diff options
author | Martin KaFai Lau <kafai@fb.com> | 2018-12-07 16:42:31 -0800 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2018-12-09 13:54:38 -0800 |
commit | 3d65014146c69bbc4d2947f60dbd722d352cdc46 (patch) | |
tree | ea591de92250d7ff871083d63bd5823c68b9bee9 /tools/lib/bpf/bpf.c | |
parent | f0187f0b17fad7439f510eff4d65606c9ea1190f (diff) |
bpf: libbpf: Add btf_line_info support to libbpf
This patch adds bpf_line_info support to libbpf:
1) Parsing the line_info sec from ".BTF.ext"
2) Relocating the line_info. If the main prog *_info relocation
fails, it will ignore the remaining subprog line_info and continue.
If the subprog *_info relocation fails, it will bail out.
3) BPF_PROG_LOAD a prog with line_info
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/lib/bpf/bpf.c')
-rw-r--r-- | tools/lib/bpf/bpf.c | 86 |
1 files changed, 57 insertions, 29 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 9fbbc0ed5952..3caaa3428774 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -173,11 +173,36 @@ int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name, -1); } +static void * +alloc_zero_tailing_info(const void *orecord, __u32 cnt, + __u32 actual_rec_size, __u32 expected_rec_size) +{ + __u64 info_len = actual_rec_size * cnt; + void *info, *nrecord; + int i; + + info = malloc(info_len); + if (!info) + return NULL; + + /* zero out bytes kernel does not understand */ + nrecord = info; + for (i = 0; i < cnt; i++) { + memcpy(nrecord, orecord, expected_rec_size); + memset(nrecord + expected_rec_size, 0, + actual_rec_size - expected_rec_size); + orecord += actual_rec_size; + nrecord += actual_rec_size; + } + + return info; +} + int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, char *log_buf, size_t log_buf_sz) { + void *finfo = NULL, *linfo = NULL; union bpf_attr attr; - void *finfo = NULL; __u32 name_len; int fd; @@ -201,6 +226,9 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.func_info_rec_size = load_attr->func_info_rec_size; attr.func_info_cnt = load_attr->func_info_cnt; attr.func_info = ptr_to_u64(load_attr->func_info); + attr.line_info_rec_size = load_attr->line_info_rec_size; + attr.line_info_cnt = load_attr->line_info_cnt; + attr.line_info = ptr_to_u64(load_attr->line_info); memcpy(attr.prog_name, load_attr->name, min(name_len, BPF_OBJ_NAME_LEN - 1)); @@ -212,36 +240,35 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, * to give user space a hint how to deal with loading failure. * Check to see whether we can make some changes and load again. */ - if (errno == E2BIG && attr.func_info_cnt && - attr.func_info_rec_size < load_attr->func_info_rec_size) { - __u32 actual_rec_size = load_attr->func_info_rec_size; - __u32 expected_rec_size = attr.func_info_rec_size; - __u32 finfo_cnt = load_attr->func_info_cnt; - __u64 finfo_len = actual_rec_size * finfo_cnt; - const void *orecord; - void *nrecord; - int i; - - finfo = malloc(finfo_len); - if (!finfo) - /* further try with log buffer won't help */ - return fd; - - /* zero out bytes kernel does not understand */ - orecord = load_attr->func_info; - nrecord = finfo; - for (i = 0; i < load_attr->func_info_cnt; i++) { - memcpy(nrecord, orecord, expected_rec_size); - memset(nrecord + expected_rec_size, 0, - actual_rec_size - expected_rec_size); - orecord += actual_rec_size; - nrecord += actual_rec_size; + while (errno == E2BIG && (!finfo || !linfo)) { + if (!finfo && attr.func_info_cnt && + attr.func_info_rec_size < load_attr->func_info_rec_size) { + /* try with corrected func info records */ + finfo = alloc_zero_tailing_info(load_attr->func_info, + load_attr->func_info_cnt, + load_attr->func_info_rec_size, + attr.func_info_rec_size); + if (!finfo) + goto done; + + attr.func_info = ptr_to_u64(finfo); + attr.func_info_rec_size = load_attr->func_info_rec_size; + } else if (!linfo && attr.line_info_cnt && + attr.line_info_rec_size < + load_attr->line_info_rec_size) { + linfo = alloc_zero_tailing_info(load_attr->line_info, + load_attr->line_info_cnt, + load_attr->line_info_rec_size, + attr.line_info_rec_size); + if (!linfo) + goto done; + + attr.line_info = ptr_to_u64(linfo); + attr.line_info_rec_size = load_attr->line_info_rec_size; + } else { + break; } - /* try with corrected func info records */ - attr.func_info = ptr_to_u64(finfo); - attr.func_info_rec_size = load_attr->func_info_rec_size; - fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); if (fd >= 0) @@ -259,6 +286,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); done: free(finfo); + free(linfo); return fd; } |