From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexei Starovoitov Subject: [PATCH tip 3/9] tracing: allow eBPF programs to call ktime_get_ns() Date: Thu, 15 Jan 2015 20:16:04 -0800 Message-ID: <1421381770-4866-4-git-send-email-ast@plumgrid.com> References: <1421381770-4866-1-git-send-email-ast@plumgrid.com> Cc: Steven Rostedt , Namhyung Kim , Arnaldo Carvalho de Melo , Jiri Olsa , "David S. Miller" , Daniel Borkmann , Hannes Frederic Sowa , Brendan Gregg , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ingo Molnar Return-path: In-Reply-To: <1421381770-4866-1-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org bpf_ktime_get_ns() is used by programs to compue time delta between events or as a timestamp Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 1 + kernel/trace/bpf_trace.c | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index ef88e3f45b85..6075c4f4b67e 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -171,6 +171,7 @@ enum bpf_func_id { BPF_FUNC_memcmp, /* int bpf_memcmp(void *unsafe_ptr, void *safe_ptr, int size) */ BPF_FUNC_dump_stack, /* void bpf_dump_stack(void) */ BPF_FUNC_printk, /* int bpf_printk(const char *fmt, int fmt_size, ...) */ + BPF_FUNC_ktime_get_ns, /* u64 bpf_ktime_get_ns(void) */ __BPF_FUNC_MAX_ID, }; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 3825d7a3cbd1..14cfbbcec32e 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -114,6 +114,11 @@ static u64 bpf_printk(u64 r1, u64 fmt_size, u64 r3, u64 r4, u64 r5) mod_l[2] ? r5 : (u32) r5); } +static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) +{ + return ktime_get_ns(); +} + static struct bpf_func_proto tracing_filter_funcs[] = { #define FETCH(SIZE) \ [BPF_FUNC_fetch_##SIZE] = { \ @@ -147,6 +152,11 @@ static struct bpf_func_proto tracing_filter_funcs[] = { .arg1_type = ARG_PTR_TO_STACK, .arg2_type = ARG_CONST_STACK_SIZE, }, + [BPF_FUNC_ktime_get_ns] = { + .func = bpf_ktime_get_ns, + .gpl_only = true, + .ret_type = RET_INTEGER, + }, }; static const struct bpf_func_proto *tracing_filter_func_proto(enum bpf_func_id func_id) -- 1.7.9.5