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* libbpf: Document API and ABI conventionsAndrey Ignatov2018-11-271-0/+139
| | | | | | | | | | | | | | | | | Document API and ABI for libbpf: naming convention, symbol visibility, ABI versioning. This is just a starting point. Documentation can be significantly extended in the future to cover more topics. ABI versioning section touches only a few basic points with a link to more comprehensive documentation from Ulrich Drepper. This section can be extended in the future when there is better understanding what works well and what not so well in libbpf development process and production usage. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: Verify versioned symbolsAndrey Ignatov2018-11-271-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since ABI versioning info is kept separately from the code it's easy to forget to update it while adding a new API. Add simple verification that all global symbols exported with LIBBPF_API are versioned in libbpf.map version script. The idea is to check that number of global symbols in libbpf-in.o, that is the input to the linker, matches with number of unique versioned symbols in libbpf.so, that is the output of the linker. If these numbers don't match, it may mean some symbol was not versioned and make will fail. "Unique" means that if a symbol is present in more than one version of ABI due to ABI changes, it'll be counted once. Another option to calculate number of global symbols in the "input" could be to count number of LIBBPF_ABI entries in C headers but it seems to be fragile. Example of output when a symbol is missing in version script: ... LD libbpf-in.o LINK libbpf.a LINK libbpf.so Warning: Num of global symbols in libbpf-in.o (115) does NOT match with num of versioned symbols in libbpf.so (114). Please make sure all LIBBPF_API symbols are versioned in libbpf.map. make: *** [check_abi] Error 1 Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: Add version script for DSOAndrey Ignatov2018-11-272-1/+124
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More and more projects use libbpf and one day it'll likely be packaged and distributed as DSO and that requires ABI versioning so that both compatible and incompatible changes to ABI can be introduced in a safe way in the future without breaking executables dynamically linked with a previous version of the library. Usual way to do ABI versioning is version script for the linker. Add such a script for libbpf. All global symbols currently exported via LIBBPF_API macro are added to the version script libbpf.map. The version name LIBBPF_0.0.1 is constructed from the name of the library + version specified by $(LIBBPF_VERSION) in Makefile. Version script does not duplicate the work done by LIBBPF_API macro, it rather complements it. The macro is used at compile time and can be used by compiler to do optimization that can't be done at link time, it is purely about global symbol visibility. The version script, in turn, is used at link time and takes care of ABI versioning. Both techniques are described in details in [1]. Whenever ABI is changed in the future, version script should be changed appropriately. [1] https://www.akkadia.org/drepper/dsohowto.pdf Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: Name changing for btf_get_from_idMartin KaFai Lau2018-11-275-6/+6
| | | | | | | | s/btf_get_from_id/btf__get_from_id/ to restore the API naming convention. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Merge branch 'non-jit-btf-func_info'Alexei Starovoitov2018-11-276-76/+55
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yonghong Song says: ==================== Commit 838e96904ff3 ("bpf: Introduce bpf_func_info") added bpf func info support. The userspace is able to get better ksym's for bpf programs with jit, and is able to print out func prototypes. For a program containing func-to-func calls, the existing implementation returns user specified number of function calls and BTF types if jit is enabled. If the jit is not enabled, it only returns the type for the main function. This is undesirable. Interpreter may still be used and we should keep feature identical regardless of whether jit is enabled or not. This patch fixed this discrepancy. The following example shows bpftool output for the bpf program in selftests test_btf_haskv.o when jit is disabled: $ bpftool prog dump xlated id 1490 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): 