizer=shadow-call-stack flag
will end up needing 1.83.0 instead, but I think it is small.

Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240829-shadow-call-stack-v7-1-2f62a4432abf@google.com
[ Fixed indentation using spaces. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-13 00:03:14 +02:00
Miguel Ojeda
5134a335cf kbuild: rust: re-run Kconfig if the version text changes
Re-run Kconfig if we detect the Rust compiler has changed via the version
text, like it is done for C.

Unlike C, and unlike `RUSTC_VERSION`, the `RUSTC_VERSION_TEXT` is kept
under `depends on RUST`, since it should not be needed unless `RUST`
is enabled.

Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240902165535.1101978-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-05 22:44:34 +02:00
Miguel Ojeda
6e74c6b5a4 kbuild: rust: add CONFIG_RUSTC_VERSION
Now that we support several Rust versions, introduce
`CONFIG_RUSTC_VERSION` so that it can be used in Kconfig to enable and
disable configuration options based on the `rustc` version.

The approach taken resembles `pahole`'s -- see commit 613fe16923
("kbuild: Add CONFIG_PAHOLE_VERSION"), i.e. a simple version parsing
without trying to identify several kinds of compilers, since so far
there is only one (`rustc`).

However, unlike `pahole`'s, we also print a zero if executing failed for
any reason, rather than checking if the command is found and executable
(which still leaves things like a file that exists and is executable,
but e.g. is built for another platform [1]). An equivalent approach to
the one here was also submitted for `pahole` [2].

Link: https://lore.kernel.org/rust-for-linux/CANiq72=4vX_tJMJLE6e+bg7ZECHkS-AQpm8GBzuK75G1EB7+Nw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/linux-kbuild/20240728125527.690726-1-ojeda@kernel.org/ [2]
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240902165535.1101978-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-05 22:44:18 +02:00
Tejun Heo
649e980dad Merge branch 'bpf/master' into for-6.12
Pull bpf/master to receive baebe9aaba ("bpf: allow passing struct
bpf_iter_<type> as kfunc arguments") and related changes in preparation for
the DSQ iterator patchset.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-04 11:41:32 -10:00
Tejun Heo
8195136669 sched_ext: Add cgroup support
Add sched_ext_ops operations to init/exit cgroups, and track task migrations
and config changes. A BPF scheduler may not implement or implement only
subset of cgroup features. The implemented features can be indicated using
%SCX_OPS_HAS_CGOUP_* flags. If cgroup configuration makes use of features
that are not implemented, a warning is triggered.

While a BPF scheduler is being enabled and disabled, relevant cgroup
operations are locked out using scx_cgroup_rwsem. This avoids situations
like task prep taking place while the task is being moved across cgroups,
making things easier for BPF schedulers.

v7: - cgroup interface file visibility toggling is dropped in favor just
      warning messages. Dynamically changing interface visiblity caused more
      confusion than helping.

v6: - Updated to reflect the removal of SCX_KF_SLEEPABLE.

    - Updated to use CONFIG_GROUP_SCHED_WEIGHT and fixes for
      !CONFIG_FAIR_GROUP_SCHED && CONFIG_EXT_GROUP_SCHED.

v5: - Flipped the locking order between scx_cgroup_rwsem and
      cpus_read_lock() to avoid locking order conflict w/ cpuset. Better
      documentation around locking.

    - sched_move_task() takes an early exit if the source and destination
      are identical. This triggered the warning in scx_cgroup_can_attach()
      as it left p->scx.cgrp_moving_from uncleared. Updated the cgroup
      migration path so that ops.cgroup_prep_move() is skipped for identity
      migrations so that its invocations always match ops.cgroup_move()
      one-to-one.

v4: - Example schedulers moved into their own patches.

    - Fix build failure when !CONFIG_CGROUP_SCHED, reported by Andrea Righi.

v3: - Make scx_example_pair switch all tasks by default.

