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2022-02-15kbuild: replace $(if A,A,B) with $(or A,B)Masahiro Yamada
$(or ...) is available since GNU Make 3.81, and useful to shorten the code in some places. Covert as follows: $(if A,A,B) --> $(or A,B) This patch also converts: $(if A, A, B) --> $(or A, B) Strictly speaking, the latter is not an equivalent conversion because GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B) expands to " A", while $(or A, B) expands to "A". Anyway, preceding spaces are not significant in the code hunks I touched. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-02-12libbpf: Use dynamically allocated buffer when receiving netlink messagesToke Høiland-Jørgensen
When receiving netlink messages, libbpf was using a statically allocated stack buffer of 4k bytes. This happened to work fine on systems with a 4k page size, but on systems with larger page sizes it can lead to truncated messages. The user-visible impact of this was that libbpf would insist no XDP program was attached to some interfaces because that bit of the netlink message got chopped off. Fix this by switching to a dynamically allocated buffer; we borrow the approach from iproute2 of using recvmsg() with MSG_PEEK|MSG_TRUNC to get the actual size of the pending message before receiving it, adjusting the buffer as necessary. While we're at it, also add retries on interrupted system calls around the recvmsg() call. v2: - Move peek logic to libbpf_netlink_recv(), don't double free on ENOMEM. Fixes: 8bbb77b7c7a2 ("libbpf: Add various netlink helpers") Reported-by: Zhiqian Guan <zhguan@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20220211234819.612288-1-toke@redhat.com
2022-02-11libbpf: Fix libbpf.map inheritance chain for LIBBPF_0.7.0Andrii Nakryiko
Ensure that LIBBPF_0.7.0 inherits everything from LIBBPF_0.6.0. Fixes: dbdd2c7f8cec ("libbpf: Add API to get/set log_level at per-program level") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220211205235.2089104-1-andrii@kernel.org
2022-02-10libbpf: Prepare light skeleton for the kernel.Alexei Starovoitov
Prepare light skeleton to be used in the kernel module and in the user space. The look and feel of lskel.h is mostly the same with the difference that for user space the skel->rodata is the same pointer before and after skel_load operation, while in the kernel the skel->rodata after skel_open and the skel->rodata after skel_load are different pointers. Typical usage of skeleton remains the same for kernel and user space: skel = my_bpf__open(); skel->rodata->my_global_var = init_val; err = my_bpf__load(skel); err = my_bpf__attach(skel); // access skel->rodata->my_global_var; // access skel->bss->another_var; Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-3-alexei.starovoitov@gmail.com
2022-02-09libbpf: Fix compilation warning due to mismatched printf formatAndrii Nakryiko
On ppc64le architecture __s64 is long int and requires %ld. Cast to ssize_t and use %zd to avoid architecture-specific specifiers. Fixes: 4172843ed4a3 ("libbpf: Fix signedness bug in btf_dump_array_data()") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220209063909.1268319-1-andrii@kernel.org
2022-02-08libbpf: Add BPF_KPROBE_SYSCALL macroHengqi Chen
Add syscall-specific variant of BPF_KPROBE named BPF_KPROBE_SYSCALL ([0]). The new macro hides the underlying way of getting syscall input arguments. With the new macro, the following code: SEC("kprobe/__x64_sys_close") int BPF_KPROBE(do_sys_close, struct pt_regs *regs) { int fd; fd = PT_REGS_PARM1_CORE(regs); /* do something with fd */ } can be written as: SEC("kprobe/__x64_sys_close") int BPF_KPROBE_SYSCALL(do_sys_close, int fd) { /* do something with fd */ } [0] Closes: https://github.com/libbpf/libbpf/issues/425 Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220207143134.2977852-2-hengqi.chen@gmail.com
2022-02-08libbpf: Fix accessing the first syscall argument on s390Ilya Leoshkevich
On s390, the first syscall argument should be accessed via orig_gpr2 (see arch/s390/include/asm/syscall.h). Currently gpr[2] is used instead, leading to bpf_syscall_macro test failure. orig_gpr2 cannot be added to user_pt_regs, since its layout is a part of the ABI. Therefore provide access to it only through PT_REGS_PARM1_CORE_SYSCALL() by using a struct pt_regs flavor. Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209021745.2215452-11-iii@linux.ibm.com
2022-02-08libbpf: Fix accessing the first syscall argument on arm64Ilya Leoshkevich
