| Message ID | 1425082135-11967-4-git-send-email-ast@plumgrid.com |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, Feb 27, 2015 at 04:08:51PM -0800, Alexei Starovoitov wrote: > bpf_ktime_get_ns() is used by programs to compue time delta between events > or as a timestamp > > Signed-off-by: Alexei Starovoitov <ast@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 4486d36d2e9e..101e509d1001 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -165,6 +165,7 @@ enum bpf_func_id { > BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */ > BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */ > BPF_FUNC_probe_read, /* int bpf_probe_read(void *dst, int size, void *src) */ > + 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 bcce9b238dad..64b918488607 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -36,6 +36,11 @@ static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) > return probe_kernel_read(dst, unsafe_ptr, size); > } > > +static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) > +{ > + return ktime_get_ns(); > +} Please use ktime_get_mono_fast_ns() instead. If you ever want to allow running BPF stuff from general tracepoints and the like you need to be NMI safe. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 4486d36d2e9e..101e509d1001 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -165,6 +165,7 @@ enum bpf_func_id { BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */ BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */ BPF_FUNC_probe_read, /* int bpf_probe_read(void *dst, int size, void *src) */ + 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 bcce9b238dad..64b918488607 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -36,6 +36,11 @@ static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) return probe_kernel_read(dst, unsafe_ptr, size); } +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 kprobe_prog_funcs[] = { [BPF_FUNC_probe_read] = { .func = bpf_probe_read, @@ -45,6 +50,11 @@ static struct bpf_func_proto kprobe_prog_funcs[] = { .arg2_type = ARG_CONST_STACK_SIZE, .arg3_type = ARG_ANYTHING, }, + [BPF_FUNC_ktime_get_ns] = { + .func = bpf_ktime_get_ns, + .gpl_only = true, + .ret_type = RET_INTEGER, + }, }; static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id)
bpf_ktime_get_ns() is used by programs to compue time delta between events or as a timestamp Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> --- include/uapi/linux/bpf.h | 1 + kernel/trace/bpf_trace.c | 10 ++++++++++ 2 files changed, 11 insertions(+)