    - Convert to BPF inline iterators.

    - scx_bpf_task_cgroup() is added to determine the current cgroup from
      CPU controller's POV. This allows BPF schedulers to accurately track
      CPU cgroup membership.

    - scx_example_flatcg added. This demonstrates flattened hierarchy
      implementation of CPU cgroup control and shows significant performance
      improvement when cgroups which are nested multiple levels are under
      competition.

v2: - Build fixes for different CONFIG combinations.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
2024-09-04 10:24:59 -10:00
Tejun Heo
e179e80c5d sched: Introduce CONFIG_GROUP_SCHED_WEIGHT
sched_ext will soon add cgroup cpu.weigh support. The cgroup interface code
is currently gated behind CONFIG_FAIR_GROUP_SCHED. As the fair class and/or
SCX may implement the feature, put the interface code behind the new
CONFIG_CGROUP_SCHED_WEIGHT which is selected by CONFIG_FAIR_GROUP_SCHED.
This allows either sched class to enable the itnerface code without ading
more complex CONFIG tests.

When !CONFIG_FAIR_GROUP_SCHED, a dummy version of sched_group_set_shares()
is added to support later CONFIG_CGROUP_SCHED_WEIGHT &&
!CONFIG_FAIR_GROUP_SCHED builds.

No functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-04 10:24:59 -10:00
Lasse Collin
7472ff8ada xz: adjust arch-specific options for better kernel compression
Use LZMA2 options that match the arch-specific alignment of instructions. 
This change reduces compressed kernel size 0-2 % depending on the arch. 
On 1-byte-aligned x86 it makes no difference and on 4-byte-aligned archs
it helps the most.

Use the ARM-Thumb filter for ARM-Thumb2 kernels.  This reduces compressed
kernel size about 5 %.[1] Previously such kernels were compressed using
the ARM filter which didn't do anything useful with ARM-Thumb2 code.

Add BCJ filter support for ARM64 and RISC-V.  Compared to unfiltered XZ or
plain LZMA, the compressed kernel size is reduced about 5 % on ARM64 and 7
% on RISC-V.  A new enough version of the xz tool is required: 5.4.0 for
ARM64 and 5.6.0 for RISC-V.  With an old xz version, a message is printed
to standard error and the kernel is compressed without the filter.

Update lib/decompress_unxz.c to match the changes to xz_wrap.sh.

Update the CONFIG_KERNEL_XZ help text in init/Kconfig:
  - Add the RISC-V and ARM64 filters.
  - Clarify that the PowerPC filter is for big endian only.
  - Omit IA-64.

Link: https://lore.kernel.org/lkml/1637379771-39449-1-git-send-email-zhongjubin@huawei.com/ [1]
Link: https://lkml.kernel.org/r/20240721133633.47721-15-lasse.collin@tukaani.org
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Reviewed-by: Sam James <sam@gentoo.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Jules Maselbas <jmaselbas@zdiv.net>
Cc: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rui Li <me@lirui.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:43:27 -07:00
Valdis Kletnieks
fcb4824b26 mm: fix typo in Kconfig
Fix typo in Kconfig help

Link: https://lkml.kernel.org/r/78656.1720853990@turing-police
Fixes: e93d4166b4 ("mm: memcg: put cgroup v1-specific code under a config option")
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:45 -07:00
Chen Ridong
1abab1ba07 cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1
This patch introduces CONFIG_CPUSETS_V1 and guard cpuset-v1 code under
CONFIG_CPUSETS_V1. The default value of CONFIG_CPUSETS_V1 is N, so that
user who adopted v2 don't have 'pay' for cpuset v1.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-08-30 10:00:16 -10:00
Jens Axboe
1802656ef8 io_uring: add GCOV_PROFILE_URING Kconfig option
If GCOV is enabled and this option is set, it enables code coverage
profiling of the io_uring subsystem. Only use this for test purposes,
as it will impact the runtime performance.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-08-30 10:52:02 -06:00
Neal Gompa
f1385dc670 init/Kconfig: Only block on RANDSTRUCT for RUST
When enabling Rust in the kernel, we only need to block on the
RANDSTRUCT feature and GCC plugin. The rest of the GCC plugins
are reasonably safe to enable.

