diff options
| -rw-r--r-- | tools/bpf/bpftool/Documentation/bpftool-btf.rst | 11 | ||||
| -rw-r--r-- | tools/bpf/bpftool/bash-completion/bpftool | 6 | ||||
| -rw-r--r-- | tools/bpf/bpftool/btf.c | 121 |
3 files changed, 121 insertions, 17 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst index d47dddc2b4ee..cf75a7fa2d6b 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst @@ -27,7 +27,7 @@ BTF COMMANDS | **bpftool** **btf dump** *BTF_SRC* [**format** *FORMAT*] [**root_id** *ROOT_ID*] | **bpftool** **btf help** | -| *BTF_SRC* := { **id** *BTF_ID* | **prog** *PROG* | **map** *MAP* [{**key** | **value** | **kv** | **all**}] | **file** *FILE* } +| *BTF_SRC* := { **id** *BTF_ID* | **prog** *PROG* | **map** *MAP* [{**key** | **value** | **kv** | **all**}] | **file** *FILE* [**file** *FILE*]... } | *FORMAT* := { **raw** | **c** [**unsorted**] } | *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } | *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* } @@ -58,9 +58,12 @@ bpftool btf dump *BTF_SRC* [format *FORMAT*] [root_id *ROOT_ID*] When **prog** is provided, it's expected that program has associated BTF object with BTF types. - When specifying *FILE*, an ELF file is expected, containing .BTF section - with well-defined BTF binary format data, typically produced by clang or - pahole. + When specifying *FILE*, an ELF file or a raw BTF file (e.g. from + ``/sys/kernel/btf/``) is expected. Multiple **file** arguments may be + given to merge BTF from several kernel modules into a single output. + When sysfs paths are used, vmlinux BTF is loaded automatically as the + base; if vmlinux itself appears in the file list it is skipped. + A base BTF can also be specified explicitly with **-B**. **format** option can be used to override default (raw) output format. Raw (**raw**) or C-syntax (**c**) output formats are supported. With C-style diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index a28f0cc522e4..babb0d4e9753 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -961,10 +961,14 @@ _bpftool() *) # emit extra options case ${words[3]} in - id|file) + id) COMPREPLY=( $( compgen -W "root_id" -- "$cur" ) ) _bpftool_once_attr 'format' ;; + file) + COMPREPLY=( $( compgen -W "root_id file" -- "$cur" ) ) + _bpftool_once_attr 'format' + ;; map|prog) if [[ ${words[3]} == "map" ]] && [[ $cword == 6 ]]; then COMPREPLY+=( $( compgen -W "key value kv all" -- "$cur" ) ) diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index 946612029dee..2e899e940034 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -28,6 +28,7 @@ #define FASTCALL_DECL_TAG "bpf_fastcall" #define MAX_ROOT_IDS 16 +#define MAX_BTF_FILES 64 static const char * const btf_kind_str[NR_BTF_KINDS] = { [BTF_KIND_UNKN] = "UNKNOWN", @@ -878,6 +879,45 @@ static bool btf_is_kernel_module(__u32 btf_id) return btf_info.kernel_btf && strncmp(btf_name, "vmlinux", sizeof(btf_name)) != 0; } +static struct btf *merge_btf_files(const char **files, int nr_files, + struct btf *vmlinux_base) +{ + struct btf *combined, *mod; + int ret; + + combined = btf__new_empty_split(vmlinux_base); + if (!combined) { + p_err("failed to create combined BTF: %s", strerror(errno)); + return NULL; + } + + for (int j = 0; j < nr_files; j++) { + mod = btf__parse_split(files[j], vmlinux_base); + if (!mod) { + p_err("failed to load BTF from %s: %s", files[j], strerror(errno)); + btf__free(combined); + return NULL; + } + + ret = btf__add_btf(combined, mod); + btf__free(mod); + if (ret < 0) { + p_err("failed to merge BTF from %s: %s", files[j], strerror(-ret)); + btf__free(combined); + return NULL; + } + } + + ret = btf__dedup(combined, NULL); + if (ret) { + p_err("failed to dedup combined BTF: %s", strerror(-ret)); + btf__free(combined); + return NULL; + } + + return combined; +} + static int do_dump(int argc, char **argv) { bool dump_c = false, sort_dump_c = true; @@ -958,20 +998,76 @@ static int do_dump(int argc, char **argv) NEXT_ARG(); } else if (is_prefix(src, "file")) { const char sysfs_prefix[] = "/sys/kernel/btf/"; + struct btf *vmlinux_base = base_btf; + const char *files[MAX_BTF_FILES]; + int nr_files = 0; - if (!base_btf && - strncmp(*argv, sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0 && - strcmp(*argv, sysfs_vmlinux) != 0) - base = get_vmlinux_btf_from_sysfs(); - - btf = btf__parse_split(*argv, base ?: base_btf); - if (!btf) { - err = -errno; - p_err("failed to load BTF from %s: %s", - *argv, strerror(errno)); - goto done; + /* First grab our argument, filtering out the sysfs_vmlinux. */ + if (strcmp(*argv, sysfs_vmlinux) != 0) { + files[nr_files++] = *argv; + } else { + p_info("skipping %s (will be loaded as base)", *argv); } NEXT_ARG(); + + while (argc && is_prefix(*argv, "file")) { + NEXT_ARG(); + if (!REQ_ARGS(1)) { + err = -EINVAL; + goto done; + } + /* Filter out any sysfs vmlinux entries. */ + if (strcmp(*argv, sysfs_vmlinux) == 0) { + p_info("skipping %s (will be loaded as base)", *argv); + NEXT_ARG(); + continue; + } + if (nr_files >= MAX_BTF_FILES) { + p_err("too many BTF files (max %d)", MAX_BTF_FILES); + err = -E2BIG; + goto done; + } + files[nr_files++] = *argv; + NEXT_ARG(); + } + + /* Auto-detect vmlinux base if any file is from sysfs */ + if (!vmlinux_base) { + for (int j = 0; j < nr_files; j++) { + if (strncmp(files[j], sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0) { + base = get_vmlinux_btf_from_sysfs(); + vmlinux_base = base; + break; + } + } + } + + /* All files were the sysfs_vmlinux, handle it like we used to */ + if (nr_files == 0) { + nr_files = 1; + files[0] = sysfs_vmlinux; + } + + if (nr_files == 1) { + btf = btf__parse_split(files[0], base ?: base_btf); + if (!btf) { + err = -errno; + p_err("failed to load BTF from %s: %s", files[0], strerror(errno)); + goto done; + } + } else { + if (!vmlinux_base) { + p_err("base BTF is required when merging multiple BTF files; use -B/--base-btf or use sysfs paths"); + err = -EINVAL; + goto done; + } + + btf = merge_btf_files(files, nr_files, vmlinux_base); + if (!btf) { + err = -errno; + goto done; + } + } } else { err = -1; p_err("unrecognized BTF source specifier: '%s'", src); @@ -1445,7 +1541,8 @@ static int do_help(int argc, char **argv) " %1$s %2$s dump BTF_SRC [format FORMAT] [root_id ROOT_ID]\n" " %1$s %2$s help\n" "\n" - " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n" + " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] |\n" + " file FILE [file FILE]... }\n" " FORMAT := { raw | c [unsorted] }\n" " " HELP_SPEC_MAP "\n" " " HELP_SPEC_PROGRAM "\n" |