1 files changed, 279 insertions, 57 deletions

diff --git a/net/core/gen_stats.c b/net/core/gen_stats.c
index 9d3d9e78397b..b71ccaec0991 100644
--- a/net/core/gen_stats.c
+++ b/net/core/gen_stats.c
@@ -1,16 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/core/gen_stats.c
  *
- *             This program is free software; you can redistribute it and/or
- *             modify it under the terms of the GNU General Public License
- *             as published by the Free Software Foundation; either version
- *             2 of the License, or (at your option) any later version.
- *
  * Authors:  Thomas Graf <tgraf@suug.ch>
  *           Jamal Hadi Salim
  *           Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  *
- * See Documentation/networking/gen_stats.txt
+ * See Documentation/networking/gen_stats.rst
  */
 
 #include <linux/types.h>
@@ -22,17 +18,21 @@
 #include <linux/gen_stats.h>
 #include <net/netlink.h>
 #include <net/gen_stats.h>
-
+#include <net/sch_generic.h>
 
 static inline int
-gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size)
+gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size, int padattr)
 {
-	if (nla_put(d->skb, type, size, buf))
+	if (nla_put_64bit(d->skb, type, size, buf, padattr))
 		goto nla_put_failure;
 	return 0;
 
 nla_put_failure:
-	spin_unlock_bh(d->lock);
+	if (d->lock)
+		spin_unlock_bh(d->lock);
+	kfree(d->xstats);
+	d->xstats = NULL;
+	d->xstats_len = 0;
 	return -1;
 }
 
@@ -44,6 +44,7 @@ nla_put_failure:
  * @xstats_type: TLV type for backward compatibility xstats TLV
  * @lock: statistics lock
  * @d: dumping handle
+ * @padattr: padding attribute
  *
  * Initializes the dumping handle, grabs the statistic lock and appends
  * an empty TLV header to the socket buffer for use a container for all
@@ -56,32 +57,48 @@ nla_put_failure:
  */
 int
 gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
-	int xstats_type, spinlock_t *lock, struct gnet_dump *d)
+			     int xstats_type, spinlock_t *lock,
+			     struct gnet_dump *d, int padattr)
 	__acquires(lock)
 {
 	memset(d, 0, sizeof(*d));
 
-	spin_lock_bh(lock);
-	d->lock = lock;
 	if (type)
 		d->tail = (struct nlattr *)skb_tail_pointer(skb);
 	d->skb = skb;
 	d->compat_tc_stats = tc_stats_type;
 	d->compat_xstats = xstats_type;
+	d->padattr = padattr;
+	if (lock) {
+		d->lock = lock;
+		spin_lock_bh(lock);
+	}
+	if (d->tail) {
+		int ret = gnet_stats_copy(d, type, NULL, 0, padattr);
 
-	if (d->tail)
-		return gnet_stats_copy(d, type, NULL, 0);
+		/* The initial attribute added in gnet_stats_copy() may be
+		 * preceded by a padding attribute, in which case d->tail will
+		 * end up pointing at the padding instead of the real attribute.
+		 * Fix this so gnet_stats_finish_copy() adjusts the length of
+		 * the right attribute.
+		 */
+		if (ret == 0 && d->tail->nla_type == padattr)
+			d->tail = (struct nlattr *)((char *)d->tail +
+						    NLA_ALIGN(d->tail->nla_len));
+		return ret;
+	}
 
 	return 0;
 }
 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
 
 /**
- * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
+ * gnet_stats_start_copy - start dumping procedure in compatibility mode
  * @skb: socket buffer to put statistics TLVs into
  * @type: TLV type for top level statistic TLV
  * @lock: statistics lock
  * @d: dumping handle
+ * @padattr: padding attribute
  *
  * Initializes the dumping handle, grabs the statistic lock and appends
  * an empty TLV header to the socket buffer for use a container for all
@@ -91,16 +108,147 @@ EXPORT_SYMBOL(gnet_stats_start_copy_compat);
  */
 int
 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
-	struct gnet_dump *d)
+		      struct gnet_dump *d, int padattr)
 {
-	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d);
+	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
 }
 EXPORT_SYMBOL(gnet_stats_start_copy);
 
