perf tools: Make find_vdso_map() more modular

In preparation for checking that the vectors page on the ARM
architecture, refactor the find_vdso_map() function to accept finding an
arbitrary string and create a dedicated helper function for that under
util/find-map.c and update the filename to find-map.c and all references
to it: perf-read-vdso.c and util/vdso.c.

Signed-off-by: Florian Fainelli <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Chris Healy <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Kim Phillips <[e-mail]>
Cc: Lucas Stach <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Ravi Bangoria <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Thomas Richter <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Makefile.perf

···
 	$(QUIET_LINK)$(CC) $(CFLAGS) -o $@ $(LDFLAGS) $(filter %.o,$^) $(LIBS)
 
 ifndef NO_PERF_READ_VDSO32
-$(OUTPUT)perf-read-vdso32: perf-read-vdso.c util/find-vdso-map.c
+$(OUTPUT)perf-read-vdso32: perf-read-vdso.c util/find-map.c
 	$(QUIET_CC)$(CC) -m32 $(filter -static,$(LDFLAGS)) -Wall -Werror -o $@ perf-read-vdso.c
 endif
 
 ifndef NO_PERF_READ_VDSOX32
-$(OUTPUT)perf-read-vdsox32: perf-read-vdso.c util/find-vdso-map.c
+$(OUTPUT)perf-read-vdsox32: perf-read-vdso.c util/find-map.c
 	$(QUIET_CC)$(CC) -mx32 $(filter -static,$(LDFLAGS)) -Wall -Werror -o $@ perf-read-vdso.c
 endif
 

tools/perf/perf-read-vdso.c

···
 #define VDSO__MAP_NAME "[vdso]"
 
 /*
- * Include definition of find_vdso_map() also used in util/vdso.c for
+ * Include definition of find_map() also used in util/vdso.c for
  * building perf.
  */
-#include "util/find-vdso-map.c"
+#include "util/find-map.c"
 
 int main(void)
 {
 	void *start, *end;
 	size_t size, written;
 
-	if (find_vdso_map(&start, &end))
+	if (find_map(&start, &end, VDSO__MAP_NAME))
 		return 1;
 
 	size = end - start;

tools/perf/util/find-vdso-map.c tools/perf/util/find-map.c

···
 // SPDX-License-Identifier: GPL-2.0
-static int find_vdso_map(void **start, void **end)
+static int find_map(void **start, void **end, const char *name)
 {
 	FILE *maps;
 	char line[128];
···
 
 	maps = fopen("/proc/self/maps", "r");
 	if (!maps) {
-		fprintf(stderr, "vdso: cannot open maps\n");
+		fprintf(stderr, "cannot open maps\n");
 		return -1;
 	}
 
···
 		if (m < 0)
 			continue;
 
-		if (!strncmp(&line[m], VDSO__MAP_NAME,
-			     sizeof(VDSO__MAP_NAME) - 1))
+		if (!strncmp(&line[m], name, strlen(name)))
 			found = 1;
 	}
 

tools/perf/util/vdso.c

···
 #include "debug.h"
 
 /*
- * Include definition of find_vdso_map() also used in perf-read-vdso.c for
+ * Include definition of find_map() also used in perf-read-vdso.c for
  * building perf-read-vdso32 and perf-read-vdsox32.
  */
-#include "find-vdso-map.c"
+#include "find-map.c"
 
 #define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
 
···
 	if (vdso_file->found)
 		return vdso_file->temp_file_name;
 
-	if (vdso_file->error || find_vdso_map(&start, &end))
+	if (vdso_file->error || find_map(&start, &end, VDSO__MAP_NAME))
 		return NULL;
 
 	size = end - start;