Merge branch 'bpf_cubic'

Martin KaFai Lau says:

====================
This set adds bpf_cubic.c example.  It was separated from the
earlier BPF STRUCT_OPS series.  Some highlights since the
last post:

1. It is based on EricD recent fixes to the kernel tcp_cubic. [1]
2. The bpf jiffies reading helper is inlined by the verifier.
   Different from the earlier version, it only reads jiffies alone
   and does not do usecs/jiffies conversion.
3. The bpf .kconfig map is used to read CONFIG_HZ.

[1]: https://patchwork.ozlabs.org/cover/1215066/

v3:
- Remove __weak from CONFIG_HZ in patch 3. (Andrii)

v2:
- Move inlining to fixup_bpf_calls() in patch 1. (Daniel)
- It is inlined for 64 BITS_PER_LONG and jit_requested
  as the map_gen_lookup().  Other cases could be
  considered together with map_gen_lookup() if needed.
- Use usec resolution in bictcp_update() calculation in patch 3.
  usecs_to_jiffies() is then removed().  (Eric)
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

include/linux/bpf.h

@@ -1414,6 +1414,7 @@ extern const struct bpf_func_proto bpf_get_local_storage_proto;
 extern const struct bpf_func_proto bpf_strtol_proto;
 extern const struct bpf_func_proto bpf_strtoul_proto;
 extern const struct bpf_func_proto bpf_tcp_sock_proto;
+extern const struct bpf_func_proto bpf_jiffies64_proto;
 
 /* Shared helpers among cBPF and eBPF. */
 void bpf_user_rnd_init_once(void);

include/uapi/linux/bpf.h

@@ -2886,6 +2886,12 @@ union bpf_attr {
  *		**-EPERM** if no permission to send the *sig*.
  *
  *		**-EAGAIN** if bpf program can try again.
+ *
+ * u64 bpf_jiffies64(void)
+ *	Description
+ *		Obtain the 64bit jiffies
+ *	Return
+ *		The 64 bit jiffies
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3005,7 +3011,8 @@ union bpf_attr {
 	FN(probe_read_user_str),	\
 	FN(probe_read_kernel_str),	\
 	FN(tcp_send_ack),		\
-	FN(send_signal_thread),
+	FN(send_signal_thread),		\
+	FN(jiffies64),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

kernel/bpf/core.c

@@ -2137,6 +2137,7 @@ const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
 const struct bpf_func_proto bpf_spin_lock_proto __weak;
 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
+const struct bpf_func_proto bpf_jiffies64_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;

kernel/bpf/helpers.c

@@ -11,6 +11,7 @@
 #include <linux/uidgid.h>
 #include <linux/filter.h>
 #include <linux/ctype.h>
+#include <linux/jiffies.h>
 
 #include "../../lib/kstrtox.h"
 
@@ -312,6 +313,17 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
 	preempt_enable();
 }
 
+BPF_CALL_0(bpf_jiffies64)
+{
+	return get_jiffies_64();
+}
+
+const struct bpf_func_proto bpf_jiffies64_proto = {
+	.func		= bpf_jiffies64,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
 #ifdef CONFIG_CGROUPS
 BPF_CALL_0(bpf_get_current_cgroup_id)
 {

kernel/bpf/verifier.c

@@ -9445,6 +9445,30 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
 			goto patch_call_imm;
 		}
 
+		if (prog->jit_requested && BITS_PER_LONG == 64 &&
+		    insn->imm == BPF_FUNC_jiffies64) {
+			struct bpf_insn ld_jiffies_addr[2] = {
+				BPF_LD_IMM64(BPF_REG_0,
+					     (unsigned long)&jiffies),
+			};
+
+			insn_buf[0] = ld_jiffies_addr[0];
+			insn_buf[1] = ld_jiffies_addr[1];
+			insn_buf[2] = BPF_LDX_MEM(BPF_DW, BPF_REG_0,
+						  BPF_REG_0, 0);
+			cnt = 3;
+
+			new_prog = bpf_patch_insn_data(env, i + delta, insn_buf,
+						       cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
 patch_call_imm:
 		fn = env->ops->get_func_proto(insn->imm, env->prog);
 		/* all functions that have prototype and verifier allowed

