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2018-11-23libbpf: make bpf_object__open default to UNSPECNikita V. Shirokov
currently by default libbpf's bpf_object__open requires bpf's program to specify version in a code because of two things: 1) default prog type is set to KPROBE 2) KPROBE requires (in kernel/bpf/syscall.c) version to be specified in this patch i'm changing default prog type to UNSPEC and also changing requirments for version's section to be present in object file. now it would reflect what we have today in kernel (only KPROBE prog type requires for version to be explicitly set). v1 -> v2: - RFC tag has been dropped Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21bpf: adding support for map in map in libbpfNikita V. Shirokov
idea is pretty simple. for specified map (pointed by struct bpf_map) we would provide descriptor of already loaded map, which is going to be used as a prototype for inner map. proposed workflow: 1) open bpf's object (bpf_object__open) 2) create bpf's map which is going to be used as a prototype 3) find (by name) map-in-map which you want to load and update w/ descriptor of inner map w/ a new helper from this patch 4) load bpf program w/ bpf_object__load Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21bpf: libbpf: don't specify prog name if kernel doesn't support itStanislav Fomichev
Use recently added capability check. See commit 23499442c319 ("bpf: libbpf: retry map creation without the name") for rationale. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21bpf: libbpf: remove map name retry from bpf_create_map_xattrStanislav Fomichev
Instead, check for a newly created caps.name bpf_object capability. If kernel doesn't support names, don't specify the attribute. See commit 23499442c319 ("bpf: libbpf: retry map creation without the name") for rationale. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21bpf, libbpf: introduce bpf_object__probe_caps to test BPF capabilitiesStanislav Fomichev
It currently only checks whether kernel supports map/prog names. This capability check will be used in the next two commits to skip setting prog/map names. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21bpf: fix a libbpf loader issueYonghong Song
Commit 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections") added support to read .BTF.ext sections from an object file, create and pass prog_btf_fd and func_info to the kernel. The program btf_fd (prog->btf_fd) is initialized to be -1 to please zclose so we do not need special handling dur prog close. Passing -1 to the kernel, however, will cause loading error. Passing btf_fd 0 to the kernel if prog->btf_fd is invalid fixed the problem. Fixes: 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections") Reported-by: Andrey Ignatov <rdna@fb.com> Reported-by: Emre Cantimur <haydum@fb.com> Tested-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-20tools/bpf: add support to read .BTF.ext sectionsYonghong Song
The .BTF section is already available to encode types. These types can be used for map pretty print. The whole .BTF will be passed to the kernel as well for which kernel can verify and return to the user space for pretty print etc. The llvm patch at https://reviews.llvm.org/D53736 will generate .BTF section and one more section .BTF.ext. The .BTF.ext section encodes function type information and line information. Note that this patch set only supports function type info. The functionality is implemented in libbpf. The .BTF section can be directly loaded into the kernel, and the .BTF.ext section cannot. The loader may need to do some relocation and merging, similar to merging multiple code sections, before loading into the kernel. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-16bpf: libbpf: Fix bpf_program__next() APIMartin KaFai Lau
This patch restores the behavior in commit eac7d84519a3 ("tools: libbpf: don't return '.text' as a program for multi-function programs") such that bpf_program__next() does not return pseudo programs in ".text". Fixes: 0c19a9fbc9cd ("libbpf: cleanup after partial failure in bpf_object__pin") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-10libbpf: add internal pin_nameStanislav Fomichev
pin_name is the same as section_name where '/' is replaced by '_'. bpf_object__pin_programs is converted to use pin_name to avoid the situation where section_name would require creating another subdirectory for a pin (as, for example, when calling bpf_object__pin_programs for programs in sections like "cgroup/connect6"). Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-10libbpf: bpf_program__pin: add special case for instances.nr == 1Stanislav Fomichev
When bpf_program has only one instance, don't create a subdirectory with per-instance pin files (<prog>/0). Instead, just create a single pin file for that single instance. This simplifies object pinning by not creating unnecessary subdirectories. This can potentially break existing users that depend on the case where '/0' is always created. However, I couldn't find any serious usage of bpf_program__pin inside the kernel tree and I suppose there should be none outside. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-10libbpf: cleanup after partial failure in bpf_object__pinStanislav Fomichev
