[bionic]: Fixing futex problem in cpuacct update.M8668AAABQNLYA1080M8660AAABQNLYA1082M8660AAABQNLYA108001M7630AABBQMLZA4030

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.

(cherry picked from commit d96ad66076c70cd472bd36fc128031750751c09b)

Change-Id: I7b0a386b1a86f2db3a1829f3d2210911febb2fbc
CRs-Fixed: 272695
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;