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 2CF1F2D3752 for ; Thu, 18 Sep 2025 13:44:01 +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=1758203043; cv=none; b=ZDMAMJaUYEZTw6SxtuyzC0lwhwvOTGu+SejmHGNyhV5/jw1ysKIlGCwXxzbCQKLAudLmURWFjnDq39pRPElhoX2c4LTUBcON/eBlsnVL2Qp4F/lEUiyiGCaImQRJGimWrXQ1120cVaukknBCytsC71Y0Y/rH7UMtkb3ir71tKxc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758203043; c=relaxed/simple; bh=6+pEBWsAwMB6bKj5yLCNgjpJI4phyW1qCZgVsyCUI+I=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=cxec9rn6kXMYLtmkh7jsju9lsP3RUtAGWFuKo0y7GGUK4LFaZRP8jCdWKJplqZiG8+UFkobie4Frtg5DEFtn9wGICm3M5zkFxSCpUA9vY26GORsw6CGkF7aChbEnJTHDFrAmR8We3S08vVYMQ/bOPBAjxsTCaYeEtamHLLenTeo= 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=Q0p/+6zz; 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="Q0p/+6zz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1758203041; 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=c6DJ2s18FdX+Nqa8e5WVMJEqWKLADAlvemQSEP0DBOU=; b=Q0p/+6zzuV5Sl1NlT30UKhhaJAOfQZ0S2/GcMyS1uQbGUJtDpo8hONlt0ZP+PnoFwibPyZ hMe/MufYJLcPzU0J7Pin3LzdeLmoLrwHTN8NPTlCc9agnNuAKh7HLR2K7fCMJr6Fge0YLB al0UG4vOmCe4PgKH56GFdUtvVLrZ/N4= Received: from mx-prod-mc-03.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-574-ptIdZqmxMSy0YJFQVGXz6Q-1; Thu, 18 Sep 2025 09:43:56 -0400 X-MC-Unique: ptIdZqmxMSy0YJFQVGXz6Q-1 X-Mimecast-MFC-AGG-ID: ptIdZqmxMSy0YJFQVGXz6Q_1758203034 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 54FCB1956054; Thu, 18 Sep 2025 13:43:53 +0000 (UTC) Received: from rotkaeppchen (unknown [10.45.225.227]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0ABDC300018D; Thu, 18 Sep 2025 13:43:45 +0000 (UTC) Date: Thu, 18 Sep 2025 15:43:42 +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: <20250918154342.0589fd4b@rotkaeppchen> In-Reply-To: References: <20250819012428.6217-1-piliu@redhat.com> <20250819012428.6217-7-piliu@redhat.com> <20250901163042.721db92d@rotkaeppchen> 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 3.4.1 on 10.30.177.4 Hi Pingfan, On Tue, 16 Sep 2025 14:52:38 +0800 Pingfan Liu wrote: > On Mon, Sep 01, 2025 at 04:30:42PM +0200, Philipp Rudo wrote: > > 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. > > > > Yes, I will introduce a macro KEXEC_RES_ARRAY_SIZE to unify all of them. Why do you want to introduce a new macro? Why not simply use ARRAY_SIZE(parsed_resource)? Thanks Philipp > Thanks, > > Pingfan > > > 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. > > >