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2025-03-17bpftool: Using the right format specifiersJiayuan Chen
Fixed some formatting specifiers errors, such as using %d for int and %u for unsigned int, as well as other byte-length types. Perform type cast using the type derived from the data type itself, for example, if it's originally an int, it will be cast to unsigned int if forced to unsigned. Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250311112809.81901-3-jiayuan.chen@linux.dev
2024-12-13bpftool: btf: Support dumping a specific types from fileDaniel Xu
Some projects, for example xdp-tools [0], prefer to check in a minimized vmlinux.h rather than the complete file which can get rather large. However, when you try to add a minimized version of a complex struct (eg struct xfrm_state), things can get quite complex if you're trying to manually untangle and deduplicate the dependencies. This commit teaches bpftool to do a minimized dump of a specific types by providing a optional root_id argument(s). Example usage: $ ./bpftool btf dump file ~/dev/linux/vmlinux | rg "STRUCT 'xfrm_state'" [12643] STRUCT 'xfrm_state' size=912 vlen=58 $ ./bpftool btf dump file ~/dev/linux/vmlinux root_id 12643 format c #ifndef __VMLINUX_H__ #define __VMLINUX_H__ [..] struct xfrm_type_offload; struct xfrm_sec_ctx; struct xfrm_state { possible_net_t xs_net; union { struct hlist_node gclist; struct hlist_node bydst; }; union { struct hlist_node dev_gclist; struct hlist_node bysrc; }; struct hlist_node byspi; [..] [0]: https://github.com/xdp-project/xdp-tools/blob/master/headers/bpf/vmlinux.h Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/04feb860c0a56a7da66f923551484e1483a72074.1734119028.git.dxu@dxuuu.xyz
2024-12-13bpftool: btf: Validate root_type_ids earlyDaniel Xu
Handle invalid root_type_ids early, as an invalid ID will cause dumpers to half-emit valid boilerplate and then bail with an unclean exit. This is ugly and possibly confusing for users, so preemptively handle the common error case before any dumping begins. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <qmo@kernel.org> Link: https://lore.kernel.org/bpf/33e09a08a6072f8381cb976218a009709309b7e1.1734119028.git.dxu@dxuuu.xyz
2024-11-13bpftool: Cast variable `var` to long longLuo Yifan
When the SIGNED condition is met, the variable `var` should be cast to `long long` instead of `unsigned long long`. Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <qmo@kernel.org> Link: https://lore.kernel.org/bpf/20241112073701.283362-1-luoyifan@cmss.chinamobile.com
2024-10-03bpftool: __bpf_fastcall for kfuncs marked with special decl_tagEduard Zingerman
Generate __attribute__((bpf_fastcall)) for kfuncs marked with "bpf_fastcall" decl tag. E.g. for the following BTF: $ bpftool btf dump file vmlinux ... [A] FUNC 'bpf_rdonly_cast' type_id=... ... [B] DECL_TAG 'bpf_kfunc' type_id=A component_idx=-1 [C] DECL_TAG 'bpf_fastcall' type_id=A component_idx=-1 Generate the following vmlinux.h: #ifndef __VMLINUX_H__ #define __VMLINUX_H__ ... #ifndef __bpf_fastcall #if __has_attribute(bpf_fastcall) #define __bpf_fastcall __attribute__((bpf_fastcall)) #else #define __bpf_fastcall #endif #endif ... __bpf_fastcall extern void *bpf_rdonly_cast(...) ...; The "bpf_fastcall" / "bpf_kfunc" tags pair would generated by pahole when constructing vmlinux BTF. While at it, sort printed kfuncs by name for better vmlinux.h stability. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240916091712.2929279-5-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-06bpftool: Improve btf c dump sorting stabilityMykyta Yatsenko
Existing algorithm for BTF C dump sorting uses only types and names of the structs and unions for ordering. As dump contains structs with the same names but different contents, relative to each other ordering of those structs will be accidental. This patch addresses this problem by introducing a new sorting field that contains hash of the struct/union field names and types to disambiguate comparison of the non-unique named structs. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240906132453.146085-1-mykyta.yatsenko5@gmail.com
2024-09-02bpftool: Fix handling enum64 in btf dump sortingMykyta Yatsenko
Wrong function is used to access the first enum64 element. Substituting btf_enum(t) with btf_enum64(t) for BTF_KIND_ENUM64. Fixes: 94133cf24bb3 ("bpftool: Introduce btf c dump sorting") Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Quentin Monnet <qmo@kernel.org> Link: https://lore.kernel.org/bpf/20240902171721.105253-1-mykyta.yatsenko5@gmail.com
