bpf tools: Add helper function for updating bpf maps elements

Add bpf_map_update_elem() helper function which calls the sys_bpf
syscall to update elements in bpf maps. Upcoming patches will use it to
adjust data in map through the perf command line.

Signed-off-by: He Kuang <hekuang@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1448372181-151723-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
He Kuang 2015-11-24 13:36:08 +00:00 committed by Arnaldo Carvalho de Melo
parent dcdd184b60
commit 43798bf372
2 changed files with 16 additions and 0 deletions

View File

@ -83,3 +83,17 @@ int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
log_buf[0] = 0;
return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
}
int bpf_map_update_elem(int fd, void *key, void *value,
u64 flags)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.value = ptr_to_u64(value);
attr.flags = flags;
return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}

View File

@ -20,4 +20,6 @@ int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
u32 kern_version, char *log_buf,
size_t log_buf_sz);
int bpf_map_update_elem(int fd, void *key, void *value,
u64 flags);
#endif