+/* Must not be inlined, due to u64_stats seqcount_t lockdep key */
+void gnet_stats_basic_sync_init(struct gnet_stats_basic_sync *b)
+{
+	u64_stats_set(&b->bytes, 0);
+	u64_stats_set(&b->packets, 0);
+	u64_stats_init(&b->syncp);
+}
+EXPORT_SYMBOL(gnet_stats_basic_sync_init);
+
+static void gnet_stats_add_basic_cpu(struct gnet_stats_basic_sync *bstats,
+				     struct gnet_stats_basic_sync __percpu *cpu)
+{
+	u64 t_bytes = 0, t_packets = 0;
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct gnet_stats_basic_sync *bcpu = per_cpu_ptr(cpu, i);
+		unsigned int start;
+		u64 bytes, packets;
+
+		do {
+			start = u64_stats_fetch_begin(&bcpu->syncp);
+			bytes = u64_stats_read(&bcpu->bytes);
+			packets = u64_stats_read(&bcpu->packets);
+		} while (u64_stats_fetch_retry(&bcpu->syncp, start));
+
+		t_bytes += bytes;
+		t_packets += packets;
+	}
+	_bstats_update(bstats, t_bytes, t_packets);
+}
+
+void gnet_stats_add_basic(struct gnet_stats_basic_sync *bstats,
+			  struct gnet_stats_basic_sync __percpu *cpu,
+			  struct gnet_stats_basic_sync *b, bool running)
+{
+	unsigned int start;
+	u64 bytes = 0;
+	u64 packets = 0;
+
+	WARN_ON_ONCE((cpu || running) && in_hardirq());
+
+	if (cpu) {
+		gnet_stats_add_basic_cpu(bstats, cpu);
+		return;
+	}
+	do {
+		if (running)
+			start = u64_stats_fetch_begin(&b->syncp);
+		bytes = u64_stats_read(&b->bytes);
+		packets = u64_stats_read(&b->packets);
+	} while (running && u64_stats_fetch_retry(&b->syncp, start));
+
+	_bstats_update(bstats, bytes, packets);
+}
+EXPORT_SYMBOL(gnet_stats_add_basic);
+
+static void gnet_stats_read_basic(u64 *ret_bytes, u64 *ret_packets,
+				  struct gnet_stats_basic_sync __percpu *cpu,
+				  struct gnet_stats_basic_sync *b, bool running)
+{
+	unsigned int start;
+
+	if (cpu) {
+		u64 t_bytes = 0, t_packets = 0;
+		int i;
+
+		for_each_possible_cpu(i) {
+			struct gnet_stats_basic_sync *bcpu = per_cpu_ptr(cpu, i);
+			unsigned int start;
+			u64 bytes, packets;
+
+			do {
+				start = u64_stats_fetch_begin(&bcpu->syncp);
+				bytes = u64_stats_read(&bcpu->bytes);
+				packets = u64_stats_read(&bcpu->packets);
+			} while (u64_stats_fetch_retry(&bcpu->syncp, start));
+
+			t_bytes += bytes;
+			t_packets += packets;
+		}
+		*ret_bytes = t_bytes;
+		*ret_packets = t_packets;
+		return;
+	}
+	do {
+		if (running)
+			start = u64_stats_fetch_begin(&b->syncp);
+		*ret_bytes = u64_stats_read(&b->bytes);
+		*ret_packets = u64_stats_read(&b->packets);
+	} while (running && u64_stats_fetch_retry(&b->syncp, start));
+}
+
+static int
+___gnet_stats_copy_basic(struct gnet_dump *d,
+			 struct gnet_stats_basic_sync __percpu *cpu,
+			 struct gnet_stats_basic_sync *b,
+			 int type, bool running)
+{
+	u64 bstats_bytes, bstats_packets;
+
+	gnet_stats_read_basic(&bstats_bytes, &bstats_packets, cpu, b, running);
+
+	if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
+		d->tc_stats.bytes = bstats_bytes;
+		d->tc_stats.packets = bstats_packets;
+	}
+
+	if (d->tail) {
+		struct gnet_stats_basic sb;
+		int res;
+
+		memset(&sb, 0, sizeof(sb));
+		sb.bytes = bstats_bytes;
+		sb.packets = bstats_packets;
+		res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
+		if (res < 0 || sb.packets == bstats_packets)
+			return res;
+		/* emit 64bit stats only if needed */
+		return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats_packets,
+				       sizeof(bstats_packets), TCA_STATS_PAD);
+	}
+	return 0;
+}
+
 /**
  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
  * @d: dumping handle
+ * @cpu: copy statistic per cpu
  * @b: basic statistics
+ * @running: true if @b represents a running qdisc, thus @b's
+ *           internal values might change during basic reads.
+ *           Only used if @cpu is NULL
+ *
+ * Context: task; must not be run from IRQ or BH contexts
  *
  * Appends the basic statistics to the top level TLV created by
  * gnet_stats_start_copy().
@@ -109,30 +257,46 @@ EXPORT_SYMBOL(gnet_stats_start_copy);
  * if the room in the socket buffer was not sufficient.
  */
 int
-gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic_packed *b)
+gnet_stats_copy_basic(struct gnet_dump *d,
+		      struct gnet_stats_basic_sync __percpu *cpu,
+		      struct gnet_stats_basic_sync *b,
+		      bool running)
 {
-	if (d->compat_tc_stats) {
-		d->tc_stats.bytes = b->bytes;
-		d->tc_stats.packets = b->packets;
-	}
-
-	if (d->tail) {
-		struct gnet_stats_basic sb;
-
-		memset(&sb, 0, sizeof(sb));
-		sb.bytes = b->bytes;
-		sb.packets = b->packets;
-		return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
-	}
-	return 0;
+	return ___gnet_stats_copy_basic(d, cpu, b, TCA_STATS_BASIC, running);
 }
 EXPORT_SYMBOL(gnet_stats_copy_basic);
 
