diff --git a/libc/bionic/semaphore.c b/libc/bionic/semaphore.c
index 0c94600..84b9314 100644
--- a/libc/bionic/semaphore.c
+++ b/libc/bionic/semaphore.c
@@ -180,7 +180,7 @@
     if (sem == NULL)
         return EINVAL;
 
-    if (__atomic_inc((volatile int*)&sem->count) == 0)
+    if (__atomic_inc((volatile int*)&sem->count) >= 0)
         __futex_wake(&sem->count, 1);
 
     return 0;
@@ -196,7 +196,8 @@
     if (__atomic_dec_if_positive(&sem->count) > 0) {
         return 0;
     } else {
-        return EAGAIN;
+        errno = EAGAIN;
+        return -1;
     }
 }
 
diff --git a/libc/bionic/stubs.c b/libc/bionic/stubs.c
index 586d497..d495674 100644
--- a/libc/bionic/stubs.c
+++ b/libc/bionic/stubs.c
@@ -185,7 +185,7 @@
         goto FAIL;
 
     id = strtoul(name+4, &end, 10);
-    if (id == 0 || *end != '\0')
+    if (*end != '\0')
         goto FAIL;
 
     id += AID_APP;
diff --git a/libc/docs/CHANGES.TXT b/libc/docs/CHANGES.TXT
index c2655c5..f59cfab 100644
--- a/libc/docs/CHANGES.TXT
+++ b/libc/docs/CHANGES.TXT
@@ -46,7 +46,17 @@
 
 - <wchar.h>: Add mbstowcs() and wcstombs()
 
-- add clone() implementation for ARM (x86 and SH-4 not working yet)
+- add clone() implementation for ARM (x86 and SH-4 not working yet).
+
+- <sys/epoll.h>: <sys/system_properties.h>: Add missing C++ inclusion guards
+
+- fix getpwnam() and getpwgrp() to accept "app_0" as a valid user name.
+
+- fix sem_trywait() to return -1 and set errno to EAGAIN, instead of
+  returning EAGAIN directly.
+
+- fix sem_post() to wake up multiple threads when called rapidly in
+  succession.
 
 -------------------------------------------------------------------------------
 Differences between Android 2.1 and 2.0.1: