From: Menglong Dong <dongmenglong.8@bytedance.com> To: andrii@kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, mykolal@fb.com, shuah@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, thinker.li@gmail.com, dongmenglong.8@bytedance.com, zhoufeng.zf@bytedance.com, davemarchevsky@fb.com, dxu@dxuuu.xyz, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH bpf-next 4/5] libbpf: add the function libbpf_find_kernel_btf_id() Date: Tue, 20 Feb 2024 11:51:04 +0800 [thread overview] Message-ID: <20240220035105.34626-5-dongmenglong.8@bytedance.com> (raw) In-Reply-To: <20240220035105.34626-1-dongmenglong.8@bytedance.com> Add new function libbpf_find_kernel_btf_id() to find the btf type id of the kernel, including vmlinux and modules. Signed-off-by: Menglong Dong <dongmenglong.8@bytedance.com> --- tools/lib/bpf/libbpf.c | 83 ++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 3 ++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 87 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 01f407591a92..44e34007de8c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9500,6 +9500,89 @@ int libbpf_find_vmlinux_btf_id(const char *name, return libbpf_err(err); } +int libbpf_find_kernel_btf_id(const char *name, + enum bpf_attach_type attach_type, + int *btf_obj_fd, int *btf_type_id) +{ + struct btf *btf, *vmlinux_btf; + struct bpf_btf_info info; + __u32 btf_id = 0, len; + char btf_name[64]; + int err, fd; + + vmlinux_btf = btf__load_vmlinux_btf(); + err = libbpf_get_error(vmlinux_btf); + if (err) + return libbpf_err(err); + + err = find_attach_btf_id(vmlinux_btf, name, attach_type); + if (err > 0) { + *btf_type_id = err; + *btf_obj_fd = 0; + err = 0; + goto out; + } + + /* kernel too old to support module BTFs */ + if (!feat_supported(NULL, FEAT_MODULE_BTF)) { + err = -EOPNOTSUPP; + goto out; + } + + while (true) { + err = bpf_btf_get_next_id(btf_id, &btf_id); + if (err) { + err = -errno; + goto out; + } + + fd = bpf_btf_get_fd_by_id(btf_id); + if (fd < 0) { + if (errno == ENOENT) + continue; + err = -errno; + goto out; + } + + len = sizeof(info); + memset(&info, 0, sizeof(info)); + info.name = ptr_to_u64(btf_name); + info.name_len = sizeof(btf_name); + + err = bpf_btf_get_info_by_fd(fd, &info, &len); + if (err) { + err = -errno; + goto fd_out; + } + + if (!info.kernel_btf || strcmp(btf_name, "vmlinux") == 0) { + close(fd); + continue; + } + + btf = btf_get_from_fd(fd, vmlinux_btf); + err = libbpf_get_error(btf); + if (err) + goto fd_out; + + err = find_attach_btf_id(btf, name, attach_type); + if (err > 0) { + *btf_type_id = err; + *btf_obj_fd = fd; + err = 0; + break; + } + close(fd); + continue; +fd_out: + close(fd); + break; + } +out: + btf__free(vmlinux_btf); + return err; +} + static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) { struct bpf_prog_info info; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5723cbbfcc41..ca151bbec833 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -306,6 +306,9 @@ LIBBPF_API int libbpf_attach_type_by_name(const char *name, enum bpf_attach_type *attach_type); LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, enum bpf_attach_type attach_type); +LIBBPF_API int libbpf_find_kernel_btf_id(const char *name, + enum bpf_attach_type attach_type, + int *btf_obj_fd, int *btf_type_id); /* Accessors of bpf_program */ struct bpf_program; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 86804fd90dd1..73c60f47b4bb 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -413,4 +413,5 @@ LIBBPF_1.4.0 { bpf_token_create; btf__new_split; btf_ext__raw_data; + libbpf_find_kernel_btf_id; } LIBBPF_1.3.0; -- 2.39.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Menglong Dong <dongmenglong.8@bytedance.com> To: andrii@kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, mykolal@fb.com, shuah@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, thinker.li@gmail.com, dongmenglong.8@bytedance.com, zhoufeng.zf@bytedance.com, davemarchevsky@fb.com, dxu@dxuuu.xyz, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH bpf-next 4/5] libbpf: add the function libbpf_find_kernel_btf_id() Date: Tue, 20 Feb 2024 11:51:04 +0800 [thread overview] Message-ID: <20240220035105.34626-5-dongmenglong.8@bytedance.com> (raw) In-Reply-To: <20240220035105.34626-1-dongmenglong.8@bytedance.com> Add new function libbpf_find_kernel_btf_id() to find the btf type id of the kernel, including vmlinux and modules. Signed-off-by: Menglong Dong <dongmenglong.8@bytedance.com> --- tools/lib/bpf/libbpf.c | 83 ++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 3 ++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 87 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 01f407591a92..44e34007de8c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9500,6 +9500,89 @@ int libbpf_find_vmlinux_btf_id(const char *name, return libbpf_err(err); } +int libbpf_find_kernel_btf_id(const char *name, + enum bpf_attach_type attach_type, + int *btf_obj_fd, int *btf_type_id) +{ + struct btf *btf, *vmlinux_btf; + struct bpf_btf_info info; + __u32 btf_id = 0, len; + char btf_name[64]; + int err, fd; + + vmlinux_btf = btf__load_vmlinux_btf(); + err = libbpf_get_error(vmlinux_btf); + if (err) + return libbpf_err(err); + + err = find_attach_btf_id(vmlinux_btf, name, attach_type); + if (err > 0) { + *btf_type_id = err; + *btf_obj_fd = 0; + err = 0; + goto out; + } + + /* kernel too old to support module BTFs */ + if (!feat_supported(NULL, FEAT_MODULE_BTF)) { + err = -EOPNOTSUPP; + goto out; + } + + while (true) { + err = bpf_btf_get_next_id(btf_id, &btf_id); + if (err) { + err = -errno; + goto out; + } + + fd = bpf_btf_get_fd_by_id(btf_id); + if (fd < 0) { + if (errno == ENOENT) + continue; + err = -errno; + goto out; + } + + len = sizeof(info); + memset(&info, 0, sizeof(info)); + info.name = ptr_to_u64(btf_name); + info.name_len = sizeof(btf_name); + + err = bpf_btf_get_info_by_fd(fd, &info, &len); + if (err) { + err = -errno; + goto fd_out; + } + + if (!info.kernel_btf || strcmp(btf_name, "vmlinux") == 0) { + close(fd); + continue; + } + + btf = btf_get_from_fd(fd, vmlinux_btf); + err = libbpf_get_error(btf); + if (err) + goto fd_out; + + err = find_attach_btf_id(btf, name, attach_type); + if (err > 0) { + *btf_type_id = err; + *btf_obj_fd = fd; + err = 0; + break; + } + close(fd); + continue; +fd_out: + close(fd); + break; + } +out: + btf__free(vmlinux_btf); + return err; +} + static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) { struct bpf_prog_info info; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5723cbbfcc41..ca151bbec833 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -306,6 +306,9 @@ LIBBPF_API int libbpf_attach_type_by_name(const char *name, enum bpf_attach_type *attach_type); LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, enum bpf_attach_type attach_type); +LIBBPF_API int libbpf_find_kernel_btf_id(const char *name, + enum bpf_attach_type attach_type, + int *btf_obj_fd, int *btf_type_id); /* Accessors of bpf_program */ struct bpf_program; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 86804fd90dd1..73c60f47b4bb 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -413,4 +413,5 @@ LIBBPF_1.4.0 { bpf_token_create; btf__new_split; btf_ext__raw_data; + libbpf_find_kernel_btf_id; } LIBBPF_1.3.0; -- 2.39.2
next prev parent reply other threads:[~2024-02-20 3:51 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-02-20 3:51 [PATCH bpf-next 0/5] bpf: make tracing program support multi-attach Menglong Dong 2024-02-20 3:51 ` Menglong Dong 2024-02-20 3:51 ` [PATCH bpf-next 1/5] bpf: tracing: add support to record and check the accessed args Menglong Dong 2024-02-20 3:51 ` Menglong Dong 2024-02-20 17:18 ` Jiri Olsa 2024-02-20 17:18 ` Jiri Olsa 2024-02-21 2:58 ` [External] " 梦龙董 2024-02-21 2:58 ` 梦龙董 2024-02-20 18:22 ` Kui-Feng Lee 2024-02-20 18:22 ` Kui-Feng Lee 2024-02-21 3:09 ` [External] " 梦龙董 2024-02-21 3:09 ` 梦龙董 2024-02-20 3:51 ` [PATCH bpf-next 2/5] bpf: tracing: support to attach program to multi hooks Menglong Dong 2024-02-20 3:51 ` Menglong Dong 2024-02-20 17:18 ` Jiri Olsa 2024-02-20 17:18 ` Jiri Olsa 2024-02-21 5:31 ` Dan Carpenter 2024-02-21 5:31 ` Dan Carpenter 2024-02-20 3:51 ` [PATCH bpf-next 3/5] libbpf: allow to set coookie when target_btf_id is set in bpf_link_create Menglong Dong 2024-02-20 3:51 ` Menglong Dong 2024-02-20 3:51 ` Menglong Dong [this message] 2024-02-20 3:51 ` [PATCH bpf-next 4/5] libbpf: add the function libbpf_find_kernel_btf_id() Menglong Dong 2024-02-20 3:51 ` [PATCH bpf-next 5/5] selftests/bpf: add test cases for multiple attach of tracing program Menglong Dong 2024-02-20 3:51 ` Menglong Dong 2024-02-21 1:24 ` [PATCH bpf-next 0/5] bpf: make tracing program support multi-attach Alexei Starovoitov 2024-02-21 1:24 ` Alexei Starovoitov 2024-02-21 2:35 ` [External] " 梦龙董 2024-02-21 2:35 ` 梦龙董 2024-02-21 2:45 ` 梦龙董 2024-02-21 2:45 ` 梦龙董 2024-02-21 3:02 ` Alexei Starovoitov 2024-02-21 3:02 ` Alexei Starovoitov 2024-02-21 3:06 ` 梦龙董 2024-02-21 3:06 ` 梦龙董 2024-02-21 3:18 ` Alexei Starovoitov 2024-02-21 3:18 ` Alexei Starovoitov 2024-02-21 3:57 ` 梦龙董 2024-02-21 3:57 ` 梦龙董
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