All of lore.kernel.org
 help / color / mirror / Atom feed
From: Roman Gushchin <guro@fb.com>
To: <netdev@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>, <kernel-team@fb.com>,
	Roman Gushchin <guro@fb.com>, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH v3 bpf-next 05/14] bpf: extend bpf_prog_array to store pointers to the cgroup storage
Date: Fri, 20 Jul 2018 10:45:49 -0700	[thread overview]
Message-ID: <20180720174558.5829-6-guro@fb.com> (raw)
In-Reply-To: <20180720174558.5829-1-guro@fb.com>

This patch converts bpf_prog_array from an array of prog pointers
to the array of struct bpf_prog_array_item elements.

This allows to save a cgroup storage pointer for each bpf program
efficiently attached to a cgroup.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
---
 drivers/media/rc/bpf-lirc.c | 10 +++---
 include/linux/bpf.h         | 19 ++++++++----
 kernel/bpf/cgroup.c         | 21 +++++++------
 kernel/bpf/core.c           | 76 +++++++++++++++++++++++----------------------
 4 files changed, 70 insertions(+), 56 deletions(-)

diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c
index fcfab6635f9c..8c26df9b96c1 100644
--- a/drivers/media/rc/bpf-lirc.c
+++ b/drivers/media/rc/bpf-lirc.c
@@ -195,14 +195,16 @@ void lirc_bpf_run(struct rc_dev *rcdev, u32 sample)
  */
 void lirc_bpf_free(struct rc_dev *rcdev)
 {
-	struct bpf_prog **progs;
+	struct bpf_prog_array_item *item;
 
 	if (!rcdev->raw->progs)
 		return;
 
-	progs = rcu_dereference(rcdev->raw->progs)->progs;
-	while (*progs)
-		bpf_prog_put(*progs++);
+	item = rcu_dereference(rcdev->raw->progs)->items;
+	while (item->prog) {
+		bpf_prog_put(item->prog);
+		item++;
+	}
 
 	bpf_prog_array_free(rcdev->raw->progs);
 }
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9d1e4727495e..16be67888c30 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -349,9 +349,14 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
  * The 'struct bpf_prog_array *' should only be replaced with xchg()
  * since other cpus are walking the array of pointers in parallel.
  */
+struct bpf_prog_array_item {
+	struct bpf_prog *prog;
+	struct bpf_cgroup_storage *cgroup_storage;
+};
+
 struct bpf_prog_array {
 	struct rcu_head rcu;
-	struct bpf_prog *progs[0];
+	struct bpf_prog_array_item items[0];
 };
 
 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags);
@@ -372,7 +377,8 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
 
 #define __BPF_PROG_RUN_ARRAY(array, ctx, func, check_non_null)	\
 	({						\
-		struct bpf_prog **_prog, *__prog;	\
+		struct bpf_prog_array_item *_item;	\
+		struct bpf_prog *_prog;			\
 		struct bpf_prog_array *_array;		\
 		u32 _ret = 1;				\
 		preempt_disable();			\
@@ -380,10 +386,11 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
 		_array = rcu_dereference(array);	\
 		if (unlikely(check_non_null && !_array))\
 			goto _out;			\
-		_prog = _array->progs;			\
-		while ((__prog = READ_ONCE(*_prog))) {	\
-			_ret &= func(__prog, ctx);	\
-			_prog++;			\
+		_item = &_array->items[0];		\
+		while ((_prog = READ_ONCE(_item->prog))) {		\
+			bpf_cgroup_storage_set(_item->cgroup_storage);	\
+			_ret &= func(_prog, ctx);	\
+			_item++;			\
 		}					\
 _out:							\
 		rcu_read_unlock();			\
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 986ff18ef92e..ac480086effd 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -117,15 +117,18 @@ static int compute_effective_progs(struct cgroup *cgrp,
 	cnt = 0;
 	p = cgrp;
 	do {
-		if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
-			list_for_each_entry(pl,
-					    &p->bpf.progs[type], node) {
-				if (!pl->prog)
-					continue;
-				progs->progs[cnt++] = pl->prog;
-			}
-		p = cgroup_parent(p);
-	} while (p);
+		if (cnt > 0 && !(p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+			continue;
+
+		list_for_each_entry(pl, &p->bpf.progs[type], node) {
+			if (!pl->prog)
+				continue;
+
+			progs->items[cnt].prog = pl->prog;
+			progs->items[cnt].cgroup_storage = pl->storage;
+			cnt++;
+		}
+	} while ((p = cgroup_parent(p)));
 
