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/helpers/build_assert.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 rust/helpers/build_assert.c (limited to 'rust/helpers/build_assert.c') diff --git a/rust/helpers/build_assert.c b/rust/helpers/build_assert.c new file mode 100644 index 000000000..6a54b2680 --- /dev/null +++ b/rust/helpers/build_assert.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +/* + * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can + * use it in contexts where Rust expects a `usize` like slice (array) indices. + * `usize` is defined to be the same as C's `uintptr_t` type (can hold any + * pointer) but not necessarily the same as `size_t` (can hold the size of any + * single object). Most modern platforms use the same concrete integer type for + * both of them, but in case we find ourselves on a platform where + * that's not true, fail early instead of risking ABI or + * integer-overflow issues. + * + * If your platform fails this assertion, it means that you are in + * danger of integer-overflow bugs (even if you attempt to add + * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on + * your platform such that `size_t` matches `uintptr_t` (i.e., to increase + * `size_t`, because `uintptr_t` has to be at least as big as `size_t`). + */ +static_assert( + sizeof(size_t) == sizeof(uintptr_t) && + __alignof__(size_t) == __alignof__(uintptr_t), + "Rust code expects C `size_t` to match Rust `usize`" +); -- cgit v1.3.1