linux-kernel - [PATCH v2 1/2] gpu: nova-core: use CStr::from_bytes_until

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

Message-ID: <20260106035226.48853-2-jhubbard@nvidia.com>
Date: Mon,  5 Jan 2026 19:52:25 -0800
From: John Hubbard <jhubbard@...dia.com>
To: Danilo Krummrich <dakr@...nel.org>
Cc: Alexandre Courbot <acourbot@...dia.com>,
	Joel Fernandes <joelagnelf@...dia.com>,
	Timur Tabi <ttabi@...dia.com>,
	Alistair Popple <apopple@...dia.com>,
	Edwin Peer <epeer@...dia.com>,
	Zhi Wang <zhiw@...dia.com>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Miguel Ojeda <ojeda@...nel.org>,
	Alex Gaynor <alex.gaynor@...il.com>,
	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>,
	nouveau@...ts.freedesktop.org,
	rust-for-linux@...r.kernel.org,
	LKML <linux-kernel@...r.kernel.org>,
	John Hubbard <jhubbard@...dia.com>
Subject: [PATCH v2 1/2] gpu: nova-core: use CStr::from_bytes_until_nul() and remove util.rs

The util.rs module contained a single helper function,
str_from_null_terminated(), which duplicated functionality that is now
available in core::ffi::CStr.

Specifically, CStr::from_bytes_until_nul() is available in the kernel's
minimum supported Rust version (1.78.0), so it time to stop using this
custom workaround.

Reviewed-by: Joel Fernandes <joelagnelf@...dia.com>
Signed-off-by: John Hubbard <jhubbard@...dia.com>
---
 drivers/gpu/nova-core/gsp/commands.rs |  5 +++--
 drivers/gpu/nova-core/nova_core.rs    |  1 -
 drivers/gpu/nova-core/util.rs         | 16 ----------------
 3 files changed, 3 insertions(+), 19 deletions(-)
 delete mode 100644 drivers/gpu/nova-core/util.rs

diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
index 0425c65b5d6f..a11fe6018091 100644
--- a/drivers/gpu/nova-core/gsp/commands.rs
+++ b/drivers/gpu/nova-core/gsp/commands.rs
@@ -30,7 +30,6 @@
         },
     },
     sbuffer::SBufferIter,
-    util,
 };
 
 /// The `GspSetSystemInfo` command.
@@ -209,7 +208,9 @@ impl GetGspStaticInfoReply {
     /// Returns the name of the GPU as a string, or `None` if the string given by the GSP was
     /// invalid.
     pub(crate) fn gpu_name(&self) -> Option<&str> {
-        util::str_from_null_terminated(&self.gpu_name)
+        CStr::from_bytes_until_nul(&self.gpu_name)
+            .ok()
+            .and_then(|cstr| cstr.to_str().ok())
     }
 }
 
diff --git a/drivers/gpu/nova-core/nova_core.rs b/drivers/gpu/nova-core/nova_core.rs
index b98a1c03f13d..c1121e7c64c5 100644
--- a/drivers/gpu/nova-core/nova_core.rs
+++ b/drivers/gpu/nova-core/nova_core.rs
@@ -16,7 +16,6 @@
 mod num;
 mod regs;
 mod sbuffer;
-mod util;
 mod vbios;
 
 pub(crate) const MODULE_NAME: &kernel::str::CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
diff --git a/drivers/gpu/nova-core/util.rs b/drivers/gpu/nova-core/util.rs
deleted file mode 100644
index 4b503249a3ef..000000000000
--- a/drivers/gpu/nova-core/util.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-/// Converts a null-terminated byte slice to a string, or `None` if the array does not
-/// contains any null byte or contains invalid characters.
-///
-/// Contrary to [`kernel::str::CStr::from_bytes_with_nul`], the null byte can be anywhere in the
-/// slice, and not only in the last position.
-pub(crate) fn str_from_null_terminated(bytes: &[u8]) -> Option<&str> {
-    use kernel::str::CStr;
-
-    bytes
-        .iter()
-        .position(|&b| b == 0)
-        .and_then(|null_pos| CStr::from_bytes_with_nul(&bytes[..=null_pos]).ok())
-        .and_then(|cstr| cstr.to_str().ok())
-}
-- 
2.52.0