From 880fa3a1e5c493d0deafe9153f8c2bed427b9428 Mon Sep 17 00:00:00 2001 From: Shivam Kalra Date: Sat, 23 May 2026 00:24:32 +0530 Subject: [PATCH] rust: helpers: add is_vmalloc_addr wrapper for NOMMU builds Commit 47ac2a4b5cd8 ("rust: kvec: implement shrink_to for KVVec") introduced a call to bindings::is_vmalloc_addr(). However, this fails to compile on architectures where CONFIG_MMU is disabled, resulting in the following build error: error[E0425]: cannot find function `is_vmalloc_addr` in crate `bindings` --> rust/kernel/alloc/kvec.rs:781:32 | 781 | if !unsafe { bindings::is_vmalloc_addr(self.ptr.as_ptr().cast()) } { | ^^^^^^^^^^^^^^^ not found in `bindings` When CONFIG_MMU is not set, is_vmalloc_addr() is defined as a static inline function in that unconditionally returns false. Because bindgen skips static inline functions when generating bindings, the symbol is completely missing from the Rust bindings crate. Fix this by providing a C helper wrapper, rust_helper_is_vmalloc_addr(), in rust/helpers/vmalloc.c. This ensures the function is reliably exposed to Rust regardless of the MMU configuration. On NOMMU builds, this allows KVVec::shrink_to() to successfully compile and correctly route all allocations through the kmalloc realloc path. Fixes: 47ac2a4b5cd8 ("rust: kvec: implement shrink_to for KVVec") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202605220811.LRplxeBR-lkp@intel.com/ Signed-off-by: Shivam Kalra Reviewed-by: Danilo Krummrich Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260523-is-vmalloc-addr-build-fix-v1-1-73c919440c41@zohomail.in [ Pasted exact compiler output and expanded it. - Miguel ] Signed-off-by: Miguel Ojeda --- rust/helpers/vmalloc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/rust/helpers/vmalloc.c b/rust/helpers/vmalloc.c index 326b030487a2..6aed13292313 100644 --- a/rust/helpers/vmalloc.c +++ b/rust/helpers/vmalloc.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include __rust_helper void *__must_check __realloc_size(2) @@ -8,3 +9,8 @@ rust_helper_vrealloc_node_align(const void *p, size_t size, unsigned long align, { return vrealloc_node_align(p, size, align, flags, node); } + +__rust_helper bool rust_helper_is_vmalloc_addr(const void *x) +{ + return is_vmalloc_addr(x); +}