bpftool will use bpf_object__pin in the next commits to pin all programs and maps from the file; in case of a partial failure, we need to get back to the clean state (undo previous program/map pins). As part of a cleanup, I've added and exported separate routines to pin all maps (bpf_object__pin_maps) and progs (bpf_object__pin_programs) of an object. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-31libbpf: Fix compile error in libbpf_attach_type_by_nameAndrey Ignatov
Arnaldo Carvalho de Melo reported build error in libbpf when clang version 3.8.1-24 (tags/RELEASE_381/final) is used: libbpf.c:2201:36: error: comparison of constant -22 with expression of type 'const enum bpf_attach_type' is always false [-Werror,-Wtautological-constant-out-of-range-compare] if (section_names[i].attach_type == -EINVAL) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~ 1 error generated. Fix the error by keeping "is_attachable" property of a program in a separate struct field instead of trying to use attach_type itself. Fixes: 956b620fcf0b ("libbpf: Introduce libbpf_attach_type_by_name") Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Andrey Ignatov <rdna@fb.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-20bpf, libbpf: simplify and cleanup perf ring buffer walkDaniel Borkmann
Simplify bpf_perf_event_read_simple() a bit and fix up some minor things along the way: the return code in the header is not of type int but enum bpf_perf_event_ret instead. Once callback indicated to break the loop walking event data, it also needs to be consumed in data_tail since it has been processed already. Moreover, bpf_perf_event_print_t callback should avoid void * as we actually get a pointer to struct perf_event_header and thus applications can make use of container_of() to have type checks. The walk also doesn't have to use modulo op since the ring size is required to be power of two. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-19bpf, libbpf: use correct barriers in perf ring buffer walkDaniel Borkmann
Given libbpf is a generic library and not restricted to x86-64 only, the compiler barrier in bpf_perf_event_read_simple() after fetching the head needs to be replaced with smp_rmb() at minimum. Also, writing out the tail we should use WRITE_ONCE() to avoid store tearing. Now that we have the logic in place in ring_buffer_read_head() and ring_buffer_write_tail() helper also used by perf tool which would select the correct and best variant for a given architecture (e.g. x86-64 can avoid CPU barriers entirely), make use of these in order to fix bpf_perf_event_read_simple(). Fixes: d0cabbb021be ("tools: bpf: move the event reading loop to libbpf") Fixes: 39111695b1b8 ("samples: bpf: add bpf_perf_event_output example") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-15bpf: bpftool, add flag to allow non-compat map definitionsJohn Fastabend
Multiple map definition structures exist and user may have non-zero fields in their definition that are not recognized by bpftool and libbpf. The normal behavior is to then fail loading the map. Although this is a good default behavior users may still want to load the map for debugging or other reasons. This patch adds a --mapcompat flag that can be used to override the default behavior and allow loading the map even when it has additional non-zero fields. For now the only user is 'bpftool prog' we can switch over other subcommands as needed. The library exposes an API that consumes a flags field now but I kept the original API around also in case users of the API don't want to expose this. The flags field is an int in case we need more control over how the API call handles errors/features/etc in the future. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-09tools/bpf: use proper type and uapi perf_event.h header for libbpfYonghong Song
Use __u32 instead u32 in libbpf.c and also use uapi perf_event.h instead of tools/perf/perf-sys.h. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-08libbpf: relicense libbpf as LGPL-2.1 OR BSD-2-ClauseAlexei Starovoitov
libbpf is maturing as a library and gaining features that no other bpf libraries support (BPF Type Format, bpf to bpf calls, etc) Many Apache2 licensed projects (like bcc, bpftrace, gobpf, cilium, etc) would like to use libbpf, but cannot do this yet, since Apache Foundation explicitly states that LGPL is incompatible with Apache2. Hence let's relicense libbpf as dual license LGPL-2.1 or BSD-2-Clause, since BSD-2 is compatible with Apache2. Dual LGPL or Apache2 is invalid combination. Fix license mistake in Makefile as well. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrey Ignatov <rdna@fb.com> Acked-by: Arnaldo Carvalho de Melo <acme@kernel.org> Acked-by: Björn Töpel <bjorn.topel@intel.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Beckett <david.beckett@netronome.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Joe Stringer <joe@ovn.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Thomas Graf <tgraf@suug.ch> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Wang Nan <wangnan0@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04libbpf: Use __u32 instead of u32 in bpf_program__loadAndrey Ignatov