2024-06-12bpftool: Support dumping kfunc prototypes from BTFDaniel Xu
This patch enables dumping kfunc prototypes from bpftool. This is useful b/c with this patch, end users will no longer have to manually define kfunc prototypes. For the kernel tree, this also means we can optionally drop kfunc prototypes from: tools/testing/selftests/bpf/bpf_kfuncs.h tools/testing/selftests/bpf/bpf_experimental.h Example usage: $ make PAHOLE=/home/dxu/dev/pahole/build/pahole -j30 vmlinux $ ./tools/bpf/bpftool/bpftool btf dump file ./vmlinux format c | rg "__ksym;" | head -3 extern void cgroup_rstat_updated(struct cgroup *cgrp, int cpu) __weak __ksym; extern void cgroup_rstat_flush(struct cgroup *cgrp) __weak __ksym; extern struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) __weak __ksym; Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/bf6c08f9263c4bd9d10a717de95199d766a13f61.1718207789.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-18bpftool: Introduce btf c dump sortingMykyta Yatsenko
Sort bpftool c dump output; aiming to simplify vmlinux.h diffing and forcing more natural type definitions ordering. Definitions are sorted first by their BTF kind ranks, then by their base type name and by their own name. Type ranks Assign ranks to btf kinds (defined in function btf_type_rank) to set next order: 1. Anonymous enums/enums64 2. Named enums/enums64 3. Trivial types typedefs (ints, then floats) 4. Structs/Unions 5. Function prototypes 6. Forward declarations Type rank is set to maximum for unnamed reference types, structs and unions to avoid emitting those types early. They will be emitted as part of the type chain starting with named type. Lexicographical ordering Each type is assigned a sort_name and own_name. sort_name is the resolved name of the final base type for reference types (typedef, pointer, array etc). Sorting by sort_name allows to group typedefs of the same base type. sort_name for non-reference type is the same as own_name. own_name is a direct name of particular type, is used as final sorting step. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <qmo@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240514131221.20585-1-yatsenko@meta.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-16bpftool: Use bpf_{btf,link,map,prog}_get_info_by_fd()Ilya Leoshkevich
Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Split the bpf_obj_get_info_by_fd() call in build_btf_type_table() in two, since knowing the type helps with the Memory Sanitizer. Improve map_parse_fd_and_info() type safety by using struct bpf_map_info * instead of void * for info. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20230214231221.249277-4-iii@linux.ibm.com
2022-11-20bpftool: clean-up usage of libbpf_get_error()Sahid Orentino Ferdjaoui
bpftool is now totally compliant with libbpf 1.0 mode and is not expected to be compiled with pre-1.0, let's clean-up the usage of libbpf_get_error(). The changes stay aligned with returned errors always negative. - In tools/bpf/bpftool/btf.c This fixes an uninitialized local variable `err` in function do_dump() because it may now be returned without having been set. - This also removes the checks on NULL pointers before calling btf__free() because that function already does the check. Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@industrialdiscipline.com> Link: https://lore.kernel.org/r/20221120112515.38165-5-sahid.ferdjaoui@industrialdiscipline.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-09libbpf: Hashmap interface update to allow both long and void* keys/valuesEduard Zingerman
An update for libbpf's hashmap interface from void* -> void* to a polymorphic one, allowing both long and void* keys and values. This simplifies many use cases in libbpf as hashmaps there are mostly integer to integer. Perf copies hashmap implementation from libbpf and has to be updated as well. Changes to libbpf, selftests/bpf and perf are packed as a single commit to avoid compilation issues with any future bisect. Polymorphic interface is acheived by hiding hashmap interface functions behind auxiliary macros that take care of necessary type casts, for example: #define hashmap_cast_ptr(p) \ ({ \ _Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\ #p " pointee should be a long-sized integer or a pointer"); \ (long *)(p); \ }) bool hashmap_find(const struct hashmap *map, long key, long *value); #define hashmap__find(map, key, value) \ hashmap_find((map), (long)(key), hashmap_cast_ptr(value)) - hashmap__find macro casts key and value parameters to long and long* respectively - hashmap_cast_ptr ensures that value pointer points to a memory of appropriate size. This hack was suggested by Andrii Nakryiko in [1]. This is a follow up for [2]. [1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/ [2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com
