From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793882789; b=lMQNLLBP1fllZfNjC0+JdllNKZ8vmlNO2tWx3ODMSHYwAEypb9Drz930B9rjFQU33RRX FBk/FIazD8uMECEq6cGh/+mz6MauaFpQd8814ziejcJ+pvmbDTw+TC37ZzV8H2ksniSaW O5inTbmMVGfDURWou563d81t9z4qecGsnfII2j8Aq8maGIfn4y6Im8kwhw35lC78ynjbF 37ow/VVBUaKsKnFZyE/ZzZunZfiuEfoYNJOcLNMVghuKdXQo1qsDBqq9Jl9yK68vpr8Hi W8z/IIT47cY4M2KKQ7zaV5+5MDEdYXIqeLJkj7CdKUrGl74kQjdkWVifdygTKBhid3A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793882789; h=Received:DKIM-Signature:Date:From:To:List-Id:Cc:Subject:Message-ID: X-Mailer:References:MIME-Version:Content-Type:Content-Disposition: In-Reply-To; bh=HyzKvsSHqgPO50rdEeW4QLU+dE7ILQaIuU/K9EajKEM=; b=191U9rBbj0qPQQOZOgbyT9ElmW/oKq0GgmKTnYHzeg9vmuPkDdHQtqEZAh+MJPNJVRBo I19nsFX3iyKZJsxDz16bsh7shDAG81Sc0oleuOrsGYED6adATktkfcPA9niuK//Ml2Re0 y+Qwm9JX8AdzItevnejIJF2xPmCl6BQB6JENfJIb200FPhpYJs8jZNc0MR4qeunBxppPE YvBrYt0oGI55GPm738OZFtBWcry3QE2mIssjQYZAWBdJ1fEtfjy63A1YKH79o66EkxbhX +ZtbIMFBle8JHmeyJCGWmEjqvDHyH0BULHYQH4hSPpAgLfZi2pRrsPgIX1ra5ZiC/Wg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="mGJrm/8U"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0642F606A339; Thu, 5 Nov 2026 12:46:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mGJrm/8U Received: by smtp.kernel.org (Postfix) with ESMTPSA id 658621F000C1; Thu, 5 Nov 2026 12:46:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793882788; bh=HyzKvsSHqgPO50rdEeW4QLU+dE7ILQaIuU/K9EajKEM=; h=Date:From:To:List-Id:Cc:Subject:References:In-Reply-To; b=mGJrm/8UYxj8MJaIQAXhg8wrElLZKDTpekKhLPyl4/R8PFwGKjUzjM77f4CoTwmCj J9AbOyK055n64ec1X0SHJm96kTl9mRAaOQ92QJ7Qe2xmWrEj6HoGdMwUxmDSO/ujg3 nUShnYQeZiHRFmdPe9uLUBFq/3VLAtztCXVXX6sNhqy4OBnU64wi9HjB+XNUdWwn7H xaleH21BsVvMdolCNvsY4OCBerTuD/Je+w2CjKhk7tZLLUvSSe4BQWFWjGhwBKjFIk f7bly4Hh1GMVftP3VLzuwbCAGB/OZHgJhBgLnN4o5fYyWhkQUVJGlc2ydqGy2S65JF i5lEy3YZZzgdQ== Date: Thu, 5 Nov 2026 13:46:20 +0100 From: Alejandro Colomar To: linux-hardening@vger.kernel.org Cc: Alejandro Colomar , alx+linux-hardening@kernel.org, Andreas Schwab , Andy Shevchenko , Bartosz Golaszewski , Daniel Scally , Danilo Krummrich , Greg Kroah-Hartman , Hans Verkuil , Heikki Krogerus , Joe Perches , Johan Hovold , Kees Cook , Laurent Pinchart , Len Brown , Linus Torvalds , Linus Walleij , Namhyung Kim , "Rafael J. Wysocki" , Rob Herring , Sakari Ailus , Saravana Kannan , Steven Rostedt , Tom Zanussi , linux-acpi@vger.kernel.org, driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org Subject: [PATCH v2 0/2] Add strprefix() and fix a bug with it Message-ID: X-Mailer: git-send-email 2.55.0 References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="jti7rjabgq6a3xqs" Content-Disposition: inline In-Reply-To: --jti7rjabgq6a3xqs Content-Type: text/plain; protected-headers=v1; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable From: Alejandro Colomar To: linux-hardening@vger.kernel.org List-Id: Cc: Alejandro Colomar , alx+linux-hardening@kernel.org, Andreas Schwab , Andy Shevchenko , Bartosz Golaszewski , Daniel Scally , Danilo Krummrich , Greg Kroah-Hartman , Hans Verkuil , Heikki Krogerus , Joe Perches , Johan Hovold , Kees Cook , Laurent Pinchart , Len Brown , Linus Torvalds , Linus Walleij , Namhyung Kim , "Rafael J. Wysocki" , Rob Herring , Sakari Ailus , Saravana Kannan , Steven Rostedt , Tom Zanussi , linux-acpi@vger.kernel.org, driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org Subject: [PATCH v2 0/2] Add strprefix() and fix a bug with it Message-ID: References: MIME-Version: 1.0 In-Reply-To: Hi! str_has_prefix() is based on sizes and lengths, which means it must overload the valid length 0 to mean not found. This is a typical consequence of choosing to design an API around sizes and lengths, and vanishes when moving to pointer-based similar APIs. This patch set adds strprefix(), deprecates str_has_prefix(), and uses strprefix() in one place to fix a bug reported by Bartosz. We can later work on replacing the other uses of str_has_prefix(), which might hide similar bugs. Changes in v2 ~~~~~~~~~~~~~ - Added tests, as suggested by Andy. - Remove Cc tags from the commit messages. [Andy] Testing ~~~~~~~ The new tests added for strprefix() pass. Below is the session I ran for testing. The important line is: [13:26:30] [PASSED] string_test_strprefix Full session: $ cat .kunitconfig=20 CONFIG_KUNIT=3Dy CONFIG_STRING_KUNIT_TEST=3Dy $ mkdir -p ~/tmp $ export TMPDIR=3D$HOME/tmp $ ./tools/testing/kunit/kunit.py run "string*" [13:26:28] Configuring KUnit Kernel ... [13:26:28] Building KUnit Kernel ... Populating config with: $ make ARCH=3Dum O=3D.kunit olddefconfig Building with: $ make all compile_commands.json scripts_gdb ARCH=3Dum O=3D.kunit --jobs= =3D24 [13:26:30] Starting KUnit Kernel (1/1)... [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Running tests with: $ .kunit/linux 'kunit.filter_glob=3Dstring*' kunit.enable=3D1 mem=3D1G con= sole=3Dtty kunit_shutdown=3Dhalt [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D string-stream-test (12 = subtests) =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [13:26:30] [PASSED] string_stream_managed_init_test [13:26:30] [PASSED] string_stream_unmanaged_init_test [13:26:30] [PASSED] string_stream_managed_free_test [13:26:30] [PASSED] string_stream_resource_free_test [13:26:30] [PASSED] string_stream_line_add_test [13:26:30] [PASSED] string_stream_variable_length_line_test [13:26:30] [PASSED] string_stream_append_test [13:26:30] [PASSED] string_stream_append_auto_newline_test [13:26:30] [PASSED] string_stream_append_empty_string_test [13:26:30] [PASSED] string_stream_no_auto_newline_test [13:26:30] [PASSED] string_stream_auto_newline_test [13:26:30] [PASSED] string_stream_performance_test [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [PASSED] string-s= tream-test =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D