Make bpf_program__load consistent with other interfaces: use __u32 instead of u32. That in turn fixes build of samples: In file included from ./samples/bpf/trace_output_user.c:21:0: ./tools/lib/bpf/libbpf.h:132:9: error: unknown type name ‘u32’ u32 kern_version); ^ Fixes: commit 29cd77f41620d ("libbpf: Support loading individual progs") Signed-off-by: Andrey Ignatov <rdna@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04libbpf: Consistent prefixes for interfaces in str_error.h.Andrey Ignatov
libbpf is used more and more outside kernel tree. That means the library should follow good practices in library design and implementation to play well with third party code that uses it. One of such practices is to have a common prefix (or a few) for every interface, function or data structure, library provides. I helps to avoid name conflicts with other libraries and keeps API consistent. Inconsistent names in libbpf already cause problems in real life. E.g. an application can't use both libbpf and libnl due to conflicting symbols. Having common prefix will help to fix current and avoid future problems. libbpf already uses the following prefixes for its interfaces: * bpf_ for bpf system call wrappers, program/map/elf-object abstractions and a few other things; * btf_ for BTF related API; * libbpf_ for everything else. The patch renames function in str_error.h to have libbpf_ prefix since it misses one and doesn't fit well into the first two categories. Signed-off-by: Andrey Ignatov <rdna@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-03libbpf: Support loading individual progsJoe Stringer
Allow the individual program load to be invoked. This will help with testing, where a single ELF may contain several sections, some of which denote subprograms that are expected to fail verification, along with some which are expected to pass verification. By allowing programs to be iterated and individually loaded, each program can be independently checked against its expected verification result. Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27libbpf: Support sk_skb/stream_{parser, verdict} section namesAndrey Ignatov
Add section names for BPF_SK_SKB_STREAM_PARSER and BPF_SK_SKB_STREAM_VERDICT attach types to be able to identify them in libbpf_attach_type_by_name. "stream_parser" and "stream_verdict" are used instead of simple "parser" and "verdict" just to avoid possible confusion in a place where attach type is used alone (e.g. in bpftool's show sub-commands) since there is another attach point that can be named as "verdict": BPF_SK_MSG_VERDICT. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27libbpf: Support cgroup_skb/{e,in}gress section namesAndrey Ignatov
Add section names for BPF_CGROUP_INET_INGRESS and BPF_CGROUP_INET_EGRESS attach types to be able to identify them in libbpf_attach_type_by_name. "cgroup_skb" is used instead of "cgroup/skb" mostly to easy possible unifying of how libbpf and bpftool works with section names: * bpftool uses "cgroup_skb" to in "prog list" sub-command; * bpftool uses "ingress" and "egress" in "cgroup list" sub-command; * having two parts instead of three in a string like "cgroup_skb/ingress" can be leveraged to split it to prog_type part and attach_type part, or vise versa: use two parts to make a section name. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27libbpf: Introduce libbpf_attach_type_by_nameAndrey Ignatov
There is a common use-case when ELF object contains multiple BPF programs and every program has its own section name. If it's cgroup-bpf then programs have to be 1) loaded and 2) attached to a cgroup. It's convenient to have information necessary to load BPF program together with program itself. This is where section name works fine in conjunction with libbpf_prog_type_by_name that identifies prog_type and expected_attach_type and these can be used with BPF_PROG_LOAD. But there is currently no way to identify attach_type by section name and it leads to messy code in user space that reinvents guessing logic every time it has to identify attach type to use with BPF_PROG_ATTACH. The patch introduces libbpf_attach_type_by_name that guesses attach type by section name if a program can be attached. The difference between expected_attach_type provided by libbpf_prog_type_by_name and attach_type provided by libbpf_attach_type_by_name is the former is used at BPF_PROG_LOAD time and can be zero if a program of prog_type X has only one corresponding attach type Y whether the latter provides specific attach type to use with BPF_PROG_ATTACH. No new section names were added to section_names array. Only existing ones were reorganized and attach_type was added where appropriate. