From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 728A6149C41 for ; Mon, 1 Sep 2025 14:31:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756737066; cv=none; b=KL3YEbbhaexlHpvrr3MONZuYSgumLLLJE6wXT86KLMFcpFdoxakiROlRtPR93oCCzykQEjutRSiRrqmLpCcchIUqcVaotr+YYRexo4Z5v9XQjlZAHdRiSvj7iPqGAY2iHTzQdetggVfHsALvfqtFM0lKDnilPcaB10D07nkoVK0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756737066; c=relaxed/simple; bh=hhXNKveroyOa6SUL4OB9gSmjm3tiQ5yrhK6pTmHqayc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=doRRB8fnMzEM5j4pZx+88UCS1Ky9g0wdZ3EW39qZZWmH/9vmRG2uy/7fyoBR4RK4otCsKO0hmdRMEgIMjh7cx3fDrDkPUqW1DroV1Z04zYS4yMor6Ywd1pH+qKZmnImY5ZhssHysFlEhwlP6mkK4XHmXUU8Mu8m20b14zlCSegc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=ME194Z2D; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ME194Z2D" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1756737062; h=from:from: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; bh=nUYaeq9idzhAgy3kGcN1jl7xeqJL2afaZsvOUDSXRMg=; b=ME194Z2DQlXRkjchI3durtKiP2Al30e5xTr5Uc8Kztf/mZoo3S2/06Cyb7ZkdJs7ki8LWl RIKTVmHkfOPQpilt5YXQ+/4EA8pkUP1XrqcrSafvcvMoup0DRGwwq1zS5D+QIlA0ExFLW7 CKtstvq1of9CnLYm2nK4VZ6tj4ozV4M= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-284-4yFJwg86OrqM4rSjzQVR7w-1; Mon, 01 Sep 2025 10:30:59 -0400 X-MC-Unique: 4yFJwg86OrqM4rSjzQVR7w-1 X-Mimecast-MFC-AGG-ID: 4yFJwg86OrqM4rSjzQVR7w_1756737057 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C460C19560B2; Mon, 1 Sep 2025 14:30:56 +0000 (UTC) Received: from rotkaeppchen (unknown [10.45.224.104]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8EE3319560B4; Mon, 1 Sep 2025 14:30:46 +0000 (UTC) Date: Mon, 1 Sep 2025 16:30:42 +0200 From: Philipp Rudo To: Pingfan Liu Cc: kexec@lists.infradead.org, Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , Jeremy Linton , Catalin Marinas , Will Deacon , Ard Biesheuvel , Simon Horman , Gerd Hoffmann , Vitaly Kuznetsov , Viktor Malik , Jan Hendrik Farr , Baoquan He , Dave Young , Andrew Morton , bpf@vger.kernel.org, systemd-devel@lists.freedesktop.org Subject: Re: [PATCHv5 06/12] kexec: Integrate with the introduced bpf kfuncs Message-ID: <20250901163042.721db92d@rotkaeppchen> In-Reply-To: <20250819012428.6217-7-piliu@redhat.com> References: <20250819012428.6217-1-piliu@redhat.com> <20250819012428.6217-7-piliu@redhat.com> Organization: Red Hat inc. Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Hi Pingfan, On Tue, 19 Aug 2025 09:24:22 +0800 Pingfan Liu wrote: > This patch does two things: > First, register as a listener on bpf_copy_to_kernel() > Second, in order that the hooked bpf-prog can call the sleepable kfuncs, > bpf_handle_pefile and bpf_post_handle_pefile are marked as > KF_SLEEPABLE. > > Signed-off-by: Pingfan Liu > Cc: Alexei Starovoitov > Cc: Philipp Rudo > Cc: Baoquan He > Cc: Dave Young > Cc: Andrew Morton > Cc: bpf@vger.kernel.org > To: kexec@lists.infradead.org > --- > kernel/kexec_pe_image.c | 67 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 67 insertions(+) > > diff --git a/kernel/kexec_pe_image.c