On arm64, the first syscall argument should be accessed via orig_x0 (see arch/arm64/include/asm/syscall.h). Currently regs[0] is used instead, leading to bpf_syscall_macro test failure. orig_x0 cannot be added to struct user_pt_regs, since its layout is a part of the ABI. Therefore provide access to it only through PT_REGS_PARM1_CORE_SYSCALL() by using a struct pt_regs flavor. Reported-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209021745.2215452-10-iii@linux.ibm.com
2022-02-08libbpf: Allow overriding PT_REGS_PARM1{_CORE}_SYSCALLIlya Leoshkevich
arm64 and s390 need a special way to access the first syscall argument. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209021745.2215452-9-iii@linux.ibm.com
2022-02-08libbpf: Fix accessing syscall arguments on riscvIlya Leoshkevich
riscv does not select ARCH_HAS_SYSCALL_WRAPPER, so its syscall handlers take "unpacked" syscall arguments. Indicate this to libbpf using PT_REGS_SYSCALL_REGS macro. Reported-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209021745.2215452-7-iii@linux.ibm.com
2022-02-08libbpf: Fix riscv register namesIlya Leoshkevich
riscv registers are accessed via struct user_regs_struct, not struct pt_regs. The program counter member in this struct is called pc, not epc. The frame pointer is called s0, not fp. Fixes: 3cc31d794097 ("libbpf: Normalize PT_REGS_xxx() macro definitions") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209021745.2215452-6-iii@linux.ibm.com
2022-02-08libbpf: Fix accessing syscall arguments on powerpcIlya Leoshkevich
powerpc does not select ARCH_HAS_SYSCALL_WRAPPER, so its syscall handlers take "unpacked" syscall arguments. Indicate this to libbpf using PT_REGS_SYSCALL_REGS macro. Reported-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Link: https://lore.kernel.org/bpf/20220209021745.2215452-5-iii@linux.ibm.com
2022-02-08libbpf: Add PT_REGS_SYSCALL_REGS macroIlya Leoshkevich
Architectures that select ARCH_HAS_SYSCALL_WRAPPER pass a pointer to struct pt_regs to syscall handlers, others unpack it into individual function parameters. Introduce a macro to describe what a particular arch does. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209021745.2215452-3-iii@linux.ibm.com
2022-02-08libbpf: Fix signedness bug in btf_dump_array_data()Dan Carpenter
The btf__resolve_size() function returns negative error codes so "elem_size" must be signed for the error handling to work. Fixes: 920d16af9b42 ("libbpf: BTF dumper support for typed data") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220208071552.GB10495@kili
2022-02-07libbpf: Remove mode check in libbpf_set_strict_mode()Mauricio Vásquez
libbpf_set_strict_mode() checks that the passed mode doesn't contain extra bits for LIBBPF_STRICT_* flags that don't exist yet. It makes it difficult for applications to disable some strict flags as something like "LIBBPF_STRICT_ALL & ~LIBBPF_STRICT_MAP_DEFINITIONS" is rejected by this check and they have to use a rather complicated formula to calculate it.[0] One possibility is to change LIBBPF_STRICT_ALL to only contain the bits of all existing LIBBPF_STRICT_* flags instead of 0xffffffff. However it's not possible because the idea is that applications compiled against older libbpf_legacy.h would still be opting into latest LIBBPF_STRICT_ALL features.[1] The other possibility is to remove that check so something like "LIBBPF_STRICT_ALL & ~LIBBPF_STRICT_MAP_DEFINITIONS" is allowed. It's what this commit does. [0]: https://lore.kernel.org/bpf/20220204220435.301896-1-mauricio@kinvolk.io/ [1]: https://lore.kernel.org/bpf/CAEf4BzaTWa9fELJLh+bxnOb0P1EMQmaRbJVG0L+nXZdy0b8G3Q@mail.gmail.com/ Fixes: 93b8952d223a ("libbpf: deprecate legacy BPF map definitions") Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220207145052.124421-2-mauricio@kinvolk.io
2022-02-04libbpf: Fix build issue with llvm-readelfYonghong Song
There are cases where clang compiler is packaged in a way readelf is a symbolic link to llvm-readelf. In such cases, llvm-readelf will be used instead of default binutils readelf, and the following error will appear during libbpf build: Warning: Num of global symbols in /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o (367) does NOT match with num of versioned symbols in /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.so libbpf.map (383). Please make sure all LIBBPF_API symbols are versioned in libbpf.map. --- /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_global_syms.tmp ... +++ /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_versioned_syms.tmp ... @@ -324,6 +324,22 @@ btf__str_by_offset btf__type_by_id btf__type_cnt +LIBBPF_0.0.1 +LIBBPF_0.0.2 +LIBBPF_0.0.3 +LIBBPF_0.0.4 +LIBBPF_0.0.5 +LIBBPF_0.0.6 +LIBBPF_0.0.7 +LIBBPF_0.0.8 +LIBBPF_0.0.9 +LIBBPF_0.1.0 +LIBBPF_0.2.0 +LIBBPF_0.3.0 +LIBBPF_0.4.0 +LIBBPF_0.5.0 +LIBBPF_0.6.0 +LIBBPF_0.7.0 libbpf_attach_type_by_name libbpf_find_kernel_btf libbpf_find_vmlinux_btf_id make[2]: *** [Makefile:184: check_abi] Error 1 make[1]: *** [Makefile:140: all] Error 2 The above failure is due to different printouts for some ABS versioned symbols. For example, with the same libbpf.so, $ /bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0 ... $ /opt/llvm/bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0@@LIBBPF_0.5.0 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0@@LIBBPF_0.6.0 ... The binutils readelf doesn't print out the symbol LIBBPF_* version and llvm-readelf does. Such a difference caused libbpf build failure with llvm-readelf. The proposed fix filters out all ABS symbols as they are not part of the comparison. This works for both binutils readelf and llvm-readelf. Reported-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220204214355.502108-1-yhs@fb.com
2022-02-04libbpf: Deprecate forgotten btf__get_map_kv_tids()Andrii Nakryiko
btf__get_map_kv_tids() is in the same group of APIs as btf_ext__reloc_func_info()/btf_ext__reloc_line_info() which were only used by BCC. It was missed to be marked as deprecated in [0]. Fixing that to complete [1]. [0] https://patchwork.kernel.org/project/netdevbpf/patch/20220201014610.3522985-1-davemarchevsky@fb.com/ [1] Closes: https://github.com/libbpf/libbpf/issues/277 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220203225017.1795946-1-andrii@kernel.org
2022-02-03libbpf: Deprecate priv/set_priv storageDelyan Kratunov
Arbitrary storage via bpf_*__set_priv/__priv is being deprecated without a replacement ([1]). perf uses this capability, but most of that is going away with the removal of prologue generation ([2]). perf is already suppressing deprecation warnings, so the remaining cleanup will happen separately. [1]: Closes: https://github.com/libbpf/libbpf/issues/294 [2]: https://lore.kernel.org/bpf/20220123221932.537060-1-jolsa@kernel.org/ Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220203180032.1921580-1-delyank@fb.com
2022-02-03libbpf: Stop using deprecated bpf_map__is_offload_neutral()Andrii Nakryiko
Open-code bpf_map__is_offload_neutral() logic in one place in to-be-deprecated bpf_prog_load_xattr2. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220202225916.3313522-2-andrii@kernel.org
2022-02-02libbpf: Deprecate bpf_prog_test_run_xattr and bpf_prog_test_runDelyan Kratunov
Deprecate non-extendable bpf_prog_test_run{,_xattr} in favor of OPTS-based bpf_prog_test_run_opts ([0]). [0] Closes: https://github.com/libbpf/libbpf/issues/286 Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220202235423.1097270-5-delyank@fb.com
2022-02-01libbpf: Open code raw_tp_open and link_create commands.Alexei Starovoitov
Open code raw_tracepoint_open and link_create used by light skeleton to be able to avoid full libbpf eventually. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-4-alexei.starovoitov@gmail.com
2022-02-01libbpf: Open code low level bpf commands.Alexei Starovoitov
Open code low level bpf commands used by light skeleton to be able to avoid full libbpf eventually. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-3-alexei.starovoitov@gmail.com
2022-02-01libbpf: Deprecate xdp_cpumap, xdp_devmap and classifier sec definitionsLorenzo Bianconi
Deprecate xdp_cpumap, xdp_devmap and classifier sec definitions. Introduce xdp/devmap and xdp/cpumap definitions according to the standard for SEC("") in libbpf: - prog_type.prog_flags/attach_place Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/5c7bd9426b3ce6a31d9a4b1f97eb299e1467fc52.1643727185.git.lorenzo@kernel.org
2022-02-01libbpf: Deprecate btf_ext rec_size APIsDave Marchevsky
btf_ext__{func,line}_info_rec_size functions are used in conjunction with already-deprecated btf_ext__reloc_{func,line}_info functions. Since struct btf_ext is opaque to the user it was necessary to expose rec_size getters in the past. btf_ext__reloc_{func,line}_info were deprecated in commit 8505e8709b5ee ("libbpf: Implement generalized .BTF.ext func/line info adjustment") as they're not compatible with support for multiple programs per section. It was decided[0] that users of these APIs should implement their own .btf.ext parsing to access this data, in which case the rec_size getters are unnecessary. So deprecate them from libbpf 0.7.0 onwards. [0] Closes: https://github.com/libbpf/libbpf/issues/277 Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220201014610.3522985-1-davemarchevsky@fb.com
