Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-03-21

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add a BPF hook for sendmsg and sendfile by reusing the ULP infrastructure
   and sockmap. Three helpers are added along with this, bpf_msg_apply_bytes(),
   bpf_msg_cork_bytes(), and bpf_msg_pull_data(). The first is used to tell
   for how many bytes the verdict should be applied to, the second to tell
   that x bytes need to be queued first to retrigger the BPF program for a
   verdict, and the third helper is mainly for the sendfile case to pull in
   data for making it private for reading and/or writing, from John.

2) Improve address to symbol resolution of user stack traces in BPF stackmap.
   Currently, the latter stores the address for each entry in the call trace,
   however to map these addresses to user space files, it is necessary to
   maintain the mapping from these virtual addresses to symbols in the binary
   which is not practical for system-wide profiling. Instead, this option for
   the stackmap rather stores the ELF build id and offset for the call trace
   entries, from Song.

3) Add support that allows BPF programs attached to perf events to read the
   address values recorded with the perf events. They are requested through
   PERF_SAMPLE_ADDR via perf_event_open(). Main motivation behind it is to
   support building memory or lock access profiling and tracing tools with
   the help of BPF, from Teng.

4) Several improvements to the tools/bpf/ Makefiles. The 'make bpf' in the
   tools directory does not provide the standard quiet output except for
   bpftool and it also does not respect specifying a build output directory.
   'make bpf_install' command neither respects specified destination nor
   prefix, all from Jiri. In addition, Jakub fixes several other minor issues
   in the Makefiles on top of that, e.g. fixing dependency paths, phony
   targets and more.

5) Various doc updates e.g. add a comment for BPF fs about reserved names
   to make the dentry lookup from there a bit more obvious, and a comment
   to the bpf_devel_QA file in order to explain the diff between native
   and bpf target clang usage with regards to pointer size, from Quentin
   and Daniel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/bpf/bpf_devel_QA.txt

@@ -539,6 +539,18 @@ A: Although LLVM IR generation and optimization try to stay architecture
        The clang option "-fno-jump-tables" can be used to disable
        switch table generation.
 
+     - For clang -target bpf, it is guaranteed that pointer or long /
+       unsigned long types will always have a width of 64 bit, no matter
+       whether underlying clang binary or default target (or kernel) is
+       32 bit. However, when native clang target is used, then it will
+       compile these types based on the underlying architecture's conventions,
+       meaning in case of 32 bit architecture, pointer or long / unsigned
+       long types e.g. in BPF context structure will have width of 32 bit
+       while the BPF LLVM back end still operates in 64 bit. The native
+       target is mostly needed in tracing for the case of walking pt_regs
+       or other kernel structures where CPU's register width matters.
+       Otherwise, clang -target bpf is generally recommended.
+
    You should use default target when:
 
      - Your program includes a header file, e.g., ptrace.h, which eventually

include/linux/bpf.h

@@ -21,6 +21,7 @@ struct bpf_verifier_env;
 struct perf_event;
 struct bpf_prog;
 struct bpf_map;
+struct sock;
 
 /* map is generic key/value storage optionally accesible by eBPF programs */
 struct bpf_map_ops {

include/linux/bpf_types.h

@@ -13,6 +13,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_inout)
 BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_XMIT, lwt_xmit)
 BPF_PROG_TYPE(BPF_PROG_TYPE_SOCK_OPS, sock_ops)
 BPF_PROG_TYPE(BPF_PROG_TYPE_SK_SKB, sk_skb)
+BPF_PROG_TYPE(BPF_PROG_TYPE_SK_MSG, sk_msg)
 #endif
 #ifdef CONFIG_BPF_EVENTS
 BPF_PROG_TYPE(BPF_PROG_TYPE_KPROBE, kprobe)

include/linux/filter.h

@@ -507,6 +507,22 @@ struct xdp_buff {
 	struct xdp_rxq_info *rxq;
 };
 
+struct sk_msg_buff {
+	void *data;
+	void *data_end;
+	__u32 apply_bytes;
+	__u32 cork_bytes;
+	int sg_copybreak;
+	int sg_start;
+	int sg_curr;
+	int sg_end;
+	struct scatterlist sg_data[MAX_SKB_FRAGS];
+	bool sg_copy[MAX_SKB_FRAGS];
+	__u32 key;
+	__u32 flags;
+	struct bpf_map *map;
+};
+
 /* Compute the linear packet data range [data, data_end) which
  * will be accessed by various program types (cls_bpf, act_bpf,
  * lwt, ...). Subsystems allowing direct data access must (!)
@@ -771,6 +787,7 @@ xdp_data_meta_unsupported(const struct xdp_buff *xdp)
 void bpf_warn_invalid_xdp_action(u32 act);
 
 struct sock *do_sk_redirect_map(struct sk_buff *skb);
+struct sock *do_msg_redirect_map(struct sk_msg_buff *md);
 
