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[209.132.180.67]) by mx.google.com with ESMTP id ct1si18197156plb.419.2019.03.26.13.35.09; Tue, 26 Mar 2019 13:35:25 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=GQ50Vj5y; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732616AbfCZUec (ORCPT + 99 others); Tue, 26 Mar 2019 16:34:32 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:35295 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731617AbfCZUeb (ORCPT ); Tue, 26 Mar 2019 16:34:31 -0400 Received: by mail-pg1-f193.google.com with SMTP id g8so8819377pgf.2; Tue, 26 Mar 2019 13:34:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=77QbSwwpZwxT2nAljwXCx6lYbZ5cGL1YooiRmXK1O5M=; b=GQ50Vj5yK0QDlmVkzRZF9PWUpv/jUCniRoeOVJWbQ/raDDf9z4F3Xxy+XIu3Z/X/Dy iwGWawkxPOLKBzh+r4TO8MrS0oSjsWSPtVGIRKqEnDQWDUzg/zuCuQpt98Gnib/3XYYa At/4JFv7VuZiukwaGEqb0Gu7EsCimxI3NR2hBSidBBLjdyhz/WM1MGlAfLEwZ7Fr4NNT hSRkNxiRIRM4769ojKWNqMDIKLQEROWqCcbfWB0zWgtqXu8l5ib24/okd+We32ixG2ik 1jBMqzVF/MxZAOXLM8MM9kxsFS1QReWT4n85QMZTvK1U768uvPWJLq/CE9a4MQTwZksG mOFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=77QbSwwpZwxT2nAljwXCx6lYbZ5cGL1YooiRmXK1O5M=; b=f2xzs4H/mL2ECdgq56OVmHl3wQzIWnGGmUQIz/E53GhQ+dCC4IDIG1SfbmGY8NcGwc TRZ6TB9dehWctfnKJbfCOmTaLv+UgXkCEv89GrtP7hD+oQC9PO5U4YxyKVJDWbfOCo0Q y6uteH0HhamSM0vzg647evzlXrZTtpfsWe/24crrKXeA+EvEl5EpmRU8PsV3XvUM3/eX f8FhYzXfXnwdyLsPIm1f6S8xTNPddhl0lILw4dUFiyC0q3oEOqAKUl0kVPcvsTnqK9I6 Wpy2AKIUdFiLC2kXFCZKYV6UP/5ehHzVa2WknWGFGn9c8qgU0Rlrc3e9LoEj/ozU1QqO x+6w== X-Gm-Message-State: APjAAAUAn1vhT3r0bquEpIXZAq8SGEeP/uTLhhsHtT+6TJ/FSCMXX4i5 ZYZn1p6dXQxTUi//HItCN68= X-Received: by 2002:a65:4bce:: with SMTP id p14mr31290225pgr.68.1553632470482; Tue, 26 Mar 2019 13:34:30 -0700 (PDT) Received: from ast-mbp ([2620:10d:c090:200::1:f1fc]) by smtp.gmail.com with ESMTPSA id e184sm30761964pfc.143.2019.03.26.13.34.29 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Mar 2019 13:34:29 -0700 (PDT) Date: Tue, 26 Mar 2019 13:34:28 -0700 From: Alexei Starovoitov To: Andrey Ignatov Cc: netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, guro@fb.com, kernel-team@fb.com, Luis Chamberlain , Kees Cook , Alexey Dobriyan , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v2 bpf-next 00/21] bpf: Sysctl hook Message-ID: <20190326203426.5qni5nnbeyr5rf52@ast-mbp> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180223 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 25, 2019 at 05:43:26PM -0700, Andrey Ignatov wrote: > v1->v2: > - add fs/proc/proc_sysctl.c mainteners to Cc:. Kees, Luis, any concerns with bpf hook in sysctl ? Pls take a look at patch 2 where it touches fs/proc/proc_sysctl.c This facility is for root to monitor dumb root tasks. More detailed description below and in patches. > The patch set introduces new BPF hook for sysctl. > > It adds new program type BPF_PROG_TYPE_CGROUP_SYSCTL and attach type > BPF_CGROUP_SYSCTL. > > BPF_CGROUP_SYSCTL hook is placed before calling to sysctl's proc_handler so > that accesses (read/write) to sysctl can be controlled for specific cgroup > and either allowed or denied, or traced. > > The hook has access to sysctl name, current sysctl value and (on write > only) to new sysctl value via corresponding helpers. New sysctl value can > be overridden by program. Both name and values (current/new) are > represented as strings same way they're visible in /proc/sys/. It is up to > program to parse these strings. > > To help with parsing the most common kind