diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 88 |
1 files changed, 39 insertions, 49 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index bd71efcc53be..d6e62e90e8d4 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -27,6 +27,7 @@ #include <linux/list.h> #include <linux/limits.h> #include <linux/perf_event.h> +#include <linux/ring_buffer.h> #include <sys/stat.h> #include <sys/types.h> #include <sys/vfs.h> @@ -2083,19 +2084,19 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog, prog->expected_attach_type = type; } -#define BPF_PROG_SEC_IMPL(string, ptype, eatype, atype) \ - { string, sizeof(string) - 1, ptype, eatype, atype } +#define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, atype) \ + { string, sizeof(string) - 1, ptype, eatype, is_attachable, atype } /* Programs that can NOT be attached. */ -#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, -EINVAL) +#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0) /* Programs that can be attached. */ #define BPF_APROG_SEC(string, ptype, atype) \ - BPF_PROG_SEC_IMPL(string, ptype, 0, atype) + BPF_PROG_SEC_IMPL(string, ptype, 0, 1, atype) /* Programs that must specify expected attach type at load time. */ #define BPF_EAPROG_SEC(string, ptype, eatype) \ - BPF_PROG_SEC_IMPL(string, ptype, eatype, eatype) + BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, eatype) /* Programs that can be attached but attach type can't be identified by section * name. Kept for backward compatibility. @@ -2107,6 +2108,7 @@ static const struct { size_t len; enum bpf_prog_type prog_type; enum bpf_attach_type expected_attach_type; + int is_attachable; enum bpf_attach_type attach_type; } section_names[] = { BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER), @@ -2197,7 +2199,7 @@ int libbpf_attach_type_by_name(const char *name, for (i = 0; i < ARRAY_SIZE(section_names); i++) { if (strncmp(name, section_names[i].sec, section_names[i].len)) continue; - if (section_names[i].attach_type == -EINVAL) + if (!section_names[i].is_attachable) return -EINVAL; *attach_type = section_names[i].attach_type; return 0; @@ -2414,61 +2416,49 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, } enum bpf_perf_event_ret -bpf_perf_event_read_simple(void *mem, unsigned long size, - unsigned long page_size, void **buf, size_t *buf_len, - bpf_perf_event_print_t fn, void *priv) +bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, + void **copy_mem, size_t *copy_size, + bpf_perf_event_print_t fn, void *private_data) { - volatile struct perf_event_mmap_page *header = mem; + struct perf_event_mmap_page *header = mmap_mem; + __u64 data_head = ring_buffer_read_head(header); __u64 data_tail = header->data_tail; - __u64 data_head = header->data_head; - int ret = LIBBPF_PERF_EVENT_ERROR; - void *base, *begin, *end; - - asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ - if (data_head == data_tail) - return LIBBPF_PERF_EVENT_CONT; - - base = ((char *)header) + page_size; - - begin = base + data_tail % size; - end = base + data_head % size; - - while (begin != end) { - struct perf_event_header *ehdr; - - ehdr = begin; - if (begin + ehdr->size > base + size) { - long len = base + size - begin; - - if (*buf_len < ehdr->size) { - free(*buf); - *buf = malloc(ehdr->size); - if (!*buf) { + void *base = ((__u8 *)header) + page_size; + int ret = LIBBPF_PERF_EVENT_CONT; + struct perf_event_header *ehdr; + size_t ehdr_size; + + while (data_head != data_tail) { + ehdr = base + (data_tail & (mmap_size - 1)); + ehdr_size = ehdr->size; + + if (((void *)ehdr) + ehdr_size > base + mmap_size) { + void *copy_start = ehdr; + size_t len_first = base + mmap_size - copy_start; + size_t len_secnd = ehdr_size - len_first; + + if (*copy_size < ehdr_size) { + free(*copy_mem); + *copy_mem = malloc(ehdr_size); + if (!*copy_mem) { + *copy_size = 0; ret = LIBBPF_PERF_EVENT_ERROR; break; } - *buf_len = ehdr->size; + *copy_size = ehdr_size; } - memcpy(*buf, begin, len); - memcpy(*buf + len, base, ehdr->size - len); - ehdr = (void *)*buf; - begin = base + ehdr->size - len; - } else if (begin + ehdr->size == base + size) { - begin = base; - } else { - begin += ehdr->size; + memcpy(*copy_mem, copy_start, len_first); + memcpy(*copy_mem + len_first, base, len_secnd); + ehdr = *copy_mem; } - ret = fn(ehdr, priv); + ret = fn(ehdr, private_data); + data_tail += ehdr_size; if (ret != LIBBPF_PERF_EVENT_CONT) break; - - data_tail += ehdr->size; } - __sync_synchronize(); /* smp_mb() */ - header->data_tail = data_tail; - + ring_buffer_write_tail(header, data_tail); return ret; } |