0: (85) call pc+2#__bpf_prog_run_args32 1: (b7) r0 = 0 2: (95) exit int test_long_fname_1(struct dummy_tracepoint_args * arg): 3: (85) call pc+1#__bpf_prog_run_args32 4: (95) exit int test_long_fname_2(struct dummy_tracepoint_args * arg): 5: (b7) r2 = 0 6: (63) *(u32 *)(r10 -4) = r2 7: (79) r1 = *(u64 *)(r1 +8) 8: (15) if r1 == 0x0 goto pc+9 9: (bf) r2 = r10 10: (07) r2 += -4 11: (18) r1 = map[id:1173] 13: (85) call bpf_map_lookup_elem#77088 14: (15) if r0 == 0x0 goto pc+3 15: (61) r1 = *(u32 *)(r0 +4) 16: (07) r1 += 1 17: (63) *(u32 *)(r0 +4) = r1 18: (95) exit $ bpftool prog dump jited id 1490 no instructions returned ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * tools/bpf: change selftest test_btf for both jit and non-jitYonghong Song2018-11-271-30/+3
| | | | | | | | | | | | | | | | | | | | The selftest test_btf is changed to test both jit and non-jit. The test result should be the same regardless of whether jit is enabled or not. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: btf: support proper non-jit func infoYonghong Song2018-11-275-46/+52
|/ | | | | | | | | | | | | | | | | | | | | | Commit 838e96904ff3 ("bpf: Introduce bpf_func_info") added bpf func info support. The userspace is able to get better ksym's for bpf programs with jit, and is able to print out func prototypes. For a program containing func-to-func calls, the existing implementation returns user specified number of function calls and BTF types if jit is enabled. If the jit is not enabled, it only returns the type for the main function. This is undesirable. Interpreter may still be used and we should keep feature identical regardless of whether jit is enabled or not. This patch fixed this discrepancy. Fixes: 838e96904ff3 ("bpf: Introduce bpf_func_info") Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Avoid unnecessary instruction in convert_bpf_ld_abs()David Miller2018-11-261-1/+2
| | | | | | | | 'offset' is constant and if it is zero, no need to subtract it from BPF_REG_TMP. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2018-11-2663-596/+4208
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2018-11-26 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Extend BTF to support function call types and improve the BPF symbol handling with this info for kallsyms and bpftool program dump to make debugging easier, from Martin and Yonghong. 2) Optimize LPM lookups by making longest_prefix_match() handle multiple bytes at a time, from Eric. 3) Adds support for loading and attaching flow dissector BPF progs from bpftool, from Stanislav. 4) Extend the sk_lookup() helper to be supported from XDP, from Nitin. 5) Enable verifier to support narrow context loads with offset > 0 to adapt to LLVM code generation (currently only offset of 0 was supported). Add test cases as well, from Andrey. 6) Simplify passing device functions for offloaded BPF progs by adding callbacks to bpf_prog_offload_ops instead of ndo_bpf. Also convert nfp and netdevsim to make use of them, from Quentin. 7) Add support for sock_ops based BPF programs to send events to the perf ring-buffer through perf_event_output helper, from Sowmini and Daniel. 8) Add read / write support for skb->tstamp from tc BPF and cg BPF programs to allow for supporting rate-limiting in EDT qdiscs like fq from BPF side, from Vlad. 9) Extend libbpf API to support map in map types and add test cases for it as well to BPF kselftests, from Nikita. 10) Account the maximum packet offset accessed by a BPF program in the verifier and use it for optimizing nfp JIT, from Jiong. 11) Fix error handling regarding kprobe_events in BPF sample loader, from Daniel T. 12) Add support for queue and stack map type in bpftool, from David. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf: align map type names formatting.David Calavera2018-11-261-23/+23
| | | | | | | | | | | | | | Make the formatting for map_type_name array consistent. Signed-off-by: David Calavera <david.calavera@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: btf: fix spelling mistake "Memmber" -> "Member"Colin Ian King2018-11-261-1/+1
| | | | | | | | | | | | | | | | There is a spelling mistake in a btf_verifier_log_member message, fix it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf, tags: Fix DEFINE_PER_CPU expansionRustam Kovhaev2018-11-261-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | Building tags produces warning: ctags: Warning: kernel/bpf/local_storage.c:10: null expansion of name pattern "\1" Let's use the same fix as in commit 25528213fe9f ("tags: Fix DEFINE_PER_CPU expansions"), even though it violates the usual code style. Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: Add BPF_MAP_TYPE_QUEUE and BPF_MAP_TYPE_STACK to bpftool-mapDavid Calavera2018-11-232-1/+4