[ Originally (years ago) we only had this restriction, but we ended up
  restricting also the rest of the GCC plugins 1) to be on the safe side,
  2) since compiler plugin support could be going away in the kernel and
  3) since mixed builds are best effort so far; so I asked Neal about
  his experience enabling the other plugins -- Neal says:

    When I originally wrote this patch two years ago to get things
    working, Fedora used all the GCC plugins, so I was trying to get GCC +
    Rust to work while minimizing the delta on build differences. This was
    the combination that worked. We've been carrying this patch in the
    Asahi tree for a year now. And while Fedora does not currently have
    GCC plugins enabled because it caused issues with some third-party
    modules (I think it was the NVIDIA driver, but I'm not sure), it was
    around long enough for me to know with some confidence that it was
    fine this way.

  - Miguel ]

Signed-off-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20240731125615.3368813-1-neal@gompa.dev
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:10:53 +02:00
Linus Torvalds
60cb1da6ed Merge tag 'rust-fixes-6.11' of https://github.com/Rust-for-Linux/linux
Pull rust fixes from Miguel Ojeda:

 - Fix '-Os' Rust 1.80.0+ builds adding more intrinsics (also tweaked in
   upstream Rust for the upcoming 1.82.0).

 - Fix support for the latest version of rust-analyzer due to a change
   on rust-analyzer config file semantics (considered a fix since most
   developers use the latest version of the tool, which is the only one
   actually supported by upstream). I am discussing stability of the
   config file with upstream -- they may be able to start versioning it.

 - Fix GCC 14 builds due to '-fmin-function-alignment' not skipped for
   libclang (bindgen).

 - A couple Kconfig fixes around '{RUSTC,BINDGEN}_VERSION_TEXT' to
   suppress error messages in a foreign architecture chroot and to use a
   proper default format.

 - Clean 'rust-analyzer' target warning due to missing recursive make
   invocation mark.

 - Clean Clippy warning due to missing indentation in docs.

 - Clean LLVM 19 build warning due to removed 3dnow feature upstream.

* tag 'rust-fixes-6.11' of https://github.com/Rust-for-Linux/linux:
  rust: x86: remove `-3dnow{,a}` from target features
  kbuild: rust-analyzer: mark `rust_is_available.sh` invocation as recursive
  rust: add intrinsics to fix `-Os` builds
  kbuild: rust: skip -fmin-function-alignment in bindgen flags
  rust: Support latest version of `rust-analyzer`
  rust: macros: indent list item in `module!`'s docs
  rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
  rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
2024-08-16 11:24:06 -07:00
Alice Ryhl
f126745da8 rust: SHADOW_CALL_STACK is incompatible with Rust
When using the shadow call stack sanitizer, all code must be compiled
with the -ffixed-x18 flag, but this flag is not currently being passed
to Rust. This results in crashes that are extremely difficult to debug.

To ensure that nobody else has to go through the same debugging session
that I had to, prevent configurations that enable both SHADOW_CALL_STACK
and RUST.

It is rather common for people to backport 724a75ac95 ("arm64: rust:
Enable Rust support for AArch64"), so I recommend applying this fix all
the way back to 6.1.

Cc: stable@vger.kernel.org # 6.1 and later
Fixes: 724a75ac95 ("arm64: rust: Enable Rust support for AArch64")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20240729-shadow-call-stack-v4-1-2a664b082ea4@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-08-01 16:15:03 +01:00
Masahiro Yamada
aacf93e87f rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
Another oddity in these config entries is their default value can fall
back to 'n', which is a value for bool or tristate symbols.