2022-09-30bpftool: Fix error message of strerrorTianyi Liu
strerror() expects a positive errno, however variable err will never be positive when an error occurs. This causes bpftool to output too many "unknown error", even a simple "file not exist" error can not get an accurate message. This patch fixed all "strerror(err)" patterns in bpftool. Specially in btf.c#L823, hashmap__append() is an internal function of libbpf and will not change errno, so there's a little difference. Some libbpf_get_error() calls are kept for return values. Changes since v1: https://lore.kernel.org/bpf/SY4P282MB1084B61CD8671DFA395AA8579D539@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM/ Check directly for NULL values instead of calling libbpf_get_error(). Signed-off-by: Tianyi Liu <i.pear@outlook.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/SY4P282MB1084AD9CD84A920F08DF83E29D549@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM
2022-09-30bpftool: Remove unused struct btf_attach_pointYuan Can
After commit 2828d0d75b73 ("bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing"), struct btf_attach_point is not used anymore and can be removed as well. Signed-off-by: Yuan Can <yuancan@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220928090440.79637-2-yuancan@huawei.com
2022-06-07bpftool: Add btf enum64 supportYonghong Song
Add BTF_KIND_ENUM64 support. For example, the following enum is defined in uapi bpf.h. $ cat core.c enum A { BPF_F_INDEX_MASK = 0xffffffffULL, BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK, BPF_F_CTXLEN_MASK = (0xfffffULL << 32), } g; Compiled with clang -target bpf -O2 -g -c core.c Using bpftool to dump types and generate format C file: $ bpftool btf dump file core.o ... [1] ENUM64 'A' encoding=UNSIGNED size=8 vlen=3 'BPF_F_INDEX_MASK' val=4294967295ULL 'BPF_F_CURRENT_CPU' val=4294967295ULL 'BPF_F_CTXLEN_MASK' val=4503595332403200ULL $ bpftool btf dump file core.o format c ... enum A { BPF_F_INDEX_MASK = 4294967295ULL, BPF_F_CURRENT_CPU = 4294967295ULL, BPF_F_CTXLEN_MASK = 4503595332403200ULL, }; ... Note that for raw btf output, the encoding (UNSIGNED or SIGNED) is printed out as well. The 64bit value is also represented properly in BTF and C dump. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220607062652.3722649-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-05-13bpftool: Use sysfs vmlinux when dumping BTF by IDLarysa Zaremba
Currently, dumping almost all BTFs specified by id requires using the -B option to pass the base BTF. For kernel module BTFs the vmlinux BTF sysfs path should work. This patch simplifies dumping by ID usage by loading vmlinux BTF from sysfs as base, if base BTF was not specified and the ID corresponds to a kernel module BTF. Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Link: https://lore.kernel.org/bpf/20220513121743.12411-1-larysa.zaremba@intel.com
2022-01-12bpftool: Fix error check when calling hashmap__new()Mauricio Vásquez
hashmap__new() encodes errors with ERR_PTR(), hence it's not valid to check the returned pointer against NULL and IS_ERR() has to be used instead. libbpf_get_error() can't be used in this case as hashmap__new() is not part of the public libbpf API and it'll continue using ERR_PTR() after libbpf 1.0. Fixes: 8f184732b60b ("bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects") Fixes: 2828d0d75b73 ("bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing") Fixes: d6699f8e0f83 ("bpftool: Switch to libbpf's hashmap for PIDs/names references") Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20220107152620.192327-2-mauricio@kinvolk.io
2021-11-14bpftool: Use libbpf_get_error() to check errorHengqi Chen
Currently, LIBBPF_STRICT_ALL mode is enabled by default for bpftool which means on error cases, some libbpf APIs would return NULL pointers. This makes IS_ERR check failed to detect such cases and result in segfault error. Use libbpf_get_error() instead like we do in libbpf itself. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211115012436.3143318-1-hengqi.chen@gmail.com