 #ifdef CONFIG_BPF_JIT
 extern int bpf_jit_enable;

include/linux/socket.h

@@ -287,6 +287,7 @@ struct ucred {
 #define MSG_SENDPAGE_NOTLAST 0x20000 /* sendpage() internal : not the last page */
 #define MSG_BATCH	0x40000 /* sendmmsg(): more messages coming */
 #define MSG_EOF         MSG_FIN
+#define MSG_NO_SHARED_FRAGS 0x80000 /* sendpage() internal : page frags are not shared */
 
 #define MSG_ZEROCOPY	0x4000000	/* Use user data in kernel path */
 #define MSG_FASTOPEN	0x20000000	/* Send data in TCP SYN */

include/net/sock.h

@@ -2141,6 +2141,10 @@ static inline struct page_frag *sk_page_frag(struct sock *sk)
 
 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
 
+int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
+		int sg_start, int *sg_curr, unsigned int *sg_size,
+		int first_coalesce);
+
 /*
  *	Default write policy as shown to user space via poll/select/SIGIO
  */

include/uapi/linux/bpf.h

@@ -133,6 +133,7 @@ enum bpf_prog_type {
 	BPF_PROG_TYPE_SOCK_OPS,
 	BPF_PROG_TYPE_SK_SKB,
 	BPF_PROG_TYPE_CGROUP_DEVICE,
+	BPF_PROG_TYPE_SK_MSG,
 };
 
 enum bpf_attach_type {
@@ -143,6 +144,7 @@ enum bpf_attach_type {
 	BPF_SK_SKB_STREAM_PARSER,
 	BPF_SK_SKB_STREAM_VERDICT,
 	BPF_CGROUP_DEVICE,
+	BPF_SK_MSG_VERDICT,
 	__MAX_BPF_ATTACH_TYPE
 };
 
@@ -231,6 +233,28 @@ enum bpf_attach_type {
 #define BPF_F_RDONLY		(1U << 3)
 #define BPF_F_WRONLY		(1U << 4)
 
+/* Flag for stack_map, store build_id+offset instead of pointer */
+#define BPF_F_STACK_BUILD_ID	(1U << 5)
+
+enum bpf_stack_build_id_status {
+	/* user space need an empty entry to identify end of a trace */
+	BPF_STACK_BUILD_ID_EMPTY = 0,
+	/* with valid build_id and offset */
+	BPF_STACK_BUILD_ID_VALID = 1,
+	/* couldn't get build_id, fallback to ip */
+	BPF_STACK_BUILD_ID_IP = 2,
+};
+
+#define BPF_BUILD_ID_SIZE 20
+struct bpf_stack_build_id {
+	__s32		status;
+	unsigned char	build_id[BPF_BUILD_ID_SIZE];
+	union {
+		__u64	offset;
+		__u64	ip;
+	};
+};
+
 union bpf_attr {
 	struct { /* anonymous struct used by BPF_MAP_CREATE command */
 		__u32	map_type;	/* one of enum bpf_map_type */
@@ -696,6 +720,15 @@ union bpf_attr {
  * int bpf_override_return(pt_regs, rc)
  *	@pt_regs: pointer to struct pt_regs
  *	@rc: the return value to set
+ *
+ * int bpf_msg_redirect_map(map, key, flags)
+ *     Redirect msg to a sock in map using key as a lookup key for the
+ *     sock in map.
+ *     @map: pointer to sockmap
+ *     @key: key to lookup sock in map
+ *     @flags: reserved for future use
+ *     Return: SK_PASS
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -757,7 +790,11 @@ union bpf_attr {
 	FN(perf_prog_read_value),	\
 	FN(getsockopt),			\
 	FN(override_return),		\
-	FN(sock_ops_cb_flags_set),
+	FN(sock_ops_cb_flags_set),	\
+	FN(msg_redirect_map),		\
+	FN(msg_apply_bytes),		\
+	FN(msg_cork_bytes),		\
+	FN(msg_pull_data),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -920,6 +957,14 @@ enum sk_action {
 	SK_PASS,
 };
 
+/* user accessible metadata for SK_MSG packet hook, new fields must
+ * be added to the end of this structure
+ */
+struct sk_msg_md {
+	void *data;
+	void *data_end;
+};
+
 #define BPF_TAG_SIZE	8
 
 struct bpf_prog_info {

include/uapi/linux/bpf_perf_event.h

@@ -13,6 +13,7 @@
 struct bpf_perf_event_data {
 	bpf_user_pt_regs_t regs;
 	__u64 sample_period;
+	__u64 addr;
 };
 
 #endif /* _UAPI__LINUX_BPF_PERF_EVENT_H__ */

kernel/bpf/inode.c

@@ -178,6 +178,9 @@ static int bpf_mkmap(struct dentry *dentry, umode_t mode, void *arg)
 static struct dentry *
 bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
 {
+	/* Dots in names (e.g. "/sys/fs/bpf/foo.bar") are reserved for future
+	 * extensions.
+	 */
 	if (strchr(dentry->d_name.name, '.'))
 		return ERR_PTR(-EPERM);