BACKPORT: bpf: add bpf_ktime_get_boot_ns()

On a device like a cellphone which is constantly suspending
and resuming CLOCK_MONOTONIC is not particularly useful for
keeping track of or reacting to external network events.
Instead you want to use CLOCK_BOOTTIME.

Hence add bpf_ktime_get_boot_ns() as a mirror of bpf_ktime_get_ns()
based around CLOCK_BOOTTIME instead of CLOCK_MONOTONIC.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
(cherry picked from commit 71d19214776e61b33da48f7c1b46e522c7f78221)
Change-Id: Ifd62c410dcc5112fd1a473a7e1f70231ca514bc0

drivers/media/rc/bpf-lirc.c

@@ -75,6 +75,8 @@ lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_map_delete_elem_proto;
 	case BPF_FUNC_ktime_get_ns:
 		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_boot_ns:
+		return &bpf_ktime_get_boot_ns_proto;
 	case BPF_FUNC_tail_call:
 		return &bpf_tail_call_proto;
 	case BPF_FUNC_get_prandom_u32:

include/linux/bpf.h

@@ -813,6 +813,7 @@ extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
 extern const struct bpf_func_proto bpf_get_numa_node_id_proto;
 extern const struct bpf_func_proto bpf_tail_call_proto;
 extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
+extern const struct bpf_func_proto bpf_ktime_get_boot_ns_proto;
 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
 extern const struct bpf_func_proto bpf_get_current_comm_proto;

include/uapi/linux/bpf.h

@@ -471,6 +471,8 @@ union bpf_attr {
  * u64 bpf_ktime_get_ns(void)
  * 	Description
  * 		Return the time elapsed since system boot, in nanoseconds.
+ * 		Does not include time the system was suspended.
+ * 		See: clock_gettime(CLOCK_MONOTONIC)
  * 	Return
  * 		Current *ktime*.
  *
@@ -2143,6 +2145,14 @@ union bpf_attr {
  *		request in the skb.
  *	Return
  *		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_ktime_get_boot_ns(void)
+ * 	Description
+ * 		Return the time elapsed since system boot, in nanoseconds.
+ * 		Does include the time the system was suspended.
+ * 		See: clock_gettime(CLOCK_BOOTTIME)
+ * 	Return
+ * 		Current *ktime*.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2228,7 +2238,49 @@ union bpf_attr {
 	FN(get_current_cgroup_id),	\
 	FN(get_local_storage),		\
 	FN(sk_select_reuseport),	\
-	FN(skb_ancestor_cgroup_id),
+	FN(skb_ancestor_cgroup_id),	\
+	FN(sk_lookup_tcp),		\
+	FN(sk_lookup_udp),		\
+	FN(sk_release),			\
+	FN(map_push_elem),		\
+	FN(map_pop_elem),		\
+	FN(map_peek_elem),		\
+	FN(msg_push_data),		\
+	FN(msg_pop_data),		\
+	FN(rc_pointer_rel),		\
+	FN(spin_lock),			\
+	FN(spin_unlock),		\
+	FN(sk_fullsock),		\
+	FN(tcp_sock),			\
+	FN(skb_ecn_set_ce),		\
+	FN(get_listener_sock),		\
+	FN(skc_lookup_tcp),		\
+	FN(tcp_check_syncookie),	\
+	FN(sysctl_get_name),		\
+	FN(sysctl_get_current_value),	\
+	FN(sysctl_get_new_value),	\
+	FN(sysctl_set_new_value),	\
+	FN(strtol),			\
+	FN(strtoul),			\
+	FN(sk_storage_get),		\
+	FN(sk_storage_delete),		\
+	FN(send_signal),		\
+	FN(tcp_gen_syncookie),		\
+	FN(skb_output),			\
+	FN(probe_read_user),		\
+	FN(probe_read_kernel),		\
+	FN(probe_read_user_str),	\
+	FN(probe_read_kernel_str),	\
+	FN(tcp_send_ack),		\
+	FN(send_signal_thread),		\
+	FN(jiffies64),			\
+	FN(read_branch_records),	\
+	FN(get_ns_current_pid_tgid),	\
+	FN(xdp_output),			\
+	FN(get_netns_cookie),		\
+	FN(get_current_ancestor_cgroup_id),	\
+	FN(sk_assign),			\
+	FN(ktime_get_boot_ns),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

kernel/bpf/core.c

@@ -1869,6 +1869,7 @@ 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_get_numa_node_id_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
+const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
 