 	rcu_assign_pointer(*array, progs);
 	return 0;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 253aa8e79c7b..9abcf25ebf9f 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1542,7 +1542,8 @@ struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
 {
 	if (prog_cnt)
 		return kzalloc(sizeof(struct bpf_prog_array) +
-			       sizeof(struct bpf_prog *) * (prog_cnt + 1),
+			       sizeof(struct bpf_prog_array_item) *
+			       (prog_cnt + 1),
 			       flags);
 
 	return &empty_prog_array.hdr;
@@ -1556,43 +1557,45 @@ void bpf_prog_array_free(struct bpf_prog_array __rcu *progs)
 	kfree_rcu(progs, rcu);
 }
 
-int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
+int bpf_prog_array_length(struct bpf_prog_array __rcu *array)
 {
-	struct bpf_prog **prog;
+	struct bpf_prog_array_item *item;
 	u32 cnt = 0;
 
 	rcu_read_lock();
-	prog = rcu_dereference(progs)->progs;
-	for (; *prog; prog++)
-		if (*prog != &dummy_bpf_prog.prog)
+	item = rcu_dereference(array)->items;
+	for (; item->prog; item++)
+		if (item->prog != &dummy_bpf_prog.prog)
 			cnt++;
 	rcu_read_unlock();
 	return cnt;
 }
 
-static bool bpf_prog_array_copy_core(struct bpf_prog **prog,
+
+static bool bpf_prog_array_copy_core(struct bpf_prog_array __rcu *array,
 				     u32 *prog_ids,
 				     u32 request_cnt)
 {
+	struct bpf_prog_array_item *item;
 	int i = 0;
 
-	for (; *prog; prog++) {
-		if (*prog == &dummy_bpf_prog.prog)
+	item = rcu_dereference(array)->items;
+	for (; item->prog; item++) {
+		if (item->prog == &dummy_bpf_prog.prog)
 			continue;
-		prog_ids[i] = (*prog)->aux->id;
+		prog_ids[i] = item->prog->aux->id;
 		if (++i == request_cnt) {
-			prog++;
+			item++;
 			break;
 		}
 	}
 
-	return !!(*prog);
+	return !!(item->prog);
 }
 
-int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
+int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *array,
 				__u32 __user *prog_ids, u32 cnt)
 {
-	struct bpf_prog **prog;
 	unsigned long err = 0;
 	bool nospc;
 	u32 *ids;
@@ -1611,8 +1614,7 @@ int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
 	if (!ids)
 		return -ENOMEM;
 	rcu_read_lock();
-	prog = rcu_dereference(progs)->progs;
-	nospc = bpf_prog_array_copy_core(prog, ids, cnt);
+	nospc = bpf_prog_array_copy_core(array, ids, cnt);
 	rcu_read_unlock();
 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
 	kfree(ids);
@@ -1623,14 +1625,14 @@ int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
 	return 0;
 }
 
-void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs,
+void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *array,
 				struct bpf_prog *old_prog)
 {
-	struct bpf_prog **prog = progs->progs;
+	struct bpf_prog_array_item *item = array->items;
 
