Merge tag 'perf-core-for-mingo-20160713' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

- Finish merging initial SDT (Statically Defined Traces) support, see
  cset comments for details about how it all works (Masami Hiramatsu)

- Support attaching eBPF programs to tracepoints (Wang Nan)

Infrastructure changes:

- Fix up BITS_PER_LONG setting (Arnaldo Carvalho de Melo)

- Add fallback from ELF_C_READ_MMAP to ELF_C_READ in objtool, fixing
  the build in libelf implementations lacking that elf_begin() cmd,
  such as Alpine Linux's (Arnaldo Carvalho de Melo)

- Avoid checking code drift on busybox's diff in objtool (Arnaldo Carvalho de Melo)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 76 insertions, 14 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3dcda9e215b0..32e6b6bc6f7d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -90,6 +90,7 @@ static const char *libbpf_strerror_table[NR_ERRNO] = {
 	[ERRCODE_OFFSET(VERIFY)]	= "Kernel verifier blocks program loading",
 	[ERRCODE_OFFSET(PROG2BIG)]	= "Program too big",
 	[ERRCODE_OFFSET(KVER)]		= "Incorrect kernel version",
+	[ERRCODE_OFFSET(PROGTYPE)]	= "Kernel doesn't support this program type",
 };
 
 int libbpf_strerror(int err, char *buf, size_t size)
@@ -158,6 +159,7 @@ struct bpf_program {
 	char *section_name;
 	struct bpf_insn *insns;
 	size_t insns_cnt;
+	enum bpf_prog_type type;
 
 	struct {
 		int insn_idx;
@@ -299,6 +301,7 @@ bpf_program__init(void *data, size_t size, char *name, int idx,
 	prog->idx = idx;
 	prog->instances.fds = NULL;
 	prog->instances.nr = -1;
+	prog->type = BPF_PROG_TYPE_KPROBE;
 
 	return 0;
 errout:
@@ -894,8 +897,8 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
 }
 
 static int
-load_program(struct bpf_insn *insns, int insns_cnt,
-	     char *license, u32 kern_version, int *pfd)
+load_program(enum bpf_prog_type type, struct bpf_insn *insns,
+	     int insns_cnt, char *license, u32 kern_version, int *pfd)
 {
 	int ret;
 	char *log_buf;
@@ -907,9 +910,8 @@ load_program(struct bpf_insn *insns, int insns_cnt,
 	if (!log_buf)
 		pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
 
-	ret = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
-			       insns_cnt, license, kern_version,
-			       log_buf, BPF_LOG_BUF_SIZE);
+	ret = bpf_load_program(type, insns, insns_cnt, license,
+			       kern_version, log_buf, BPF_LOG_BUF_SIZE);
 
 	if (ret >= 0) {
 		*pfd = ret;
@@ -925,15 +927,27 @@ load_program(struct bpf_insn *insns, int insns_cnt,
 		pr_warning("-- BEGIN DUMP LOG ---\n");
 		pr_warning("\n%s\n", log_buf);
 		pr_warning("-- END LOG --\n");
+	} else if (insns_cnt >= BPF_MAXINSNS) {
+		pr_warning("Program too large (%d insns), at most %d insns\n",
+			   insns_cnt, BPF_MAXINSNS);
+		ret = -LIBBPF_ERRNO__PROG2BIG;
 	} else {
-		if (insns_cnt >= BPF_MAXINSNS) {
-			pr_warning("Program too large (%d insns), at most %d insns\n",
-				   insns_cnt, BPF_MAXINSNS);
-			ret = -LIBBPF_ERRNO__PROG2BIG;
-		} else if (log_buf) {
-			pr_warning("log buffer is empty\n");
-			ret = -LIBBPF_ERRNO__KVER;
+		/* Wrong program type? */
+		if (type != BPF_PROG_TYPE_KPROBE) {
+			int fd;
+
+			fd = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
+					      insns_cnt, license, kern_version,
+					      NULL, 0);
+			if (fd >= 0) {
+				close(fd);
+				ret = -LIBBPF_ERRNO__PROGTYPE;
+				goto out;
+			}
 		}
+
+		if (log_buf)
+			ret = -LIBBPF_ERRNO__KVER;
 	}
 
 out:
@@ -968,7 +982,7 @@ bpf_program__load(struct bpf_program *prog,
 			pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
 				   prog->section_name, prog->instances.nr);
 		}
-		err = load_program(prog->insns, prog->insns_cnt,
+		err = load_program(prog->type, prog->insns, prog->insns_cnt,
 				   license, kern_version, &fd);
 		if (!err)
 			prog->instances.fds[0] = fd;
@@ -997,7 +1011,7 @@ bpf_program__load(struct bpf_program *prog,
 			continue;
 		}
 
-		err = load_program(result.new_insn_ptr,
+		err = load_program(prog->type, result.new_insn_ptr,
 				   result.new_insn_cnt,
 				   license, kern_version, &fd);
 
@@ -1316,6 +1330,44 @@ int bpf_program__nth_fd(struct bpf_program *prog, int n)
 	return fd;
 }
 
+static void bpf_program__set_type(struct bpf_program *prog,
+				  enum bpf_prog_type type)
+{
+	prog->type = type;
+}
+
+int bpf_program__set_tracepoint(struct bpf_program *prog)
+{
+	if (!prog)
+		return -EINVAL;
+	bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT);
+	return 0;
+}
+
+int bpf_program__set_kprobe(struct bpf_program *prog)
+{
+	if (!prog)
+		return -EINVAL;
+	bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE);
+	return 0;
+}
+
+static bool bpf_program__is_type(struct bpf_program *prog,
+				 enum bpf_prog_type type)
+{
+	return prog ? (prog->type == type) : false;
+}
+
+bool bpf_program__is_tracepoint(struct bpf_program *prog)
+{
+	return bpf_program__is_type(prog, BPF_PROG_TYPE_TRACEPOINT);
+}
+
+bool bpf_program__is_kprobe(struct bpf_program *prog)
+{
+	return bpf_program__is_type(prog, BPF_PROG_TYPE_KPROBE);
+}
+
 int bpf_map__fd(struct bpf_map *map)
 {
 	return map ? map->fd : -EINVAL;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f392c5e04cc1..dd7a513efb10 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -39,6 +39,7 @@ enum libbpf_errno {
 	LIBBPF_ERRNO__VERIFY,	/* Kernel verifier blocks program loading */
 	LIBBPF_ERRNO__PROG2BIG,	/* Program too big */
 	LIBBPF_ERRNO__KVER,	/* Incorrect kernel version */
+	LIBBPF_ERRNO__PROGTYPE,	/* Kernel doesn't support this program type */
 	__LIBBPF_ERRNO__END,
 };
 
@@ -165,6 +166,15 @@ int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
 int bpf_program__nth_fd(struct bpf_program *prog, int n);
 
 /*
+ * Adjust type of bpf program. Default is kprobe.
+ */
+int bpf_program__set_tracepoint(struct bpf_program *prog);
+int bpf_program__set_kprobe(struct bpf_program *prog);
+
+bool bpf_program__is_tracepoint(struct bpf_program *prog);
+bool bpf_program__is_kprobe(struct bpf_program *prog);
+
+/*
  * We don't need __attribute__((packed)) now since it is
  * unnecessary for 'bpf_map_def' because they are all aligned.
  * In addition, using it will trigger -Wpacked warning message,