Use mkstemp for host ashmem.
Bug: 19310167
Change-Id: Ic4e32b3924a9aa0b0d095d445108cbcf2231cd91
diff --git a/libcutils/ashmem-host.c b/libcutils/ashmem-host.c
index 4ac4f57..abc4f94 100644
--- a/libcutils/ashmem-host.c
+++ b/libcutils/ashmem-host.c
@@ -22,7 +22,6 @@
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
-#include <pthread.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
@@ -33,51 +32,18 @@
#include <unistd.h>
#include <cutils/ashmem.h>
+#include <utils/Compat.h>
#ifndef __unused
#define __unused __attribute__((__unused__))
#endif
-static pthread_once_t seed_initialized = PTHREAD_ONCE_INIT;
-static void initialize_random() {
- srand(time(NULL) + getpid());
-}
-
int ashmem_create_region(const char *ignored __unused, size_t size)
{
- static const char txt[] = "abcdefghijklmnopqrstuvwxyz"
- "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
- char name[64];
- unsigned int retries = 0;
- pid_t pid = getpid();
- int fd;
- if (pthread_once(&seed_initialized, &initialize_random) != 0) {
- return -1;
- }
- do {
- /* not beautiful, its just wolf-like loop unrolling */
- snprintf(name, sizeof(name), "/tmp/android-ashmem-%d-%c%c%c%c%c%c%c%c",
- pid,
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))],
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))],
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))],
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))],
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))],
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))],
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))],
- txt[(int) ((sizeof(txt) - 1) * (rand() / (RAND_MAX + 1.0)))]);
-
- /* open O_EXCL & O_CREAT: we are either the sole owner or we fail */
- fd = open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
- if (fd == -1) {
- /* unlikely, but if we failed because `name' exists, retry */
- if (errno != EEXIST || ++retries >= 6) {
- return -1;
- }
- }
- } while (fd == -1);
- /* truncate the file to `len' bytes */
- if (ftruncate(fd, size) != -1 && unlink(name) != -1) {
+ char template[PATH_MAX];
+ snprintf(template, sizeof(template), "/tmp/android-ashmem-%d-XXXXXXXXX", getpid());
+ int fd = mkstemp(template);
+ if (fd != -1 && TEMP_FAILURE_RETRY(ftruncate(fd, size)) != -1 && unlink(template) != -1) {
return fd;
}
close(fd);
@@ -102,9 +68,7 @@
int ashmem_get_size_region(int fd)
{
struct stat buf;
- int result;
-
- result = fstat(fd, &buf);
+ int result = fstat(fd, &buf);
if (result == -1) {
return -1;
}
@@ -116,5 +80,5 @@
return -1;
}
- return (int)buf.st_size; // TODO: care about overflow (> 2GB file)?
+ return buf.st_size;
}