2022-01-25libbpf: deprecate bpf_program__is_<type>() and bpf_program__set_<type>() APIsAndrii Nakryiko
Not sure why these APIs were added in the first place instead of a completely generic (and not requiring constantly adding new APIs with each new BPF program type) bpf_program__type() and bpf_program__set_type() APIs. But as it is right now, there are 13 such specialized is_type/set_type APIs, while latest kernel is already at 30+ BPF program types. Instead of completing the set of APIs and keep chasing kernel's bpf_prog_type enum, deprecate existing subset and recommend generic bpf_program__type() and bpf_program__set_type() APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220124194254.2051434-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-25libbpf: deprecate bpf_map__resize()Andrii Nakryiko
Deprecated bpf_map__resize() in favor of bpf_map__set_max_entries() setter. In addition to having a surprising name (users often don't realize that they need to use bpf_map__resize()), the name also implies some magic way of resizing BPF map after it is created, which is clearly not the case. Another minor annoyance is that bpf_map__resize() disallows 0 value for max_entries, which in some cases is totally acceptable (e.g., like for BPF perf buf case to let libbpf auto-create one buffer per each available CPU core). [0] Closes: https://github.com/libbpf/libbpf/issues/304 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220124194254.2051434-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-25libbpf: hide and discourage inconsistently named gettersAndrii Nakryiko
Move a bunch of "getters" into libbpf_legacy.h to keep them there in libbpf 1.0. See [0] for discussion of "Discouraged APIs". These getters don't add any maintenance burden and are simple alias, but they are inconsistent in naming. So keep them in libbpf_legacy.h instead of libbpf.h to "hide" them in favor of preferred getters ([1]). Also add two missing getters: bpf_program__type() and bpf_program__expected_attach_type(). [0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#handling-deprecation-of-apis-and-functionality [1] Closes: https://github.com/libbpf/libbpf/issues/307 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220124194254.2051434-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-24libbpf: Fix the incorrect register read for syscalls on x86_64Kenta Tada
Currently, rcx is read as the fourth parameter of syscall on x86_64. But x86_64 Linux System Call convention uses r10 actually. This commit adds the wrapper for users who want to access to syscall params to analyze the user space. Signed-off-by: Kenta Tada <Kenta.Tada@sony.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220124141622.4378-3-Kenta.Tada@sony.com
2022-01-24libbpf: Mark bpf_object__open_xattr() deprecatedChristy Lee
Mark bpf_object__open_xattr() as deprecated, use bpf_object__open_file() instead. [0] Closes: https://github.com/libbpf/libbpf/issues/287 Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220125010917.679975-1-christylee@fb.com
2022-01-24libbpf: Mark bpf_object__open_buffer() API deprecatedChristy Lee
Deprecate bpf_object__open_buffer() API in favor of the unified opts-based bpf_object__open_mem() API. Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220125005923.418339-2-christylee@fb.com
2022-01-24libbpf: Add "iter.s" section for sleepable bpf iterator programsKenny Yu
This adds a new bpf section "iter.s" to allow bpf iterator programs to be sleepable. Signed-off-by: Kenny Yu <kennyyu@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220124185403.468466-4-kennyyu@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-21libbpf: Add SEC name for xdp frags programsLorenzo Bianconi
Introduce support for the following SEC entries for XDP frags property: - SEC("xdp.frags") - SEC("xdp.frags/devmap") - SEC("xdp.frags/cpumap") Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/af23b6e4841c171ad1af01917839b77847a4bc27.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-20libbpf: streamline low-level XDP APIsAndrii Nakryiko
