From mboxrd@z Thu Jan 1 00:00:00 1970 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 7240B15FD01; Mon, 27 May 2024 19:24:00 +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=1716837840; cv=none; b=sZVMKSLR7mBIvoQpGni1y5KMDohEPe2R+FyWfk9o9oEGAbjGOJqbjlb+mXWoTF1iBxnjyWW2pC9oWfTV2RBcw24p5AudZ6wi9H5nTxLOXLNYmkJtuFCcHXdwukN4FzjlI/cGfxE34SbPKyr6N0dnl/q/zqeARbQK+lMmprdhdqY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716837840; c=relaxed/simple; bh=pT//9vMRpcXBkc81H9+4CWJpZw0LwhgcJONegBeDawg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t8SPLkTQRs6VdF+Lp9GrdTzaVU5YLqQTmSTT6WJqeiR0tOTYQamD8B9xDJeOy4SIGjeDYyIbXtAYra+GKsilfecYaBAzWi+IO56qrFixHe599J6x71LpX4PEz/IpjaPG2UTekErrb14++jvlnExmmeW62rjdSAl6eJEd2AcMnuw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YigcOQ7n; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="YigcOQ7n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0658CC2BBFC; Mon, 27 May 2024 19:23:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1716837840; bh=pT//9vMRpcXBkc81H9+4CWJpZw0LwhgcJONegBeDawg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YigcOQ7nHocLC1dVYn41NS0WRY+Z8U3/77OkBzoEMQH/uhTa18dqpuL9kjrnctBUk FQT8sIbE43Dpur5pAbUtXB7TQILLJHi+zRpI2ESGX5n0ckzy3q8a9ww0zy1gH+kQv8 G01kBEGwTQSMjLJqIV9C/kQKVvoUCdvJJ8lhHn74= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yonghong Song , Andrii Nakryiko , Quentin Monnet , Sasha Levin Subject: [PATCH 6.8 164/493] bpftool: Fix missing pids during link show Date: Mon, 27 May 2024 20:52:46 +0200 Message-ID: <20240527185635.739855071@linuxfoundation.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240527185626.546110716@linuxfoundation.org> References: <20240527185626.546110716@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yonghong Song [ Upstream commit fe879bb42f8a6513ed18e9d22efb99cb35590201 ] Current 'bpftool link' command does not show pids, e.g., $ tools/build/bpftool/bpftool link ... 4: tracing prog 23 prog_type lsm attach_type lsm_mac target_obj_id 1 target_btf_id 31320 Hack the following change to enable normal libbpf debug output, # --- a/tools/bpf/bpftool/pids.c # +++ b/tools/bpf/bpftool/pids.c # @@ -121,9 +121,9 @@ int build_obj_refs_table(struct hashmap **map, enum bpf_obj_type type) # /* we don't want output polluted with libbpf errors if bpf_iter is not # * supported # */ # - default_print = libbpf_set_print(libbpf_print_none); # + /* default_print = libbpf_set_print(libbpf_print_none); */ # err = pid_iter_bpf__load(skel); # - libbpf_set_print(default_print); # + /* libbpf_set_print(default_print); */ Rerun the above bpftool command: $ tools/build/bpftool/bpftool link libbpf: prog 'iter': BPF program load failed: Permission denied libbpf: prog 'iter': -- BEGIN PROG LOAD LOG -- 0: R1=ctx() R10=fp0 ; struct task_struct *task = ctx->task; @ pid_iter.bpf.c:69 0: (79) r6 = *(u64 *)(r1 +8) ; R1=ctx() R6_w=ptr_or_null_task_struct(id=1) ; struct file *file = ctx->file; @ pid_iter.bpf.c:68 ... ; struct bpf_link *link = (struct bpf_link *) file->private_data; @ pid_iter.bpf.c:103 80: (79) r3 = *(u64 *)(r8 +432) ; R3_w=scalar() R8=ptr_file() ; if (link->type == bpf_core_enum_value(enum bpf_link_type___local, @ pid_iter.bpf.c:105 81: (61) r1 = *(u32 *)(r3 +12) R3 invalid mem access 'scalar' processed 39 insns (limit 1000000) max_states_per_insn 0 total_states 3 peak_states 3 mark_read 2 -- END PROG LOAD LOG -- libbpf: prog 'iter': failed to load: -13 ... The 'file->private_data' returns a 'void' type and this caused subsequent 'link->type' (insn #81) failed in verification. To fix the issue, restore the previous BPF_CORE_READ so old kernels can also work. With this patch, the 'bpftool link' runs successfully with 'pids'. $ tools/build/bpftool/bpftool link ... 4: tracing prog 23 prog_type lsm attach_type lsm_mac target_obj_id 1 target_btf_id 31320 pids systemd(1) Fixes: 44ba7b30e84f ("bpftool: Use a local copy of BPF_LINK_TYPE_PERF_EVENT in pid_iter.bpf.c") Signed-off-by: Yonghong Song Signed-off-by: Andrii Nakryiko Tested-by: Quentin Monnet Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20240312023249.3776718-1-yonghong.song@linux.dev Signed-off-by: Sasha Levin --- tools/bpf/bpftool/skeleton/pid_iter.bpf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c index 26004f0c5a6ae..7bdbcac3cf628 100644 --- a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c +++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c @@ -102,8 +102,8 @@ int iter(struct bpf_iter__task_file *ctx) BPF_LINK_TYPE_PERF_EVENT___local)) { struct bpf_link *link = (struct bpf_link *) file->private_data; - if (link->type == bpf_core_enum_value(enum bpf_link_type___local, - BPF_LINK_TYPE_PERF_EVENT___local)) { + if (BPF_CORE_READ(link, type) == bpf_core_enum_value(enum bpf_link_type___local, + BPF_LINK_TYPE_PERF_EVENT___local)) { e.has_bpf_cookie = true; e.bpf_cookie = get_bpf_cookie(link); } -- 2.43.0