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 picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7E68AC02194 for ; Thu, 6 Feb 2025 13:36:47 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id E8DF03C04A5 for ; Thu, 6 Feb 2025 14:36:45 +0100 (CET) Received: from in-5.smtp.seeweb.it (in-5.smtp.seeweb.it [IPv6:2001:4b78:1:20::5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 12C523C04A5 for ; Thu, 6 Feb 2025 14:36:30 +0100 (CET) Authentication-Results: in-5.smtp.seeweb.it; spf=pass (sender SPF authorized) smtp.mailfrom=suse.cz (client-ip=195.135.223.130; helo=smtp-out1.suse.de; envelope-from=chrubis@suse.cz; receiver=lists.linux.it) Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (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 in-5.smtp.seeweb.it (Postfix) with ESMTPS id E7BDF6296BE for ; Thu, 6 Feb 2025 14:36:28 +0100 (CET) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id D00B1210F5; Thu, 6 Feb 2025 13:36:27 +0000 (UTC) Authentication-Results: smtp-out1.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id C185413697; Thu, 6 Feb 2025 13:36:27 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Zdl4Ltu6pGdvFAAAD6G6ig (envelope-from ); Thu, 06 Feb 2025 13:36:27 +0000 Date: Thu, 6 Feb 2025 14:36:21 +0100 From: Cyril Hrubis To: Jan Stancek Message-ID: References: <89d0fb724ea534419942c2647e1ef7ca98f9e72d.1738846569.git.jstancek@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <89d0fb724ea534419942c2647e1ef7ca98f9e72d.1738846569.git.jstancek@redhat.com> X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU] X-Rspamd-Queue-Id: D00B1210F5 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Virus-Scanned: clamav-milter 1.0.3 at in-5.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH] syscalls/bpf: zero-initialize bpf_attr including padding bits X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ltp@lists.linux.it Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hi! > gcc 15 stopped zero-initializing padding bits: > https://gcc.gnu.org/gcc-15/changes.html I would even call this a bug even if it's allowed by the C standard. > However kernel bpf syscall checks that all unused fields for a command > are set to zero in CHECK_ATTR() macro, which causes tests to fail with > EINVAL. > > Signed-off-by: Jan Stancek > --- > testcases/kernel/syscalls/bpf/bpf_common.c | 32 ++++++++++++---------- > 1 file changed, 18 insertions(+), 14 deletions(-) > > diff --git a/testcases/kernel/syscalls/bpf/bpf_common.c b/testcases/kernel/syscalls/bpf/bpf_common.c > index 95b5bc12eaa4..d765c4e32936 100644 > --- a/testcases/kernel/syscalls/bpf/bpf_common.c > +++ b/testcases/kernel/syscalls/bpf/bpf_common.c > @@ -49,13 +49,14 @@ int bpf_map_create(union bpf_attr *const attr) > > int bpf_map_array_create(const uint32_t max_entries) > { > - union bpf_attr map_attr = { > - .map_type = BPF_MAP_TYPE_ARRAY, > - .key_size = 4, > - .value_size = 8, > - .max_entries = max_entries, > - .map_flags = 0 > - }; > + /* zero-initialize entire struct including padding bits */ > + union bpf_attr map_attr = {}; > + > + map_attr.map_type = BPF_MAP_TYPE_ARRAY; > + map_attr.key_size = 4; > + map_attr.value_size = 8; > + map_attr.max_entries = max_entries; > + map_attr.map_flags = 0; So struct foo bar = {.bar = foo}; does not work, but struct foo bar = {}: bar.bar = foo; does? That is insane... > return bpf_map_create(&map_attr); > } > @@ -64,13 +65,16 @@ void bpf_map_array_get(const int map_fd, > const uint32_t *const array_indx, > uint64_t *const array_val) > { > - union bpf_attr elem_attr = { > - .map_fd = map_fd, > - .key = ptr_to_u64(array_indx), > - .value = ptr_to_u64(array_val), > - .flags = 0 > - }; > - const int ret = bpf(BPF_MAP_LOOKUP_ELEM, &elem_attr, sizeof(elem_attr)); > + /* zero-initialize entire struct including padding bits */ > + union bpf_attr elem_attr = {}; > + int ret; > + > + elem_attr.map_fd = map_fd; > + elem_attr.key = ptr_to_u64(array_indx); > + elem_attr.value = ptr_to_u64(array_val); > + elem_attr.flags = 0; > + > + ret = bpf(BPF_MAP_LOOKUP_ELEM, &elem_attr, sizeof(elem_attr)); > > if (ret) { > tst_brk(TBROK | TTERRNO, > -- > 2.43.0 > > > -- > Mailing list info: https://lists.linux.it/listinfo/ltp -- Cyril Hrubis chrubis@suse.cz -- Mailing list info: https://lists.linux.it/listinfo/ltp