The '|| echo n' is an incorrect workaround to avoid the syntax error.
This is not a big deal, as the entry is hidden by 'depends on RUST' in
situations where '$(RUSTC) --version' or '$(BINDGEN) --version' fails.
Anyway, it looks odd.

The default of a string type symbol should be a double-quoted string
literal. Turn it into an empty string when the version command fails.

Fixes: 2f7ab1267d ("Kbuild: add Rust support")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240727140302.1806011-2-masahiroy@kernel.org
[ Rebased on top of v6.11-rc1. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-29 00:48:26 +02:00
Masahiro Yamada
5ce86c6c86 rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
While this is a somewhat unusual case, I encountered odd error messages
when I ran Kconfig in a foreign architecture chroot.

  $ make allmodconfig
  sh: 1: rustc: not found
  sh: 1: bindgen: not found
  #
  # configuration written to .config
  #

The successful execution of 'command -v rustc' does not necessarily mean
that 'rustc --version' will succeed.

  $ sh -c 'command -v rustc'
  /home/masahiro/.cargo/bin/rustc
  $ sh -c 'rustc --version'
  sh: 1: rustc: not found

Here, 'rustc' is built for x86, and I ran it in an arm64 system.

The current code:

  command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n

can be turned into:

  command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version 2>/dev/null || echo n

However, I did not understand the necessity of 'command -v $(RUSTC)'.

I simplified it to:

  $(RUSTC) --version 2>/dev/null || echo n

Fixes: 2f7ab1267d ("Kbuild: add Rust support")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240727140302.1806011-1-masahiroy@kernel.org
[ Rebased on top of v6.11-rc1. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-29 00:48:12 +02:00
Linus Torvalds
910bfc26d1 Merge tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux
Pull Rust updates from Miguel Ojeda:
 "The highlight is the establishment of a minimum version for the Rust
  toolchain, including 'rustc' (and bundled tools) and 'bindgen'.

  The initial minimum will be the pinned version we currently have, i.e.
  we are just widening the allowed versions. That covers three stable
  Rust releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow),
  plus beta, plus nightly.

  This should already be enough for kernel developers in distributions
  that provide recent Rust compiler versions routinely, such as Arch
  Linux, Debian Unstable (outside the freeze period), Fedora Linux,
  Gentoo Linux (especially the testing channel), Nix (unstable) and
  openSUSE Slowroll and Tumbleweed.

  In addition, the kernel is now being built-tested by Rust's pre-merge
  CI. That is, every change that is attempting to land into the Rust
  compiler is tested against the kernel, and it is merged only if it
  passes. Similarly, the bindgen tool has agreed to build the kernel in
  their CI too.

  Thus, with the pre-merge CI in place, both projects hope to avoid
  unintentional changes to Rust that break the kernel. This means that,
  in general, apart from intentional changes on their side (that we will
  need to workaround conditionally on our side), the upcoming Rust
  compiler versions should generally work.

  In addition, the Rust project has proposed getting the kernel into
  stable Rust (at least solving the main blockers) as one of its three
  flagship goals for 2024H2 [1].

  I would like to thank Niko, Sid, Emilio et al. for their help
  promoting the collaboration between Rust and the kernel.

  Toolchain and infrastructure:

   - Support several Rust toolchain versions.

   - Support several bindgen versions.

   - Remove 'cargo' requirement and simplify 'rusttest', thanks to
     'alloc' having been dropped last cycle.

   - Provide proper error reporting for the 'rust-analyzer' target.

  'kernel' crate:

   - Add 'uaccess' module with a safe userspace pointers abstraction.

   - Add 'page' module with a 'struct page' abstraction.

   - Support more complex generics in workqueue's 'impl_has_work!'
     macro.

  'macros' crate:

   - Add 'firmware' field support to the 'module!' macro.

   - Improve 'module!' macro documentation.