net/core/filter.c

@@ -5923,6 +5923,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 		return &bpf_spin_unlock_proto;
 	case BPF_FUNC_trace_printk:
 		return bpf_get_trace_printk_proto();
+	case BPF_FUNC_jiffies64:
+		return &bpf_jiffies64_proto;
 	default:
 		return NULL;
 	}

tools/include/uapi/linux/bpf.h

@@ -2886,6 +2886,12 @@ union bpf_attr {
  *		**-EPERM** if no permission to send the *sig*.
  *
  *		**-EAGAIN** if bpf program can try again.
+ *
+ * u64 bpf_jiffies64(void)
+ *	Description
+ *		Obtain the 64bit jiffies
+ *	Return
+ *		The 64 bit jiffies
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3005,7 +3011,8 @@ union bpf_attr {
 	FN(probe_read_user_str),	\
 	FN(probe_read_kernel_str),	\
 	FN(tcp_send_ack),		\
-	FN(send_signal_thread),
+	FN(send_signal_thread),		\
+	FN(jiffies64),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

tools/testing/selftests/bpf/bpf_tcp_helpers.h

@@ -6,13 +6,28 @@
 #include <linux/types.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_core_read.h>
+#include "bpf_trace_helpers.h"
+
+#define BPF_STRUCT_OPS(name, args...) \
+SEC("struct_ops/"#name) \
+BPF_PROG(name, args)
+
+#define tcp_jiffies32 ((__u32)bpf_jiffies64())
 
 struct sock_common {
 	unsigned char	skc_state;
 } __attribute__((preserve_access_index));
 
+enum sk_pacing {
+	SK_PACING_NONE		= 0,
+	SK_PACING_NEEDED	= 1,
+	SK_PACING_FQ		= 2,
+};
+
 struct sock {
 	struct sock_common	__sk_common;
+	unsigned long		sk_pacing_rate;
+	__u32			sk_pacing_status; /* see enum sk_pacing */
 } __attribute__((preserve_access_index));
 
 struct inet_sock {
@@ -54,6 +69,7 @@ struct tcp_sock {
 	__u32	max_packets_out;
 	__u32	lsndtime;
 	__u32	prior_cwnd;
+	__u64	tcp_mstamp;	/* most recent packet received/sent */
 } __attribute__((preserve_access_index));
 
 static __always_inline struct inet_connection_sock *inet_csk(const struct sock *sk)

tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c

@@ -4,6 +4,7 @@
 #include <linux/err.h>
 #include <test_progs.h>
 #include "bpf_dctcp.skel.h"
+#include "bpf_cubic.skel.h"
 
 #define min(a, b) ((a) < (b) ? (a) : (b))
 
@@ -158,6 +159,28 @@ static void do_test(const char *tcp_ca)
 	close(fd);
 }
 
+static void test_cubic(void)
+{
+	struct bpf_cubic *cubic_skel;
+	struct bpf_link *link;
+
+	cubic_skel = bpf_cubic__open_and_load();
+	if (CHECK(!cubic_skel, "bpf_cubic__open_and_load", "failed\n"))
+		return;
+
+	link = bpf_map__attach_struct_ops(cubic_skel->maps.cubic);
+	if (CHECK(IS_ERR(link), "bpf_map__attach_struct_ops", "err:%ld\n",
+		  PTR_ERR(link))) {
+		bpf_cubic__destroy(cubic_skel);
+		return;
+	}
+
+	do_test("bpf_cubic");
+
+	bpf_link__destroy(link);
+	bpf_cubic__destroy(cubic_skel);
+}
+
 static void test_dctcp(void)
 {
 	struct bpf_dctcp *dctcp_skel;
@@ -184,4 +207,6 @@ void test_bpf_tcp_ca(void)
 {
 	if (test__start_subtest("dctcp"))
 		test_dctcp();
+	if (test__start_subtest("cubic"))
+		test_cubic();
 }