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-09-25 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Allow for RX stack hardening by implementing the kernel's flow dissector in BPF. Idea was originally presented at netconf 2017 [0]. Quote from merge commit: [...] Because of the rigorous checks of the BPF verifier, this provides significant security guarantees. In particular, the BPF flow dissector cannot get inside of an infinite loop, as with CVE-2013-4348, because BPF programs are guaranteed to terminate. It cannot read outside of packet bounds, because all memory accesses are checked. Also, with BPF the administrator can decide which protocols to support, reducing potential attack surface. Rarely encountered protocols can be excluded from dissection and the program can be updated without kernel recompile or reboot if a bug is discovered. [...] Also, a sample flow dissector has been implemented in BPF as part of this work, from Petar and Willem. [0] http://vger.kernel.org/netconf2017_files/rx_hardening_and_udp_gso.pdf 2) Add support for bpftool to list currently active attachment points of BPF networking programs providing a quick overview similar to bpftool's perf subcommand, from Yonghong. 3) Fix a verifier pruning instability bug where a union member from the register state was not cleared properly leading to branches not being pruned despite them being valid candidates, from Alexei. 4) Various smaller fast-path optimizations in XDP's map redirect code, from Jesper. 5) Enable to recognize BPF_MAP_TYPE_REUSEPORT_SOCKARRAY maps in bpftool, from Roman. 6) Remove a duplicate check in libbpf that probes for function storage, from Taeung. 7) Fix an issue in test_progs by avoid checking for errno since on success its value should not be checked, from Mauricio. 8) Fix unused variable warning in bpf_getsockopt() helper when CONFIG_INET is not configured, from Anders. 9) Fix a compilation failure in the BPF sample code's use of bpf_flow_keys, from Prashant. 10) Minor cleanups in BPF code, from Yue and Zhong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-18tools lib bpf: Provide wrapper for strerror_r to build in !_GNU_SOURCE systemsArnaldo Carvalho de Melo
Same problem that got fixed in a similar fashion in tools/perf/ in c8b5f2c96d1b ("tools: Introduce str_error_r()"), fix it in the same way, licensing needs to be sorted out to libbpf to use libapi, so, for this simple case, just get the same wrapper in tools/lib/bpf. This makes libbpf and its users (bpftool, selftests, perf) to build again in Alpine Linux 3.[45678] and edge. Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: Hendrik Brueckner <brueckner@linux.ibm.com> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Quentin Monnet <quentin.monnet@netronome.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Cc: Yonghong Song <yhs@fb.com> Fixes: 1ce6a9fc1549 ("bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"") Link: https://lkml.kernel.org/r/20180917151636.GA21790@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-09-14bpf: support flow dissector in libbpf and bpftoolPetar Penkov
This patch extends libbpf and bpftool to work with programs of type BPF_PROG_TYPE_FLOW_DISSECTOR. Signed-off-by: Petar Penkov <ppenkov@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-05libbpf: Remove the duplicate checking of function storageTaeung Song
After the commit eac7d84519a3 ("tools: libbpf: don't return '.text' as a program for multi-function programs"), bpf_program__next() in bpf_object__for_each_program skips the function storage such as .text, so eliminate the duplicate checking. Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Taeung Song <treeze.taeung@gmail.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-11bpf: test BPF_MAP_TYPE_REUSEPORT_SOCKARRAYMartin KaFai Lau
This patch adds tests for the new BPF_MAP_TYPE_REUSEPORT_SOCKARRAY. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-08-07 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add cgroup local storage for BPF programs, which provides a fast accessible memory for storing various per-cgroup data like number of transmitted packets, etc, from Roman. 2) Support bpf_get_socket_cookie() BPF helper in several more program types that have a full socket available, from Andrey. 3) Significantly improve the performance of perf events which are reported from BPF offload. Also convert a couple of BPF AF_XDP samples overto use libbpf, both from Jakub. 4) seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header. Adds this action now to the seg6local BPF interface, from Mathieu. 5) Do not mark dst register as unbounded in MOV64 instruction when both src and dst register are the same, from Arthur. 6) Define u_smp_rmb() and u_smp_wmb() to their respective barrier instructions on arm64 for the AF_XDP sample code, from Brian. 7) Convert the tcp_client.py and tcp_server.py BPF selftest scripts over from Python 2 to Python 3, from Jeremy. 8) Enable BTF build flags to the BPF sample code Makefile, from Taeung. 9) Remove an unnecessary rcu_read_lock() in run_lwt_bpf(), from Taehee. 10) Several improvements to the README.rst from the BPF documentation to make it more consistent with RST format, from Tobin. 11) Replace all occurrences of strerror() by calls to strerror_r() in libbpf and fix a FORTIFY_SOURCE build error along with it, from Thomas. 12) Fix a bug in bpftool's get_btf() function to correctly propagate an error via PTR_ERR(), from Yue. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The BTF conflicts were simple overlapping changes. The virtio_net conflict was an overlap of a fix of statistics counter, happening alongisde a move over to a bonafide statistics structure rather than counting value on the stack. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-31bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"Thomas Richter
