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=1792702966; b=nyK2BXe6gkCvcDmtiLaJ1OYwccnlBtUNBvmnxnpYctpEDoeBrSfBlXOmFrD7nk4awzwh 2d8mp/E9GpGMCK60YPP1tswRA44Jj3U/2rrMtc81N4GerQ7ViTK5cwr5ghREH6bKVU3kf Y8BwrtpkBYuqKeTJGPrhw8mqwebmBx6r2fykXrV52+70pB6T9hJj6gNQOG0HT+m9hDJHY g2G8fJeLX97k+GiVrRwySsH4gFrEa8hSW6ez0g0sEh6grKQDFlKTFSDul2tYD640AySMD 4O9PI8ZsnRAv/W2Jsx2MR+qG/Qqwjgcto1gFJEu7gTqzNqhimI2KIZHv2vZwjoPvm2A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792702966; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=Tj37OmA+fKNRhE1Yis70rKCpc+GQO8jtJOfAeK4DI24=; b=qGMTGCC3kuDWrouz2MDM6AsmM01Vv7oybZ8mY3rU7qw0a8KCWcegvIUl/A6jFGYOBV1k Zw9Gr5llWIGMtuxJSqQ+9oKU/zSoHi68JqwQBTGIWVWiVzs4uOM2Kshlz6AujZVW2SENP cDaAGpkbZWndyCJOahkLgAztCigW6glJn1r8m+A09tYzOHQfYIn1l9Msi5i04zpRMkRCr Nl4PtaqTU+0r5cIgrx1lmXJ0lLDKWJOuf5ZKqJQ712tvZP9d2gdSPwmGhYakVeUOJAcj1 /TeLCx0z2augivdq2PTr6PJNSPUwzwaHqxUZ3gbVCg5e6VmRJZ8BJIAyfFhBeIE1C0A== 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=jAquE23J; 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 7AA95606A31A; Thu, 22 Oct 2026 21:02:46 +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=jAquE23J Received: by smtp.kernel.org (Postfix) with ESMTPSA id 049CB1F01825; Thu, 22 Oct 2026 21:02:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792702966; bh=Tj37OmA+fKNRhE1Yis70rKCpc+GQO8jtJOfAeK4DI24=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=jAquE23J1qKmy9gw4YNOQvQ8blj+GO1/UfILYA3orebphMxHa++Fj+H1EWQ007chh oOcWf+Rz5eplf8HuGz3GTmlqoR1+oq5APAgjLvV/3EOYOxgTdnKAV7545npyLtGYei pBnNvSNli3CZJ/x0QpsF6MNpqLZwj5rrAaRqtPBr9VW9ryG7shuMfZGz//KstmaUFt 6EPAND4+ETavC7bLqUs5/Hjo0bGlnRewTARfgS6xpXiBnNEZw8LexUSzkMskFfDeW1 tl+CawI0Pxa6BQgRYoXLtPGNTbwMct+A6rXRc8kWuO2ZPeRzpozIQEhVfFh2w0x+uQ BAA73Wlqv505g== Date: Thu, 22 Oct 2026 23:02:36 +0200 From: Alejandro Colomar To: Steven Rostedt Cc: Kees Cook , Bill Wendling , "Matthew Wilcox (Oracle)" , Andrew Morton , Andy Shevchenko , David Gow , Petr Mladek , Shuvam Pandey , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH v5 06/12] seq_buf: Add seq_buf_strlen() Message-ID: References: <20261005155653.late.426-kees@kernel.org> <20261005155708.1471260-6-kees@kernel.org> <20261016145928.16eddc9a@gandalf.local.home> <202610221058.C5626C5172@keescook> <20261022155726.7f20c4cb@gandalf.local.home> <20261022162000.18aa4162@gandalf.local.home> <20261022165336.3100a5be@gandalf.local.home> 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="nwadrhiqndqcdlwt" Content-Disposition: inline In-Reply-To: <20261022165336.3100a5be@gandalf.local.home> --nwadrhiqndqcdlwt Content-Type: text/plain; protected-headers=v1; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable From: Alejandro Colomar To: Steven Rostedt Cc: Kees Cook , Bill Wendling , "Matthew Wilcox (Oracle)" , Andrew Morton , Andy Shevchenko , David Gow , Petr Mladek , Shuvam Pandey , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH v5 06/12] seq_buf: Add seq_buf_strlen() Message-ID: References: <20261005155653.late.426-kees@kernel.org> <20261005155708.1471260-6-kees@kernel.org> <20261016145928.16eddc9a@gandalf.local.home> <202610221058.C5626C5172@keescook> <20261022155726.7f20c4cb@gandalf.local.home> <20261022162000.18aa4162@gandalf.local.home> <20261022165336.3100a5be@gandalf.local.home> MIME-Version: 1.0 In-Reply-To: <20261022165336.3100a5be@gandalf.local.home> Hi Steven, > Date: 2026-10-22 16:53:36-0400 > From: Steven Rostedt > [...] > > struct my_seq_buf { > > // .buffer points to the start of the buffer > > char *buffer; > >=20 > > /* .p points to the current position. This is the last > > * '\0' that has been written to the buffer. On > > * truncation, it is a NULL pointer. > > */ > > char *p; > >=20 > > /* .end always holds ARRAY_END(buffer). It is a pointer > > * one-past-the-last character in the buffer. > > */ > > char *end; > > }; > >=20 [...] >=20 > I rather not increase its size. It is embedded in the trace_seq. The size shouldn't change: alx@debian:~/tmp$ cat seq_buf_size_comparison.c=20 #include #include struct seq_buf { char *buffer; size_t size; size_t len; }; struct alx_seq_buf { char *buffer; char *p; char *end; }; int main(void) { printf("%zu\n", sizeof(struct seq_buf)); printf("%zu\n", sizeof(struct alx_seq_buf)); } alx@debian:~/tmp$ gcc -Wall -Wextra seq_buf_size_comparison.c=20 alx@debian:~/tmp$ ./a.out=20 24 24 size_t and pointers should always have the same size, so this doesn't change the size. Am I missing something? Cheers, Alex > Yes the seq_buf code can be complex, but it's in one location where it can > be highly tested and verified. The point of seq_buf is to do the complexi= ty > so that other places in the kernel doesn't need to. >=20 > -- Steve >=20 >=20 --=20 --nwadrhiqndqcdlwt Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEES7Jt9u9GbmlWADAi64mZXMKQwqkFAmraeewACgkQ64mZXMKQ wql3NA/+J2kecD0AF8NgnxOuKJBkL6tW7SHIExPHo7ltr04Has8hMB0XCSRA83W9 k8S89DHv6ChbLZ/ubST01VPhdRFlUJIKG4Vw2UFpK4ejbWwI8V5Bqf1A5muKHXm3 AEmTVxbGgJmqdZmbYKTnpkYpbc8x9Czvg77j6jWQaPXq8lE39b8kCCNwrIYHfki1 Z7J3cYuOP10wzC3vb7cwDpmwSuveGl1KmMYDDngeufU99h0A6r6iG5i3qyJKAbID pl2yK/i61vHGKVwieh+zT0dXfQU9Mh+Kjd+4X9f6UqLlJEreNPocJR+5M3uDByoT 6NGFsBjKngtllmmF+43cJISwGwFIPPmIxcue/WPgXM0hsQar2oyk3TRm4BWViswX dqDt20Q0Bmhw5cps6jmCvGsMGtMUlD6t2/tICMgukjt4+Gsa8YddRMt+jFucN6c5 nIJA2Z+Vc/U3r0+2pDYaX+Qk8U23zVarsS2CGF9W5vYAsWEeJo76a/L4AgE9wYaP CQhBJ6krYcuI45JP/Bz7A9DJEe3L2s/caQjb+TdmBwaZ2ARLnkKbzRKNUWeb0DFG Y/NcQYn7LZrnFaOI8nx7XWDflFthzKFD3CfsETu5V7ur6nVQDd1bitMZrzK6s6Cu 8aUmZwMCydAdpaLhFclr18aKIR5dkebk90FV+FkpyccJ5XCCoNI= =BPHW -----END PGP SIGNATURE----- --nwadrhiqndqcdlwt--