[tip:perf/core] perf tools: Allow generating per-arch syscall table arrays

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  5af56fab2b11769e35ce96613d321bcc0f7b84c1
Gitweb:     http://git.kernel.org/tip/5af56fab2b11769e35ce96613d321bcc0f7b84c1
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Mon, 4 Apr 2016 17:52:18 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 8 Apr 2016 09:58:14 -0300

perf tools: Allow generating per-arch syscall table arrays

Tools should use a mechanism similar to arch/x86/entry/syscalls/ to
generate a header file with the definitions for two variables:

  static const char *syscalltbl_x86_64[] = {
	[0] = "read",
	[1] = "write",
  <SNIP>
	[324] = "membarrier",
	[325] = "mlock2",
	[326] = "copy_file_range",
  };
  static const int syscalltbl_x86_64_max_id = 326;

In a per arch file that should then be included in
tools/perf/util/syscalltbl.c.

First one will be for x86_64.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-02uuamkxgccczdth8komspgp@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/syscalltbl.c | 89 +++++++++++++++++++++++++++++++++++++++++++-
 tools/perf/util/syscalltbl.h |  4 ++
 2 files changed, 91 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/syscalltbl.c b/tools/perf/util/syscalltbl.c
index 1f13e57..eb74a97 100644
--- a/tools/perf/util/syscalltbl.c
+++ b/tools/perf/util/syscalltbl.c
@@ -14,21 +14,105 @@
  */
 
 #include "syscalltbl.h"
+#include <stdlib.h>
+
+#ifdef HAVE_SYSCALL_TABLE
+#include <linux/compiler.h>
 #include <string.h>
-#include <libaudit.h>
+#include "util.h"
+
+struct syscall {
+	int id;
+	const char *name;
+};
 
+static int syscallcmpname(const void *vkey, const void *ventry)
+{
+	const char *key = vkey;
+	const struct syscall *entry = ventry;
+
+	return strcmp(key, entry->name);
+}
+
+static int syscallcmp(const void *va, const void *vb)
+{
+	const struct syscall *a = va, *b = vb;
+
+	return strcmp(a->name, b->name);
+}
+
+static int syscalltbl__init_native(struct syscalltbl *tbl)
+{
+	int nr_entries = 0, i, j;
+	struct syscall *entries;
+
+	for (i = 0; i <= syscalltbl_native_max_id; ++i)
+		if (syscalltbl_native[i])
+			++nr_entries;
+
+	entries = tbl->syscalls.entries = malloc(sizeof(struct syscall) * nr_entries);
+	if (tbl->syscalls.entries == NULL)
+		return -1;
+
+	for (i = 0, j = 0; i <= syscalltbl_native_max_id; ++i) {
+		if (syscalltbl_native[i]) {
+			entries[j].name = syscalltbl_native[i];
+			entries[j].id = i;
+			++j;
+		}
+	}
+
+	qsort(tbl->syscalls.entries, nr_entries, sizeof(struct syscall), syscallcmp);
+	tbl->syscalls.nr_entries = nr_entries;
+	return 0;
+}
 
 struct syscalltbl *syscalltbl__new(void)
 {
 	struct syscalltbl *tbl = malloc(sizeof(*tbl));
 	if (tbl) {
-		tbl->audit_machine = audit_detect_machine();
+		if (syscalltbl__init_native(tbl)) {
+			free(tbl);
+			return NULL;
+		}
 	}
 	return tbl;
 }
 
 void syscalltbl__delete(struct syscalltbl *tbl)
 {
+	zfree(&tbl->syscalls.entries);
+	free(tbl);
+}
+
+const char *syscalltbl__name(const struct syscalltbl *tbl __maybe_unused, int id)
+{
+	return id <= syscalltbl_native_max_id ? syscalltbl_native[id]: NULL;
+}
+
+int syscalltbl__id(struct syscalltbl *tbl, const char *name)
+{
+	struct syscall *sc = bsearch(name, tbl->syscalls.entries,
+				     tbl->syscalls.nr_entries, sizeof(*sc),
+				     syscallcmpname);
+
+	return sc ? sc->id : -1;
+}
+
+#else /* HAVE_SYSCALL_TABLE */
+
+#include <libaudit.h>
+
+struct syscalltbl *syscalltbl__new(void)
+{
+	struct syscalltbl *tbl = malloc(sizeof(*tbl));
+	if (tbl)
+		tbl->audit_machine = audit_detect_machine();
+	return tbl;
+}
+
+void syscalltbl__delete(struct syscalltbl *tbl)
+{
 	free(tbl);
 }
 
@@ -41,3 +125,4 @@ int syscalltbl__id(struct syscalltbl *tbl, const char *name)
 {
 	return audit_name_to_syscall(name, tbl->audit_machine);
 }
+#endif /* HAVE_SYSCALL_TABLE */
diff --git a/tools/perf/util/syscalltbl.h b/tools/perf/util/syscalltbl.h
index 9dee73c..e295151 100644
--- a/tools/perf/util/syscalltbl.h
+++ b/tools/perf/util/syscalltbl.h
@@ -4,6 +4,10 @@
 struct syscalltbl {
 	union {
 		int audit_machine;
+		struct {
+			int nr_entries;
+			void *entries;
+		} syscalls;
 	};
 };