b/kernel/kexec_pe_image.c > index b0cf9942e68d2..f8debcde6b516 100644 > --- a/kernel/kexec_pe_image.c > +++ b/kernel/kexec_pe_image.c > @@ -38,6 +38,51 @@ static struct kexec_res parsed_resource[3] = { > { KEXEC_RES_CMDLINE_NAME, }, > }; > > +/* > + * @name should be one of : kernel, initrd, cmdline > + */ > +static int bpf_kexec_carrier(const char *name, struct mem_range_result *r) > +{ > + struct kexec_res *res; > + int i; > + > + if (!r || !name) > + return -EINVAL; > + > + for (i = 0; i < 3; i++) { > + if (!strcmp(parsed_resource[i].name, name)) > + break; > + } > + if (i >= 3) > + return -EINVAL; Can you please replace the magic '3' by ARRAY_SIZE, just like you did below when (un-)registering the listener. Thanks Philipp > + > + res = &parsed_resource[i]; > + /* > + * Replace the intermediate resource generated by the previous step. > + */ > + if (!!res->r) > + mem_range_result_put(res->r); > + mem_range_result_get(r); > + res->r = r; > + return 0; > +} > + > +static struct carrier_listener kexec_res_listener[3] = { > + { .name = KEXEC_RES_KERNEL_NAME, > + .alloc_type = 1, > + .handler = bpf_kexec_carrier, > + }, > + { .name = KEXEC_RES_INITRD_NAME, > + .alloc_type = 1, > + .handler = bpf_kexec_carrier, > + }, > + { .name = KEXEC_RES_CMDLINE_NAME, > + /* kmalloc-ed */ > + .alloc_type = 0, > + .handler = bpf_kexec_carrier, > + }, > +}; > + > static bool pe_has_bpf_section(const char *file_buf, unsigned long pe_sz); > > static bool is_valid_pe(const char *kernel_buf, unsigned long kernel_len) > @@ -159,6 +204,22 @@ __attribute__((used, optimize("O0"))) void bpf_post_handle_pefile(struct kexec_c > dummy += 2; > } > > +BTF_KFUNCS_START(kexec_modify_return_ids) > +BTF_ID_FLAGS(func, bpf_handle_pefile, KF_SLEEPABLE) > +BTF_ID_FLAGS(func, bpf_post_handle_pefile, KF_SLEEPABLE) > +BTF_KFUNCS_END(kexec_modify_return_ids) > + > +static const struct btf_kfunc_id_set kexec_modify_return_set = { > + .owner = THIS_MODULE, > + .set = &kexec_modify_return_ids, > +}; > + > +static int __init kexec_bpf_prog_run_init(void) > +{ > + return register_btf_fmodret_id_set(&kexec_modify_return_set); > +} > +late_initcall(kexec_bpf_prog_run_init); > + > /* > * PE file may be nested and should be unfold one by one. > * Query 'kernel', 'initrd', 'cmdline' in cur_phase, as they are inputs for the > @@ -213,6 +274,9 @@ static void *pe_image_load(struct kimage *image, > cmdline_start = cmdline; > cmdline_sz = cmdline_len; > > + for (int i = 0; i < ARRAY_SIZE(kexec_res_listener); i++) > + register_carrier_listener(&kexec_res_listener[i]); > + > while (is_valid_format(linux_start, linux_sz) && > pe_has_bpf_section(linux_start, linux_sz)) { > struct kexec_context context; > @@ -250,6 +314,9 @@ static void *pe_image_load(struct kimage *image, > disarm_bpf_prog(); > } > > + for (int i = 0; i < ARRAY_SIZE(kexec_res_listener); i++) > + unregister_carrier_listener(kexec_res_listener[i].name); > + > /* > * image's kernel_buf, initrd_buf, cmdline_buf are set. Now they should > * be updated to the new content.