| | | | | | | | | | | | | | | | | | I noticed that these two new BPF Maps are not defined in bpftool. This patch defines those two maps and adds their names to the bpftool-map documentation. Signed-off-by: David Calavera <david.calavera@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * samples: bpf: fix: error handling regarding kprobe_eventsDaniel T. Lee2018-11-231-9/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, kprobe_events failure won't be handled properly. Due to calling system() indirectly to write to kprobe_events, it can't be identified whether an error is derived from kprobe or system. // buf = "echo '%c:%s %s' >> /s/k/d/t/kprobe_events" err = system(buf); if (err < 0) { printf("failed to create kprobe .."); return -1; } For example, running ./tracex7 sample in ext4 partition, "echo p:open_ctree open_ctree >> /s/k/d/t/kprobe_events" gets 256 error code system() failure. => The error comes from kprobe, but it's not handled correctly. According to man of system(3), it's return value just passes the termination status of the child shell rather than treating the error as -1. (don't care success) Which means, currently it's not working as desired. (According to the upper code snippet) ex) running ./tracex7 with ext4 env. # Current Output sh: echo: I/O error failed to open event open_ctree # Desired Output failed to create kprobe 'open_ctree' error 'No such file or directory' The problem is, error can't be verified whether from child ps or system. But using write() directly can verify the command failure, and it will treat all error as -1. So I suggest using write() directly to 'kprobe_events' rather than calling system(). Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * libbpf: make bpf_object__open default to UNSPECNikita V. Shirokov2018-11-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * bpf: add skb->tstamp r/w access from tc clsact and cg skb progsVlad Dumitrescu2018-11-234-0/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This could be used to rate limit egress traffic in concert with a qdisc which supports Earliest Departure Time, such as FQ. Write access from cg skb progs only with CAP_SYS_ADMIN, since the value will be used by downstream qdiscs. It might make sense to relax this. Changes v1 -> v2: - allow access from cg skb, write only with CAP_SYS_ADMIN Signed-off-by: Vlad Dumitrescu <vladum@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * tools/bpf: fix spelling mistake "memeory" -> "memory"Colin Ian King2018-11-221-2/+2
| | | | | | | | | | | | | | The CHECK message contains a spelling mistake, fix it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf, lpm: make longest_prefix_match() fasterEric Dumazet2018-11-221-10/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At LPC 2018 in Vancouver, Vlad Dumitrescu mentioned that longest_prefix_match() has a high cost [1]. One reason for that cost is a loop handling one byte at a time. We can handle more bytes at a time, if enough attention is paid to endianness. I was able to remove ~55 % of longest_prefix_match() cpu costs. [1] https://linuxplumbersconf.org/event/2/contributions/88/attachments/76/87/lpc-bpf-2018-shaping.pdf Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Vlad Dumitrescu <vladum@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * Merge branch 'bpf-libbpf-mapinmap'Daniel Borkmann2018-11-215-7/+177
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nikita V. Shirokov says: ==================== In this patch series I'm adding a helper for libbpf which would allow it to load map-in-map(BPF_MAP_TYPE_ARRAY_OF_MAPS and BPF_MAP_TYPE_HASH_OF_MAPS). First patch contains new helper + explains proposed workflow second patch contains tests which also could be used as example usage. v4->v5: - naming: renamed everything to map_in_map instead of mapinmap - start to return nonzero val if set_inner_map_fd failed v3->v4: - renamed helper to set_inner_map_fd - now we set this value only if it haven't been set before and only for (array|hash) of maps v2->v3: - fixing typo in patch description - initializing inner_map_fd to -1 by default v1->v2: - addressing nits - removing const identifier from fd in new helper - starting to check return val for bpf_map_update_elem ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * bpf: adding tests for map_in_map helpber in libbpfNikita V. Shirokov2018-11-213-1/+141
