From: KP Singh <kpsingh@chromium.org>
To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
linux-security-module@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Paul Turner <pjt@google.com>,
Jann Horn <jannh@google.com>,
Florent Revest <revest@chromium.org>
Subject: [PATCH bpf-next v6 2/7] bpf: Generalize caching for sk_storage.
Date: Thu, 23 Jul 2020 13:50:27 +0200 [thread overview]
Message-ID: <20200723115032.460770-3-kpsingh@chromium.org> (raw)
In-Reply-To: <20200723115032.460770-1-kpsingh@chromium.org>
From: KP Singh <kpsingh@google.com>
Provide the a ability to define local storage caches on a per-object
type basis. The caches and caching indices for different objects should
not be inter-mixed as suggested in:
https://lore.kernel.org/bpf/20200630193441.kdwnkestulg5erii@kafai-mbp.dhcp.thefacebook.com/
"Caching a sk-storage at idx=0 of a sk should not stop an
inode-storage to be cached at the same idx of a inode."
Signed-off-by: KP Singh <kpsingh@google.com>
---
include/net/bpf_sk_storage.h | 19 +++++++++++++++++++
net/core/bpf_sk_storage.c | 31 +++++++++++++++----------------
2 files changed, 34 insertions(+), 16 deletions(-)
diff --git a/include/net/bpf_sk_storage.h b/include/net/bpf_sk_storage.h
index 5036c94c0503..950c5aaba15e 100644
--- a/include/net/bpf_sk_storage.h
+++ b/include/net/bpf_sk_storage.h
@@ -3,6 +3,9 @@
#ifndef _BPF_SK_STORAGE_H
#define _BPF_SK_STORAGE_H
+#include <linux/types.h>
+#include <linux/spinlock.h>
+
struct sock;
void bpf_sk_storage_free(struct sock *sk);
@@ -15,6 +18,22 @@ struct sk_buff;
struct nlattr;
struct sock;
+#define BPF_LOCAL_STORAGE_CACHE_SIZE 16
+
+struct bpf_local_storage_cache {
+ spinlock_t idx_lock;
+ u64 idx_usage_counts[BPF_LOCAL_STORAGE_CACHE_SIZE];
+};
+
+#define DEFINE_BPF_STORAGE_CACHE(name) \
+static struct bpf_local_storage_cache name = { \
+ .idx_lock = __SPIN_LOCK_UNLOCKED(name.idx_lock), \
+}
+
+u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache);
+void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache,
+ u16 idx);
+
#ifdef CONFIG_BPF_SYSCALL
int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk);
struct bpf_sk_storage_diag *
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index fb7ea6f4174d..aa3e3a47acb5 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -13,6 +13,8 @@
#define BPF_LOCAL_STORAGE_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_CLONE)
+DEFINE_BPF_STORAGE_CACHE(sk_cache);
+
struct bpf_local_storage_map_bucket {
struct hlist_head list;
raw_spinlock_t lock;
@@ -77,10 +79,6 @@ struct bpf_local_storage_elem {
#define SELEM(_SDATA) \
container_of((_SDATA), struct bpf_local_storage_elem, sdata)
#define SDATA(_SELEM) (&(_SELEM)->sdata)
-#define BPF_LOCAL_STORAGE_CACHE_SIZE 16
-
-static DEFINE_SPINLOCK(cache_idx_lock);
-static u64 cache_idx_usage_counts[BPF_LOCAL_STORAGE_CACHE_SIZE];
struct bpf_local_storage {
struct bpf_local_storage_data __rcu *cache[BPF_LOCAL_STORAGE_CACHE_SIZE];
@@ -516,16 +514,16 @@ static int sk_storage_delete(struct sock *sk, struct bpf_map *map)
return 0;
}
-static u16 cache_idx_get(void)
+u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache)
{
u64 min_usage = U64_MAX;
u16 i, res = 0;
- spin_lock(&cache_idx_lock);
+ spin_lock(&cache->idx_lock);
for (i = 0; i < BPF_LOCAL_STORAGE_CACHE_SIZE; i++) {
- if (cache_idx_usage_counts[i] < min_usage) {
- min_usage = cache_idx_usage_counts[i];
+ if (cache->idx_usage_counts[i] < min_usage) {
+ min_usage = cache->idx_usage_counts[i];
res = i;
/* Found a free cache_idx */
@@ -533,18 +531,19 @@ static u16 cache_idx_get(void)
break;
}
}
- cache_idx_usage_counts[res]++;
+ cache->idx_usage_counts[res]++;
- spin_unlock(&cache_idx_lock);
+ spin_unlock(&cache->idx_lock);
return res;
}
-static void cache_idx_free(u16 idx)
+void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache,
+ u16 idx)
{
- spin_lock(&cache_idx_lock);
- cache_idx_usage_counts[idx]--;
- spin_unlock(&cache_idx_lock);
+ spin_lock(&cache->idx_lock);
+ cache->idx_usage_counts[idx]--;
+ spin_unlock(&cache->idx_lock);
}
/* Called by __sk_destruct() & bpf_sk_storage_clone() */
@@ -596,7 +595,7 @@ static void bpf_local_storage_map_free(struct bpf_map *map)
smap = (struct bpf_local_storage_map *)map;
- cache_idx_free(smap->cache_idx);
+ bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx);
/* Note that this map might be concurrently cloned from
* bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone
@@ -712,7 +711,7 @@ static struct bpf_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
}
smap->elem_size = sizeof(struct bpf_local_storage_elem) + attr->value_size;
- smap->cache_idx = cache_idx_get();
+ smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache);
return &smap->map;
}
--
2.28.0.rc0.105.gf9edc3c819-goog
next prev parent reply other threads:[~2020-07-23 11:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 11:50 [PATCH bpf-next v6 0/7] Generalizing bpf_local_storage KP Singh
2020-07-23 11:50 ` [PATCH bpf-next v6 1/7] bpf: Renames to prepare for generalizing sk_storage KP Singh
2020-07-24 5:31 ` Martin KaFai Lau
2020-07-24 15:44 ` KP Singh
2020-07-23 11:50 ` KP Singh [this message]
2020-07-23 11:50 ` [PATCH bpf-next v6 3/7] bpf: Generalize bpf_sk_storage KP Singh
2020-07-25 1:13 ` Martin KaFai Lau
2020-07-27 20:28 ` KP Singh
2020-07-25 1:30 ` [RFC PATCH bpf-next] bpf: POC on local_storage charge and uncharge map_ops Martin KaFai Lau
2020-07-27 20:26 ` KP Singh
2020-07-27 21:43 ` Martin KaFai Lau
2020-07-23 11:50 ` [PATCH bpf-next v6 4/7] bpf: Split bpf_local_storage to bpf_sk_storage KP Singh
2020-07-23 11:50 ` [PATCH bpf-next v6 5/7] bpf: Implement bpf_local_storage for inodes KP Singh
2020-07-23 11:50 ` [PATCH bpf-next v6 6/7] bpf: Allow local storage to be used from LSM programs KP Singh
2020-07-23 11:50 ` [PATCH bpf-next v6 7/7] bpf: Add selftests for local_storage KP Singh
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