2021-11-11bpftool: Support BTF_KIND_TYPE_TAGYonghong Song
Add bpftool support for BTF_KIND_TYPE_TAG. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211112012620.1505506-1-yhs@fb.com
2021-11-11bpftool: Update btf_dump__new() and perf_buffer__new_raw() callsAndrii Nakryiko
Use v1.0-compatible variants of btf_dump and perf_buffer "constructors". This is also a demonstration of reusing struct perf_buffer_raw_opts as OPTS-style option struct for new perf_buffer__new_raw() API. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211111053624.190580-10-andrii@kernel.org
2021-10-25bpftool: Switch to libbpf's hashmap for PIDs/names referencesQuentin Monnet
In order to show PIDs and names for processes holding references to BPF programs, maps, links, or BTF objects, bpftool creates hash maps to store all relevant information. This commit is part of a set that transitions from the kernel's hash map implementation to the one coming with libbpf. The motivation is to make bpftool less dependent of kernel headers, to ease the path to a potential out-of-tree mirror, like libbpf has. This is the third and final step of the transition, in which we convert the hash maps used for storing the information about the processes holding references to BPF objects (programs, maps, links, BTF), and at last we drop the inclusion of tools/include/linux/hashtable.h. Note: Checkpatch complains about the use of __weak declarations, and the missing empty lines after the bunch of empty function declarations when compiling without the BPF skeletons (none of these were introduced in this patch). We want to keep things as they are, and the reports should be safe to ignore. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-6-quentin@isovalent.com
2021-10-25bpftool: Switch to libbpf's hashmap for programs/maps in BTF listingQuentin Monnet
In order to show BPF programs and maps using BTF objects when the latter are being listed, bpftool creates hash maps to store all relevant items. This commit is part of a set that transitions from the kernel's hash map implementation to the one coming with libbpf. The motivation is to make bpftool less dependent of kernel headers, to ease the path to a potential out-of-tree mirror, like libbpf has. This commit focuses on the two hash maps used by bpftool when listing BTF objects to store references to programs and maps, and convert them to the libbpf's implementation. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-5-quentin@isovalent.com
2021-10-22bpftool: Switch to new btf__type_cnt APIHengqi Chen
Replace the call to btf__get_nr_types with new API btf__type_cnt. The old API will be deprecated in libbpf v0.7+. No functionality change. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-5-hengqi.chen@gmail.com
2021-10-18bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAGYonghong Song
Patch set [1] introduced BTF_KIND_TAG to allow tagging declarations for struct/union, struct/union field, var, func and func arguments and these tags will be encoded into dwarf. They are also encoded to btf by llvm for the bpf target. After BTF_KIND_TAG is introduced, we intended to use it for kernel __user attributes. But kernel __user is actually a type attribute. Upstream and internal discussion showed it is not a good idea to mix declaration attribute and type attribute. So we proposed to introduce btf_type_tag as a type attribute and existing btf_tag renamed to btf_decl_tag ([2]). This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some other declarations with *_tag to *_decl_tag to make it clear the tag is for declaration. In the future, BTF_KIND_TYPE_TAG might be introduced per [3]. [1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/ [2] https://reviews.llvm.org/D111588 [3] https://reviews.llvm.org/D111199 Fixes: b5ea834dde6b ("bpf: Support for new btf kind BTF_KIND_TAG") Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG") Fixes: 5c07f2fec003 ("bpftool: Add support for BTF_KIND_TAG") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
2021-09-14bpftool: Add support for BTF_KIND_TAGYonghong Song
Added bpftool support to dump BTF_KIND_TAG information. The new bpftool will be used in later patches to dump btf in the test bpf program object file. Currently, the tags are not emitted with bpftool btf dump file <path> format c and they are silently ignored. The tag information is mostly used in the kernel for verification purpose and the kernel uses its own btf to check. With adding these tags to vmlinux.h, tags will be encoded in program's btf but they will not be used by the kernel, at least for now. So let us delay adding these tags to format C header files until there is a real need. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210914223031.246951-1-yhs@fb.com