| | | | | | | | | | | | | | | | | | | | | | | | adding test/example of bpf_map__set_inner_map_fd usage Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * bpf: adding support for map in map in libbpfNikita V. Shirokov2018-11-212-6/+36
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * bpf: libbpf: don't specify prog name if kernel doesn't support itStanislav Fomichev2018-11-211-1/+2
| | | | | | | | | | | | | | | | | | | | 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>
| * bpf: libbpf: remove map name retry from bpf_create_map_xattrStanislav Fomichev2018-11-212-11/+3
| | | | | | | | | | | | | | | | | | | | | | 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>
| * bpf, libbpf: introduce bpf_object__probe_caps to test BPF capabilitiesStanislav Fomichev2018-11-211-0/+58
| | | | | | | | | | | | | | | | | | | | 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>
| * libbpf: make sure bpf headers are c++ include-ableStanislav Fomichev2018-11-215-3/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wrap headers in extern "C", to turn off C++ mangling. This simplifies including libbpf in c++ and linking against it. v2 changes: * do the same for btf.h v3 changes: * test_libbpf.cpp to test for possible future c++ breakages Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: fix a libbpf loader issueYonghong Song2018-11-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * bpf: fix a compilation error when CONFIG_BPF_SYSCALL is not definedYonghong Song2018-11-211-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernel test robot (lkp@intel.com) reports a compilation error at https://www.spinics.net/lists/netdev/msg534913.html introduced by commit 838e96904ff3 ("bpf: Introduce bpf_func_info"). If CONFIG_BPF is defined and CONFIG_BPF_SYSCALL is not defined, the following error will appear: kernel/bpf/core.c:414: undefined reference to `btf_type_by_id' kernel/bpf/core.c:415: undefined reference to `btf_name_by_offset' When CONFIG_BPF_SYSCALL is not defined, let us define stub inline functions for btf_type_by_id() and btf_name_by_offset() in include/linux/btf.h. This way, the compilation failure can be avoided. Fixes: 838e96904ff3 ("bpf: Introduce bpf_func_info") Reported-by: kbuild test robot <lkp@intel.com> Cc: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * Merge branch 'btf-func-info'Alexei Starovoitov2018-11-2027-173/+2317
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Martin KaFai Lau says: ==================== The BTF support was added to kernel by Commit 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)"), which introduced .BTF section into ELF file and is primarily used for map pretty print. pahole is used to convert dwarf to BTF for ELF files. This patch added func info support to the kernel so we can get better ksym's for bpf function calls. Basically, function call types are passed to kernel and the kernel extract function names from these types in order to contruct ksym for these functions. 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. The following is a sample output for selftests test_btf with file test_btf_haskv.o for translated insns and jited insns respectively. $ bpftool prog dump xlated id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): 0: (85) call pc+2#bpf_prog_2dcecc18072623fc_test_long_fname_1 1: (b7) r0 = 0 2: (95) exit int test_long_fname_1(struct dummy_tracepoint_args * arg): 3: (85) call pc+1#bpf_prog_89d64e4abf0f0126_test_long_fname_2 4: (95) exit int test_long_fname_2(struct dummy_tracepoint_args * arg): 5: (b7) r2 = 0 6: (63) *(u32 *)(r10 -4) = r2 7: (79) r1 = *(u64 *)(r1 +8) ... 22: (07) r1 += 1 23: (63) *(u32 *)(r0 +4) = r1 24: (95) exit $ bpftool prog dump jited id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): bpf_prog_b07ccb89267cf242__dummy_tracepoint: 0: push %rbp 1: mov %rsp,%rbp ...... 3c: add $0x28,%rbp 40: leaveq 41: retq int test_long_fname_1(struct dummy_tracepoint_args * arg): bpf_prog_2dcecc18072623fc_test_long_fname_1: 0: push %rbp 1: mov %rsp,%rbp ...... 3a: add $0x28,%rbp 3e: leaveq 3f: retq int test_long_fname_2(struct dummy_tracepoint_args * arg): bpf_prog_89d64e4abf0f0126_test_long_fname_2: 0: push %rbp 1: mov %rsp,%rbp ...... 