netdev - [PATCH v4 bpf-next 03/14] bpf: pass a pointer to a cgroup storage using pcpu variable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180727215243.3850-4-guro@fb.com>
Date:   Fri, 27 Jul 2018 14:52:32 -0700
From:   Roman Gushchin <guro@...com>
To:     <netdev@...r.kernel.org>
CC:     <linux-kernel@...r.kernel.org>, <kernel-team@...com>,
        Roman Gushchin <guro@...com>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>
Subject: [PATCH v4 bpf-next 03/14] bpf: pass a pointer to a cgroup storage using pcpu variable

This commit introduces the bpf_cgroup_storage_set() helper,
which will be used to pass a pointer to a cgroup storage
to the bpf helper.

Signed-off-by: Roman Gushchin <guro@...com>
Cc: Alexei Starovoitov <ast@...nel.org>
Cc: Daniel Borkmann <daniel@...earbox.net>
Acked-by: Martin KaFai Lau <kafai@...com>
---
 include/linux/bpf-cgroup.h | 15 +++++++++++++++
 kernel/bpf/local_storage.c |  2 ++
 2 files changed, 17 insertions(+)

diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 7d00d58869ed..9a144ddbbc8f 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -4,6 +4,7 @@
 
 #include <linux/errno.h>
 #include <linux/jump_label.h>
+#include <linux/percpu.h>
 #include <linux/rbtree.h>
 #include <uapi/linux/bpf.h>
 
@@ -21,6 +22,8 @@ struct bpf_cgroup_storage;
 extern struct static_key_false cgroup_bpf_enabled_key;
 #define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key)
 
+DECLARE_PER_CPU(void*, bpf_cgroup_storage);
+
 struct bpf_cgroup_storage_map;
 
 struct bpf_storage_buffer {
@@ -97,6 +100,17 @@ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
 int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
 				      short access, enum bpf_attach_type type);
 
+static inline void bpf_cgroup_storage_set(struct bpf_cgroup_storage *storage)
+{
+	struct bpf_storage_buffer *buf;
+
+	if (!storage)
+		return;
+
+	buf = READ_ONCE(storage->buf);
+	this_cpu_write(bpf_cgroup_storage, &buf->data[0]);
+}
+
 struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog);
 void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage);
 void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
@@ -250,6 +264,7 @@ static inline int cgroup_bpf_prog_query(const union bpf_attr *attr,
 	return -EINVAL;
 }
 
+static inline void bpf_cgroup_storage_set(struct bpf_cgroup_storage *storage) {}
 static inline int bpf_cgroup_storage_assign(struct bpf_prog *prog,
 					    struct bpf_map *map) { return 0; }
 static inline void bpf_cgroup_storage_release(struct bpf_prog *prog,
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index 395e7278ec75..62feded85e6b 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -7,6 +7,8 @@
 #include <linux/rbtree.h>
 #include <linux/slab.h>
 
+DEFINE_PER_CPU(void*, bpf_cgroup_storage);
+
 #ifdef CONFIG_CGROUP_BPF
 
 struct bpf_cgroup_storage_map {
-- 
2.14.4