 /**
- * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
+ * gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
  * @d: dumping handle
+ * @cpu: copy statistic per cpu
  * @b: basic statistics
- * @r: rate estimator statistics
+ * @running: true if @b represents a running qdisc, thus @b's
+ *           internal values might change during basic reads.
+ *           Only used if @cpu is NULL
+ *
+ * Context: task; must not be run from IRQ or BH contexts
+ *
+ * Appends the basic statistics to the top level TLV created by
+ * gnet_stats_start_copy().
+ *
+ * Returns 0 on success or -1 with the statistic lock released
+ * if the room in the socket buffer was not sufficient.
+ */
+int
+gnet_stats_copy_basic_hw(struct gnet_dump *d,
+			 struct gnet_stats_basic_sync __percpu *cpu,
+			 struct gnet_stats_basic_sync *b,
+			 bool running)
+{
+	return ___gnet_stats_copy_basic(d, cpu, b, TCA_STATS_BASIC_HW, running);
+}
+EXPORT_SYMBOL(gnet_stats_copy_basic_hw);
+
+/**
+ * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
+ * @d: dumping handle
+ * @rate_est: rate estimator
  *
  * Appends the rate estimator statistics to the top level TLV created by
  * gnet_stats_start_copy().
@@ -142,18 +306,17 @@ EXPORT_SYMBOL(gnet_stats_copy_basic);
  */
 int
 gnet_stats_copy_rate_est(struct gnet_dump *d,
-			 const struct gnet_stats_basic_packed *b,
-			 struct gnet_stats_rate_est64 *r)
+			 struct net_rate_estimator __rcu **rate_est)
 {
+	struct gnet_stats_rate_est64 sample;
 	struct gnet_stats_rate_est est;
 	int res;
 
-	if (b && !gen_estimator_active(b, r))
+	if (!gen_estimator_read(rate_est, &sample))
 		return 0;
-
-	est.bps = min_t(u64, UINT_MAX, r->bps);
+	est.bps = min_t(u64, UINT_MAX, sample.bps);
 	/* we have some time before reaching 2^32 packets per second */
-	est.pps = r->pps;
+	est.pps = sample.pps;
 
 	if (d->compat_tc_stats) {
 		d->tc_stats.bps = est.bps;
@@ -161,40 +324,86 @@ gnet_stats_copy_rate_est(struct gnet_dump *d,
 	}
 
 	if (d->tail) {
-		res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est));
-		if (res < 0 || est.bps == r->bps)
+		res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
+				      TCA_STATS_PAD);
+		if (res < 0 || est.bps == sample.bps)
 			return res;
 		/* emit 64bit stats only if needed */
-		return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r));
+		return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
+				       sizeof(sample), TCA_STATS_PAD);
 	}
 