80: add $0x28,%rbp 84: leaveq 85: retq Changelogs: v4 -> v5: . Add back BTF_KIND_FUNC_PROTO as v1 did. The difference is BTF_KIND_FUNC_PROTO cannot have t->name_off now. All param metadata is defined in BTF_KIND_FUNC_PROTO. BTF_KIND_FUNC must have t->name_off != 0 and t->type refers to a BTF_KIND_FUNC_PROTO. The above is the conclusion after the discussion between Edward Cree, Alexei, Daniel, Yonghong and Martin. v3 -> v4: . Remove BTF_KIND_FUNC_PROTO. BTF_KIND_FUNC is used for both function pointer and subprogram. The name_off field is used to distinguish both. . The record size is added to the func_info subsection in .BTF.ext to enable future extension. . The bpf_prog_info interface change to make it similar bpf_prog_load. . Related kernel and libbpf changes to accommodate the new .BTF.ext and kernel interface changes. v2 -> v3: . Removed kernel btf extern functions btf_type_id_func() and btf_get_name_by_id(). Instead, exposing existing functions btf_type_by_id() and btf_name_by_offset(). . Added comments about ELF section .BTF.ext layout. . Better codes in btftool as suggested by Edward Cree. v1 -> v2: . Added missing sign-off. . Limited the func_name/struct_member_name length for validity test. . Removed/changed several verifier messages. . Modified several commit messages to remove line_off reference. ==================== Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * tools/bpf: bpftool: add support for func typesYonghong Song2018-11-205-0/+230
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch added support to print function signature if btf func_info is available. Note that ksym now uses function name instead of prog_name as prog_name has a limit of 16 bytes including ending '\0'. The following is a sample output for selftests test_btf with file test_btf_haskv.o for translated insns and jited insns respectively. $ bpftool prog dump xlated id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): 0: (85) call pc+2#bpf_prog_2dcecc18072623fc_test_long_fname_1 1: (b7) r0 = 0 2: (95) exit int test_long_fname_1(struct dummy_tracepoint_args * arg): 3: (85) call pc+1#bpf_prog_89d64e4abf0f0126_test_long_fname_2 4: (95) exit int test_long_fname_2(struct dummy_tracepoint_args * arg): 5: (b7) r2 = 0 6: (63) *(u32 *)(r10 -4) = r2 7: (79) r1 = *(u64 *)(r1 +8) ... 22: (07) r1 += 1 23: (63) *(u32 *)(r0 +4) = r1 24: (95) exit $ bpftool prog dump jited id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): bpf_prog_b07ccb89267cf242__dummy_tracepoint: 0: push %rbp 1: mov %rsp,%rbp ...... 3c: add $0x28,%rbp 40: leaveq 41: retq int test_long_fname_1(struct dummy_tracepoint_args * arg): bpf_prog_2dcecc18072623fc_test_long_fname_1: 0: push %rbp 1: mov %rsp,%rbp ...... 3a: add $0x28,%rbp 3e: leaveq 3f: retq int test_long_fname_2(struct dummy_tracepoint_args * arg): bpf_prog_89d64e4abf0f0126_test_long_fname_2: 0: push %rbp 1: mov %rsp,%rbp ...... 80: add $0x28,%rbp 84: leaveq 85: retq 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>
| | * tools/bpf: enhance test_btf file testing to test func infoYonghong Song2018-11-203-13/+136
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the bpf programs test_btf_haskv.c and test_btf_nokv.c to have two sections, and enhance test_btf.c test_file feature to test btf func_info returned by 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>
| | * tools/bpf: refactor to implement btf_get_from_id() in lib/bpfYonghong Song2018-11-203-66/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function get_btf() is implemented in tools/bpf/bpftool/map.c to get a btf structure given a map_info. This patch refactored this function to be function btf_get_from_id() in tools/lib/bpf so that it can be used later. 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>
| | * tools/bpf: do not use pahole if clang/llvm can generate BTF sectionsYonghong Song2018-11-202-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add additional checks in tools/testing/selftests/bpf and samples/bpf such that if clang/llvm compiler can generate BTF sections, do not use pahole. 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>
| | * tools/bpf: add support to read .BTF.ext sectionsYonghong Song2018-11-204-15/+442
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * tools/bpf: extends test_btf to test load/retrieve func_type infoYonghong Song2018-11-201-3/+329