  Documentation:

   - Provide instructions on what packages should be installed to build
     the kernel in some popular Linux distributions.

   - Introduce the new kernel.org LLVM+Rust toolchains.

   - Explain '#[no_std]'.

  And a few other small bits"

Link: https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals [1]

* tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux: (26 commits)
  docs: rust: quick-start: add section on Linux distributions
  rust: warn about `bindgen` versions 0.66.0 and 0.66.1
  rust: start supporting several `bindgen` versions
  rust: work around `bindgen` 0.69.0 issue
  rust: avoid assuming a particular `bindgen` build
  rust: start supporting several compiler versions
  rust: simplify Clippy warning flags set
  rust: relax most deny-level lints to warnings
  rust: allow `dead_code` for never constructed bindings
  rust: init: simplify from `map_err` to `inspect_err`
  rust: macros: indent list item in `paste!`'s docs
  rust: add abstraction for `struct page`
  rust: uaccess: add typed accessors for userspace pointers
  uaccess: always export _copy_[from|to]_user with CONFIG_RUST
  rust: uaccess: add userspace pointers
  kbuild: rust-analyzer: improve comment documentation
  kbuild: rust-analyzer: better error handling
  docs: rust: no_std is used
  rust: alloc: add __GFP_HIGHMEM flag
  rust: alloc: fix typo in docs for GFP_NOWAIT
  ...
2024-07-27 13:44:54 -07:00
Linus Torvalds
ca83c61cb3 Merge tag 'kbuild-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Remove tristate choice support from Kconfig

 - Stop using the PROVIDE() directive in the linker script

 - Reduce the number of links for the combination of CONFIG_KALLSYMS and
   CONFIG_DEBUG_INFO_BTF

 - Enable the warning for symbol reference to .exit.* sections by
   default

 - Fix warnings in RPM package builds

 - Improve scripts/make_fit.py to generate a FIT image with separate
   base DTB and overlays

 - Improve choice value calculation in Kconfig

 - Fix conditional prompt behavior in choice in Kconfig

 - Remove support for the uncommon EMAIL environment variable in Debian
   package builds

 - Remove support for the uncommon "name <email>" form for the DEBEMAIL
   environment variable

 - Raise the minimum supported GNU Make version to 4.0

 - Remove stale code for the absolute kallsyms

 - Move header files commonly used for host programs to scripts/include/

 - Introduce the pacman-pkg target to generate a pacman package used in
   Arch Linux

 - Clean up Kconfig

* tag 'kbuild-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (65 commits)
  kbuild: doc: gcc to CC change
  kallsyms: change sym_entry::percpu_absolute to bool type
  kallsyms: unify seq and start_pos fields of struct sym_entry
  kallsyms: add more original symbol type/name in comment lines
  kallsyms: use \t instead of a tab in printf()
  kallsyms: avoid repeated calculation of array size for markers
  kbuild: add script and target to generate pacman package
  modpost: use generic macros for hash table implementation
  kbuild: move some helper headers from scripts/kconfig/ to scripts/include/
  Makefile: add comment to discourage tools/* addition for kernel builds
  kbuild: clean up scripts/remove-stale-files
  kconfig: recursive checks drop file/lineno
  kbuild: rpm-pkg: introduce a simple changelog section for kernel.spec
  kallsyms: get rid of code for absolute kallsyms
  kbuild: Create INSTALL_PATH directory if it does not exist
  kbuild: Abort make on install failures
  kconfig: remove 'e1' and 'e2' macros from expression deduplication
  kconfig: remove SYMBOL_CHOICEVAL flag
  kconfig: add const qualifiers to several function arguments
  kconfig: call expr_eliminate_yn() at least once in expr_eliminate_dups()
  ...
2024-07-23 14:32:21 -07:00
Linus Torvalds
fbc90c042c Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Jann Horn
64e166099b kallsyms: get rid of code for absolute kallsyms
Commit cf8e865810 ("arch: Remove Itanium (IA-64) architecture")
removed the last use of the absolute kallsyms.

Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/all/20240221202655.2423854-1-jannh@google.com/
[masahiroy@kernel.org: rebase the code and reword the commit description]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-20 16:33:21 +09:00
Mark Rutland
f2f6a8e887 init/Kconfig: remove CONFIG_GCC_ASM_GOTO_OUTPUT_WORKAROUND
Several versions of GCC mis-compile asm goto with outputs. We try to
workaround this, but our workaround is demonstrably incomplete and
liable to result in subtle bugs, especially on arm64 where get_user()
has recently been moved over to using asm goto with outputs.

From discussion(s) with Linus at:

  https://lore.kernel.org/linux-arm-kernel/Zpfv2tnlQ-gOLGac@J2N7QTR9R3.cambridge.arm.com/
  https://lore.kernel.org/linux-arm-kernel/ZpfxLrJAOF2YNqCk@J2N7QTR9R3.cambridge.arm.com/

... it sounds like the best thing to do for now is to remove the
workaround and make CC_HAS_ASM_GOTO_OUTPUT depend on working compiler
versions.

The issue was originally reported to GCC by Sean Christopherson:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921

... and Jakub Jelinek fixed this for GCC 14, with the fix backported to
13.3.0, 12.4.0, and 11.5.0.

In the kernel, we tried to workaround broken compilers in commits:

  4356e9f841 ("work around gcc bugs with 'asm goto' with outputs")
  68fb3ca0e4 ("update workarounds for gcc "asm goto" issue")

... but the workaround of adding an empty asm("") after the asm volatile
goto(...) demonstrably does not always avoid the problem, as can be seen
in the following test case:

| #define asm_goto_output(x...) \
|         do { asm volatile goto(x); asm (""); } while (0)
|
| #define __good_or_bad(__val, __key)                                     \
| do {                                                                    \
|         __label__ __failed;                                             \
|         unsigned long __tmp;                                            \
|         asm_goto_output(                                                \
|         "       cbnz    %[key], %l[__failed]\n"                         \
|         "       mov     %[val], #0x900d\n"                              \
|         : [val] "=r" (__tmp)                                            \
|         : [key] "r" (__key)                                             \
|         :                                                               \
|         : __failed);                                                    \
|         (__val) = __tmp;                                                \
|         break;                                                          \
| __failed:                                                               \
|         (__val) = 0xbad;                                                \
| } while (0)
|
| unsigned long get_val(unsigned long key);
| unsigned long get_val(unsigned long key)
| {
|         unsigned long val = 0xbad;
|
|         __good_or_bad(val, key);
|
|         return val;
| }

GCC 13.2.0 (at -O2) compiles this to:

| 	cbnz    x0, .Lfailed
| 	mov     x0, #0x900d
| .Lfailed:
| 	ret

GCC 14.1.0 (at -O2) compiles this to:

| 	cbnz    x0, .Lfailed
| 	mov     x0, #0x900d
| 	ret
| .Lfailed:
| 	mov     x0, #0xbad
| 	ret

Note that GCC 13.2.0 erroneously omits the assignment to 'val' in the
error path (even though this does not depend on an output of the asm
goto). GCC 14.1.0 correctly retains the assignment.

This problem can be seen within the kernel with the following test case:

| #include <linux/uaccess.h>
| #include <linux/types.h>
|
| noinline unsigned long test_unsafe_get_user(unsigned long __user *ptr);
| noinline unsigned long test_unsafe_get_user(unsigned long __user *ptr)
| {
|         unsigned long val;
|
|         unsafe_get_user(val, ptr, Efault);
|         return val;
|
| Efault:
|         val = 0x900d;
|         return val;
| }

GCC 13.2.0 (arm64 defconfig) compiles this to:

|         and     x0, x0, #0xff7fffffffffffff
|         ldtr    x0, [x0]
| .Lextable_fixup:
|         ret

GCC 13.2.0 (x86_64 defconfig + MITIGATION_RETPOLINE=n) compiles this to:

|         endbr64
|         mov    (%rdi),%rax
| .Lextable_fixup:
|         ret

... omitting the assignment to 'val' in the error path, and leaving
garbage in the result register returned by the function (which happens
to contain the faulting address in the generated code).