 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;

kernel/bpf/helpers.c

@@ -116,6 +116,18 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = {
 	.ret_type	= RET_INTEGER,
 };
 
+BPF_CALL_0(bpf_ktime_get_boot_ns)
+{
+	/* NMI safe access to clock boottime */
+	return ktime_get_boot_fast_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
+	.func		= bpf_ktime_get_boot_ns,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
 BPF_CALL_0(bpf_get_current_pid_tgid)
 {
 	struct task_struct *task = current;

kernel/trace/bpf_trace.c

@@ -561,6 +561,8 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_probe_read_proto;
 	case BPF_FUNC_ktime_get_ns:
 		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_boot_ns:
+		return &bpf_ktime_get_boot_ns_proto;
 	case BPF_FUNC_tail_call:
 		return &bpf_tail_call_proto;
 	case BPF_FUNC_get_current_pid_tgid:

net/core/filter.c

@@ -4844,6 +4844,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 		return &bpf_tail_call_proto;
 	case BPF_FUNC_ktime_get_ns:
 		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_boot_ns:
+		return &bpf_ktime_get_boot_ns_proto;
 	case BPF_FUNC_trace_printk:
 		if (capable(CAP_SYS_ADMIN))
 			return bpf_get_trace_printk_proto();

tools/include/uapi/linux/bpf.h

@@ -469,6 +469,8 @@ union bpf_attr {
  * u64 bpf_ktime_get_ns(void)
  * 	Description
  * 		Return the time elapsed since system boot, in nanoseconds.
+ * 		Does not include time the system was suspended.
+ * 		See: clock_gettime(CLOCK_MONOTONIC)
  * 	Return
  * 		Current *ktime*.
  *
@@ -2141,6 +2143,14 @@ union bpf_attr {
  *		request in the skb.
  *	Return
  *		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_ktime_get_boot_ns(void)
+ * 	Description
+ * 		Return the time elapsed since system boot, in nanoseconds.
+ * 		Does include the time the system was suspended.
+ * 		See: clock_gettime(CLOCK_BOOTTIME)
+ * 	Return
+ * 		Current *ktime*.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2226,7 +2236,49 @@ union bpf_attr {
 	FN(get_current_cgroup_id),	\
 	FN(get_local_storage),		\
 	FN(sk_select_reuseport),	\
-	FN(skb_ancestor_cgroup_id),
+	FN(skb_ancestor_cgroup_id),	\
+	FN(sk_lookup_tcp),		\
+	FN(sk_lookup_udp),		\
+	FN(sk_release),			\
+	FN(map_push_elem),		\
+	FN(map_pop_elem),		\
+	FN(map_peek_elem),		\
+	FN(msg_push_data),		\
+	FN(msg_pop_data),		\
+	FN(rc_pointer_rel),		\
+	FN(spin_lock),			\
+	FN(spin_unlock),		\
+	FN(sk_fullsock),		\
+	FN(tcp_sock),			\
+	FN(skb_ecn_set_ce),		\
+	FN(get_listener_sock),		\
+	FN(skc_lookup_tcp),		\
+	FN(tcp_check_syncookie),	\
+	FN(sysctl_get_name),		\
+	FN(sysctl_get_current_value),	\
+	FN(sysctl_get_new_value),	\
+	FN(sysctl_set_new_value),	\
+	FN(strtol),			\
+	FN(strtoul),			\
+	FN(sk_storage_get),		\
+	FN(sk_storage_delete),		\
+	FN(send_signal),		\
+	FN(tcp_gen_syncookie),		\
+	FN(skb_output),			\
+	FN(probe_read_user),		\
+	FN(probe_read_kernel),		\
+	FN(probe_read_user_str),	\
+	FN(probe_read_kernel_str),	\
+	FN(tcp_send_ack),		\
+	FN(send_signal_thread),		\
+	FN(jiffies64),			\
+	FN(read_branch_records),	\
+	FN(get_ns_current_pid_tgid),	\
+	FN(xdp_output),			\
+	FN(get_netns_cookie),		\
+	FN(get_current_ancestor_cgroup_id),	\
+	FN(sk_assign),			\
+	FN(ktime_get_boot_ns),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call