kernel/linux.git/rust, branch v6.6.131

rust: pin-init: internal: init: document load-bearing fact of field accessors

2026-04-02T11:07:30+00:00

[ Upstream commit 580cc37b1de4fcd9997c48d7080e744533f09f36 ] The functions `[Pin]Init::__[pinned_]init` and `ptr::write` called from the `init!` macro require the passed pointer to be aligned. This fact is ensured by the creation of field accessors to previously initialized fields. Since we missed this very important fact from the beginning [1], document it in the code. Link: https://rust-for-linux.zulipchat.com/#narrow/channel/561532-pin-init/topic/initialized.20field.20accessor.20detection/with/576210658 [1] Fixes: 90e53c5e70a6 ("rust: add pin-init API core") Cc: # 6.6.y, 6.12.y: 42415d163e5d: rust: pin-init: add references to previously initialized fields Cc: # 6.6.y, 6.12.y, 6.18.y, 6.19.y Signed-off-by: Benno Lossin Reviewed-by: Gary Guo Link: https://patch.msgid.link/20260302140424.4097655-2-lossin@kernel.org [ Updated Cc: stable@ tags as discussed. - Miguel ] Signed-off-by: Miguel Ojeda [ Moved changes to the declarative macro, because 6.19.y and earlier do not have `syn`. Also duplicated the comment for all field accessor creations. - Benno ] Signed-off-by: Benno Lossin Signed-off-by: Greg Kroah-Hartman

rust: pin-init: add references to previously initialized fields

2026-04-02T11:07:29+00:00

[ Upstream commit 42415d163e5df6db799c7de6262d707e402c2c7e ] After initializing a field in an initializer macro, create a variable holding a reference that points at that field. The type is either `Pin<&mut T>` or `&mut T` depending on the field's structural pinning kind. [ Applied fixes to devres and rust_driver_pci sample - Benno] Reviewed-by: Danilo Krummrich Signed-off-by: Benno Lossin [ Removed the devres changes, because devres is not present in 6.12.y and earlier. Also adjusted paths in the macro to account for the fact that pin-init is part of the kernel crate in 6.12.y and earlier. - Benno ] Signed-off-by: Benno Lossin Signed-off-by: Greg Kroah-Hartman

rust: kunit: fix warning when !CONFIG_PRINTK

2026-03-25T10:05:40+00:00

[ Upstream commit 7dd34dfc8dfa92a7244242098110388367996ac3 ] If `CONFIG_PRINTK` is not set, then the following warnings are issued during build: warning: unused variable: `args` --> ../rust/kernel/kunit.rs:16:12 | 16 | pub fn err(args: fmt::Arguments<'_>) { | ^^^^ help: if this is intentional, prefix it with an underscore: `_args` | = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default warning: unused variable: `args` --> ../rust/kernel/kunit.rs:32:13 | 32 | pub fn info(args: fmt::Arguments<'_>) { | ^^^^ help: if this is intentional, prefix it with an underscore: `_args` Fix this by adding a no-op assignment using `args` when `CONFIG_PRINTK` is not set. Fixes: a66d733da801 ("rust: support running Rust documentation tests as KUnit ones") Signed-off-by: Alexandre Courbot Reviewed-by: Alice Ryhl Reviewed-by: David Gow Signed-off-by: Shuah Khan Signed-off-by: Sasha Levin

mm/ksm: fix flag-dropping behavior in ksm_madvise

2025-10-23T14:16:44+00:00

commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 upstream. syzkaller discovered the following crash: (kernel BUG) [ 44.607039] ------------[ cut here ]------------ [ 44.607422] kernel BUG at mm/userfaultfd.c:2067! [ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none) [ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460 [ 44.617726] Call Trace: [ 44.617926] [ 44.619284] userfaultfd_release+0xef/0x1b0 [ 44.620976] __fput+0x3f9/0xb60 [ 44.621240] fput_close_sync+0x110/0x210 [ 44.622222] __x64_sys_close+0x8f/0x120 [ 44.622530] do_syscall_64+0x5b/0x2f0 [ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 44.623244] RIP: 0033:0x7f365bb3f227 Kernel panics because it detects UFFD inconsistency during userfaultfd_release_all(). Specifically, a VMA which has a valid pointer to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags. The inconsistency is caused in ksm_madvise(): when user calls madvise() with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode, it accidentally clears all flags stored in the upper 32 bits of vma->vm_flags. Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and int are 32-bit wide. This setup causes the following mishap during the &= ~VM_MERGEABLE assignment. VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then promoted to unsigned long before the & operation. This promotion fills upper 32 bits with leading 0s, as we're doing unsigned conversion (and even for a signed conversion, this wouldn't help as the leading bit is 0). & operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears the upper 32-bits of its value. Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the BIT() macro. Note: other VM_* flags are not affected: This only happens to the VM_MERGEABLE flag, as the other VM_* flags are all constants of type int and after ~ operation, they end up with leading 1 and are thus converted to unsigned long with leading 1s. Note 2: After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is no longer a kernel BUG, but a WARNING at the same place: [ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067 but the root-cause (flag-drop) remains the same. [akpm@linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel] Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/ Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode") Signed-off-by: Jakub Acs Signed-off-by: Miguel Ojeda Acked-by: David Hildenbrand Acked-by: SeongJae Park Tested-by: Alice Ryhl Tested-by: Miguel Ojeda Cc: Xu Xin Cc: Chengming Zhou Cc: Peter Xu Cc: Axel Rasmussen Cc: Signed-off-by: Andrew Morton [acsjakub@amazon.de: adapt rust bindgen const to older versions] Signed-off-by: Jakub Acs Signed-off-by: Greg Kroah-Hartman

rust: module: place cleanup_module() in .exit.text section

2025-07-06T09:00:06+00:00

[ Upstream commit 249c3a0e53acefc2b06d3b3e1fc28fb2081f878d ] Place cleanup_module() in .exit.text section. Currently, cleanup_module() is likely placed in the .text section. It's inconsistent with the layout of C modules, where cleanup_module() is placed in .exit.text. [ Boqun asked for an example of how the section changed to be put in the log. Tomonori provided the following examples: C module: $ objdump -t ~/build/x86/drivers/block/loop.o|grep clean 0000000000000000 l O .exit.data 0000000000000008 __UNIQUE_ID___addressable_cleanup_module412 0000000000000000 g F .exit.text 000000000000009c cleanup_module Rust module without this patch: $ objdump -t ~/build/x86/samples/rust/rust_minimal.o|grep clean 00000000000002b0 g F .text 00000000000000c6 cleanup_module 0000000000000000 g O .exit.data 0000000000000008 _R...___UNIQUE_ID___addressable_cleanup_module Rust module with this patch: $ objdump -t ~/build/x86/samples/rust/rust_minimal.o|grep clean 0000000000000000 g F .exit.text 00000000000000c6 cleanup_module 0000000000000000 g O .exit.data 0000000000000008 _R...___UNIQUE_ID___addressable_cleanup_module - Miguel ] Signed-off-by: FUJITA Tomonori Acked-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20250308044506.14458-1-fujita.tomonori@gmail.com Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: lockdep: Remove support for dynamically allocated LockClassKeys

2025-03-22T19:50:50+00:00

commit 966944f3711665db13e214fef6d02982c49bb972 upstream. Currently, dynamically allocated LockCLassKeys can be used from the Rust side without having them registered. This is a soundness issue, so remove them. Fixes: 6ea5aa08857a ("rust: sync: introduce `LockClassKey`") Suggested-by: Alice Ryhl Signed-off-by: Mitchell Levy Signed-off-by: Boqun Feng Signed-off-by: Ingo Molnar Reviewed-by: Benno Lossin Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250307232717.1759087-11-boqun.feng@gmail.com Signed-off-by: Boqun Feng Signed-off-by: Greg Kroah-Hartman

