| Message ID | 20191108064039.2041889-17-ast@kernel.org |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | Introduce BPF trampoline | expand |
> On Nov 7, 2019, at 10:40 PM, Alexei Starovoitov <ast@kernel.org> wrote: > > Extend libbpf api to pass attach_prog_fd into bpf_object__open. > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > --- [...] > +static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) > +{ > + struct bpf_prog_info_linear *info_linear; > + struct bpf_prog_info *info; > + struct btf *btf = NULL; > + int err = -EINVAL; > + > + info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0); > + if (IS_ERR_OR_NULL(info_linear)) { > + pr_warn("failed get_prog_info_linear for FD %d\n", > + attach_prog_fd); > + return -EINVAL; > + } > + info = &info_linear->info; > + if (!info->btf_id) { > + pr_warn("The target program doesn't have BTF\n"); > + goto out; > + } > + if (btf__get_from_id(info->btf_id, &btf)) { > + pr_warn("Failed to get BTF of the program\n"); > + goto out; > + } > + err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); > + btf__free(btf); > + if (err <= 0) { > + pr_warn("%s is not found in prog's BTF\n", name); > + goto out; ^^^ This goto doesn't really do much. > + } > +out: > + free(info_linear); > + return err; > +} Otherwise Acked-by: Song Liu <songliubraving@fb.com>
On 11/8/19 10:57 AM, Song Liu wrote: > > >> On Nov 7, 2019, at 10:40 PM, Alexei Starovoitov <ast@kernel.org> wrote: >> >> Extend libbpf api to pass attach_prog_fd into bpf_object__open. >> >> Signed-off-by: Alexei Starovoitov <ast@kernel.org> >> --- > > [...] > >> +static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) >> +{ >> + struct bpf_prog_info_linear *info_linear; >> + struct bpf_prog_info *info; >> + struct btf *btf = NULL; >> + int err = -EINVAL; >> + >> + info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0); >> + if (IS_ERR_OR_NULL(info_linear)) { >> + pr_warn("failed get_prog_info_linear for FD %d\n", >> + attach_prog_fd); >> + return -EINVAL; >> + } >> + info = &info_linear->info; >> + if (!info->btf_id) { >> + pr_warn("The target program doesn't have BTF\n"); >> + goto out; >> + } >> + if (btf__get_from_id(info->btf_id, &btf)) { >> + pr_warn("Failed to get BTF of the program\n"); >> + goto out; >> + } >> + err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); >> + btf__free(btf); >> + if (err <= 0) { >> + pr_warn("%s is not found in prog's BTF\n", name); >> + goto out; > ^^^ This goto doesn't really do much. yeah. it does look a bit weird. I wanted to keep uniform error handling, but can remove it if you insist. >> + } >> +out: >> + free(info_linear); >> + return err; >> +} > > Otherwise > > Acked-by: Song Liu <songliubraving@fb.com> >
> On Nov 8, 2019, at 11:13 AM, Alexei Starovoitov <ast@fb.com> wrote: > > On 11/8/19 10:57 AM, Song Liu wrote: >> >> >>> On Nov 7, 2019, at 10:40 PM, Alexei Starovoitov <ast@kernel.org> wrote: >>> >>> Extend libbpf api to pass attach_prog_fd into bpf_object__open. >>> >>> Signed-off-by: Alexei Starovoitov <ast@kernel.org> >>> --- >> >> [...] >> >>> +static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) >>> +{ >>> + struct bpf_prog_info_linear *info_linear; >>> + struct bpf_prog_info *info; >>> + struct btf *btf = NULL; >>> + int err = -EINVAL; >>> + >>> + info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0); >>> + if (IS_ERR_OR_NULL(info_linear)) { >>> + pr_warn("failed get_prog_info_linear for FD %d\n", >>> + attach_prog_fd); >>> + return -EINVAL; >>> + } >>> + info = &info_linear->info; >>> + if (!info->btf_id) { >>> + pr_warn("The target program doesn't have BTF\n"); >>> + goto out; >>> + } >>> + if (btf__get_from_id(info->btf_id, &btf)) { >>> + pr_warn("Failed to get BTF of the program\n"); >>> + goto out; >>> + } >>> + err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); >>> + btf__free(btf); >>> + if (err <= 0) { >>> + pr_warn("%s is not found in prog's BTF\n", name); >>> + goto out; >> ^^^ This goto doesn't really do much. > > yeah. it does look a bit weird. > I wanted to keep uniform error handling, but can remove it > if you insist. I think it is good as-is. Thanks, Song