 	return 0;
 }
 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 
+static void gnet_stats_add_queue_cpu(struct gnet_stats_queue *qstats,
+				     const struct gnet_stats_queue __percpu *q)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
+
+		qstats->qlen += qcpu->qlen;
+		qstats->backlog += qcpu->backlog;
+		qstats->drops += qcpu->drops;
+		qstats->requeues += qcpu->requeues;
+		qstats->overlimits += qcpu->overlimits;
+	}
+}
+
+void gnet_stats_add_queue(struct gnet_stats_queue *qstats,
+			  const struct gnet_stats_queue __percpu *cpu,
+			  const struct gnet_stats_queue *q)
+{
+	if (cpu) {
+		gnet_stats_add_queue_cpu(qstats, cpu);
+	} else {
+		qstats->qlen += q->qlen;
+		qstats->backlog += q->backlog;
+		qstats->drops += q->drops;
+		qstats->requeues += q->requeues;
+		qstats->overlimits += q->overlimits;
+	}
+}
+EXPORT_SYMBOL(gnet_stats_add_queue);
+
 /**
  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
  * @d: dumping handle
+ * @cpu_q: per cpu queue statistics
  * @q: queue statistics
+ * @qlen: queue length statistics
  *
  * Appends the queue statistics to the top level TLV created by
- * gnet_stats_start_copy().
+ * gnet_stats_start_copy(). Using per cpu queue statistics if
+ * they are available.
  *
  * Returns 0 on success or -1 with the statistic lock released
  * if the room in the socket buffer was not sufficient.
  */
 int
-gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue *q)
+gnet_stats_copy_queue(struct gnet_dump *d,
+		      struct gnet_stats_queue __percpu *cpu_q,
+		      struct gnet_stats_queue *q, __u32 qlen)
 {
+	struct gnet_stats_queue qstats = {0};
+
+	gnet_stats_add_queue(&qstats, cpu_q, q);
+	qstats.qlen = qlen;
+
 	if (d->compat_tc_stats) {
-		d->tc_stats.drops = q->drops;
-		d->tc_stats.qlen = q->qlen;
-		d->tc_stats.backlog = q->backlog;
-		d->tc_stats.overlimits = q->overlimits;
+		d->tc_stats.drops = qstats.drops;
+		d->tc_stats.qlen = qstats.qlen;
+		d->tc_stats.backlog = qstats.backlog;
+		d->tc_stats.overlimits = qstats.overlimits;
 	}
 
 	if (d->tail)
-		return gnet_stats_copy(d, TCA_STATS_QUEUE, q, sizeof(*q));
+		return gnet_stats_copy(d, TCA_STATS_QUEUE,
+				       &qstats, sizeof(qstats),
+				       TCA_STATS_PAD);
 
 	return 0;
 }
@@ -206,7 +415,7 @@ EXPORT_SYMBOL(gnet_stats_copy_queue);
  * @st: application specific statistics data
  * @len: length of data
  *
- * Appends the application sepecific statistics to the top level TLV created by
+ * Appends the application specific statistics to the top level TLV created by
  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
  * handle is in backward compatibility mode.
  *
@@ -217,14 +426,23 @@ int
 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 {
 	if (d->compat_xstats) {
-		d->xstats = st;
+		d->xstats = kmemdup(st, len, GFP_ATOMIC);
+		if (!d->xstats)
+			goto err_out;
 		d->xstats_len = len;
 	}
 
 	if (d->tail)
-		return gnet_stats_copy(d, TCA_STATS_APP, st, len);
+		return gnet_stats_copy(d, TCA_STATS_APP, st, len,
+				       TCA_STATS_PAD);
 
 	return 0;
+
+err_out:
+	if (d->lock)
+		spin_unlock_bh(d->lock);
+	d->xstats_len = 0;
+	return -1;
 }
 EXPORT_SYMBOL(gnet_stats_copy_app);
 
@@ -248,16 +466,20 @@ gnet_stats_finish_copy(struct gnet_dump *d)
 
 	if (d->compat_tc_stats)
 		if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
-			sizeof(d->tc_stats)) < 0)
+				    sizeof(d->tc_stats), d->padattr) < 0)
 			return -1;
 
 	if (d->compat_xstats && d->xstats) {
 		if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
-			d->xstats_len) < 0)
+				    d->xstats_len, d->padattr) < 0)
 			return -1;
 	}
 
-	spin_unlock_bh(d->lock);
+	if (d->lock)
+		spin_unlock_bh(d->lock);
+	kfree(d->xstats);
+	d->xstats = NULL;
+	d->xstats_len = 0;
 	return 0;
 }
 EXPORT_SYMBOL(gnet_stats_finish_copy);