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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 v6 bpf-next 01/14] bpf: add ability to charge bpf maps memory dynamically
Date: Wed, 1 Aug 2018 15:37:27 -0700	[thread overview]
Message-ID: <20180801223740.11252-2-guro@fb.com> (raw)
In-Reply-To: <20180801223740.11252-1-guro@fb.com>

This commits extends existing bpf maps memory charging API
to support dynamic charging/uncharging.

This is required to account memory used by maps,
if all entries are created dynamically after
the map initialization.

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>
---
 include/linux/bpf.h  |  2 ++
 kernel/bpf/syscall.c | 58 ++++++++++++++++++++++++++++++++++++++--------------
 2 files changed, 45 insertions(+), 15 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 5b5ad95cf339..5a4a256473c3 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -435,6 +435,8 @@ struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref);
 void bpf_map_put_with_uref(struct bpf_map *map);
 void bpf_map_put(struct bpf_map *map);
 int bpf_map_precharge_memlock(u32 pages);
+int bpf_map_charge_memlock(struct bpf_map *map, u32 pages);
+void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages);
 void *bpf_map_area_alloc(size_t size, int numa_node);
 void bpf_map_area_free(void *base);
 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index a31a1ba0f8ea..7958252a4d29 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -181,32 +181,60 @@ int bpf_map_precharge_memlock(u32 pages)
 	return 0;
 }
 
-static int bpf_map_charge_memlock(struct bpf_map *map)
+static int bpf_charge_memlock(struct user_struct *user, u32 pages)
 {
-	struct user_struct *user = get_current_user();
-	unsigned long memlock_limit;
+	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 
-	memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+	if (atomic_long_add_return(pages, &user->locked_vm) > memlock_limit) {
+		atomic_long_sub(pages, &user->locked_vm);
+		return -EPERM;
+	}
+	return 0;
+}
 
-	atomic_long_add(map->pages, &user->locked_vm);
+static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
+{
+	atomic_long_sub(pages, &user->locked_vm);
+}
+
+static int bpf_map_init_memlock(struct bpf_map *map)
+{
+	struct user_struct *user = get_current_user();
+	int ret;
 
-	if (atomic_long_read(&user->locked_vm) > memlock_limit) {
-		atomic_long_sub(map->pages, &user->locked_vm);
+	ret = bpf_charge_memlock(user, map->pages);
+	if (ret) {
 		free_uid(user);
-		return -EPERM;
+		return ret;
 	}
 	map->user = user;
-	return 0;
+	return ret;
 }
 
-static void bpf_map_uncharge_memlock(struct bpf_map *map)
+static void bpf_map_release_memlock(struct bpf_map *map)
 {
 	struct user_struct *user = map->user;
-
-	atomic_long_sub(map->pages, &user->locked_vm);
+	bpf_uncharge_memlock(user, map->pages);
 	free_uid(user);
 }
 
+int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
+{
+	int ret;
+
+	ret = bpf_charge_memlock(map->user, pages);
+	if (ret)
+		return ret;
+	map->pages += pages;
+	return ret;
+}
+
+void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
+{
+	bpf_uncharge_memlock(map->user, pages);
+	map->pages -= pages;
+}
+
 static int bpf_map_alloc_id(struct bpf_map *map)
 {
 	int id;
@@ -256,7 +284,7 @@ static void bpf_map_free_deferred(struct work_struct *work)
 {
 	struct bpf_map *map = container_of(work, struct bpf_map, work);
 
-	bpf_map_uncharge_memlock(map);
+	bpf_map_release_memlock(map);
 	security_bpf_map_free(map);
 	/* implementation dependent freeing */
 	map->ops->map_free(map);
@@ -492,7 +520,7 @@ static int map_create(union bpf_attr *attr)
 	if (err)
 		goto free_map_nouncharge;
 
-	err = bpf_map_charge_memlock(map);
+	err = bpf_map_init_memlock(map);
 	if (err)
 		goto free_map_sec;
 
@@ -515,7 +543,7 @@ static int map_create(union bpf_attr *attr)
 	return err;
 
 free_map:
-	bpf_map_uncharge_memlock(map);
+	bpf_map_release_memlock(map);
 free_map_sec:
 	security_bpf_map_free(map);
 free_map_nouncharge:
-- 
2.14.4

  reply	other threads:[~2018-08-01 22:37 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-01 22:37 [PATCH v6 bpf-next 00/14] bpf: cgroup local storage Roman Gushchin
2018-08-01 22:37 ` Roman Gushchin [this message]
2018-08-01 22:37 ` [PATCH v6 bpf-next 02/14] bpf: introduce cgroup storage maps Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 03/14] bpf: pass a pointer to a cgroup storage using pcpu variable Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 04/14] bpf: allocate cgroup storage entries on attaching bpf programs Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 05/14] bpf: extend bpf_prog_array to store pointers to the cgroup storage Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 06/14] bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 07/14] bpf: don't allow create maps of cgroup local storages Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 08/14] bpf: introduce the bpf_get_local_storage() helper function Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 09/14] bpf: sync bpf.h to tools/ Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 10/14] bpftool: add support for CGROUP_STORAGE maps Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 11/14] bpf/test_run: support cgroup local storage Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 12/14] selftests/bpf: add verifier cgroup storage tests Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 13/14] selftests/bpf: add a cgroup storage test Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 14/14] samples/bpf: extend test_cgrp2_attach2 test to use cgroup storage Roman Gushchin
2018-08-02  8:53 ` [PATCH v6 bpf-next 00/14] bpf: cgroup local storage Daniel Borkmann

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