On Thu, Nov 7, 2019 at 10:41 PM Alexei Starovoitov <ast@kernel.org> wrote: > > Extend libbpf api to pass attach_prog_fd into bpf_object__open. > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > --- > tools/include/uapi/linux/bpf.h | 1 + > tools/lib/bpf/bpf.c | 9 +++-- > tools/lib/bpf/bpf.h | 5 ++- > tools/lib/bpf/libbpf.c | 65 +++++++++++++++++++++++++++++----- > tools/lib/bpf/libbpf.h | 3 +- > 5 files changed, 69 insertions(+), 14 deletions(-) > > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > index 69c200e6e696..4842a134b202 100644 > --- a/tools/include/uapi/linux/bpf.h > +++ b/tools/include/uapi/linux/bpf.h > @@ -425,6 +425,7 @@ union bpf_attr { > __aligned_u64 line_info; /* line info */ > __u32 line_info_cnt; /* number of bpf_line_info records */ > __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ > + __u32 attach_prog_fd; /* 0 to attach to vmlinux */ > }; > > struct { /* anonymous struct used by BPF_OBJ_* commands */ > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c > index b3e3e99a0f28..f805787c8efd 100644 > --- a/tools/lib/bpf/bpf.c > +++ b/tools/lib/bpf/bpf.c > @@ -228,10 +228,14 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, > memset(&attr, 0, sizeof(attr)); > attr.prog_type = load_attr->prog_type; > attr.expected_attach_type = load_attr->expected_attach_type; > - if (attr.prog_type == BPF_PROG_TYPE_TRACING) > + if (attr.prog_type == BPF_PROG_TYPE_TRACING) { > attr.attach_btf_id = load_attr->attach_btf_id; > - else > + if (load_attr->attach_prog_fd) > + attr.attach_prog_fd = load_attr->attach_prog_fd; why the if? if it's zero, attr.attach_prog_fd will stay zero. > + } else { > attr.prog_ifindex = load_attr->prog_ifindex; > + attr.kern_version = load_attr->kern_version; > + } > attr.insn_cnt = (__u32)load_attr->insns_cnt; > attr.insns = ptr_to_u64(load_attr->insns); > attr.license = ptr_to_u64(load_attr->license); [...] > CHECK_ERR(bpf_object__elf_init(obj), err, out); > CHECK_ERR(bpf_object__check_endianness(obj), err, out); > @@ -3927,10 +3934,12 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, > bpf_program__set_expected_attach_type(prog, attach_type); > if (prog_type == BPF_PROG_TYPE_TRACING) { > err = libbpf_attach_btf_id_by_name(prog->section_name, > - attach_type); > + attach_type, > + attach_prog_fd); libbpf_find_attach_btf_id seems like a better name at this point > if (err <= 0) > goto out; > prog->attach_btf_id = err; > + prog->attach_prog_fd = attach_prog_fd; > } > } > [...]
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 69c200e6e696..4842a134b202 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -425,6 +425,7 @@ union bpf_attr { __aligned_u64 line_info; /* line info */ __u32 line_info_cnt; /* number of bpf_line_info records */ __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ + __u32 attach_prog_fd; /* 0 to attach to vmlinux */ }; struct { /* anonymous struct used by BPF_OBJ_* commands */ diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index b3e3e99a0f28..f805787c8efd 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -228,10 +228,14 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, memset(&attr, 0, sizeof(attr)); attr.prog_type = load_attr->prog_type; attr.expected_attach_type = load_attr->expected_attach_type; - if (attr.prog_type == BPF_PROG_TYPE_TRACING) + if (attr.prog_type == BPF_PROG_TYPE_TRACING) { attr.attach_btf_id = load_attr->attach_btf_id; - else + if (load_attr->attach_prog_fd) + attr.attach_prog_fd = load_attr->attach_prog_fd; + } else { attr.prog_ifindex = load_attr->prog_ifindex; + attr.kern_version = load_attr->kern_version; + } attr.insn_cnt = (__u32)load_attr->insns_cnt; attr.insns = ptr_to_u64(load_attr->insns); attr.license = ptr_to_u64(load_attr->license); @@ -245,7 +249,6 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.log_size = 0; } - attr.kern_version = load_attr->kern_version; attr.prog_btf_fd = load_attr->prog_btf_fd; attr.func_info_rec_size = load_attr->func_info_rec_size; attr.func_info_cnt = load_attr->func_info_cnt; diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 1c53bc5b4b3c..3c791fa8e68e 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -77,7 +77,10 @@ struct bpf_load_program_attr { const struct bpf_insn *insns; size_t insns_cnt; const char *license; - __u32 kern_version; + union { + __u32 kern_version; + __u32 attach_prog_fd; + }; union { __u32 prog_ifindex; __u32 attach_btf_id; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e9c9961bbb9f..93188c35d76a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -189,6 +189,7 @@ struct bpf_program { enum bpf_attach_type expected_attach_type; __u32 attach_btf_id; + __u32 attach_prog_fd; void *func_info; __u32 func_info_rec_size; __u32 func_info_cnt; @@ -3681,8 +3682,13 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.insns = insns; load_attr.insns_cnt = insns_cnt; load_attr.license = license; - load_attr.kern_version = kern_version; - load_attr.prog_ifindex = prog->prog_ifindex; + if (prog->type == BPF_PROG_TYPE_TRACING) { + load_attr.attach_prog_fd = prog->attach_prog_fd; + load_attr.attach_btf_id = prog->attach_btf_id; + } else { + load_attr.kern_version = kern_version; + load_attr.prog_ifindex = prog->prog_ifindex; + } /* if .BTF.ext was loaded, kernel supports associated BTF for prog */ if (prog->obj->btf_ext) btf_fd = bpf_object__btf_fd(prog->obj); @@ -3697,7 +3703,6 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.line_info_cnt = prog->line_info_cnt; load_attr.log_level = prog->log_level; load_attr.prog_flags = prog->prog_flags; - load_attr.attach_btf_id = prog->attach_btf_id; retry_load: log_buf = malloc(log_buf_size); @@ -3860,8 +3865,8 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level) } static int libbpf_attach_btf_id_by_name(const char *name, - enum bpf_attach_type attach_type); - + enum bpf_attach_type attach_type, + __u32 attach_prog_fd); static struct bpf_object * __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, struct bpf_object_open_opts *opts) @@ -3872,6 +3877,7 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, const char *obj_name; char tmp_name[64]; bool relaxed_maps; + __u32 attach_prog_fd; int err; if (elf_version(EV_CURRENT) == EV_NONE) { @@ -3902,6 +3908,7 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, obj->relaxed_core_relocs = OPTS_GET(opts, relaxed_core_relocs, false); relaxed_maps = OPTS_GET(opts, relaxed_maps, false); pin_root_path = OPTS_GET(opts, pin_root_path, NULL); + attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0); CHECK_ERR(bpf_object__elf_init(obj), err, out); CHECK_ERR(bpf_object__check_endianness(obj), err, out); @@ -3927,10 +3934,12 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, bpf_program__set_expected_attach_type(prog, attach_type); if (prog_type == BPF_PROG_TYPE_TRACING) { err = libbpf_attach_btf_id_by_name(prog->section_name, - attach_type); + attach_type, + attach_prog_fd); if (err <= 0) goto out; prog->attach_btf_id = err; + prog->attach_prog_fd = attach_prog_fd; } } @@ -5079,8 +5088,42 @@ int libbpf_find_vmlinux_btf_id(const char *name, return err; } +static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) +{ + struct bpf_prog_info_linear *info_linear; + struct bpf_prog_info *info; + struct btf *btf = NULL; + int err = -EINVAL; + + info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0); + if (IS_ERR_OR_NULL(info_linear)) { + pr_warn("failed get_prog_info_linear for FD %d\n", + attach_prog_fd); + return -EINVAL; + } + info = &info_linear->info; + if (!info->btf_id) { + pr_warn("The target program doesn't have BTF\n"); + goto out; + } + if (btf__get_from_id(info->btf_id, &btf)) { + pr_warn("Failed to get BTF of the program\n"); + goto out; + } + err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); + btf__free(btf); + if (err <= 0) { + pr_warn("%s is not found in prog's BTF\n", name); + goto out; + } +out: + free(info_linear); + return err; +} + static int libbpf_attach_btf_id_by_name(const char *name, - enum bpf_attach_type attach_type) + enum bpf_attach_type attach_type, + __u32 attach_prog_fd) { int i, err; @@ -5092,8 +5135,12 @@ static int libbpf_attach_btf_id_by_name(const char *name, continue; if (strncmp(name, section_names[i].sec, section_names[i].len)) continue; - err = libbpf_find_vmlinux_btf_id(name + section_names[i].len, - attach_type); + if (attach_prog_fd) + err = libbpf_find_prog_btf_id(name + section_names[i].len, + attach_prog_fd); + else + err = libbpf_find_vmlinux_btf_id(name + section_names[i].len, + attach_type); if (err <= 0) pr_warn("%s is not found in vmlinux BTF\n", name); return err; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 0fe47807916d..d6b23d81c975 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -108,8 +108,9 @@ struct bpf_object_open_opts { * auto-pinned to that path on load; defaults to "/sys/fs/bpf". */ const char *pin_root_path; + __u32 attach_prog_fd; }; -#define bpf_object_open_opts__last_field pin_root_path +#define bpf_object_open_opts__last_field attach_prog_fd LIBBPF_API struct bpf_object *bpf_object__open(const char *path); LIBBPF_API struct bpf_object *
Extend libbpf api to pass attach_prog_fd into bpf_object__open. Signed-off-by: Alexei Starovoitov <ast@kernel.org> --- tools/include/uapi/linux/bpf.h | 1 + tools/lib/bpf/bpf.c | 9 +++-- tools/lib/bpf/bpf.h | 5 ++- tools/lib/bpf/libbpf.c | 65 +++++++++++++++++++++++++++++----- tools/lib/bpf/libbpf.h | 3 +- 5 files changed, 69 insertions(+), 14 deletions(-)