rust: init: add missing newline to pr_info! calls

2025-03-22T19:50:48+00:00

[ Upstream commit 6933c1067fe6df8ddb34dd68bdb2aa172cbd08c8 ] Several pr_info! calls in rust/kernel/init.rs (both in code examples and macro documentation) were missing a newline, causing logs to run together. This commit updates these calls to include a trailing newline, improving readability and consistency with the C side. Fixes: 6841d45a3030 ("rust: init: add `stack_pin_init!` macro") Fixes: 7f8977a7fe6d ("rust: init: add `{pin_}chain` functions to `{Pin}Init`") Fixes: d0fdc3961270 ("rust: init: add `PinnedDrop` trait and macros") Fixes: 4af84c6a85c6 ("rust: init: update expanded macro explanation") Reported-by: Miguel Ojeda Link: https://github.com/Rust-for-Linux/linux/issues/1139 Signed-off-by: Alban Kurti Link: https://lore.kernel.org/r/20250206-printing_fix-v3-3-a85273b501ae@invicto.ai [ Replaced Closes with Link since it fixes part of the issue. Added one more Fixes tag (still same set of stable kernels). - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: error: add missing newline to pr_warn! calls

2025-03-22T19:50:48+00:00

[ Upstream commit 6f5c36f56d475732981dcf624e0ac0cc7c8984c8 ] Added missing newline at the end of pr_warn! usage so the log is not missed. Fixes: 6551a7fe0acb ("rust: error: Add Error::from_errno{_unchecked}()") Reported-by: Miguel Ojeda Link: https://github.com/Rust-for-Linux/linux/issues/1139 Signed-off-by: Alban Kurti Link: https://lore.kernel.org/r/20250206-printing_fix-v3-2-a85273b501ae@invicto.ai [ Replaced Closes with Link since it fixes part of the issue. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: init: fix `Zeroable` implementation for `Option>` and `Option>`

2025-03-22T19:50:48+00:00

commit df27cef153603b18a7d094b53cc3d5264ff32797 upstream. According to [1], `NonNull` and `#[repr(transparent)]` wrapper types such as our custom `KBox` have the null pointer optimization only if `T: Sized`. Thus remove the `Zeroable` implementation for the unsized case. Link: https://doc.rust-lang.org/stable/std/option/index.html#representation [1] Reported-by: Alice Ryhl Closes: https://lore.kernel.org/rust-for-linux/CAH5fLghL+qzrD8KiCF1V3vf2YcC6aWySzkmaE2Zzrnh1gKj-hw@mail.gmail.com/ Cc: stable@vger.kernel.org # v6.12+ (a custom patch will be needed for 6.6.y) Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function") Signed-off-by: Benno Lossin Reviewed-by: Alice Ryhl Reviewed-by: Andreas Hindborg Link: https://lore.kernel.org/r/20250305132836.2145476-1-benno.lossin@proton.me [ Added Closes tag and moved up the Reported-by one. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: init: use explicit ABI to clean warning in future compilers

2025-02-17T08:40:27+00:00

commit c21bdb3d8a850afdfa4afe77eea39ae9533629b0 upstream. Starting with Rust 1.86.0 (currently in nightly, to be released on 2025-04-03), the `missing_abi` lint is warn-by-default [1]: error: extern declarations without an explicit ABI are deprecated --> rust/doctests_kernel_generated.rs:3158:1 | 3158 | extern { | ^^^^^^ help: explicitly specify the C ABI: `extern "C"` | = note: `-D missing-abi` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(missing_abi)]` Thus clean it up. Cc: # Needed in 6.12.y and 6.13.y only (Rust is pinned in older LTSs). Fixes: 7f8977a7fe6d ("rust: init: add `{pin_}chain` functions to `{Pin}Init`") Link: https://github.com/rust-lang/rust/pull/132397 [1] Reviewed-by: Gary Guo Reviewed-by: Alice Ryhl Reviewed-by: Fiona Behrens Link: https://lore.kernel.org/r/20250121200934.222075-1-ojeda@kernel.org [ Added 6.13.y to Cc: stable tag. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman