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* tools/libbpf: handle issues with bpf ELF objects containing .eh_framesJesper Dangaard Brouer2018-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | V3: More generic skipping of relo-section (suggested by Daniel) If clang >= 4.0.1 is missing the option '-target bpf', it will cause llc/llvm to create two ELF sections for "Exception Frames", with section names '.eh_frame' and '.rel.eh_frame'. The BPF ELF loader library libbpf fails when loading files with these sections. The other in-kernel BPF ELF loader in samples/bpf/bpf_load.c, handle this gracefully. And iproute2 loader also seems to work with these "eh" sections. The issue in libbpf is caused by bpf_object__elf_collect() skipping some sections, and later when performing relocation it will be pointing to a skipped section, as these sections cannot be found by bpf_object__find_prog_by_idx() in bpf_object__collect_reloc(). This is a general issue that also occurs for other sections, like debug sections which are also skipped and can have relo section. As suggested by Daniel. To avoid keeping state about all skipped sections, instead perform a direct qlookup in the ELF object. Lookup the section that the relo-section points to and check if it contains executable machine instructions (denoted by the sh_flags SHF_EXECINSTR). Use this check to also skip irrelevant relo-sections. Note, for samples/bpf/ the '-target bpf' parameter to clang cannot be used due to incompatibility with asm embedded headers, that some of the samples include. This is explained in more details by Yonghong Song in bpf_devel_QA. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* tools/libbpf: improve the pr_debug statements to contain section numbersJesper Dangaard Brouer2018-02-09
| | | | | | | | | | | | | | | | While debugging a bpf ELF loading issue, I needed to correlate the ELF section number with the failed relocation section reference. Thus, add section numbers/index to the pr_debug. In debug mode, also print section that were skipped. This helped me identify that a section (.eh_frame) was skipped, and this was the reason the relocation section (.rel.eh_frame) could not find that section number. The section numbers corresponds to the readelf tools Section Headers [Nr]. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: complete list of strings for guessing program typeQuentin Monnet2018-02-08
| | | | | | | | | | | | | | | | | It seems that the type guessing feature for libbpf, based on the name of the ELF section the program is located in, was inspired from samples/bpf/prog_load.c, which was not used by any sample for loading programs of certain types such as TC actions and classifiers, or LWT-related types. As a consequence, libbpf is not able to guess the type of such programs and to load them automatically if type is not provided to the `bpf_load_prog()` function. Add ELF section names associated to those eBPF program types so that they can be loaded with e.g. bpftool as well. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: add missing SPDX-License-IdentifierEric Leblond2018-02-02
| | | | | | Signed-off-by: Eric Leblond <eric@regit.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: add function to setup XDPEric Leblond2018-02-02
| | | | | | | | | Most of the code is taken from set_link_xdp_fd() in bpf_load.c and slightly modified to be library compliant. Signed-off-by: Eric Leblond <eric@regit.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: fix string comparison for guessing eBPF program typeQuentin Monnet2018-01-17
| | | | | | | | | | | | | | | | | | | | | libbpf is able to deduce the type of a program from the name of the ELF section in which it is located. However, the comparison is made on the first n characters, n being determined with sizeof() applied to the reference string (e.g. "xdp"). When such section names are supposed to receive a suffix separated with a slash (e.g. "kprobe/"), using sizeof() takes the final NUL character of the reference string into account, which implies that both strings must be equal. Instead, the desired behaviour would consist in taking the length of the string, *without* accounting for the ending NUL character, and to make sure the reference string is a prefix to the ELF section name. Subtract 1 to the total size of the string for obtaining the length for the comparison. Fixes: 583c90097f72 ("libbpf: add ability to guess program type based on section name") Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: Fix build errors.David Miller2017-12-20
| | | | | | | | | | | These elf object pieces are of type Elf64_Xword and therefore could be "long long" on some builds. Cast to "long long" and use printf format %lld to deal with this since we are building with -Werror=format. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: add support for bpf_callAlexei Starovoitov2017-12-17
| | | | | | | | | | | | | | | | | | | - recognize relocation emitted by llvm - since all regular function will be kept in .text section and llvm takes care of pc-relative offsets in bpf_call instruction simply copy all of .text to relevant program section while adjusting bpf_call instructions in program section to point to newly copied body of instructions from .text - do so for all programs in the elf file - set all programs types to the one passed to bpf_prog_load() Note for elf files with multiple programs that use different functions in .text section we need to do 'linker' style logic. This work is still TBD Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: prefer global symbols as bpf program name sourceRoman Gushchin2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Libbpf picks the name of the first symbol in the corresponding elf section to use as a program name. But without taking symbol's scope into account it may end's up with some local label as a program name. E.g.: $ bpftool prog 1: type 15 name LBB0_10 tag 0390a5136ba23f5c loaded_at Dec 07/17:22 uid 0 xlated 456B not jited memlock 4096B Fix this by preferring global symbols as program name. For instance: $ bpftool prog 1: type 15 name bpf_prog1 tag 0390a5136ba23f5c loaded_at Dec 07/17:26 uid 0 xlated 456B not jited memlock 4096B Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Quentin Monnet <quentin.monnet@netronome.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: add ability to guess program type based on section nameRoman Gushchin2017-12-14
| | | | | | | | | | | | | | | | The bpf_prog_load() function will guess program type if it's not specified explicitly. This functionality will be used to implement loading of different programs without asking a user to specify the program type. In first order it will be used by bpftool. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Quentin Monnet <quentin.monnet@netronome.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: use map_flags when creating mapsCraig Gallek2017-10-05
| | | | | | | | | This is required to use BPF_MAP_TYPE_LPM_TRIE or any other map type which requires flags. Signed-off-by: Craig Gallek <kraig@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* libbpf: parse maps sections of varying sizeCraig Gallek2017-10-05
| | | | | | | | | | | | | | | | | | | This library previously assumed a fixed-size map options structure. Any new options were ignored. In order to allow the options structure to grow and to support parsing older programs, this patch updates the maps section parsing to handle varying sizes. Object files with maps sections smaller than expected will have the new fields initialized to zero. Object files which have larger than expected maps sections will be rejected unless all of the unrecognized data is zero. This change still assumes that each map definition in the maps section is the same size. Signed-off-by: Craig Gallek <kraig@google.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: libbpf: Provide basic API support to specify BPF obj nameMartin KaFai Lau2017-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch extends the libbpf to provide API support to allow specifying BPF object name. In tools/lib/bpf/libbpf, the C symbol of the function and the map is used. Regarding section name, all maps are under the same section named "maps". Hence, section name is not a good choice for map's name. To be consistent with map, bpf_prog also follows and uses its function symbol as the prog's name. This patch adds logic to collect function's symbols in libbpf. There is existing codes to collect the map's symbols and no change is needed. The bpf_load_program_name() and bpf_map_create_name() are added to take the name argument. For the other bpf_map_create_xxx() variants, a name argument is directly added to them. In samples/bpf, bpf_load.c in particular, the symbol is also used as the map's name and the map symbols has already been collected in the existing code. For bpf_prog, bpf_load.c does not collect the function symbol name. We can consider to collect them later if there is a need to continue supporting the bpf_load.c. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2017-08-21
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| * tools lib bpf: improve warningEric Leblond2017-08-20
| | | | | | | | | | | | | | Signed-off-by: Eric Leblond <eric@regit.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | bpf: selftests add sockmap testsJohn Fastabend2017-08-16
|/ | | | | | | | | | This generates a set of sockets, attaches BPF programs, and sends some simple traffic using basic send/recv pattern. Additionally, we do a bunch of negative tests to ensure adding/removing socks out of the sockmap fail correctly. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tools/lib/bpf: expose bpf_program__set_type()Alexei Starovoitov2017-04-01
| | | | | | | | | expose bpf_program__set_type() to set program type Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tools lib bpf: Add bpf_object__pin()Joe Stringer2017-01-31
| | | | | | | | | | | | | | | | | | | | | | | | | Add a new API to pin a BPF object to the filesystem. The user can specify the path within a BPF filesystem to pin the object. Programs will be pinned under a subdirectory named the same as the program, with each instance appearing as a numbered file under that directory, and maps will be pinned under the path using the name of the map as the file basename. For example, with the directory '/sys/fs/bpf/foo' and a BPF object which contains two instances of a program named 'bar', and a map named 'baz': /sys/fs/bpf/foo/bar/0 /sys/fs/bpf/foo/bar/1 /sys/fs/bpf/foo/baz Signed-off-by: Joe Stringer <joe@ovn.org> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170126212001.14103-4-joe@ovn.org [ Check snprintf >= for truncation, as snprintf(bf, size, ...) == size also means truncation ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Add bpf_map__pin()Joe Stringer2017-01-31
| | | | | | | | | | | | | Add a new API to pin a BPF map to the filesystem. The user can specify the path full path within a BPF filesystem to pin the map. Signed-off-by: Joe Stringer <joe@ovn.org> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170126212001.14103-3-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Add BPF program pinning APIsJoe Stringer2017-01-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add new APIs to pin a BPF program (or specific instances) to the filesystem. The user can specify the path full path within a BPF filesystem to pin the program. bpf_program__pin_instance(prog, path, n) will pin the nth instance of 'prog' to the specified path. bpf_program__pin(prog, path) will create the directory 'path' (if it does not exist) and pin each instance within that directory. For instance, path/0, path/1, path/2. Committer notes: - Add missing headers for mkdir() - Check strdup() for failure - Check snprintf >= size, not >, as == also means truncated, see 'man snprintf', return value. - Conditionally define BPF_FS_MAGIC, as it isn't in magic.h in older systems and we're not yet having a tools/include/uapi/linux/magic.h copy. - Do not include linux/magic.h, not present in older distros. Signed-off-by: Joe Stringer <joe@ovn.org> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170126212001.14103-2-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Add libbpf_get_error()Joe Stringer2017-01-26
| | | | | | | | | | | | | | | | | This function will turn a libbpf pointer into a standard error code (or 0 if the pointer is valid). This also allows removal of the dependency on linux/err.h in the public header file, which causes problems in userspace programs built against libbpf. Signed-off-by: Joe Stringer <joe@ovn.org> Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170123011128.26534-5-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Add set/is helpers for all prog typesJoe Stringer2017-01-26
| | | | | | | | | | | | | These bpf_prog_types were exposed in the uapi but there were no corresponding functions to set these types for programs in libbpf. Signed-off-by: Joe Stringer <joe@ovn.org> Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170123011128.26534-4-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Define prog_type fns with macroJoe Stringer2017-01-26
| | | | | | | | | | | | | Turning this into a macro allows future prog types to be added with a single line per type. Signed-off-by: Joe Stringer <joe@ovn.org> Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170123011128.26534-3-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Fix map offsets in relocationJoe Stringer2017-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4708bbda5cb2 ("tools lib bpf: Fix maps resolution") attempted to fix map resolution by identifying the number of symbols that point to maps, and using this number to resolve each of the maps. However, during relocation the original definition of the map size was still in use. For up to two maps, the calculation was correct if there was a small difference in size between the map definition in libbpf and the one that the client library uses. However if the difference was large, particularly if more than two maps were used in the BPF program, the relocation would fail. For example, when using a map definition with size 28, with three maps, map relocation would count: (sym_offset / sizeof(struct bpf_map_def) => map_idx) (0 / 16 => 0), ie map_idx = 0 (28 / 16 => 1), ie map_idx = 1 (56 / 16 => 3), ie map_idx = 3 So, libbpf reports: libbpf: bpf relocation: map_idx 3 large than 2 Fix map relocation by checking the exact offset of maps when doing relocation. Signed-off-by: Joe Stringer <joe@ovn.org> [Allow different map size in an object] Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: netdev@vger.kernel.org Fixes: 4708bbda5cb2 ("tools lib bpf: Fix maps resolution") Link: http://lkml.kernel.org/r/20170123011128.26534-2-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Add flags to bpf_create_map()Joe Stringer2016-12-15
| | | | | | | | | | | | | | | | | Commit 6c905981743 ("bpf: pre-allocate hash map elements") introduces map_flags to bpf_attr for BPF_MAP_CREATE command. Expose this new parameter in libbpf. By exposing it, users can access flags such as whether or not to preallocate the map. Signed-off-by: Joe Stringer <joe@ovn.org> Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Link: http://lkml.kernel.org/r/20161209024620.31660-4-joe@ovn.org [ Added clarifying comment made by Wang Nan ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Retrive bpf_map through offset of bpf_map_defWang Nan2016-11-29
| | | | | | | | | | | | | | | | | Add a new API to libbpf, caller is able to get bpf_map through the offset of bpf_map_def to 'maps' section. The API will be used to help jitted perf hook code find fd of a map. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Joe Stringer <joe@ovn.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/20161126070354.141764-4-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Add private field for bpf_objectWang Nan2016-11-29
| | | | | | | | | | | | | | Similar to other classes defined in libbpf.h (map and program), allow 'object' class has its own private data. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Joe Stringer <joe@ovn.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/20161126070354.141764-3-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Fix maps resolutionEric Leblond2016-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is not correct to assimilate the elf data of the maps section to an array of map definition. In fact the sizes differ. The offset provided in the symbol section has to be used instead. This patch fixes a bug causing a elf with two maps not to load correctly. Wang Nan added: This patch requires a name for each BPF map, so array of BPF maps is not allowed. This restriction is reasonable, because kernel verifier forbid indexing BPF map from such array unless the index is a fixed value, but if the index is fixed why not merging it into name? For example: Program like this: ... unsigned long cpu = get_smp_processor_id(); int *pval = map_lookup_elem(&map_array[cpu], &key); ... Generates bytecode like this: 0: (b7) r1 = 0 1: (63) *(u32 *)(r10 -4) = r1 2: (b7) r1 = 680997 3: (63) *(u32 *)(r10 -8) = r1 4: (85) call 8 5: (67) r0 <<= 4 6: (18) r1 = 0x112dd000 8: (0f) r0 += r1 9: (bf) r2 = r10 10: (07) r2 += -4 11: (bf) r1 = r0 12: (85) call 1 Where instruction 8 is the computation, 8 and 11 render r1 to an invalid value for function map_lookup_elem, causes verifier report error. Signed-off-by: Eric Leblond <eric@regit.org> Cc: Alexei Starovoitov <ast@fb.com> Cc: He Kuang <hekuang@huawei.com> Cc: Wang Nan <wangnan0@huawei.com> [ Merge bpf_object__init_maps_name into bpf_object__init_maps. Fix segfault for buggy BPF script Validate obj->maps ] Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/20161115040617.69788-5-wangnan0@huawei.com Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Use official ELF e_machine valueWang Nan2016-07-26
| | | | | | | | | | | | | | New LLVM will issue newly assigned EM_BPF machine code. The new code will be propagated to glibc and libelf. This patch introduces the new machine code to libbpf. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1468821668-60088-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Report error when kernel doesn't support program typeWang Nan2016-07-13
| | | | | | | | | | | | | Now libbpf support tracepoint program type. Report meaningful error when kernel version is less than 4.7. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1468406646-21642-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: New API to adjust type of a BPF programWang Nan2016-07-13
| | | | | | | | | | | | | | Add 4 new APIs to adjust and query the type of a BPF program. Load program according to type set by caller. Default is set to BPF_PROG_TYPE_KPROBE. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1468406646-21642-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Add license headerWang Nan2016-07-04
| | | | | | | | | | | | | | Adding a missing license descriptopn header to files in libbpf, make it LGPL-2.1. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Eric Leblond <eleblond@stamus-networks.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1467630162-193121-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Fix spelling mistake: "missmatch" -> "mismatch"Colin Ian King2016-06-29
| | | | | | | | | | | | Trivial fix to spelling mistake Signed-off-by: Colin King <colin.king@canonical.com> Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1467116617-8318-1-git-send-email-colin.king@canonical.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Rename set_private() to set_priv()Arnaldo Carvalho de Melo2016-06-06
| | | | | | | | | | | | | | For consistency with class__priv() elsewhere, and with the callback typedef for clearing those areas (e.g. bpf_map_clear_priv_t). Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/n/tip-rnbiyv27ohw8xppsgx0el3xb@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Make bpf_program__get_private() use IS_ERR()Arnaldo Carvalho de Melo2016-06-06
| | | | | | | | | | | | | For consistency with bpf_map__priv() and elsewhere. Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/n/tip-x17nk5mrazkf45z0l0ahlmo8@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Remove _get_ from non-refcount method namesArnaldo Carvalho de Melo2016-06-06
| | | | | | | | | | | | | | The use of this term is not warranted here, we use it in the kernel sources and in tools/ for refcounting, so, for consistency, rename them. Acked-bu: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/n/tip-4ya1ot2e2fkrz48ws9ebiofs@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Rename bpf_map__get_fd() to bpf_map__fd()Arnaldo Carvalho de Melo2016-06-06
| | | | | | | | | | | | | For consistency, leaving "get" for reference counting. Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/n/tip-msy8sxfz9th6gl2xjeci2btm@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Use IS_ERR() reporting macros with bpf_map__get_def()Arnaldo Carvalho de Melo2016-06-06
| | | | | | | | | | | | | | | | And for consistency, rename it to bpf_map__def(), leaving "get" for reference counting. Also make it return a const pointer, as suggested by Wang. Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/n/tip-mer00xqkiho0ymg66b5i9luw@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Rename bpf_map__get_name() to bpf_map__name()Arnaldo Carvalho de Melo2016-06-06
| | | | | | | | | | | | | For consistency, leaving "get" for reference counting. Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/n/tip-crnflv84ejyhpba933ec71gs@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Use IS_ERR() reporting macros with bpf_map__get_private()Arnaldo Carvalho de Melo2016-06-06
| | | | | | | | | | | | | | | | | | | | | | | | To try to, over time, consistently use the IS_ERR() interface instead of using two return values, i.e. the integer return value for an error and the pointer address to return the bpf_map->priv pointer. Also rename it to bpf__priv(), to leave the "get" term for reference counting. Noticed while working on using BPF for collecting non-integer syscall argument payloads (struct sockaddr in calls such as connect(), for instance), where we need to use BPF maps and thus generalise bpf__setup_stdout() to connect bpf_output events with maps in a bpf proggie. Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/n/tip-saypxyd6ptrct379jqgxx4bl@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf bpf: Check relocation target sectionWang Nan2016-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Libbpf should check the target section before doing relocation to ensure the relocation is correct. If not, a bug in LLVM causes an error. See [1]. Also, if an incorrect BPF script uses both global variable and map, global variable whould be treated as map and be relocated without error. This patch saves the id of the map section into obj->efile and compare target section of a relocation symbol against it during relocation. Previous patch introduces a test case about this problem. After this patch: # ~/perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok 37.3: Test BPF relocation checker : Ok # perf test -v BPF ... 37.3: Test BPF relocation checker : ... libbpf: loading object '[bpf_relocation_test]' from buffer libbpf: section .strtab, size 126, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=sys_write, size 104, link 0, flags 6, type=1 libbpf: found program func=sys_write libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: maps in [bpf_relocation_test]: 16 bytes libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_relocation_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_relocation_test] is 40400 libbpf: section .symtab, size 144, link 1, flags 0, type=2 libbpf: map 0 is "my_table" libbpf: collecting relocating info for: 'func=sys_write' libbpf: Program 'func=sys_write' contains non-map related relo data pointing to section 65522 bpf: failed to load buffer Compile BPF program failed. test child finished with 0 ---- end ---- Test BPF filter subtest 2: Ok [1] https://llvm.org/bugs/show_bug.cgi?id=26243 Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1453715801-7732-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Fetch map names from correct strtabWang Nan2015-12-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Namhyung Kim pointed out a potential problem in original code that it fetches names of maps from section header string table, which is used to store section names. Original code doesn't cause error because of a LLVM behavior that, it combines shstrtab into strtab. For example: $ echo 'int func() {return 0;}' | x86_64-oe-linux-clang -x c -o temp.o -c - $ readelf -h ./temp.o ELF Header: Magic: 7f 45 4c 46 02 01 01 03 00 00 00 00 00 00 00 00 ... Section header string table index: 1 $ readelf -S ./temp.o There are 10 section headers, starting at offset 0x288: Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align [ 0] NULL 0000000000000000 00000000 0000000000000000 0000000000000000 0 0 0 [ 1] .strtab STRTAB 0000000000000000 00000230 0000000000000051 0000000000000000 0 0 1 ... $ readelf -p .strtab ./temp.o String dump of section '.strtab': [ 1] .text [ 7] .comment [ 10] .bss [ 15] .note.GNU-stack [ 25] .rela.eh_frame [ 34] func [ 39] .strtab [ 41] .symtab [ 49] .data [ 4f] - $ readelf -p .shstrtab ./temp.o readelf: Warning: Section '.shstrtab' was not dumped because it does not exist! Where, 'section header string table index' points to '.strtab', and symbol names are also stored there. However, in case of gcc: $ echo 'int func() {return 0;}' | gcc -x c -o temp.o -c - $ readelf -p .shstrtab ./temp.o String dump of section '.shstrtab': [ 1] .symtab [ 9] .strtab [ 11] .shstrtab [ 1b] .text [ 21] .data [ 27] .bss [ 2c] .comment [ 35] .note.GNU-stack [ 45] .rela.eh_frame $ readelf -p .strtab ./temp.o String dump of section '.strtab': [ 1] func They are separated sections. Although original code doesn't cause error, we'd better use canonical method for fetching symbol names to avoid potential behavior changing. This patch learns from readelf's code, fetches string from sh_link of .symbol section. Signed-off-by: Wang Nan <wangnan0@huawei.com> Reported-and-Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1449541544-67621-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Check return value of strdup when reading map namesWang Nan2015-12-11
| | | | | | | | | | | | | | | Commit 561bbccac72d08babafaa33fd7fa9100ec4c9fb6 ("tools lib bpf: Extract and collect map names from BPF object file") forgets checking return value of strdup(). This patch fixes it. It also checks names pointer before strcmp() for safety. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Fixes: 561bbccac72d ("tools lib bpf: Extract and collect map names from BPF object file") Link: http://lkml.kernel.org/r/1449541544-67621-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Extract and collect map names from BPF object fileWang Nan2015-11-27
| | | | | | | | | | | | | | | | | This patch collects name of maps in BPF object files and saves them into 'maps' field in 'struct bpf_object'. 'bpf_object__get_map_by_name' is introduced to retrive fd and definitions of a map through its name. Signed-off-by: He Kuang <hekuang@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1448614067-197576-3-git-send-email-wangnan0@huawei.com Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Collect map definition in bpf_objectWang Nan2015-11-27
| | | | | | | | | | | | | | | | | | | This patch collects more information from maps sections in BPF object files into 'struct bpf_object', enables later patches access those information (such as the type and size of the map). In this patch, a new handler 'struct bpf_map' is extracted in parallel with bpf_object and bpf_program. Its iterator and accessor is also created. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1448614067-197576-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* bpf tools: Load a program with different instances using preprocessorWang Nan2015-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a preparation for BPF prologue support which allows generating a series of BPF bytecode for fetching kernel data before calling program code. With the newly introduced multiple instances support, perf is able to create different prologues for different kprobe points. Before this patch, a bpf_program can be loaded into kernel only once, and get the only resulting fd. What this patch does is to allow creating and loading different variants of one bpf_program, then fetching their fds. Here we describe the basic idea in this patch. The detailed description of the newly introduced APIs can be found in comments in the patch body. The key of this patch is the new mechanism in bpf_program__load(). Instead of loading BPF program into kernel directly, it calls a 'pre-processor' to generate program instances which would be finally loaded into the kernel based on the original code. To enable the generation of multiple instances, libbpf passes an index to the pre-processor so it know which instance is being loaded. Pre-processor should be called from libbpf's user (perf) using bpf_program__set_prep(). The number of instances and the relationship between indices and the target instance should be clear when calling bpf_program__set_prep(). To retrieve a fd for a specific instance of a program, bpf_program__nth_fd() is introduced. It returns the resulting fd according to index. Signed-off-by: He Kuang <hekuang@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1447675815-166222-8-git-send-email-wangnan0@huawei.com Signed-off-by: Wang Nan <wangnan0@huawei.com> [ Enclosed multi-line if/else blocks with {}, (*func_ptr)() -> func_ptr() ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* bpf tools: Add new API bpf_object__get_kversion()Wang Nan2015-11-06
| | | | | | | | | | | | | bpf_object__get_kversion() can be used to fetch value of object's 'version' section. Following patch will use it for error reporting. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* bpf tools: Improve libbpf error reportingWang Nan2015-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this patch, a series of libbpf specific error numbers and libbpf_strerror() are introduced to help reporting errors. Functions are updated to pass correct the error number through the CHECK_ERR() macro. All users of bpf_object__open{_buffer}() and bpf_program__title() in perf are modified accordingly. In addition, due to the error codes changing, bpf__strerror_load() is also modified to use them. bpf__strerror_head() is also changed accordingly so it can parse libbpf errors. bpf_loader_strerror() is introduced for that purpose, and will be improved by the following patch. load_program() is improved not to dump log buffer if it is empty. log buffer is also used to deduce whether the error was caused by an invalid program or other problem. v1 -> v2: - Using macro for error code. - Fetch error message based on array index, eliminate for-loop. - Use log buffer to detect the reason of failure. 3 new error code are introduced to replace LIBBPF_ERRNO__LOAD. In v1: # perf record -e ./test_ill_program.o ls event syntax error: './test_ill_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP # perf record -e ./test_kversion_nomatch_program.o ls event syntax error: './test_kversion_nomatch_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP # perf record -e ./test_big_program.o ls event syntax error: './test_big_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP In v2: # perf record -e ./test_ill_program.o ls event syntax error: './test_ill_program.o' \___ Kernel verifier blocks program loading SKIP # perf record -e ./test_kversion_nomatch_program.o event syntax error: './test_kversion_nomatch_program.o' \___ Incorrect kernel version SKIP (Will be further improved by following patches) # perf record -e ./test_big_program.o event syntax error: './test_big_program.o' \___ Program too big SKIP Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools lib bpf: Fix compiler warning on CentOS 6Namhyung Kim2015-11-03
| | | | | | | | | | | | | | | | | | | | | CC libbpf.o cc1: warnings being treated as errors libbpf.c: In function 'bpf_program__title': libbpf.c:1037: error: declaration of 'dup' shadows a global declaration /usr/include/unistd.h:528: error: shadowed declaration is here mv: cannot stat `./.libbpf.o.tmp': No such file or directory make[3]: *** [libbpf.o] Error 1 make[2]: *** [libbpf-in.o] Error 2 make[1]: *** [/linux/tools/lib/bpf/libbpf.a] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1446549665-2342-1-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* bpf tools: New API to get name from a BPF objectWang Nan2015-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch there's no way to connect a loaded bpf object to its source file. However, during applying perf's '--filter' to BPF object, without this connection makes things harder, because perf loads all programs together, but '--filter' setting is for each object. The API of bpf_object__open_buffer() is changed to allow passing a name. Fortunately, at this time there's only one user of it (perf test LLVM), so we change it together. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1440742821-44548-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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