From 6d2d73cdd673d493f9f3751188757129b1d23fb7 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 29 Jul 2021 17:20:21 +0100 Subject: libbpf: Return non-null error on failures in libbpf_find_prog_btf_id() Variable "err" is initialised to -EINVAL so that this error code is returned when something goes wrong in libbpf_find_prog_btf_id(). However, a recent change in the function made use of the variable in such a way that it is set to 0 if retrieving linear information on the program is successful, and this 0 value remains if we error out on failures at later stages. Let's fix this by setting err to -EINVAL later in the function. Fixes: e9fc3ce99b34 ("libbpf: Streamline error reporting for high-level APIs") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210729162028.29512-2-quentin@isovalent.com --- tools/lib/bpf/libbpf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index a1ca6fb0c6d8..7b2b5d261a08 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8317,7 +8317,7 @@ 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; + int err; info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0); err = libbpf_get_error(info_linear); @@ -8326,6 +8326,8 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) attach_prog_fd); return err; } + + err = -EINVAL; info = &info_linear->info; if (!info->btf_id) { pr_warn("The target program doesn't have BTF\n"); -- cgit v1.2.3 From 3c7e58590600eca3402f08e7fbdf4f2d1e36c5c8 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 29 Jul 2021 17:20:22 +0100 Subject: libbpf: Rename btf__load() as btf__load_into_kernel() As part of the effort to move towards a v1.0 for libbpf, rename btf__load() function, used to "upload" BTF information into the kernel, as btf__load_into_kernel(). This new name better reflects what the function does. References: - https://github.com/libbpf/libbpf/issues/278 - https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#btfh-apis Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210729162028.29512-3-quentin@isovalent.com --- tools/lib/bpf/btf.c | 3 ++- tools/lib/bpf/btf.h | 1 + tools/lib/bpf/libbpf.c | 2 +- tools/lib/bpf/libbpf.map | 1 + 4 files changed, 5 insertions(+), 2 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index b46760b93bb4..7e0de560490e 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1180,7 +1180,7 @@ int btf__finalize_data(struct bpf_object *obj, struct btf *btf) static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian); -int btf__load(struct btf *btf) +int btf__load_into_kernel(struct btf *btf) { __u32 log_buf_size = 0, raw_size; char *log_buf = NULL; @@ -1228,6 +1228,7 @@ done: free(log_buf); return libbpf_err(err); } +int btf__load(struct btf *) __attribute__((alias("btf__load_into_kernel"))); int btf__fd(const struct btf *btf) { diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 374e9f15de2e..fd8a21d936ef 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -46,6 +46,7 @@ LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_b LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); LIBBPF_API int btf__load(struct btf *btf); +LIBBPF_API int btf__load_into_kernel(struct btf *btf); LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, const char *type_name); LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7b2b5d261a08..9a657d6d7da3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2769,7 +2769,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) */ btf__set_fd(kern_btf, 0); } else { - err = btf__load(kern_btf); + err = btf__load_into_kernel(kern_btf); } if (sanitize) { if (!err) { diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index c240d488eb5e..4d80eb8c56b0 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -375,6 +375,7 @@ LIBBPF_0.5.0 { bpf_map_lookup_and_delete_elem_flags; bpf_program__attach_kprobe_opts; bpf_object__gen_loader; + btf__load_into_kernel; btf_dump__dump_type_data; libbpf_set_strict_mode; } LIBBPF_0.4.0; -- cgit v1.2.3 From 6cc93e2f2c1c865acadedfea174bde893a2aa376 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 29 Jul 2021 17:20:23 +0100 Subject: libbpf: Rename btf__get_from_id() as btf__load_from_kernel_by_id() Rename function btf__get_from_id() as btf__load_from_kernel_by_id() to better indicate what the function does. Change the new function so that, instead of requiring a pointer to the pointer to update and returning with an error code, it takes a single argument (the id of the BTF object) and returns the corresponding pointer. This is more in line with the existing constructors. The other tools calling the (soon-to-be) deprecated btf__get_from_id() function will be updated in a future commit. References: - https://github.com/libbpf/libbpf/issues/278 - https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#btfh-apis Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210729162028.29512-4-quentin@isovalent.com --- tools/lib/bpf/btf.c | 25 +++++++++++++++++-------- tools/lib/bpf/btf.h | 4 +++- tools/lib/bpf/libbpf.c | 5 +++-- tools/lib/bpf/libbpf.map | 1 + 4 files changed, 24 insertions(+), 11 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 7e0de560490e..948c29fee447 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1383,21 +1383,30 @@ exit_free: return btf; } -int btf__get_from_id(__u32 id, struct btf **btf) +struct btf *btf__load_from_kernel_by_id(__u32 id) { - struct btf *res; - int err, btf_fd; + struct btf *btf; + int btf_fd; - *btf = NULL; btf_fd = bpf_btf_get_fd_by_id(id); if (btf_fd < 0) - return libbpf_err(-errno); - - res = btf_get_from_fd(btf_fd, NULL); - err = libbpf_get_error(res); + return libbpf_err_ptr(-errno); + btf = btf_get_from_fd(btf_fd, NULL); close(btf_fd); + return libbpf_ptr(btf); +} + +int btf__get_from_id(__u32 id, struct btf **btf) +{ + struct btf *res; + int err; + + *btf = NULL; + res = btf__load_from_kernel_by_id(id); + err = libbpf_get_error(res); + if (err) return libbpf_err(err); diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index fd8a21d936ef..5d955329a1f4 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -44,6 +44,9 @@ LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_b LIBBPF_API struct btf *btf__parse_raw(const char *path); LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf); +LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id); +LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); + LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); LIBBPF_API int btf__load(struct btf *btf); LIBBPF_API int btf__load_into_kernel(struct btf *btf); @@ -67,7 +70,6 @@ LIBBPF_API void btf__set_fd(struct btf *btf, int fd); LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size); LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset); -LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, __u32 expected_key_size, __u32 expected_value_size, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 9a657d6d7da3..313883179919 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8316,7 +8316,7 @@ 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; + struct btf *btf; int err; info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0); @@ -8333,7 +8333,8 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) pr_warn("The target program doesn't have BTF\n"); goto out; } - if (btf__get_from_id(info->btf_id, &btf)) { + btf = btf__load_from_kernel_by_id(info->btf_id); + if (libbpf_get_error(btf)) { pr_warn("Failed to get BTF of the program\n"); goto out; } diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 4d80eb8c56b0..3a9c6939301e 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -375,6 +375,7 @@ LIBBPF_0.5.0 { bpf_map_lookup_and_delete_elem_flags; bpf_program__attach_kprobe_opts; bpf_object__gen_loader; + btf__load_from_kernel_by_id; btf__load_into_kernel; btf_dump__dump_type_data; libbpf_set_strict_mode; -- cgit v1.2.3 From 61fc51b1d3e5915e356f2c0b67cd3bb13b640413 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 29 Jul 2021 17:20:27 +0100 Subject: libbpf: Add split BTF support for btf__load_from_kernel_by_id() Add a new API function btf__load_from_kernel_by_id_split(), which takes a pointer to a base BTF object in order to support split BTF objects when retrieving BTF information from the kernel. Reference: https://github.com/libbpf/libbpf/issues/314 Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210729162028.29512-8-quentin@isovalent.com --- tools/lib/bpf/btf.c | 9 +++++++-- tools/lib/bpf/btf.h | 1 + tools/lib/bpf/libbpf.map | 1 + 3 files changed, 9 insertions(+), 2 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 948c29fee447..cafa4f6bd9b1 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1383,7 +1383,7 @@ exit_free: return btf; } -struct btf *btf__load_from_kernel_by_id(__u32 id) +struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf) { struct btf *btf; int btf_fd; @@ -1392,12 +1392,17 @@ struct btf *btf__load_from_kernel_by_id(__u32 id) if (btf_fd < 0) return libbpf_err_ptr(-errno); - btf = btf_get_from_fd(btf_fd, NULL); + btf = btf_get_from_fd(btf_fd, base_btf); close(btf_fd); return libbpf_ptr(btf); } +struct btf *btf__load_from_kernel_by_id(__u32 id) +{ + return btf__load_from_kernel_by_id_split(id, NULL); +} + int btf__get_from_id(__u32 id, struct btf **btf) { struct btf *res; diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 5d955329a1f4..596a42c8f4f5 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -45,6 +45,7 @@ LIBBPF_API struct btf *btf__parse_raw(const char *path); LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf); LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id); +LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf); LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 3a9c6939301e..5aca3686ca5e 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -376,6 +376,7 @@ LIBBPF_0.5.0 { bpf_program__attach_kprobe_opts; bpf_object__gen_loader; btf__load_from_kernel_by_id; + btf__load_from_kernel_by_id_split; btf__load_into_kernel; btf_dump__dump_type_data; libbpf_set_strict_mode; -- cgit v1.2.3