From 2270dfa0c418ab06e89412ea7b4ffe650490bcc9 Mon Sep 17 00:00:00 2001
From: Srinavasa Nagaraju <srinavasa.x.nagaraju@sonyericsson.com>
Date: Tue, 28 Feb 2012 12:08:22 +0900
Subject: [PATCH] fix __cxa_finalize() implementation to be thread safe.

__cxa_finalize() modifies the access permissions of __atexit
global variable without acquiring  _ATEXIT_LOCK(). Fix it prevent
any possible races.

Change-Id: I11939d0ebcbf6f360c14163222d40a449d96948e
---
 libc/stdlib/atexit.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libc/stdlib/atexit.c b/libc/stdlib/atexit.c
index f4bcab99e..55b7132e6 100644
--- a/libc/stdlib/atexit.c
+++ b/libc/stdlib/atexit.c
@@ -131,6 +131,7 @@ __cxa_finalize(void *dso)
 	if (__atexit_invalid)
 		return;
 
+	_ATEXIT_LOCK();
 	call_depth++;
 
 	for (p = __atexit; p != NULL; p = p->next) {
@@ -149,6 +150,7 @@ __cxa_finalize(void *dso)
 				p->fns[n].fn_ptr.cxa_func = NULL;
 				mprotect(p, pgsize, PROT_READ);
 			}
+			_ATEXIT_UNLOCK();
 #if ANDROID
                         /* it looks like we should always call the function
                          * with an argument, even if dso is not NULL. Otherwise
@@ -162,6 +164,7 @@ __cxa_finalize(void *dso)
 			else
 				(*fn.fn_ptr.std_func)();
 #endif /* !ANDROID */
+			_ATEXIT_LOCK();
 		}
 	}
 
@@ -178,6 +181,7 @@ __cxa_finalize(void *dso)
 		}
 		__atexit = NULL;
 	}
+	_ATEXIT_UNLOCK();
 }
 
 /*