perf jit: Move test functionality in to a test

Adds a test for minimal jit_write_elf functionality.

Committer testing:

# perf test jit
61: Test jit_write_elf : Ok
#

# perf test -v jit
61: Test jit_write_elf :
--- start ---
test child forked, pid 10460
Writing jit code to: /tmp/perf-test-KqxURR
test child finished with 0
---- end ----
Test jit_write_elf: Ok
#

Committer notes:

Fix up the case where HAVE_JITDUMP is no defined.

Signed-off-by: Ian Rogers <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Alexios Zavras <[e-mail]>
Cc: Allison Randal <[e-mail]>
Cc: Florian Fainelli <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Kate Stewart <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Michael Petlan <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Song Liu <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Link: http://lore.kernel.org/lkml/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/Build

···
 perf-y += mem2node.o
 perf-y += maps.o
 perf-y += time-utils-test.o
+perf-y += genelf.o
 
 $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
 	$(call rule_mkdir)

tools/perf/tests/builtin-test.c

···
 		.func = test__time_utils,
 	},
 	{
+		.desc = "Test jit_write_elf",
+		.func = test__jit_write_elf,
+	},
+	{
 		.desc = "maps__merge_in",
 		.func = test__maps__merge_in,
 	},

tools/perf/tests/genelf.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/compiler.h>
+
+#include "debug.h"
+#include "tests.h"
+
+#ifdef HAVE_JITDUMP
+#include <libelf.h>
+#include "../util/genelf.h"
+#endif
+
+#define TEMPL "/tmp/perf-test-XXXXXX"
+
+int test__jit_write_elf(struct test *test __maybe_unused,
+			int subtest __maybe_unused)
+{
+#ifdef HAVE_JITDUMP
+	static unsigned char x86_code[] = {
+		0xBB, 0x2A, 0x00, 0x00, 0x00, /* movl $42, %ebx */
+		0xB8, 0x01, 0x00, 0x00, 0x00, /* movl $1, %eax */
+		0xCD, 0x80            /* int $0x80 */
+	};
+	char path[PATH_MAX];
+	int fd, ret;
+
+	strcpy(path, TEMPL);
+
+	fd = mkstemp(path);
+	if (fd < 0) {
+		perror("mkstemp failed");
+		return TEST_FAIL;
+	}
+
+	pr_info("Writing jit code to: %s\n", path);
+
+	ret = jit_write_elf(fd, 0, "main", x86_code, sizeof(x86_code),
+			NULL, 0, NULL, 0, 0);
+	close(fd);
+
+	unlink(path);
+
+	return ret ? TEST_FAIL : 0;
+#else
+	return TEST_SKIP;
+#endif
+}

tools/perf/tests/tests.h

···
 int test__mem2node(struct test *t, int subtest);
 int test__maps__merge_in(struct test *t, int subtest);
 int test__time_utils(struct test *t, int subtest);
+int test__jit_write_elf(struct test *test, int subtest);
 
 bool test__bp_signal_is_supported(void);
 bool test__bp_account_is_supported(void);

tools/perf/util/genelf.c

···
  */
 
 #include <sys/types.h>
-#include <stdio.h>
-#include <getopt.h>
 #include <stddef.h>
 #include <libelf.h>
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <inttypes.h>
-#include <limits.h>
 #include <fcntl.h>
 #include <err.h>
 #ifdef HAVE_DWARF_SUPPORT
···
 #ifndef NT_GNU_BUILD_ID
 #define NT_GNU_BUILD_ID 3
 #endif
-
-#define JVMTI
 
 #define BUILD_ID_URANDOM /* different uuid for each run */
 
···
 
 	return retval;
 }
-
-#ifndef JVMTI
-
-static unsigned char x86_code[] = {
-    0xBB, 0x2A, 0x00, 0x00, 0x00, /* movl $42, %ebx */
-    0xB8, 0x01, 0x00, 0x00, 0x00, /* movl $1, %eax */
-    0xCD, 0x80            /* int $0x80 */
-};
-
-static struct options options;
-
-int main(int argc, char **argv)
-{
-	int c, fd, ret;
-
-	while ((c = getopt(argc, argv, "o:h")) != -1) {
-		switch (c) {
-		case 'o':
-			options.output = optarg;
-			break;
-		case 'h':
-			printf("Usage: genelf -o output_file [-h]\n");
-			return 0;
-		default:
-			errx(1, "unknown option");
-		}
-	}
-
-	fd = open(options.output, O_CREAT|O_TRUNC|O_RDWR, 0666);
-	if (fd == -1)
-		err(1, "cannot create file %s", options.output);
-
-	ret = jit_write_elf(fd, "main", x86_code, sizeof(x86_code));
-	close(fd);
-
-	if (ret != 0)
-		unlink(options.output);
-
-	return ret;
-}
-#endif