From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D99A39E18F; Thu, 15 Oct 2026 16:19:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792081179; cv=none; b=T5B5x6lmPfv20dpkliGb7gCyt/4Ogw8PqKvwR/BTbIsMLdlma8SER+dFB3yB1k25hdOX2ZWlwkP4eUExs8H6TyZJm+0QeAEnHhXfe0BxiLHE4ugf706TwHkdpDcEfwL8p0Iudm4PR2CvrnhYamFsiY3GRNITTQ4s6LWr0Drn1YA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792081179; c=relaxed/simple; bh=uiZwL32INsf6gWCDDMVmM0dirvQNYaZ9w9sYmIrzE28=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=Y/8B5hXROgSuVqq022FFCBYgYTkY8UpdFIx6b/9+2UTKKnd42sHsvyZlwSZB4evJo9rP3ikzJ59ABEPEkgNVog+7YXqEQHGgkD4YMdwZP6pqgVkf7iUvTPsuZavb2F3ip4GvtCfa1VlaaBV9QnaJi/jjRw010LzMZqNNn9PkJt0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IusWLQXa; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IusWLQXa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA2D51F000C5; Thu, 15 Oct 2026 16:19:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792081167; bh=PIBFLItZ4V5cAmzj5Xcdj2gfvndzkJvcHnICXv18F7s=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=IusWLQXaauc+8BtXqJ61en+ufethH6O9W4ytYQl05XQMjEAXiLInOFCIreQ0iH0Cf RHbCW8+ZGEcIfbF1BqlBf7s97c0e4pubOQ5nbAudRRfY3hf9EZ9yRBmY8smeXMQBNf bs01L0Sp9/imv7mhcQlntYfkG83ybNr4+kA0EvW+d+l9DIplS5ybMpyX927cdLTPXR Ypk/DnzzssqynODPSIE4SyvwIgH5TE95Foq/CSczP6pAsewPnI37MAmGHfzwGbDWFq mGKNoDYeRU+Rzo3VEMDVM83wlBnOOHl3q+CS7YpSgJCAcaalDYdXMJik6A608zGiX1 +ZGUI9D7GTFfw== From: =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= To: Karl Mehltretter , Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: Karl Mehltretter , Alexandre Ghiti , Mike Rapoport , Luis Chamberlain , linux-riscv@lists.infradead.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] riscv: mm: Pre-allocate module page tables for execmem In-Reply-To: <20261015033643.84972-1-kmehltretter@gmail.com> References: <20261015033643.84972-1-kmehltretter@gmail.com> Date: Thu, 15 Oct 2026 18:19:24 +0200 Message-ID: <87a4of5437.fsf@all.your.base.are.belong.to.us> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Karl Mehltretter writes: > RV64 pre-allocates page-table levels for late kernel mappings. The module > range is guarded by CONFIG_MODULES, although execmem can use it without > modules. > > With CONFIG_BPF_JIT=3Dy and CONFIG_MODULES=3Dn, execmem adds a mapping to > init_mm while the current process retains an empty PGD entry. Initializing > a BPF program pack then faults: > > Unable to handle kernel paging request ... > [ffffffff78000000] pgd=3D0000000000000000 > ... > bpf_jit_fill_hole_with_zero > bpf_prog_pack_alloc > > Use CONFIG_EXECMEM for the module-range pre-allocation, as powerpc does > for its execmem page-table setup. Both CONFIG_MODULES and CONFIG_BPF_JIT > select it. > > Fixes: 2c9e5d4a0082 ("bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MOD= ULES of") > Cc: stable@vger.kernel.org > Assisted-by: LLM > Signed-off-by: Karl Mehltretter TY! Acked-by: Bj=C3=B6rn T=C3=B6pel