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A two function bpf program is loaded with btf and func_info. After successful prog load, the bpf_get_info syscall is called to retrieve prog info to ensure the types returned from the kernel matches the types passed to the kernel from the user space. Several negative tests are also added to test loading/retriving of func_type info. 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>
| | * tools/bpf: add new fields for program load in lib/bpfYonghong Song2018-11-202-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new fields are added for program load in lib/bpf so application uses api bpf_load_program_xattr() is able to load program with btf and func_info data. This functionality will be used in next patch by bpf selftest test_btf. 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>
| | * tools/bpf: sync kernel uapi bpf.h header to tools directoryYonghong Song2018-11-201-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | The kernel uapi bpf.h is synced to tools directory. 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>
| | * bpf: Introduce bpf_func_infoYonghong Song2018-11-208-8/+209
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch added interface to load a program with the following additional information: . prog_btf_fd . func_info, func_info_rec_size and func_info_cnt where func_info will provide function range and type_id corresponding to each function. The func_info_rec_size is introduced in the UAPI to specify struct bpf_func_info size passed from user space. This intends to make bpf_func_info structure growable in the future. If the kernel gets a different bpf_func_info size from userspace, it will try to handle user request with part of bpf_func_info it can understand. In this patch, kernel can understand struct bpf_func_info { __u32 insn_offset; __u32 type_id; }; If user passed a bpf func_info record size of 16 bytes, the kernel can still handle part of records with the above definition. If verifier agrees with function range provided by the user, the bpf_prog ksym for each function will use the func name provided in the type_id, which is supposed to provide better encoding as it is not limited by 16 bytes program name limitation and this is better for bpf program which contains multiple subprograms. The bpf_prog_info interface is also extended to return btf_id, func_info, func_info_rec_size and func_info_cnt to userspace, so userspace can print out the function prototype for each xlated function. The insn_offset in the returned func_info corresponds to the insn offset for xlated functions. With other jit related fields in bpf_prog_info, userspace can also print out function prototypes for each jited function. 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>
| | * tools/bpf: Add tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNCMartin KaFai Lau2018-11-202-2/+476
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds unit tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNC to test_btf. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * tools/bpf: Sync kernel btf.h headerMartin KaFai Lau2018-11-201-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | The kernel uapi btf.h is synced to the tools directory. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * bpf: btf: Add BTF_KIND_FUNC and BTF_KIND_FUNC_PROTOMartin KaFai Lau2018-11-202-53/+354
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO to support the function debug info. BTF_KIND_FUNC_PROTO must not have a name (i.e. !t->name_off) and it is followed by >= 0 'struct bpf_param' objects to describe the function arguments. The BTF_KIND_FUNC must have a valid name and it must refer back to a BTF_KIND_FUNC_PROTO. The above is the conclusion after the discussion between Edward Cree, Alexei, Daniel, Yonghong and Martin. By combining BTF_KIND_FUNC and BTF_LIND_FUNC_PROTO, a complete function signature can be obtained. It will be used in the later patches to learn the function signature of a running bpf program. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * bpf: btf: Break up btf_type_is_void()Martin KaFai Lau2018-11-201-15/+22
| |/ | | | | | | | | | | | | | | | | | | | | This patch breaks up btf_type_is_void() into btf_type_is_void() and btf_type_is_fwd(). It also adds btf_type_nosize() to better describe it is testing a type has nosize info. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * Merge branch 'bpf-zero-hash-seed'Daniel Borkmann2018-11-204-17/+82