2021-07-30tools: bpftool: Document and add bash completion for -L, -B optionsQuentin Monnet
The -L|--use-loader option for using loader programs when loading, or when generating a skeleton, did not have any documentation or bash completion. Same thing goes for -B|--base-btf, used to pass a path to a base BTF object for split BTF such as BTF for kernel modules. This patch documents and adds bash completion for those options. Fixes: 75fa1777694c ("tools/bpftool: Add bpftool support for split BTF") Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210730215435.7095-7-quentin@isovalent.com
2021-07-30tools: bpftool: Update and synchronise option list in doc and help msgQuentin Monnet
All bpftool commands support the options for JSON output and debug from libbpf. In addition, some commands support additional options corresponding to specific use cases. The list of options described in the man pages for the different commands are not always accurate. The messages for interactive help are mostly limited to HELP_SPEC_OPTIONS, and are even less representative of the actual set of options supported for the commands. Let's update the lists: - HELP_SPEC_OPTIONS is modified to contain the "default" options (JSON and debug), and to be extensible (no ending curly bracket). - All commands use HELP_SPEC_OPTIONS in their help message, and then complete the list with their specific options. - The lists of options in the man pages are updated. - The formatting of the list for bpftool.rst is adjusted to match formatting for the other man pages. This is for consistency, and also because it will be helpful in a future patch to automatically check that the files are synchronised. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210730215435.7095-5-quentin@isovalent.com
2021-07-29tools: bpftool: Support dumping split BTF by idQuentin Monnet
Split BTF objects are typically BTF objects for kernel modules, which are incrementally built on top of kernel BTF instead of redefining all kernel symbols they need. We can use bpftool with its -B command-line option to dump split BTF objects. It works well when the handle provided for the BTF object to dump is a "path" to the BTF object, typically under /sys/kernel/btf, because bpftool internally calls btf__parse_split() which can take a "base_btf" pointer and resolve the BTF reconstruction (although in that case, the "-B" option is unnecessary because bpftool performs autodetection). However, it did not work so far when passing the BTF object through its id, because bpftool would call btf__get_from_id() which did not provide a way to pass a "base_btf" pointer. In other words, the following works: # bpftool btf dump file /sys/kernel/btf/i2c_smbus -B /sys/kernel/btf/vmlinux But this was not possible: # bpftool btf dump id 6 -B /sys/kernel/btf/vmlinux The libbpf API has recently changed, and btf__get_from_id() has been deprecated in favour of btf__load_from_kernel_by_id() and its version with support for split BTF, btf__load_from_kernel_by_id_split(). Let's update bpftool to make it able to dump the BTF object in the second case as well. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210729162028.29512-9-quentin@isovalent.com
2021-07-29tools: Replace btf__get_from_id() with btf__load_from_kernel_by_id()Quentin Monnet
Replace the calls to function btf__get_from_id(), which we plan to deprecate before the library reaches v1.0, with calls to btf__load_from_kernel_by_id() in tools/ (bpftool, perf, selftests). Update the surrounding code accordingly (instead of passing a pointer to the btf struct, get it as a return value from the function). Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210729162028.29512-6-quentin@isovalent.com
2021-04-23bpftool: Dump more info about DATASEC membersAndrii Nakryiko