Introduce 4 new netlink-based XDP APIs for attaching, detaching, and querying XDP programs: - bpf_xdp_attach; - bpf_xdp_detach; - bpf_xdp_query; - bpf_xdp_query_id. These APIs replace bpf_set_link_xdp_fd, bpf_set_link_xdp_fd_opts, bpf_get_link_xdp_id, and bpf_get_link_xdp_info APIs ([0]). The latter don't follow a consistent naming pattern and some of them use non-extensible approaches (e.g., struct xdp_link_info which can't be modified without breaking libbpf ABI). The approach I took with these low-level XDP APIs is similar to what we did with low-level TC APIs. There is a nice duality of bpf_tc_attach vs bpf_xdp_attach, and so on. I left bpf_xdp_attach() to support detaching when -1 is specified for prog_fd for generality and convenience, but bpf_xdp_detach() is preferred due to clearer naming and associated semantics. Both bpf_xdp_attach() and bpf_xdp_detach() accept the same opts struct allowing to specify expected old_prog_fd. While doing the refactoring, I noticed that old APIs require users to specify opts with old_fd == -1 to declare "don't care about already attached XDP prog fd" condition. Otherwise, FD 0 is assumed, which is essentially never an intended behavior. So I made this behavior consistent with other kernel and libbpf APIs, in which zero FD means "no FD". This seems to be more in line with the latest thinking in BPF land and should cause less user confusion, hopefully. For querying, I left two APIs, both more generic bpf_xdp_query() allowing to query multiple IDs and attach mode, but also a specialization of it, bpf_xdp_query_id(), which returns only requested prog_id. Uses of prog_id returning bpf_get_link_xdp_id() were so prevalent across selftests and samples, that it seemed a very common use case and using bpf_xdp_query() for doing it felt very cumbersome with a highly branches if/else chain based on flags and attach mode. Old APIs are scheduled for deprecation in libbpf 0.8 release. [0] Closes: https://github.com/libbpf/libbpf/issues/309 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20220120061422.2710637-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-20libbpf: deprecate legacy BPF map definitionsAndrii Nakryiko
Enact deprecation of legacy BPF map definition in SEC("maps") ([0]). For the definitions themselves introduce LIBBPF_STRICT_MAP_DEFINITIONS flag for libbpf strict mode. If it is set, error out on any struct bpf_map_def-based map definition. If not set, libbpf will print out a warning for each legacy BPF map to raise awareness that it goes away. For any use of BPF_ANNOTATE_KV_PAIR() macro providing a legacy way to associate BTF key/value type information with legacy BPF map definition, warn through libbpf's pr_warn() error message (but don't fail BPF object open). BPF-side struct bpf_map_def is marked as deprecated. User-space struct bpf_map_def has to be used internally in libbpf, so it is left untouched. It should be enough for bpf_map__def() to be marked deprecated to raise awareness that it goes away. bpftool is an interesting case that utilizes libbpf to open BPF ELF object to generate skeleton. As such, even though bpftool itself uses full on strict libbpf mode (LIBBPF_STRICT_ALL), it has to relax it a bit for BPF map definition handling to minimize unnecessary disruptions. So opt-out of LIBBPF_STRICT_MAP_DEFINITIONS for bpftool. User's code that will later use generated skeleton will make its own decision whether to enforce LIBBPF_STRICT_MAP_DEFINITIONS or not. There are few tests in selftests/bpf that are consciously using legacy BPF map definitions to test libbpf functionality. For those, temporary opt out of LIBBPF_STRICT_MAP_DEFINITIONS mode for the duration of those tests. [0] Closes: https://github.com/libbpf/libbpf/issues/272 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120060529.1890907-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-19libbpf: Improve btf__add_btf() with an additional hashmap for strings.Kui-Feng Lee
Add a hashmap to map the string offsets from a source btf to the string offsets from a target btf to reduce overheads. btf__add_btf() calls btf__add_str() to add strings from a source to a target btf. It causes many string comparisons, and it is a major hotspot when adding a big btf. btf__add_str() uses strcmp() to check if a hash entry is the right one. The extra hashmap here compares offsets of strings, that are much cheaper. It remembers the results of btf__add_str() for later uses to reduce the cost. We are parallelizing BTF encoding for pahole by creating separated btf instances for worker threads. These per-thread btf instances will be added to the btf instance of the main thread by calling btf__add_str() to deduplicate and write out. With this patch and -j4, the running time of pahole drops to about 6.0s from 6.6s. The following lines are the summary of 'perf stat' w/o the change. 6.668126396 seconds time elapsed 13.451054000 seconds user 0.715520000 seconds sys The following lines are the summary w/ the change. 5.986973919 seconds time elapsed 12.939903000 seconds user 0.724152000 seconds sys V4 fixes a bug of error checking against the pointer returned by hashmap__new(). [v3] https://lore.kernel.org/bpf/20220118232053.2113139-1-kuifeng@fb.com/ [v2] https://lore.kernel.org/bpf/20220114193713.461349-1-kuifeng@fb.com/ Signed-off-by: Kui-Feng Lee <kuifeng@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220119180214.255634-1-kuifeng@fb.com
