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=1794682830; b=WdQq+QN62ZQz50e0GLA7SprPEya4ShIY8tq/LFpPSO7qSf9zgKq988c3LZgT7jYRRLHP 6jFWsy28Lej/JIwkWlJV/2KNsXi7ssD/zAyvDP6Iyu3KLOXUmRTaTeArlnWhuawkOndmb rrsl33Vp/5dOLon/GK673vWyli9hp5TZeAvRONZd/0U7l+l35y48yxmKuo6Yhm4fhkdxe JwL6NZ7WCUGSZKhEgkI1gOihdGsKxpQDItJOM7d13ORTorpGLCng691wswNi0d1dHh271 ikImBOzqAsQdf4AF7VYN3gbpfFJ5aWV6FfXLSi4bWxi3cXRGI8aSN6q8PyiC6mEI6FQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794682830; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=ykOliHYisYLBLFi//mbVDidPMVZQXccME0RpNUmjbYw=; b=4OIdeg1NFWgjD13W9996t1foyvMhdP+Eym5eeI3mcpD0AripfaAzoBCOuMR0hW6yIbi5 IK0sfVCKA/ZJdE13eePO/H7rip2/YPJv0OFE0IRad3QwC/YCRHo3XJyGB8lVFNWPFarLK M/2AxT6/ILbDG4j/jkFexUv0bgJ+z0MiM1i23FtCSojyGLaaftCsy4XqosfkNkl6ImAPW 9DEidL+vu/+iG/x0RSm5nQSDWektzPO6jp7sN2WTO9j3xauWpDFqrOJURl82b0w9d8VJJ zvcshHIC2A3nv8YYI26jnZm7LVWqOMnjSu2IXx5zUlZPHuTXiPJgleS9aZz+WvwOhIQ== 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="Rfg0/1Pk"; 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 30936606A334; Sat, 14 Nov 2026 19:00:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Rfg0/1Pk Received: by smtp.kernel.org (Postfix) with ESMTPSA id 001B61F000C5; Sat, 14 Nov 2026 19:00:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794682830; bh=ykOliHYisYLBLFi//mbVDidPMVZQXccME0RpNUmjbYw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Rfg0/1Pk8suTUhXDA0y90Ui/FXQ4F06sERFWjW4pyC83dFj8izLJwUt7QzrrMFNSD ql02v31bmtjF8ZR2YRHnahby7K2E6o11BVCT3FxRQB5JRjSO9UPLAsrQmkyAXmxIxF 3CBMYWmhQ8oNeyiaEoEaEgdsShOFnvbCBLpTckOIoErmebq8wvG4f6h5Ey11vHlWRc NRJD7ylckfHUYWfHmH9DdnC5aUgBSOrwgc1H1JYVNImibEi5ELw3xbDgj+d0BYBj5v cDIJNe0+wwVKhNrh8gT6BWrLRsSxMKT20yN5fX8fonNWqvshzQl/ifdqQ6nFhte+BJ OIY+K2eSyrv5Q== Date: Sat, 14 Nov 2026 20:00:22 +0100 From: Alejandro Colomar To: Joe Perches Cc: Alejandro Colomar , linux-hardening@vger.kernel.org, Krzysztof Kozlowski , "Maciej W. Rozycki" , Geert Uytterhoeven , Andreas Schwab , Andy Shevchenko , Bartosz Golaszewski , Daniel Scally , Danilo Krummrich , Greg Kroah-Hartman , Hans Verkuil , Heikki Krogerus , 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, Bartosz Golaszewski Subject: Re: [PATCH v6 02/19] string: Add strprefix() Message-ID: References: <0eaa4ce73a2b164fd49e3a9f71244a2e3f45b7bb.1794667407.git.alx@kernel.org> <32e7bdb5b8a4a522566b00763ba13974733290dd.camel@perches.com> X-Mailing-List: linux-gpio@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="35i2uj2e65774ccj" Content-Disposition: inline In-Reply-To: <32e7bdb5b8a4a522566b00763ba13974733290dd.camel@perches.com> --35i2uj2e65774ccj Content-Type: text/plain; protected-headers=v1; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable From: Alejandro Colomar To: Joe Perches Cc: Alejandro Colomar , linux-hardening@vger.kernel.org, Krzysztof Kozlowski , "Maciej W. Rozycki" , Geert Uytterhoeven , Andreas Schwab , Andy Shevchenko , Bartosz Golaszewski , Daniel Scally , Danilo Krummrich , Greg Kroah-Hartman , Hans Verkuil , Heikki Krogerus , 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, Bartosz Golaszewski Subject: Re: [PATCH v6 02/19] string: Add strprefix() Message-ID: References: <0eaa4ce73a2b164fd49e3a9f71244a2e3f45b7bb.1794667407.git.alx@kernel.org> <32e7bdb5b8a4a522566b00763ba13974733290dd.camel@perches.com> MIME-Version: 1.0 In-Reply-To: <32e7bdb5b8a4a522566b00763ba13974733290dd.camel@perches.com> Hi Joe, > Date: 2026-11-14 10:24:26-0800 > From: Joe Perches > > On Sat, 2026-11-14 at 17:59 +0100, Alejandro Colomar wrote: > > > A negative of this is that it implies the return should > > > always be tested even though it can be known that the > > > return is effectively bool. > >=20 > > I'm not sure I follow. The attribute is about the arguments, not the > > return value. Perhaps I don't understand what you mean by "this". >=20 > 'this' is the return of the strprefix function itself. >=20 > It returns either a const char * or a char * or NULL. >=20 > Because it can return NULL, then the return value > could/should be tested. Yes, it must be tested, when not used as a boolean. The usual replacement of s +=3D str_has_prefix(s, prefix); would be s =3D strprefix(s, prefix) ?: s; The boolean use remains trivial: - return strstarts(name, ".init") || - strstarts(name, ".ARM.extab.init") || - strstarts(name, ".ARM.exidx.init"); + return strprefix(name, ".init") || + strprefix(name, ".ARM.extab.init") || + strprefix(name, ".ARM.exidx.init"); and - if (!str_has_prefix(p, "console=3D") && !strstr(p, " console=3D"))= { + if (!strprefix(p, "console=3D") && !strstr(p, " console=3D")) { The non-boolean use would look like this (actual diffs from the patch set): - prefix_len =3D str_has_prefix(name, PDSC_FW_COMPONENT_PREFIX); - if (prefix_len) - name +=3D prefix_len; + name =3D strprefix(name, PDSC_FW_COMPONENT_PREFIX) ?: name; (the old code, actually, didn't need that test, and could have been simply 'name +=3D str_has_prefix(name, PDSC_FW_COMPONENT_PREFIX);') and - len =3D str_has_prefix(*str, "brl,"); - if (len) { + p =3D strprefix(*str, "brl,"); + if (p) { *brl_options =3D ""; - *str +=3D len; + *str =3D p; return 0; } and cmp =3D strstrip(option); =20 - len =3D str_has_prefix(cmp, "no"); - if (len) + p =3D strprefix(cmp, "no"); + if (p) { neg =3D 1; - - cmp +=3D len; + cmp =3D p; + } Have a lovely night! 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