Dump succinct information for each member of DATASEC: its kinds and name. This is extremely helpful to see at a quick glance what is inside each DATASEC of a given BTF. Without this, one has to jump around BTF data to just find out the name of a VAR or FUNC. DATASEC's var_secinfo member is special in that regard because it doesn't itself contain the name of the member, delegating that to the referenced VAR and FUNC kinds. Other kinds, like STRUCT/UNION/FUNC/ENUM, encode member names directly and thus are clearly identifiable in BTF dump. The new output looks like this: [35] DATASEC '.bss' size=0 vlen=6 type_id=8 offset=0 size=4 (VAR 'input_bss1') type_id=13 offset=0 size=4 (VAR 'input_bss_weak') type_id=16 offset=0 size=4 (VAR 'output_bss1') type_id=17 offset=0 size=4 (VAR 'output_data1') type_id=18 offset=0 size=4 (VAR 'output_rodata1') type_id=20 offset=0 size=8 (VAR 'output_sink1') [36] DATASEC '.data' size=0 vlen=2 type_id=9 offset=0 size=4 (VAR 'input_data1') type_id=14 offset=0 size=4 (VAR 'input_data_weak') [37] DATASEC '.kconfig' size=0 vlen=2 type_id=25 offset=0 size=4 (VAR 'LINUX_KERNEL_VERSION') type_id=28 offset=0 size=1 (VAR 'CONFIG_BPF_SYSCALL') [38] DATASEC '.ksyms' size=0 vlen=1 type_id=30 offset=0 size=1 (VAR 'bpf_link_fops') [39] DATASEC '.rodata' size=0 vlen=2 type_id=12 offset=0 size=4 (VAR 'input_rodata1') type_id=15 offset=0 size=4 (VAR 'input_rodata_weak') [40] DATASEC 'license' size=0 vlen=1 type_id=24 offset=0 size=4 (VAR 'LICENSE') 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/20210423181348.1801389-3-andrii@kernel.org
2021-04-23bpftool: Support dumping BTF VAR's "extern" linkageAndrii Nakryiko
Add dumping of "extern" linkage for BTF VAR kind. Also shorten "global-allocated" to "global" to be in line with FUNC's "global". 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/20210423181348.1801389-2-andrii@kernel.org
2021-03-16bpftool: Fix maybe-uninitialized warningsAndrii Nakryiko
Somehow when bpftool is compiled in -Og mode, compiler produces new warnings about possibly uninitialized variables. Fix all the reported problems. Fixes: 2119f2189df1 ("bpftool: add C output format option to btf dump subcommand") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210313210920.1959628-3-andrii@kernel.org
2021-03-04tools/bpftool: Add BTF_KIND_FLOAT supportIlya Leoshkevich
Only dumping support needs to be adjusted, the code structure follows that of BTF_KIND_INT. Example plain and JSON outputs: [4] FLOAT 'float' size=4 {"id":4,"kind":"FLOAT","name":"float","size":4} Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210226202256.116518-5-iii@linux.ibm.com
2020-12-04Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-12-03 The main changes are: 1) Support BTF in kernel modules, from Andrii. 2) Introduce preferred busy-polling, from Björn. 3) bpf_ima_inode_hash() and bpf_bprm_opts_set() helpers, from KP Singh. 4) Memcg-based memory accounting for bpf objects, from Roman. 5) Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks, from Stanislav. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (118 commits) selftests/bpf: Fix invalid use of strncat in test_sockmap libbpf: Use memcpy instead of strncpy to please GCC selftests/bpf: Add fentry/fexit/fmod_ret selftest for kernel module selftests/bpf: Add tp_btf CO-RE reloc test for modules libbpf: Support attachment of BPF tracing programs to kernel modules libbpf: Factor out low-level BPF program loading helper bpf: Allow to specify kernel module BTFs when attaching BPF programs bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier selftests/bpf: Add CO-RE relocs selftest relying on kernel module BTF selftests/bpf: Add support for marking sub-tests as skipped selftests/bpf: Add bpf_testmod kernel module for testing libbpf: Add kernel module BTF support for CO-RE relocations libbpf: Refactor CO-RE relocs to not assume a single BTF object libbpf: Add internal helper to load BTF data by FD bpf: Keep module's btf_data_size intact after load bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address() selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP bpf: Adds support for setting window clamp samples/bpf: Fix spelling mistake "recieving" -> "receiving" bpf: Fix cold build of test_progs-no_alu32 ... ==================== Link: https://lore.kernel.org/r/20201204021936.85653-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Conflicts: drivers/net/ethernet/ibm/ibmvnic.c Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-03tools/bpftool: Auto-detect split BTFs in common casesAndrii Nakryiko
In case of working with module's split BTF from /sys/kernel/btf/*, auto-substitute /sys/kernel/btf/vmlinux as the base BTF. This makes using bpftool with module BTFs faster and simpler. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201202065244.530571-4-andrii@kernel.org
2020-12-03tools/bpftool: Emit name <anon> for anonymous BTFsAndrii Nakryiko