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lorenz Bauer says: ==================== Allow forcing the seed of a hash table to zero, for deterministic execution during benchmarking and testing. Changes from v2: * Change ordering of BPF_F_ZERO_SEED in linux/bpf.h Comments adressed from v1: * Add comment to discourage production use to linux/bpf.h * Require CAP_SYS_ADMIN ==================== Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * tools: add selftest for BPF_F_ZERO_SEEDLorenz Bauer2018-11-201-9/+55
| | | | | | | | | | | | | | | | | | | | | | | | Check that iterating two separate hash maps produces the same order of keys if BPF_F_ZERO_SEED is used. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * tools: sync linux/bpf.hLorenz Bauer2018-11-201-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | Synchronize changes to linux/bpf.h from * "bpf: allow zero-initializing hash map seed" * "bpf: move BPF_F_QUERY_EFFECTIVE after map flags" Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * bpf: move BPF_F_QUERY_EFFECTIVE after map flagsLorenz Bauer2018-11-201-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | BPF_F_QUERY_EFFECTIVE is in the middle of the flags valid for BPF_MAP_CREATE. Move it to its own section to reduce confusion. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * bpf: allow zero-initializing hash map seedLorenz Bauer2018-11-202-2/+14
| |/ | | | | | | | | | | | | | | | | | | Add a new flag BPF_F_ZERO_SEED, which forces a hash map to initialize the seed to zero. This is useful when doing performance analysis both on individual BPF programs, as well as the kernel's hash table implementation. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: libbpf: retry map creation without the nameStanislav Fomichev2018-11-201-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 88cda1c9da02 ("bpf: libbpf: Provide basic API support to specify BPF obj name"), libbpf unconditionally sets bpf_attr->name for maps. Pre v4.14 kernels don't know about map names and return an error about unexpected non-zero data. Retry sys_bpf without a map name to cover older kernels. v2 changes: * check for errno == EINVAL as suggested by Daniel Borkmann Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: fix null pointer dereference on pointer offloadColin Ian King2018-11-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Pointer offload is being null checked however the following statement dereferences the potentially null pointer offload when assigning offload->dev_state. Fix this by only assigning it if offload is not null. Detected by CoverityScan, CID#1475437 ("Dereference after null check") Fixes: 00db12c3d141 ("bpf: call verifier_prep from its callback in struct bpf_offload_dev") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpftool: make libbfd optionalStanislav Fomichev2018-11-175-6/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it possible to build bpftool without libbfd. libbfd and libopcodes are typically provided in dev/dbg packages (binutils-dev in debian) which we usually don't have installed on the fleet machines and we'd like a way to have bpftool version that works without installing any additional packages. This excludes support for disassembling jit-ted code and prints an error if the user tries to use these features. Tested by: cat > FEATURES_DUMP.bpftool <<EOF feature-libbfd=0 feature-disassembler-four-args=1 feature-reallocarray=0 feature-libelf=1 feature-libelf-mmap=1 feature-bpf=1 EOF FEATURES_DUMP=$PWD/FEATURES_DUMP.bpftool make ldd bpftool | grep libbfd Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * Merge branch 'socket-lookup-cg_sock'Alexei Starovoitov2018-11-173-24/+125
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrey Ignatov says: ==================== This patch set makes bpf_sk_lookup_tcp, bpf_sk_lookup_udp and bpf_sk_release helpers available in programs of type BPF_PROG_TYPE_CGROUP_SOCK_ADDR. Patch 1 is a fix for bpf_sk_lookup_udp that was already merged to bpf (stable) tree. Here it's prerequisite for patch 3. Patch 2 is the main patch in the set, it makes the helpers available for BPF_PROG_TYPE_CGROUP_SOCK_ADDR and provides more details about use-case. Patch 3 adds selftest for new functionality. v1->v2: - remove "Split bpf_sk_lookup" patch since it was already split by: commit c8123ead13a5 ("bpf: Extend the sk_lookup() helper to XDP hookpoint."); - avoid unnecessary bpf_sock_addr_sk_lookup function. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>