From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- rust/ffi.rs | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 rust/ffi.rs (limited to 'rust/ffi.rs') diff --git a/rust/ffi.rs b/rust/ffi.rs new file mode 100644 index 000000000..f961e9728 --- /dev/null +++ b/rust/ffi.rs @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Foreign function interface (FFI) types. +//! +//! This crate provides mapping from C primitive types to Rust ones. +//! +//! The Rust [`core`] crate provides [`core::ffi`], which maps integer types to the platform default +//! C ABI. The kernel does not use [`core::ffi`], so it can customise the mapping that deviates from +//! the platform default. + +#![no_std] + +macro_rules! alias { + ($($name:ident = $ty:ty;)*) => {$( + #[allow(non_camel_case_types, missing_docs)] + pub type $name = $ty; + + // Check size compatibility with `core`. + const _: () = assert!( + ::core::mem::size_of::<$name>() == ::core::mem::size_of::<::core::ffi::$name>() + ); + )*} +} + +alias! { + // `core::ffi::c_char` is either `i8` or `u8` depending on architecture. In the kernel, we use + // `-funsigned-char` so it's always mapped to `u8`. + c_char = u8; + + c_schar = i8; + c_uchar = u8; + + c_short = i16; + c_ushort = u16; + + c_int = i32; + c_uint = u32; + + // In the kernel, `intptr_t` is defined to be `long` in all platforms, so we can map the type to + // `isize`. + c_long = isize; + c_ulong = usize; + + c_longlong = i64; + c_ulonglong = u64; +} + +pub use core::ffi::c_void; + +pub use core::ffi::CStr; -- cgit v1.3.1