Commit 531b014e7a2f ("tools: bpf: make use of reallocarray") causes a compiler error when building the perf tool in the linux-next tree. Compile file tools/lib/bpf/libbpf.c on a FEDORA 28 installation with gcc compiler version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20) shows this error message: [root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2" [...] make -f /home6/tmricht/linux-next/tools/build/Makefile.build dir=./util/scripting-engines obj=libperf libbpf.c: In function ‘bpf_object__elf_collect’: libbpf.c:811:15: error: ignoring return value of ‘strerror_r’, declared with attribute warn_unused_result [-Werror=unused-result] strerror_r(-err, errmsg, sizeof(errmsg)); ^ cc1: all warnings being treated as errors mv: cannot stat './.libbpf.o.tmp': No such file or directory /home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed Replace all occurrences of strerror() by calls to strerror_r(). To keep the compiler quiet also use the return value from strerror_r() otherwise a 'variable set but not use' warning which is treated as error terminates the compile. Fixes: 531b014e7a2f ("tools: bpf: make use of reallocarray") Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-28perf build: Build error in libbpf missing initializationThomas Richter
In linux-next tree compiling the perf tool with additional make flags EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2" causes a compiler error. It is the warning 'variable may be used uninitialized' which is treated as error: I compile it using a FEDORA 28 installation, my gcc compiler version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20). The file that causes the error is tools/lib/bpf/libbpf.c. [root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2" [...] Makefile.config:849: No openjdk development package found, please install JDK package, e.g. openjdk-8-jdk, java-1.8.0-openjdk-devel Warning: Kernel ABI header at 'tools/include/uapi/linux/if_link.h' differs from latest version at 'include/uapi/linux/if_link.h' CC libbpf.o libbpf.c: In function ‘bpf_perf_event_read_simple’: libbpf.c:2342:6: error: ‘ret’ may be used uninitialized in this function [-Werror=maybe-uninitialized] int ret; ^ cc1: all warnings being treated as errors mv: cannot stat './.libbpf.o.tmp': No such file or directory /home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27tools: libbpf: add bpf_object__find_program_by_title()Jakub Kicinski
Allow users to find programs by section names. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27tools: libbpf: handle NULL program gracefully in bpf_program__nth_fd()Jakub Kicinski
bpf_map__fd() handles NULL map gracefully and returns -EINVAL. bpf_program__fd() and bpf_program__nth_fd() crash in this case. Make the behaviour more consistent by validating prog pointer as well. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25bpf: Introduce BPF_ANNOTATE_KV_PAIRMartin KaFai Lau
This patch introduces BPF_ANNOTATE_KV_PAIR to signal the bpf loader about the btf key_type and value_type of a bpf map. Please refer to the changes in test_btf_haskv.c for its usage. Both iproute2 and libbpf loader will then have the same convention to find out the map's btf_key_type_id and btf_value_type_id from a map's name. Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf") Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25bpf: Replace [u]int32_t and [u]int64_t in libbpfMartin KaFai Lau
This patch replaces [u]int32_t and [u]int64_t usage with __[su]32 and __[su]64. The same change goes for [u]int16_t and [u]int8_t. Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11tools: libbpf: allow map reuseJakub Kicinski
More advanced applications may want to only replace programs without destroying associated maps. Allow libbpf users to achieve that. Instead of always creating all of the maps at load time, expose to users an API to reconstruct the map object from already existing map. The map parameters are read from the kernel and replace the parameters of the ELF map. libbpf does not restrict the map replacement, i.e. the reused map does not have to be compatible with the ELF map definition. We relay on the verifier for checking the compatibility between maps and programs. The ELF map definition is completely overwritten by the information read from the kernel, to make sure libbpf's view of map object corresponds to the actual map. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11tools: bpf: make use of reallocarrayJakub Kicinski
