[bionic]: Fixing futex problem in cpuacct update.M8260AAABQNLZA301103

With fprintf, sometimes after fork child process gets stuck in fuxtex
waiting queue. To fix this problem this change opens the file in SYNC
mode using open command and writes to the file using write command.

CRs-Fixed: 272695

Change-Id: Ia91b789effca2dafa12ee388211f7e54001fb8cb
Signed-off-by: Shashank Mittal <mittals@codeaurora.org>

1 files changed, 8 insertions, 7 deletions

diff --git a/libc/bionic/cpuacct.c b/libc/bionic/cpuacct.c
index 7317073..1d12308 100644..100755
--- a/libc/bionic/cpuacct.c
+++ b/libc/bionic/cpuacct.c
@@ -29,17 +29,18 @@
 #include <stdio.h>
 #include <errno.h>
 #include <sys/stat.h>
+#include <fcntl.h>
 #include "cpuacct.h"
 
 int cpuacct_add(uid_t uid)
 {
     int count;
-    FILE *fp;
+    int fd;
     char buf[80];
 
     count = snprintf(buf, sizeof(buf), "/acct/uid/%d/tasks", uid);
-    fp = fopen(buf, "w+");
-    if (!fp) {
+    fd = open(buf, O_RDWR| O_SYNC);
+    if (fd < 0) {
         /* Note: sizeof("tasks") returns 6, which includes the NULL char */
         buf[count - sizeof("tasks")] = 0;
         if (mkdir(buf, 0775) < 0)
@@ -47,13 +48,13 @@ int cpuacct_add(uid_t uid)
 
         /* Note: sizeof("tasks") returns 6, which includes the NULL char */
         buf[count - sizeof("tasks")] = '/';
-        fp = fopen(buf, "w+");
+        fd = open(buf, O_RDWR| O_SYNC);
     }
-    if (!fp)
+    if (fd < 0)
         return -errno;
 
-    fprintf(fp, "0");
-    if (fclose(fp))
+    write(fd, "0", 2);
+    if (close(fd))
         return -errno;
 
     return 0;