2022-01-18libbpf: Define BTF_KIND_* constants in btf.h to avoid compilation errorsToke Høiland-Jørgensen
The btf.h header included with libbpf contains inline helper functions to check for various BTF kinds. These helpers directly reference the BTF_KIND_* constants defined in the kernel header, and because the header file is included in user applications, this happens in the user application compile units. This presents a problem if a user application is compiled on a system with older kernel headers because the constants are not available. To avoid this, add #defines of the constants directly in btf.h before using them. Since the kernel header moved to an enum for BTF_KIND_*, the #defines can shadow the enum values without any errors, so we only need #ifndef guards for the constants that predates the conversion to enum. We group these so there's only one guard for groups of values that were added together. [0] Closes: https://github.com/libbpf/libbpf/issues/436 Fixes: 223f903e9c83 ("bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG") Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lore.kernel.org/bpf/20220118141327.34231-1-toke@redhat.com
2022-01-12libbpf: Deprecate bpf_map__def() APIChristy Lee
All fields accessed via bpf_map_def can now be accessed via appropirate getters and setters. Mark bpf_map__def() API as deprecated. Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220108004218.355761-6-christylee@fb.com
2022-01-12libbpf: Fix possible NULL pointer dereference when destroying skeletonYafang Shao
When I checked the code in skeleton header file generated with my own bpf prog, I found there may be possible NULL pointer dereference when destroying skeleton. Then I checked the in-tree bpf progs, finding that is a common issue. Let's take the generated samples/bpf/xdp_redirect_cpu.skel.h for example. Below is the generated code in xdp_redirect_cpu__create_skeleton(): xdp_redirect_cpu__create_skeleton struct bpf_object_skeleton *s; s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s)); if (!s) goto error; ... error: bpf_object__destroy_skeleton(s); return -ENOMEM; After goto error, the NULL 's' will be deferenced in bpf_object__destroy_skeleton(). We can simply fix this issue by just adding a NULL check in bpf_object__destroy_skeleton(). Fixes: d66562fba1ce ("libbpf: Add BPF object skeleton support") Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220108134739.32541-1-laoar.shao@gmail.com
2022-01-12libbpf: Rename bpf_prog_attach_xattr() to bpf_prog_attach_opts()Christy Lee
All xattr APIs are being dropped, let's converge to the convention used in high-level APIs and rename bpf_prog_attach_xattr to bpf_prog_attach_opts. Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220107184604.3668544-2-christylee@fb.com
2022-01-12libbpf: Use IS_ERR_OR_NULL() in hashmap__free()Mauricio Vásquez
hashmap__new() uses ERR_PTR() to return an error so it's better to use IS_ERR_OR_NULL() in order to check the pointer before calling free(). This will prevent freeing an invalid pointer if somebody calls hashmap__free() with the result of a failed hashmap__new() call. Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20220107152620.192327-1-mauricio@kinvolk.io
2022-01-06libbpf: Add documentation for bpf_map batch operationsGrant Seltzer
This adds documention for: - bpf_map_delete_batch() - bpf_map_lookup_batch() - bpf_map_lookup_and_delete_batch() - bpf_map_update_batch() This also updates the public API for the `keys` parameter of `bpf_map_delete_batch()`, and both the `keys` and `values` parameters of `bpf_map_update_batch()` to be constants. Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220106201304.112675-1-grantseltzer@gmail.com
2022-01-05libbpf 1.0: Deprecate bpf_object__find_map_by_offset() APIChristy Lee