strin= g (29 subtests) =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [13:26:30] [PASSED] string_test_memset16 [13:26:30] [PASSED] string_test_memset32 [13:26:30] [PASSED] string_test_memset64 [13:26:30] [PASSED] string_test_strlen [13:26:30] [PASSED] string_test_strnlen [13:26:30] [PASSED] string_test_strchr [13:26:30] [PASSED] string_test_strnchr [13:26:30] [PASSED] string_test_strrchr [13:26:30] [PASSED] string_test_strspn [13:26:30] [PASSED] string_test_strprefix [13:26:30] [PASSED] string_test_strcmp [13:26:30] [PASSED] string_test_strcmp_long_strings [13:26:30] [PASSED] string_test_strncmp [13:26:30] [PASSED] string_test_strncmp_long_strings [13:26:30] [PASSED] string_test_strcasecmp [13:26:30] [PASSED] string_test_strcasecmp_long_strings [13:26:30] [PASSED] string_test_strncasecmp [13:26:30] [PASSED] string_test_strncasecmp_long_strings [13:26:30] [PASSED] string_test_strscpy [13:26:30] [PASSED] string_test_strcat [13:26:30] [PASSED] string_test_strncat [13:26:30] [PASSED] string_test_strlcat [13:26:30] [PASSED] string_test_strtomem [13:26:30] [PASSED] string_test_memtostr [13:26:30] [PASSED] string_test_strends [13:26:30] [SKIPPED] string_bench_strlen (not enabled) [13:26:30] [SKIPPED] string_bench_strnlen (not enabled) [13:26:30] [SKIPPED] string_bench_strchr (not enabled) [13:26:30] [SKIPPED] string_bench_strrchr (not enabled) [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= [PASSED] string =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D string_helpers (4= subtests) =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [13:26:30] [PASSED] test_get_size [13:26:30] [PASSED] test_upper_lower [13:26:30] [PASSED] test_unescape [13:26:30] [PASSED] test_escape [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [PASSED] st= ring_helpers =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [13:26:30] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [13:26:30] Testing complete. Ran 45 tests: passed: 41, skipped: 4 [13:26:31] Elapsed time: 2.509s total, 0.001s configuring, 2.192s building= , 0.271s running Cheers, Alex Alejandro Colomar (2): string: Add strprefix(), and deprecate str_has_prefix() device property: Fix fwnode_name_eq() for empty node names drivers/base/property.c | 5 +---- include/linux/string.h | 19 ++++++++++++++++++- lib/tests/string_kunit.c | 9 +++++++++ 3 files changed, 28 insertions(+), 5 deletions(-) Range-diff against v1: 1: 9c81f6f62fd0 ! 1: d3b325ecefd1 string: Add strprefix(), and deprecate = str_has_prefix() @@ Commit message We'll slowly migrate existing code from str_has_prefix() to strpre= fix(). =20 Reported-by: Bartosz Golaszewski - Cc: Andreas Schwab - Cc: Andy Shevchenko Cc: Andy Shevchenko - Cc: Bartosz Golaszewski - Cc: Daniel Scally - Cc: Danilo Krummrich - Cc: Greg Kroah-Hartman - Cc: Hans Verkuil - Cc: Heikki Krogerus - Cc: Joe Perches - Cc: Johan Hovold - Cc: Kees Cook - Cc: Laurent Pinchart - Cc: Len Brown - Cc: Linus Torvalds - Cc: Linus Walleij - Cc: Namhyung Kim - Cc: "Rafael J. Wysocki" - Cc: Rob Herring - Cc: Sakari Ailus - Cc: Saravana Kannan - Cc: Steven Rostedt - Cc: Tom Zanussi =20 ## include/linux/string.h ## @@ include/linux/string.h: void memcpy_and_pad(void *dest, size_t dest_= len, const v * * Returns: * * strlen(@prefix) if @str starts with @prefix + + ## lib/tests/string_kunit.c ## +@@ lib/tests/string_kunit.c: static void string_test_strspn(struct kun= it *test) + } + } +=20 ++static void string_test_strprefix(struct kunit *test) ++{ ++ KUNIT_ASSERT_EQ(test, 0, strcmp(strprefix("foobar", "foo"), "bar")); ++ KUNIT_ASSERT_EQ(test, 0, strcmp(strprefix("foobar", ""), "foobar")); ++ KUNIT_ASSERT_EQ(test, 0, strcmp(strprefix("foobar", "foobar"), "")); ++ KUNIT_ASSERT_NULL(test, strprefix("foobar", "bar")); ++} ++ + static char strcmp_buffer1[STRCMP_LARGE_BUF_LEN]; + static char strcmp_buffer2[STRCMP_LARGE_BUF_LEN]; +=20 +@@ lib/tests/string_kunit.c: static struct kunit_case string_test_case= s[] =3D { + KUNIT_CASE(string_test_strnchr), + KUNIT_CASE(string_test_strrchr), + KUNIT_CASE(string_test_strspn), ++ KUNIT_CASE(string_test_strprefix), + KUNIT_CASE(string_test_strcmp), + KUNIT_CASE(string_test_strcmp_long_strings), + KUNIT_CASE(string_test_strncmp), 2: 37eafcd682b0 ! 2: ac9728afa027 device property: Fix fwnode_name_eq() f= or empty node names @@ Commit message =20 Fixes: a9c8c738066b7 ("device property: Add fwnode_name_eq()") Reported-by: Bartosz Golaszewski - Cc: Andreas Schwab - Cc: Andy Shevchenko Cc: Andy Shevchenko - Cc: Bartosz Golaszewski - Cc: Daniel Scally - Cc: Danilo Krummrich - Cc: Greg Kroah-Hartman - Cc: Hans Verkuil - Cc: Heikki Krogerus - Cc: Joe Perches - Cc: Johan Hovold - Cc: Kees Cook - Cc: Laurent Pinchart - Cc: Len Brown - Cc: Linus Torvalds - Cc: Linus Walleij - Cc: Namhyung Kim - Cc: "Rafael J. Wysocki" - Cc: Rob Herring - Cc: Sakari Ailus - Cc: Saravana Kannan - Cc: Steven Rostedt - Cc: Tom Zanussi =20 ## drivers/base/property.c ## --=20 2.55.0 --jti7rjabgq6a3xqs Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEES7Jt9u9GbmlWADAi64mZXMKQwqkFAmrsepwACgkQ64mZXMKQ wqlGEg//VGEqCjaZlhibqTKSLSnyKsgDN6teK1rp/OtYo6FgO5AJq8gImQig7LyH wMuQJiWdCvHBxngMNyijtu3N5JMG9H1btdxzihjiz0PxX9RXxwsoWdcSMJb2ZZJL Fe8qPynXr8MDLYlwjFOvuXfAYG3RWM0pSWg2omzowFQaeTweXNVjC0fsar6JE0Pz vNLGYt4HHtZ5XdO3LjWrcm++iFvS5f2S4bI3si/qIyMN23VzgtIeBUbW2zqtPsqz TvgrzvzwB6HzUs7znLZshAEvibPgQYa3id/82lFN/BHrQwG41J8rz5zDOY8yeymN gGvf0kxWWABFxGhNhW2KZzRRSlDxW/sMISuQa7N/zynGW5Pn0+NOUf/kP4YR2L5d +3kDP1vexWtjGTLr5wz35+dQQjzMfOJzj7UxQaAXbpnS2gQoCkKa8J/r1j6tzH+t Bsk+mOx0yNJuLvHjszeapZZOjpxszqGxVO+iSYYDNVzkqVg6tRDLNQB+iVf0NWNy Nq2p+m4pU251Z0a61S2AZUZMjXyBK375/ShAf1qKWctoqzjPt2SemqXhEaOaCYCh Ms1C0oZagRE9LW2GH3mhvG66munv9A8TKi8cPr2ozseuUmv11zy6qg0N4qsPAamx ELkWBJzFRjrByv7WRIUy2zbNGnUIyLkh9d3gA8vXjTaml4V7NGw= =Yrxs -----END PGP SIGNATURE----- --jti7rjabgq6a3xqs--