of sysctl value, vector of > integers, two new helpers are provided: bpf_strtol and bpf_strtoul with > semantic similar to user space strtol(3) and strtoul(3). > > The hook also provides bpf_sysctl context with two fields: > * @write indicates whether sysctl is being read (= 0) or written (= 1); > * @file_pos is sysctl file position to read from or write to, can be > overridden. > > The hook allows to make better isolation for containerized applications > that are run as root so that one container can't change a sysctl and affect > all other containers on a host, make changes to allowed sysctl in a safer > way and simplify sysctl tracing for cgroups. > > Patch 1 is preliminary refactoring. > Patch 2 adds new program and attach types. > Patches 3-5 implement helpers to access sysctl name and value. > Patch 6 adds file_pos field to bpf_sysctl context. > Patch 7 updates UAPI in tools. > Patches 8-9 add support for the new hook to libbpf and corresponding test. > Patches 10-14 add selftests for the new hook. > Patch 15 adds support for new arg types to verifier: pointer to integer. > Patch 16 adds bpf_strto{l,ul} helpers to parse integers from sysctl value. > Patch 17 updates UAPI in tools. > Patch 18 updates bpf_helpers.h. > Patch 19 adds selftests for pointer to integer in verifier. > Patches 20-21 add selftests for bpf_strto{l,ul}, including integration > C based test for sysctl value parsing. > > > Andrey Ignatov (21): > bpf: Add base proto function for cgroup-bpf programs > bpf: Sysctl hook > bpf: Introduce bpf_sysctl_get_name helper > bpf: Introduce bpf_sysctl_get_current_value helper > bpf: Introduce bpf_sysctl_{get,set}_new_value helpers > bpf: Add file_pos field to bpf_sysctl ctx > bpf: Sync bpf.h to tools/ > libbpf: Support sysctl hook > selftests/bpf: Test sysctl section name > selftests/bpf: Test BPF_CGROUP_SYSCTL > selftests/bpf: Test bpf_sysctl_get_name helper > selftests/bpf: Test sysctl_get_current_value helper > selftests/bpf: Test bpf_sysctl_{get,set}_new_value helpers > selftests/bpf: Test file_pos field in bpf_sysctl ctx > bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types > bpf: Introduce bpf_strtol and bpf_strtoul helpers > bpf: Sync bpf.h to tools/ > selftests/bpf: Add sysctl and strtoX helpers to bpf_helpers.h > selftests/bpf: Test ARG_PTR_TO_LONG arg type > selftests/bpf: Test bpf_strtol and bpf_strtoul helpers > selftests/bpf: C based test for sysctl and strtoX > > fs/proc/proc_sysctl.c | 25 +- > include/linux/bpf-cgroup.h | 21 + > include/linux/bpf.h | 4 + > include/linux/bpf_types.h | 1 + > include/linux/filter.h | 16 + > include/uapi/linux/bpf.h | 139 +- > kernel/bpf/cgroup.c | 364 +++- > kernel/bpf/helpers.c | 131 ++ > kernel/bpf/syscall.c | 7 + > kernel/bpf/verifier.c | 30 + > tools/include/uapi/linux/bpf.h | 139 +- > tools/lib/bpf/libbpf.c | 3 + > tools/lib/bpf/libbpf_probes.c | 1 + > tools/testing/selftests/bpf/Makefile | 3 +- > tools/testing/selftests/bpf/bpf_helpers.h | 19 + > .../selftests/bpf/progs/test_sysctl_prog.c | 89 + > .../selftests/bpf/test_section_names.c | 5 + > tools/testing/selftests/bpf/test_sysctl.c | 1567 +++++++++++++++++ > .../testing/selftests/bpf/verifier/int_ptr.c | 160 ++ > 19 files changed, 2716 insertions(+), 8 deletions(-) > create mode 100644 tools/testing/selftests/bpf/progs/test_sysctl_prog.c > create mode 100644 tools/testing/selftests/bpf/test_sysctl.c > create mode 100644 tools/testing/selftests/bpf/verifier/int_ptr.c > > -- > 2.17.1 >