bpf_ktime_get_ns() is used by programs to compue time delta between events
or as a timestamp
Signed-off-by: Alexei Starovoitov <a...@plumgrid.com>
---
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
--
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