For consistency of output, emit "name <anon>" for BTFs without the name. This keeps output more consistent and obvious. Suggested-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201202065244.530571-2-andrii@kernel.org
2020-11-24bpftool: Fix error return value in build_btf_type_tableZhen Lei
An appropriate return value should be set on the failed path. Fixes: 4d374ba0bf30 ("tools: bpftool: implement "bpftool btf show|list"") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201124104100.491-1-thunder.leizhen@huawei.com
2020-11-10tools/bpftool: Add support for in-kernel and named BTF in `btf show`Andrii Nakryiko
Display vmlinux BTF name and kernel module names when listing available BTFs on the system. In human-readable output mode, module BTFs are reported with "name [module-name]", while vmlinux BTF will be reported as "name [vmlinux]". Square brackets are added by bpftool and follow kernel convention when displaying modules in human-readable text outputs. [vmuser@archvm bpf]$ sudo ../../../bpf/bpftool/bpftool btf s 1: name [vmlinux] size 4082281B 6: size 2365B prog_ids 8,6 map_ids 3 7: name [button] size 46895B 8: name [pcspkr] size 42328B 9: name [serio_raw] size 39375B 10: name [floppy] size 57185B 11: name [i2c_core] size 76186B 12: name [crc32c_intel] size 16036B 13: name [i2c_piix4] size 50497B 14: name [irqbypass] size 14124B 15: name [kvm] size 197985B 16: name [kvm_intel] size 123564B 17: name [cryptd] size 42466B 18: name [crypto_simd] size 17187B 19: name [glue_helper] size 39205B 20: name [aesni_intel] size 41034B 25: size 36150B pids bpftool(2519) In JSON mode, two fields (boolean "kernel" and string "name") are reported for each BTF object. vmlinux BTF is reported with name "vmlinux" (kernel itself returns and empty name for vmlinux BTF). [vmuser@archvm bpf]$ sudo ../../../bpf/bpftool/bpftool btf s -jp [{ "id": 1, "size": 4082281, "prog_ids": [], "map_ids": [], "kernel": true, "name": "vmlinux" },{ "id": 6, "size": 2365, "prog_ids": [8,6 ], "map_ids": [3 ], "kernel": false },{ "id": 7, "size": 46895, "prog_ids": [], "map_ids": [], "kernel": true, "name": "button" },{ ... Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20201110011932.3201430-6-andrii@kernel.org
2020-11-05tools/bpftool: Add bpftool support for split BTFAndrii Nakryiko
Add ability to work with split BTF by providing extra -B flag, which allows to specify the path to the base BTF file. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20201105043402.2530976-12-andrii@kernel.org
2020-08-03tools/bpftool: Use libbpf's btf__parse() API for parsing BTF from fileAndrii Nakryiko
Use generic libbpf API to parse BTF data from file, instead of re-implementing it in bpftool. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200802013219.864880-3-andriin@fb.com
2020-08-03tools, bpftool: Fix wrong return value in do_dump()Tianjia Zhang
In case of btf_id does not exist, a negative error code -ENOENT should be returned. Fixes: c93cc69004df3 ("bpftool: add ability to dump BTF types") Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200802111540.5384-1-tianjia.zhang@linux.alibaba.com
2020-06-22tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDsAndrii Nakryiko
Add bpf_iter-based way to find all the processes that hold open FDs against BPF object (map, prog, link, btf). bpftool always attempts to discover this, but will silently give up if kernel doesn't yet support bpf_iter BPF programs. Process name and PID are emitted for each process (task group). Sample output for each of 4 BPF objects: $ sudo ./bpftool prog show 2694: cgroup_device tag 8c42dee26e8cd4c2 gpl loaded_at 2020-06-16T15:34:32-0700 uid 0 xlated 648B jited 409B memlock 4096B pids systemd(1) 2907: cgroup_skb name egress tag 9ad187367cf2b9e8 gpl loaded_at 2020-06-16T18:06:54-0700 uid 0 xlated 48B jited 59B memlock 4096B map_ids 2436 btf_id 1202 pids test_progs(2238417), test_progs(2238445) $ sudo ./bpftool map show 2436: array name test_cgr.bss flags 0x400 key 4B value 8B max_entries 1 memlock 8192B btf_id 1202 pids test_progs(2238417), test_progs(2238445) 2445: array name pid_iter.rodata flags 0x480 key 4B value 4B max_entries 1 memlock 8192B btf_id 1214 frozen pids bpftool(2239612) $ sudo ./bpftool link show 61: cgroup prog 2908 cgroup_id 375301 attach_type egress pids test_progs(2238417), test_progs(2238445) 62: cgroup prog 2908 cgroup_id 375344 attach_type egress pids test_progs(2238417), test_progs(2238445) $ sudo ./bpftool btf show 1202: size 1527B prog_ids 2908,2907 map_ids 2436 pids test_progs(2238417), test_progs(2238445) 1242: size 34684B pids bpftool(2258892) Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-9-andriin@fb.com
