From 43798bf37215fe242e592fd4605d804e2da0781b Mon Sep 17 00:00:00 2001 From: He Kuang Date: Tue, 24 Nov 2015 13:36:08 +0000 Subject: [PATCH] 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 Cc: Alexei Starovoitov Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Wang Nan Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1448372181-151723-4-git-send-email-wangnan0@huawei.com Signed-off-by: Wang Nan Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/bpf.c | 14 ++++++++++++++ tools/lib/bpf/bpf.h | 2 ++ 2 files changed, 16 insertions(+) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index a633105..5bdc6ea 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -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)); +} diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 854b736..a764655 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -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 -- 2.7.4