mirror of https://gitee.com/openkylin/linux.git
112 lines
1.7 KiB
C
112 lines
1.7 KiB
C
|
|
#include <unistd.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <stdlib.h>
|
|
#include <linux/kernel.h>
|
|
|
|
#include "vdso.h"
|
|
#include "util.h"
|
|
#include "symbol.h"
|
|
#include "linux/string.h"
|
|
|
|
static bool vdso_found;
|
|
static char vdso_file[] = "/tmp/perf-vdso.so-XXXXXX";
|
|
|
|
static int find_vdso_map(void **start, void **end)
|
|
{
|
|
FILE *maps;
|
|
char line[128];
|
|
int found = 0;
|
|
|
|
maps = fopen("/proc/self/maps", "r");
|
|
if (!maps) {
|
|
pr_err("vdso: cannot open maps\n");
|
|
return -1;
|
|
}
|
|
|
|
while (!found && fgets(line, sizeof(line), maps)) {
|
|
int m = -1;
|
|
|
|
/* We care only about private r-x mappings. */
|
|
if (2 != sscanf(line, "%p-%p r-xp %*x %*x:%*x %*u %n",
|
|
start, end, &m))
|
|
continue;
|
|
if (m < 0)
|
|
continue;
|
|
|
|
if (!strncmp(&line[m], VDSO__MAP_NAME,
|
|
sizeof(VDSO__MAP_NAME) - 1))
|
|
found = 1;
|
|
}
|
|
|
|
fclose(maps);
|
|
return !found;
|
|
}
|
|
|
|
static char *get_file(void)
|
|
{
|
|
char *vdso = NULL;
|
|
char *buf = NULL;
|
|
void *start, *end;
|
|
size_t size;
|
|
int fd;
|
|
|
|
if (vdso_found)
|
|
return vdso_file;
|
|
|
|
if (find_vdso_map(&start, &end))
|
|
return NULL;
|
|
|
|
size = end - start;
|
|
|
|
buf = memdup(start, size);
|
|
if (!buf)
|
|
return NULL;
|
|
|
|
fd = mkstemp(vdso_file);
|
|
if (fd < 0)
|
|
goto out;
|
|
|
|
if (size == (size_t) write(fd, buf, size))
|
|
vdso = vdso_file;
|
|
|
|
close(fd);
|
|
|
|
out:
|
|
free(buf);
|
|
|
|
vdso_found = (vdso != NULL);
|
|
return vdso;
|
|
}
|
|
|
|
void vdso__exit(void)
|
|
{
|
|
if (vdso_found)
|
|
unlink(vdso_file);
|
|
}
|
|
|
|
struct dso *vdso__dso_findnew(struct list_head *head)
|
|
{
|
|
struct dso *dso = dsos__find(head, VDSO__MAP_NAME, true);
|
|
|
|
if (!dso) {
|
|
char *file;
|
|
|
|
file = get_file();
|
|
if (!file)
|
|
return NULL;
|
|
|
|
dso = dso__new(VDSO__MAP_NAME);
|
|
if (dso != NULL) {
|
|
dsos__add(head, dso);
|
|
dso__set_long_name(dso, file, false);
|
|
}
|
|
}
|
|
|
|
return dso;
|
|
}
|