From patchwork Wed Oct 16 19:05:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthieu Baerts X-Patchwork-Id: 13838780 X-Patchwork-Delegate: matthieu.baerts@tessares.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9EE011885BB for ; Wed, 16 Oct 2024 19:05:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729105535; cv=none; b=gr+rFDeHU2Hiz3EF8qJhNKAN5i/9ZQwmZO3Z/nBp6C2GsNlhJeds1FKjigAtLnd28wQDKeoo9C5mFe7aFPJ8DI0xSRQWMHAtbkgFnTfTpO3tFedBqOBNtZn21uURXxLjaw6frULu52AuVpBoNt/cXYFYXDzU3yTpnO0F+yAaDdE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729105535; c=relaxed/simple; bh=d1ENJp7kJFfhdTpnxBulsp99HA/PzWELEryOO3PkslU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=VW136Iobk03NGFSHXU4G3kiXHwrGeQluwszbfaXdtmbO+G6ihX0FbEsPOMy4Lb6ZfyfK36zls0wyDIxjXeI88F27IlRqhcm/Woboehrovh3DkRZ/HViTinjuM3NPLWPlyWDL2k7uPo0Xh5EAELCR15sMynF860MDLk2sx6aiNKc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JPh7X/Vf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JPh7X/Vf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99C3FC4CECF; Wed, 16 Oct 2024 19:05:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729105535; bh=d1ENJp7kJFfhdTpnxBulsp99HA/PzWELEryOO3PkslU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=JPh7X/VfS9wmz0WjO/Ee9Xb6oQdda3NQhc1peeUxjW+EnV0XDDPtYVaJ9/fofPhhp C08jRemvK/bObys6pyzjwEgoEpz0znyY2Zjd1sfcO6wE+J7DNqQ4q4sC2ea9Nr0MLB w9N5V7CIKpAsZXAxQ8M5R/NvbfcSDFW8TpKcd2gZfn/my0lPvY+NYNC+u8rLgc4+D2 IoKEJ8ZZOXPN1WHBgEVkkrakpaLRDNIuwqbdLuvp7aaBsr56/YYvZ1jKvJym0iEBK3 A/ayS59IX6LpCS5tzyR/wt+deY7GojK3fr8LU3mDB/5+R8O5hOZbaDrXIq3dmArMAt r2zFbboamNIFw== From: "Matthieu Baerts (NGI0)" Date: Wed, 16 Oct 2024 21:05:20 +0200 Subject: [PATCH mptcp-net 2/2] Squash to "bpf: Add bpf_mptcp_sched_ops" Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241016-mptcp-sched-find-rcu-v1-2-5e9af4fbce11@kernel.org> References: <20241016-mptcp-sched-find-rcu-v1-0-5e9af4fbce11@kernel.org> In-Reply-To: <20241016-mptcp-sched-find-rcu-v1-0-5e9af4fbce11@kernel.org> To: mptcp@lists.linux.dev Cc: "Matthieu Baerts (NGI0)" X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=3232; i=matttbe@kernel.org; h=from:subject:message-id; bh=d1ENJp7kJFfhdTpnxBulsp99HA/PzWELEryOO3PkslU=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBnEA57tWZscxcDpD95R/BG+jxyrTuE/R4PCE9KI 3RkDKphdgyJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZxAOewAKCRD2t4JPQmmg c39SD/0bpHdYpw+5+DyCje7LFix1kJYhJnFBmSwQYYjrSN97pL8Y6b6c3HYtHRLRVwd2um2I0gt I9dEjnymRrilu5zUzokYFiiEgZR5x/LFtjSDelkykoD5xPsam07h3G+fTUaY6LgIQ6dNdSivwPg P3xpAU/G6fP0G9WmwBX5UnMK1FeshdPbioeT3zmG9ikyrJAnOtgkr5n4MEUIM5HWFLxx3LPWf7d Mk4ldXIID0xnXFCPoz0r6H28tDeIW5ZKpasgdOoBwyX8/ZpYpG6SD7ZvvbKMhPqtP8Qx4j9d72+ mqoEemNAJmvGWaLIAlamyaNCzJ4J9h8vuLbnJXmPOiwN1zHsVqZ6ja/ooJL8b4lnpRx1FD/uH2V