perf tests: Add framework for automated perf_event_attr tests

The idea is run perf session with kidnapping sys_perf_event_open
function. For each sys_perf_event_open call we store the perf_event_attr
data to the file to be checked later against what we expect.

You can run this by:
  $ python ./tests/attr.py -d ./tests/attr/ -p ./perf -v

v2 changes:
  - preserve errno value in the hook

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20121031145247.GB1027@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 140 insertions, 0 deletions

diff --git a/tools/perf/tests/attr.c b/tools/perf/tests/attr.c
new file mode 100644
index 000000000000..55e9a873a5cb
--- /dev/null
+++ b/tools/perf/tests/attr.c
@@ -0,0 +1,140 @@
+
+/*
+ * The struct perf_event_attr test support.
+ *
+ * This test is embedded inside into perf directly and is governed
+ * by the PERF_TEST_ATTR environment variable and hook inside
+ * sys_perf_event_open function.
+ *
+ * The general idea is to store 'struct perf_event_attr' details for
+ * each event created within single perf command. Each event details
+ * are stored into separate text file. Once perf command is finished
+ * these files can be checked for values we expect for command.
+ *
+ * Besides 'struct perf_event_attr' values we also store 'fd' and
+ * 'group_fd' values to allow checking for groups created.
+ *
+ * This all is triggered by setting PERF_TEST_ATTR environment variable.
+ * It must contain name of existing directory with access and write
+ * permissions. All the event text files are stored there.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include "../perf.h"
+#include "util.h"
+
+#define ENV "PERF_TEST_ATTR"
+
+bool test_attr__enabled;
+
+static char *dir;
+
+void test_attr__init(void)
+{
+	dir = getenv(ENV);
+	test_attr__enabled = (dir != NULL);
+}
+
+#define BUFSIZE 1024
+
+#define WRITE_ASS(str, fmt, data)					\
+do {									\
+	char buf[BUFSIZE];						\
+	size_t size;							\
+									\
+	size = snprintf(buf, BUFSIZE, #str "=%"fmt "\n", data);		\
+	if (1 != fwrite(buf, size, 1, file)) {				\
+		perror("test attr - failed to write event file");	\
+		fclose(file);						\
+		return -1;						\
+	}								\
+									\
+} while (0)
+
+static int store_event(struct perf_event_attr *attr, pid_t pid, int cpu,
+		       int fd, int group_fd, unsigned long flags)
+{
+	FILE *file;
+	char path[PATH_MAX];
+
+	snprintf(path, PATH_MAX, "%s/event-%d-%llu-%d", dir,
+		 attr->type, attr->config, fd);
+
+	file = fopen(path, "w+");
+	if (!file) {
+		perror("test attr - failed to open event file");
+		return -1;
+	}
+
+	if (fprintf(file, "[event-%d-%llu-%d]\n",
+		    attr->type, attr->config, fd) < 0) {
+		perror("test attr - failed to write event file");
+		fclose(file);
+		return -1;
+	}
+
+	/* syscall arguments */
+	WRITE_ASS(fd,       "d", fd);
+	WRITE_ASS(group_fd, "d", group_fd);
+	WRITE_ASS(cpu,      "d", cpu);
+	WRITE_ASS(pid,      "d", pid);
+	WRITE_ASS(flags,   "lu", flags);
+
+	/* struct perf_event_attr */
+	WRITE_ASS(type,   PRIu32,  attr->type);
+	WRITE_ASS(size,   PRIu32,  attr->size);
+	WRITE_ASS(config,  "llu",  attr->config);
+	WRITE_ASS(sample_period, "llu", attr->sample_period);
+	WRITE_ASS(sample_type,   "llu", attr->sample_type);
+	WRITE_ASS(read_format,   "llu", attr->read_format);
+	WRITE_ASS(disabled,       "d", attr->disabled);
+	WRITE_ASS(inherit,        "d", attr->inherit);
+	WRITE_ASS(pinned,         "d", attr->pinned);
+	WRITE_ASS(exclusive,      "d", attr->exclusive);
+	WRITE_ASS(exclude_user,   "d", attr->exclude_user);
+	WRITE_ASS(exclude_kernel, "d", attr->exclude_kernel);
+	WRITE_ASS(exclude_hv,     "d", attr->exclude_hv);
+	WRITE_ASS(exclude_idle,   "d", attr->exclude_idle);
+	WRITE_ASS(mmap,           "d", attr->mmap);
+	WRITE_ASS(comm,           "d", attr->comm);
+	WRITE_ASS(freq,           "d", attr->freq);
+	WRITE_ASS(inherit_stat,   "d", attr->inherit_stat);
+	WRITE_ASS(enable_on_exec, "d", attr->enable_on_exec);
+	WRITE_ASS(task,           "d", attr->task);
+	WRITE_ASS(watermask,      "d", attr->watermark);
+	WRITE_ASS(precise_ip,     "d", attr->precise_ip);
+	WRITE_ASS(mmap_data,      "d", attr->mmap_data);
+	WRITE_ASS(sample_id_all,  "d", attr->sample_id_all);
+	WRITE_ASS(exclude_host,   "d", attr->exclude_host);
+	WRITE_ASS(exclude_guest,  "d", attr->exclude_guest);
+	WRITE_ASS(exclude_callchain_kernel, "d",
+		  attr->exclude_callchain_kernel);
+	WRITE_ASS(exclude_callchain_user, "d",
+		  attr->exclude_callchain_user);
+	WRITE_ASS(wakeup_events, PRIu32, attr->wakeup_events);
+	WRITE_ASS(bp_type, PRIu32, attr->bp_type);
+	WRITE_ASS(config1, "llu", attr->config1);
+	WRITE_ASS(config2, "llu", attr->config2);
+	WRITE_ASS(branch_sample_type, "llu", attr->branch_sample_type);
+	WRITE_ASS(sample_regs_user,   "llu", attr->sample_regs_user);
+	WRITE_ASS(sample_stack_user,  PRIu32, attr->sample_stack_user);
+	WRITE_ASS(optional, "d", 0);
+
+	fclose(file);
+	return 0;
+}
+
+void test_attr__open(struct perf_event_attr *attr, pid_t pid, int cpu,
+		     int fd, int group_fd, unsigned long flags)
+{
+	int errno_saved = errno;
+
+	if (store_event(attr, pid, cpu, fd, group_fd, flags))
+		die("test attr FAILED");
+
+	errno = errno_saved;
+}