From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0BBEDF588DF for ; Mon, 20 Apr 2026 14:27:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5640A6B0005; Mon, 20 Apr 2026 10:27:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 514966B008A; Mon, 20 Apr 2026 10:27:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 40AD26B0005; Mon, 20 Apr 2026 10:27:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 2F91D6B0005 for ; Mon, 20 Apr 2026 10:27:38 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 005E9E57D4 for ; Mon, 20 Apr 2026 14:27:37 +0000 (UTC) X-FDA: 84679162596.21.AE55A7A Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) by imf06.hostedemail.com (Postfix) with ESMTP id B4759180012 for ; Mon, 20 Apr 2026 14:27:35 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=bootlin.com header.s=dkim header.b=cQx3iAWh; spf=pass (imf06.hostedemail.com: domain of alexis.lothore@bootlin.com designates 185.246.85.4 as permitted sender) smtp.mailfrom=alexis.lothore@bootlin.com; dmarc=pass (policy=reject) header.from=bootlin.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1776695256; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7iZB9lVR4tjlUQWISf4C9RaUtnMV6A5tolEZjLKPmq0=; b=UNlz+vNCy5oISP4peuDahFlFBaVkjcfOLB0lmHcGw6Ashq1E4B6Suoun2LOwJyfL1IFP2m UdUya1Rr0bV505ihHZUMU4fgXDMFmG5BYzSkU4fW9jYl5qn5nNIRF6tjzHHVIXARrArM+1 GNvDgxnlOV4ewkyxo7m3oilgP0S8AWE= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=bootlin.com header.s=dkim header.b=cQx3iAWh; spf=pass (imf06.hostedemail.com: domain of alexis.lothore@bootlin.com designates 185.246.85.4 as permitted sender) smtp.mailfrom=alexis.lothore@bootlin.com; dmarc=pass (policy=reject) header.from=bootlin.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1776695256; a=rsa-sha256; cv=none; b=gohEiPRIilKDC3+KM4rsgHtaH6YZmDg01OgQRpwKFFpGXgg2Jj7BBvORonPyO0ofBsaEi9 rT1keDmo4SdUlxStgLfZBmG0l+ZltmGxyWBNdCEeamrhllHsDknvgcfofI7ECbqGxhR3ML /J6IC0j/BmAA7B0ESbYDffWODIax3Nw= Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 7518B4E42A74; Mon, 20 Apr 2026 14:27:33 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 4520E5FFA5; Mon, 20 Apr 2026 14:27:33 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id D76FA104609E1; Mon, 20 Apr 2026 16:27:19 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1776695251; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=7iZB9lVR4tjlUQWISf4C9RaUtnMV6A5tolEZjLKPmq0=; b=cQx3iAWhs/KPT6ZKsayEJ77QUJ33XBAG/t0wnqcTpu3msayl+KXgWefDzyP6FHZbfakEkZ mUR9idudII95auF9BStFdEyg/ZfrWZJCELMf6aEJ9nJnKcF3lYW4yWiIbwvmeXqGWTpGmf 6EF//PlEz9TgQjwnfV7Im08Tdi8PN2MJhTmQrHK3ZcYqVN+h4i1NR1PcJfySN2cwnhClDq 928UAmnD/sIgSbP085aDV8aYk/2N8juRaUClIP5Mya/PjkZy+fiJZcnNXxg9mz4R2m4w41 IRTL6ZhZmOioqx+JmCYgjuunP3yDG68/rxphRxpBvUN8z7Kr2df9dCBqhog1xw== Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 20 Apr 2026 16:27:19 +0200 Message-Id: From: =?utf-8?q?Alexis_Lothor=C3=A9?= To: "Alexei Starovoitov" , "Andrey Konovalov" Subject: Re: [PATCH RFC bpf-next 1/8] kasan: expose generic kasan helpers Cc: =?utf-8?q?Alexis_Lothor=C3=A9?