Commit 43798bf3 authored Nov 24, 2015 by He Kuang Committed by Arnaldo Carvalho de Melo Nov 26, 2015

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>

parent dcdd184b

tools/lib/bpf/bpf.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -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));
		}

tools/lib/bpf/bpf.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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

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