-	for (; *prog; prog++)
-		if (*prog == old_prog) {
-			WRITE_ONCE(*prog, &dummy_bpf_prog.prog);
+	for (; item->prog; item++)
+		if (item->prog == old_prog) {
+			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
 			break;
 		}
 }
@@ -1641,7 +1643,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
 			struct bpf_prog_array **new_array)
 {
 	int new_prog_cnt, carry_prog_cnt = 0;
-	struct bpf_prog **existing_prog;
+	struct bpf_prog_array_item *existing;
 	struct bpf_prog_array *array;
 	bool found_exclude = false;
 	int new_prog_idx = 0;
@@ -1650,15 +1652,15 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
 	 * the new array.
 	 */
 	if (old_array) {
-		existing_prog = old_array->progs;
-		for (; *existing_prog; existing_prog++) {
-			if (*existing_prog == exclude_prog) {
+		existing = old_array->items;
+		for (; existing->prog; existing++) {
+			if (existing->prog == exclude_prog) {
 				found_exclude = true;
 				continue;
 			}
-			if (*existing_prog != &dummy_bpf_prog.prog)
+			if (existing->prog != &dummy_bpf_prog.prog)
 				carry_prog_cnt++;
-			if (*existing_prog == include_prog)
+			if (existing->prog == include_prog)
 				return -EEXIST;
 		}
 	}
@@ -1684,15 +1686,17 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
 
 	/* Fill in the new prog array */
 	if (carry_prog_cnt) {
-		existing_prog = old_array->progs;
-		for (; *existing_prog; existing_prog++)
-			if (*existing_prog != exclude_prog &&
-			    *existing_prog != &dummy_bpf_prog.prog)
-				array->progs[new_prog_idx++] = *existing_prog;
+		existing = old_array->items;
+		for (; existing->prog; existing++)
+			if (existing->prog != exclude_prog &&
+			    existing->prog != &dummy_bpf_prog.prog) {
+				array->items[new_prog_idx++].prog =
+					existing->prog;
+			}
 	}
 	if (include_prog)
-		array->progs[new_prog_idx++] = include_prog;
-	array->progs[new_prog_idx] = NULL;
+		array->items[new_prog_idx++].prog = include_prog;
+	array->items[new_prog_idx].prog = NULL;
 	*new_array = array;
 	return 0;
 }
@@ -1701,7 +1705,6 @@ int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array,
 			     u32 *prog_ids, u32 request_cnt,
 			     u32 *prog_cnt)
 {
-	struct bpf_prog **prog;
 	u32 cnt = 0;
 
 	if (array)
@@ -1714,8 +1717,7 @@ int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array,
 		return 0;
 
 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
-	prog = rcu_dereference_check(array, 1)->progs;
-	return bpf_prog_array_copy_core(prog, prog_ids, request_cnt) ? -ENOSPC
+	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
 								     : 0;
 }
 
-- 
2.14.4


  parent reply	other threads:[~2018-07-20 17:47 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-20 17:45 [PATCH v3 bpf-next 00/14] bpf: cgroup local storage Roman Gushchin
2018-07-20 17:45 ` Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 01/14] bpf: add ability to charge bpf maps memory dynamically Roman Gushchin
2018-07-27 18:01   ` Daniel Borkmann
2018-07-20 17:45 ` [PATCH v3 bpf-next 02/14] bpf: introduce cgroup storage maps Roman Gushchin
2018-07-20 17:45   ` Roman Gushchin
2018-07-27  4:11   ` Daniel Borkmann
2018-07-27 17:12     ` Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 03/14] bpf: pass a pointer to a cgroup storage using pcpu variable Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 04/14] bpf: allocate cgroup storage entries on attaching bpf programs Roman Gushchin
2018-07-27  4:21   ` Daniel Borkmann
2018-07-20 17:45 ` Roman Gushchin [this message]
2018-07-20 17:45 ` [PATCH v3 bpf-next 06/14] bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 07/14] bpf: don't allow create maps of cgroup local storages Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 08/14] bpf: introduce the bpf_get_local_storage() helper function Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 09/14] bpf: sync bpf.h to tools/ Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 10/14] bpftool: add support for CGROUP_STORAGE maps Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 11/14] bpf/test_run: support cgroup local storage Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 12/14] selftests/bpf: add verifier cgroup storage tests Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 13/14] selftests/bpf: add a cgroup storage test Roman Gushchin
2018-07-20 17:45 ` [PATCH v3 bpf-next 14/14] samples/bpf: extend test_cgrp2_attach2 test to use cgroup storage Roman Gushchin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180720174558.5829-6-guro@fb.com \
    --to=guro@fb.com \
    --cc=ast@kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=kernel-team@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.