= , "Alexei Starovoitov" , "Daniel Borkmann" , "Andrii Nakryiko" , "Martin KaFai Lau" , "Eduard Zingerman" , "Kumar Kartikeya Dwivedi" , "Song Liu" , "Yonghong Song" , "Jiri Olsa" , "John Fastabend" , "David S. Miller" , "David Ahern" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , "X86 ML" , "H. Peter Anvin" , "Shuah Khan" , "Maxime Coquelin" , "Alexandre Torgue" , "Andrey Ryabinin" , "Alexander Potapenko" , "Dmitry Vyukov" , "Vincenzo Frascino" , "Andrew Morton" , , "Bastien Curutchet" , "Thomas Petazzoni" , "Xu Kuohai" , "bpf" , "LKML" , "Network Development" , "open list:KERNEL SELFTEST FRAMEWORK" , , "linux-arm-kernel" , "kasan-dev" , "linux-mm" X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260413-kasan-v1-0-1a5831230821@bootlin.com> <20260413-kasan-v1-1-1a5831230821@bootlin.com> In-Reply-To: X-Last-TLS-Session-Version: TLSv1.3 X-Stat-Signature: x138c8iokugi9azxps3hrb8wpqwhus36 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: B4759180012 X-HE-Tag: 1776695255-886 X-HE-Meta: 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 rYY1qmyg LXhcKMClHtIx30jChwMpiz1A2jVS0opnECLkj497wvND0hGtY8y3JMfwiz8c6wh7CcGrnKF1qo04p792bpPxIO2BOFNDRtMkB9P0v8fwNGRHnHJV0Gtaf15m+JXozBV5uKE46jthptATefdNu03T2kVI6VYvvVQDjxNrWv53s0fOrqWW448nmGsWuWftoCNXc0DkFeVSFD5Px6v7i2dp0GerauJYNxgngZNHkRharQpKisbHbDz4/AQnrKdUxtvwjTFk3oU3BafJu9ohUut7Ep7CQfp9eylfjx3HSC/k1TDp3BITxKIZdvWFzXa9bemSg/p/ml10PtLH19R/mhLAtEgyLmuty760BAb6MlylUTbwHoYEWxlYC1a9psVv25rYfR1rfySaG/bWvUftf0nY/YoBc13+f+5QajFhsZfoAu8Eijjk8o2NMTSIDx2nLcc6+cEx4LGrSMrEBQxjHJUMgXdyxoQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon Apr 20, 2026 at 12:51 AM CEST, Alexei Starovoitov wrote: > On Sun, Apr 19, 2026 at 2:49=E2=80=AFPM Andrey Konovalov wrote: >> >> On Tue, Apr 14, 2026 at 5:58=E2=80=AFPM Alexei Starovoitov >> wrote: >> > >> > I think we're talking past each other. >> > We're not interested in KASAN_SW_TAGS or KASAN_HW_TAGS. >> > We're not going to modify arm64 JIT at all. >> > >> > This is purely KASAN_GENRIC and only on x86-64. >> > JIT will emit exactly what compilers emit for generic >> > which is __asan_load/store. This is as stable ABI as it can get >> > and we don't want to deviate from it. >> >> OK, I supposed that's fair. You did throw me off point with your >> performance comment. But if you decide to add SW_TAGS support at some >> point, I think this discussion needs to be revisited. >> >> But please add a comment saying that those functions are only exposed >> for BPF JIT and they are not supposed to be used by other parts of the >> kernel. And in case you do end up adding a new config option, guard >> the public declarations by a corresponding ifdef. > > I feel concerns of misuse are overblown. > Being in include/linux/kasan.h doesn't make them free-for-all > all of a sudden, but if you prefer we can just copy paste: > +void __asan_load1(void *p); > +void __asan_store1(void *p); > into bpf_jit_comp.c That's actually what I initially went with when working on this, but it did look a bit fragile, and suspected that I would rather be asked to expor= t them properly through a dedicated header. I'm fine with putting back the manual declarations in jit comp, though. > >> > The goal here is to find bugs in the verifier. >> > If something got past it, that shouldn't have, >> > kasan generic on x86-64 is enough. >> >> FWIW, I suspect HW_TAGS KASAN already just works with JITed BPF code. > > Ohh. Good point. Looks like modern arm64 cpus in public clouds > don't have that enabled, so one would need pixel phone to > catch verifier bugs via hw_tags. > So we still need this x86-specific jit kasan. > I guess eventually it can be removed when hw_tags support is widespread. --=20 Alexis Lothor=C3=A9, Bootlin Embedded Linux and Kernel engineering https://bootlin.com