2020-06-01tools, bpftool: Print correct error message when failing to load BTFTobias Klauser
btf__parse_raw and btf__parse_elf return negative error numbers wrapped in an ERR_PTR, so the extracted value needs to be negated before passing them to strerror which expects a positive error number. Before: Error: failed to load BTF from .../vmlinux: Unknown error -2 After: Error: failed to load BTF from .../vmlinux: No such file or directory Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200525135421.4154-1-tklauser@distanz.ch Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-06-01tools, bpftool: Clean subcommand help messagesQuentin Monnet
This is a clean-up for the formatting of the do_help functions for bpftool's subcommands. The following fixes are included: - Do not use argv[-2] for "iter" help message, as the help is shown by default if no "iter" action is selected, resulting in messages looking like "./bpftool bpftool pin...". - Do not print unused HELP_SPEC_PROGRAM in help message for "bpftool link". - Andrii used argument indexing to avoid having multiple occurrences of bin_name and argv[-2] in the fprintf() for the help message, for "bpftool gen" and "bpftool link". Let's reuse this for all other help functions. We can remove up to thirty arguments for the "bpftool map" help message. - Harmonise all functions, e.g. use ending quotes-comma on a separate line. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200523010751.23465-1-quentin@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-04-26tools/bpf/bpftool: Remove duplicate headersJagadeesh Pagadala
Code cleanup: Remove duplicate headers which are included twice. Signed-off-by: Jagadeesh Pagadala <jagdsh.linux@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/1587274757-14101-1-git-send-email-jagdsh.linux@gmail.com
2020-03-02bpftool: Add header guards to generated vmlinux.hAndrii Nakryiko
Add canonical #ifndef/#define/#endif guard for generated vmlinux.h header with __VMLINUX_H__ symbol. __VMLINUX_H__ is also going to play double role of identifying whether vmlinux.h is being used, versus, say, BCC or non-CO-RE libbpf modes with dependency on kernel headers. This will make it possible to write helper macro/functions, agnostic to exact BPF program set up. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200229231112.1240137-2-andriin@fb.com
2020-01-24bpftool: Print function linkage in BTF dumpAndrii Nakryiko
Add printing out BTF_KIND_FUNC's linkage. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200124054317.2459436-1-andriin@fb.com
2020-01-20bpftool: Use consistent include paths for libbpfToke Høiland-Jørgensen
Fix bpftool to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To make sure no new files are introduced that doesn't include the bpf/ prefix in its include, remove tools/lib/bpf from the include path entirely, and use tools/lib instead. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560684.1683545.4765181397974997027.stgit@toke.dk
2020-01-13bpftool: Apply preserve_access_index attribute to all types in BTF dumpAndrii Nakryiko
This patch makes structs and unions, emitted through BTF dump, automatically CO-RE-relocatable (unless disabled with `#define BPF_NO_PRESERVE_ACCESS_INDEX`, specified before including generated header file). This effectivaly turns usual bpf_probe_read() call into equivalent of bpf_core_read(), by automatically applying builtin_preserve_access_index to any field accesses of types in generated C types header. This is especially useful for tp_btf/fentry/fexit BPF program types. They allow direct memory access, so BPF C code just uses straightfoward a->b->c access pattern to read data from kernel. But without kernel structs marked as CO-RE relocatable through preserve_access_index attribute, one has to enclose all the data reads into a special __builtin_preserve_access_index code block, like so: __builtin_preserve_access_index(({ x = p->pid; /* where p is struct task_struct *, for example */ })); This is very inconvenient and obscures the logic quite a bit. By marking all auto-generated types with preserve_access_index attribute the above code is reduced to just a clean and natural `x = p->pid;`. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200113073143.1779940-5-andriin@fb.com
generated by cgit v1.2.3 (git 2.39.1) at 2025-06-16 02:14:14 +0000