GCC 14.1.0 (arm64 defconfig) compiles this to:

|         and     x0, x0, #0xff7fffffffffffff
|         ldtr    x0, [x0]
|         ret
| .Lextable_fixup:
|         mov     x0, #0x900d                     // #36877
|         ret

GCC 14.1.0 (x86_64 defconfig + MITIGATION_RETPOLINE=n) compiles this to:

|         endbr64
|         mov    (%rdi),%rax
|         ret
| .Lextable_fixup:
|         mov    $0x900d,%eax
|         ret

... retaining the expected assignment to 'val' in the error path.

We don't have a complete and reasonable workaround. While placing empty
asm("") blocks after each goto label *might* be sufficient, we don't
know for certain, this is tedious and error-prone, and there doesn't
seem to be a neat way to wrap this up (which is especially painful for
cases with multiple goto labels).

Avoid this issue by disabling CONFIG_CC_HAS_ASM_GOTO_OUTPUT for
known-broken compiler versions and removing the workaround (along with
the CONFIG_GCC_ASM_GOTO_OUTPUT_WORKAROUND config option).

For the moment I've left the default implementation of asm_goto_output()
unchanged. This should now be redundant since any compiler with the fix
for the clobbering issue whould also have a fix for the (earlier)
volatile issue, but it's far less churny to leave it around, which makes
it easier to backport this patch if necessary.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alex Coplan <alex.coplan@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jakub Jelinek <jakub@gcc.gnu.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-18 10:33:14 -07:00
Johannes Weiner
3a3b7fec39 mm: remove CONFIG_MEMCG_KMEM
CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab
tracking is enabled.  It has been default-enabled and equivalent to
CONFIG_MEMCG for almost a decade.  We've only grown more kernel memory
accounting sites since, and there is no imaginable cgroup usecase going
forward that wants to track user pages but not the multitude of
user-drivable kernel allocations.

Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10 12:14:54 -07:00
Miguel Ojeda
9e98db1783 rust: work around bindgen 0.69.0 issue
`bindgen` 0.69.0 contains a bug: `--version` does not work without
providing a header [1]:

    error: the following required arguments were not provided:
      <HEADER>

    Usage: bindgen <FLAGS> <OPTIONS> <HEADER> -- <CLANG_ARGS>...

Thus, in preparation for supporting several `bindgen` versions, work
around the issue by passing a dummy argument.

Include a comment so that we can remove the workaround in the future.

Link: https://github.com/rust-lang/rust-bindgen/pull/2678 [1]
Reviewed-by: Finn Behrens <me@kloenk.dev>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:52 +02:00
Roman Gushchin
e93d4166b4 mm: memcg: put cgroup v1-specific code under a config option
Put legacy cgroup v1 memory controller code under a new CONFIG_MEMCG_V1
config option.  The option is turned off by default.  Nobody except those
who are still using cgroup v1 should turn it on.

If the option is not set, memory controller can still be mounted under
cgroup v1, but none of memcg-specific control files are present.

Please note, that not all cgroup v1's memory controller code is guarded
yet (but most of it), it's a subject for some follow-up work.

Thanks to Michal Hocko for providing a better Kconfig option description.

[roman.gushchin@linux.dev: better config option description provided by Michal]
  Link: https://lkml.kernel.org/r/ZnxXNtvqllc9CDoo@google.com
Link: https://lkml.kernel.org/r/20240625005906.106920-14-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:54 -07:00