linux-kernel - [RFC PATCH 2/2] kbuild: rust: use klint to provide CONFIG_FRAME

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260127172330.1492107-3-gary@kernel.org>
Date: Tue, 27 Jan 2026 17:11:04 +0000
From: Gary Guo <gary@...nel.org>
To: Miguel Ojeda <ojeda@...nel.org>,
	Boqun Feng <boqun.feng@...il.com>,
	Gary Guo <gary@...yguo.net>,
	Björn Roy Baron <bjorn3_gh@...tonmail.com>,
	Benno Lossin <lossin@...nel.org>,
	Andreas Hindborg <a.hindborg@...nel.org>,
	Alice Ryhl <aliceryhl@...gle.com>,
	Trevor Gross <tmgross@...ch.edu>,
	Danilo Krummrich <dakr@...nel.org>,
	Nathan Chancellor <nathan@...nel.org>,
	Nicolas Schier <nsc@...nel.org>,
	Thomas Weißschuh <linux@...ssschuh.net>,
	Masahiro Yamada <masahiroy@...nel.org>,
	Kees Cook <kees@...nel.org>
Cc: rust-for-linux@...r.kernel.org,
	linux-kbuild@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [RFC PATCH 2/2] kbuild: rust: use klint to provide CONFIG_FRAME_WARN

From: Gary Guo <gary@...yguo.net>

klint is able to analyze frame size and warn on frames that are too big.

With `register_tool(klint)` support, we can simply instruct rust to turn on
`klint::stack_frame_too_large`. This is a no-op if normal rustc (or Clippy)
is invoked, but will perform the check if klint is used.

This is an example of a bug caught using this option:

warning: stack size of `gsp::cmdq::Cmdq::new` is 8216 bytes, exceeds the 2048-byte limit
   --> drivers/gpu/nova-core/gsp/cmdq.rs:453:5
    |
453 |     pub(crate) fn new(dev: &device::Device<device::Bound>) -> Result<Cmdq> {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the stack size is inferred from instruction `sub $0x2018,%rsp` at .text+32778

Signed-off-by: Gary Guo <gary@...yguo.net>
---
 scripts/Makefile.warn | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/Makefile.warn b/scripts/Makefile.warn
index 5567da6c7dfe..254a4d53f8f3 100644
--- a/scripts/Makefile.warn
+++ b/scripts/Makefile.warn
@@ -23,6 +23,7 @@ KBUILD_CFLAGS += -Wmissing-prototypes
 
 ifneq ($(CONFIG_FRAME_WARN),0)
 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
+KBUILD_RUSTFLAGS += -Wklint::stack-frame-too-large
 endif
 
 KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
-- 
2.51.2