API created with simplistic assumptions about BPF map definitions. It hasn’t worked for a while, deprecate it in preparation for libbpf 1.0. [0] Closes: https://github.com/libbpf/libbpf/issues/302 Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220105003120.2222673-1-christylee@fb.com
2022-01-05libbpf 1.0: Deprecate bpf_map__is_offload_neutral()Christy Lee
Deprecate bpf_map__is_offload_neutral(). It’s most probably broken already. PERF_EVENT_ARRAY isn’t the only map that’s not suitable for hardware offloading. Applications can directly check map type instead. [0] Closes: https://github.com/libbpf/libbpf/issues/306 Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220105000601.2090044-1-christylee@fb.com
2022-01-05libbpf: Support repeated legacy kprobes on same functionQiang Wang
If repeated legacy kprobes on same function in one process, libbpf will register using the same probe name and got -EBUSY error. So append index to the probe name format to fix this problem. Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Qiang Wang <wangqiang.wq.frank@bytedance.com> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211227130713.66933-2-wangqiang.wq.frank@bytedance.com
2022-01-05libbpf: Use probe_name for legacy kprobeQiang Wang
Fix a bug in commit 46ed5fc33db9, which wrongly used the func_name instead of probe_name to register legacy kprobe. Fixes: 46ed5fc33db9 ("libbpf: Refactor and simplify legacy kprobe code") Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Qiang Wang <wangqiang.wq.frank@bytedance.com> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Hengqi Chen <hengqi.chen@gmail.com> Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com> Link: https://lore.kernel.org/bpf/20211227130713.66933-1-wangqiang.wq.frank@bytedance.com
2022-01-05libbpf: Deprecate bpf_perf_event_read_simple() APIChristy Lee
With perf_buffer__poll() and perf_buffer__consume() APIs available, there is no reason to expose bpf_perf_event_read_simple() API to users. If users need custom perf buffer, they could re-implement the function. Mark bpf_perf_event_read_simple() and move the logic to a new static function so it can still be called by other functions in the same file. [0] Closes: https://github.com/libbpf/libbpf/issues/310 Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211229204156.13569-1-christylee@fb.com
2021-12-28libbpf: Improve LINUX_VERSION_CODE detectionAndrii Nakryiko
Ubuntu reports incorrect kernel version through uname(), which on older kernels leads to kprobe BPF programs failing to load due to the version check mismatch. Accommodate Ubuntu's quirks with LINUX_VERSION_CODE by using Ubuntu-specific /proc/version_code to fetch major/minor/patch versions to form LINUX_VERSION_CODE. While at it, consolide libbpf's kernel version detection code between libbpf.c and libbpf_probes.c. [0] Closes: https://github.com/libbpf/libbpf/issues/421 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211222231003.2334940-1-andrii@kernel.org
2021-12-28libbpf: Use 100-character limit to make bpf_tracing.h easier to readAndrii Nakryiko
Improve bpf_tracing.h's macro definition readability by keeping them single-line and better aligned. This makes it easier to follow all those variadic patterns. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211222213924.1869758-2-andrii@kernel.org
2021-12-28libbpf: Normalize PT_REGS_xxx() macro definitionsAndrii Nakryiko
Refactor PT_REGS macros definitions in bpf_tracing.h to avoid excessive duplication. We currently have classic PT_REGS_xxx() and CO-RE-enabled PT_REGS_xxx_CORE(). We are about to add also _SYSCALL variants, which would require excessive copying of all the per-architecture definitions. Instead, separate architecture-specific field/register names from the final macro that utilize them. That way for upcoming _SYSCALL variants we'll be able to just define x86_64 exception and otherwise have one common set of _SYSCALL macro definitions common for all architectures. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/20211222213924.1869758-1-andrii@kernel.org
2021-12-23libbpf: Do not use btf_dump__new() macro in C++ modeJiri Olsa
As reported in here [0], C++ compilers don't support __builtin_types_compatible_p(), so at least don't screw up compilation for them and let C++ users pick btf_dump__new vs btf_dump__new_deprecated explicitly. [0] https://github.com/libbpf/libbpf/issues/283#issuecomment-986100727 Fixes: 6084f5dc928f ("libbpf: Ensure btf_dump__new() and btf_dump_opts are future-proof") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211223131736.483956-1-jolsa@kernel.org
generated by cgit (git 2.34.1) at 2025-06-19 20:30:19 +0000