kVegeYJM0SvMPSnr1nOiq/e24HmUOhVpizRyee+qYI66qoa2lfjgJZsepQ3SIOkcjpzOBJqbvou SCGqKC5YfbwtYKLnCEhY2IY32lqJzU2056lnEwXrUKt+lZDQbN6s0LT7uiTDQLK/a2/foLymLJq feqROrTwcAQxRXHoJ3zOlnizXpwisxVJ7RrhQlAOBa8hDch3eNA0AJJk3Zr/uOs1/XOHFcswNwD iVRjEu4JzROj+Ks+Cv/Wi6FH1zqjslK+hDJts7FPh1+EGl8XSOi7EY7pGrDTv1cO1twAw3jO07Z /vGCixVnKZGhTrw== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 Similar to the previous commit, this splat can be seen: ============================= WARNING: suspicious RCU usage 6.12.0-rc2+ #1 Tainted: G OE ----------------------------- net/mptcp/sched.c:44 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by test_progs/323: ffff888007e16a40 (&st_map->lock){+.+.}-{3:3}, at: bpf_struct_ops_map_update_elem (kernel/bpf/bpf_struct_ops.c:632) stack backtrace: CPU: 0 UID: 0 PID: 323 Comm: test_progs Tainted: G OE 6.12.0-rc2+ #1 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7)) bpf_mptcp_sched_init_member (net/mptcp/bpf.c:128 net/mptcp/bpf.c:109) ? btf_type_resolve_ptr (include/linux/btf.h:252 kernel/bpf/btf.c:637) bpf_struct_ops_map_update_elem (kernel/bpf/bpf_struct_ops.c:658) ? __might_fault (mm/memory.c:6700 (discriminator 5) mm/memory.c:6693 (discriminator 5)) ? __pfx_bpf_struct_ops_map_update_elem (kernel/bpf/bpf_struct_ops.c:591) ? __pfx___might_resched (kernel/sched/core.c:8593) ? kasan_save_track (arch/x86/include/asm/current.h:49 (discriminator 1) mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) bpf_map_update_value (kernel/bpf/syscall.c:169) map_update_elem (kernel/bpf/syscall.c:1627) ? __pfx_map_update_elem (kernel/bpf/syscall.c:1586) __sys_bpf (kernel/bpf/syscall.c:5622) ? __pfx___sys_bpf (kernel/bpf/syscall.c:5596) __x64_sys_bpf (kernel/bpf/syscall.c:5739) ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Also similar to the previous commit, this can be fixed by adding the missing rcu_read_lock(). Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/bpf.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 6414824402e6449ba01efb9093b2293232a67915..a9d6b5b939a2631f17a468ee6ba4867dc33dda63 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -113,6 +113,7 @@ static int bpf_mptcp_sched_init_member(const struct btf_type *t, const struct mptcp_sched_ops *usched; struct mptcp_sched_ops *sched; u32 moff; + int ret; usched = (const struct mptcp_sched_ops *)udata; sched = (struct mptcp_sched_ops *)kdata; @@ -123,9 +124,12 @@ static int bpf_mptcp_sched_init_member(const struct btf_type *t, if (bpf_obj_name_cpy(sched->name, usched->name, sizeof(sched->name)) <= 0) return -EINVAL; - if (mptcp_sched_find(usched->name)) - return -EEXIST; - return 1; + + rcu_read_lock(); + ret = mptcp_sched_find(usched->name) ? -EEXIST : 1; + rcu_read_unlock(); + + return ret; } return 0;