reallocarray() is a safer variant of realloc which checks for multiplication overflow in case of array allocation. Since it's not available in Glibc < 2.26 import kernel's overflow.h and add a static inline implementation when needed. Use feature detection to probe for existence of reallocarray. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11tools: libbpf: move library error code into a separate fileJakub Kicinski
libbpf_strerror() depends on XSI-compliant (POSIX) version of strerror_r(), which prevents us from using GNU-extensions in libbpf.c, like reallocarray() or dup3(). Move error printing code into a separate file to allow it to continue using POSIX strerror_r(). No functional changes. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11tools: libbpf: add extended attributes version of bpf_object__open()Jakub Kicinski
Similarly to bpf_prog_load() users of bpf_object__open() may need to specify the expected program type. Program type is needed at open to avoid the kernel version check for program types which don't require it. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11tools: libbpf: recognize offload neutral mapsJakub Kicinski
Add helper to libbpf for recognizing maps which should not have ifindex set when program is loaded. These maps only contain host metadata and therefore are not marked for offload, e.g. the perf event map. Use this helper in bpf_prog_load_xattr(). Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11tools: libbpf: expose the prog type guessing from section name logicJakub Kicinski
libbpf can guess program type based on ELF section names. As libbpf becomes more popular its association between section name strings and types becomes more of a standard. Allow libbpf users to use the same logic for matching strings to types, e.g. when the string originates from command line. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01tools: libbpf: don't return '.text' as a program for multi-function programsJakub Kicinski
Make bpf_program__next() skip over '.text' section if object file has pseudo calls. The '.text' section is hardly a program in that case, it's more of a storage for code of functions other than main. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01tools: libbpf: restore the ability to load programs from .text sectionJakub Kicinski
libbpf used to be able to load programs from the default section called '.text'. It's not very common to leave sections unnamed, but if it happens libbpf will fail to load the programs reporting -EINVAL from the kernel. The -EINVAL comes from bpf_obj_name_cpy() because since 48cca7e44f9f ("libbpf: add support for bpf_call") libbpf does not resolve program names for programs in '.text', defaulting to '.text'. '.text', however, does not pass the (isalnum(*src) || *src == '_') check in bpf_obj_name_cpy(). With few extra lines of code we can limit the pseudo call assumptions only to objects which actually contain code relocations. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01tools: libbpf: allow setting ifindex for programs and mapsJakub Kicinski
Users of bpf_object__open()/bpf_object__load() APIs may want to load the programs and maps onto a device for offload. Allow setting ifindex on those sub-objects. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01tools: libbpf: add section names for missing program typesJakub Kicinski
Specify default section names for BPF_PROG_TYPE_LIRC_MODE2 and BPF_PROG_TYPE_LWT_SEG6LOCAL, these are the only two missing right now. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-30bpf: add selftest for lirc_mode2 type programSean Young
This is simple test over rc-loopback. Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-28libbpf: Support guessing sendmsg{4,6} progsAndrey Ignatov
libbpf can guess prog type and expected attach type based on section name. Add hints for "cgroup/sendmsg4" and "cgroup/sendmsg6" section names. Signed-off-by: Andrey Ignatov <rdna@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2018-05-24 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Björn Töpel cleans up AF_XDP (removes rebind, explicit cache alignment from uapi, etc). 2) David Ahern adds mtu checks to bpf_ipv{4,6}_fib_lookup() helpers. 3) Jesper Dangaard Brouer adds bulking support to ndo_xdp_xmit. 4) Jiong Wang adds support for indirect and arithmetic shifts to NFP 5) Martin KaFai Lau cleans up BTF uapi and makes the btf_header extensible. 6) Mathieu Xhonneux adds an End.BPF action to seg6local with BPF helpers allowing to edit/grow/shrink a SRH and apply on a packet generic SRv6 actions. 7) Sandipan Das adds support for bpf2bpf function calls in ppc64 JIT. 8) Yonghong Song adds BPF_TASK_FD_QUERY command for introspection of tracing events. 9) other misc fixes from Gustavo A. R. Silva, Sirio Balmelli, John Fastabend, and Magnus Karlsson ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24ipv6: sr: Add seg6local action End.BPFMathieu Xhonneux
This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>