Commit 17ca8cbf authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

ebpf: allow bpf_ktime_get_ns_proto also for networking 



As this is already exported from tracing side via commit d9847d31
("tracing: Allow BPF programs to call bpf_ktime_get_ns()"), we might
as well want to move it to the core, so also networking users can make
use of it, e.g. to measure diffs for certain flows from ingress/egress.

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a24c85ab

include/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -186,5 +186,6 @@ extern const struct bpf_func_proto bpf_map_delete_elem_proto; 
extern const struct bpf_func_proto bpf_get_prandom_u32_proto;

extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;

extern const struct bpf_func_proto bpf_tail_call_proto;

extern const struct bpf_func_proto bpf_ktime_get_ns_proto;



#endif /* _LINUX_BPF_H */

kernel/bpf/core.c

+1 −0
Original line number Diff line number Diff line
@@ -734,6 +734,7 @@ const struct bpf_func_proto bpf_map_delete_elem_proto __weak; 


const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;

const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;

const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;



/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call

 * skb_copy_bits(), so provide a weak definition of it for NET-less config.

kernel/bpf/helpers.c

+13 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/rcupdate.h>

#include <linux/random.h>

#include <linux/smp.h>

#include <linux/ktime.h>



/* If kernel subsystem is allowing eBPF programs to call this function,

 * inside its own verifier_ops->get_func_proto() callback it should return
@@ -111,3 +112,15 @@ const struct bpf_func_proto bpf_get_smp_processor_id_proto = { 
	.gpl_only	= false,

	.ret_type	= RET_INTEGER,

};



static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)

{

	/* NMI safe access to clock monotonic */

	return ktime_get_mono_fast_ns();

}



const struct bpf_func_proto bpf_ktime_get_ns_proto = {

	.func		= bpf_ktime_get_ns,

	.gpl_only	= true,

	.ret_type	= RET_INTEGER,

};

kernel/trace/bpf_trace.c

+0 −12
Original line number Diff line number Diff line
@@ -79,18 +79,6 @@ static const struct bpf_func_proto bpf_probe_read_proto = { 
	.arg3_type	= ARG_ANYTHING,

};



static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)

{

	/* NMI safe access to clock monotonic */

	return ktime_get_mono_fast_ns();

}



static const struct bpf_func_proto bpf_ktime_get_ns_proto = {

	.func		= bpf_ktime_get_ns,

	.gpl_only	= true,

	.ret_type	= RET_INTEGER,

};



/*

 * limited trace_printk()

 * only %d %u %x %ld %lu %lx %lld %llu %llx %p conversion specifiers allowed

net/core/filter.c

+2 −0
Original line number Diff line number Diff line
@@ -1423,6 +1423,8 @@ sk_filter_func_proto(enum bpf_func_id func_id) 
		return &bpf_get_smp_processor_id_proto;

	case BPF_FUNC_tail_call:

		return &bpf_tail_call_proto;

	case BPF_FUNC_ktime_get_ns:

		return &bpf_ktime_get_ns_proto;

	default:

		return NULL;

	}

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