path: root/firmware/libc
diff options
authorMichael Sevakis <>2014-04-28 09:15:06 -0400
committerMichael Sevakis <>2014-05-09 23:14:58 +0200
commit355b5406fafe0d45285e70a0b01d5e674d6a2c16 (patch)
treeb17e42d8e36182280cf7399c9063a6db8b2f4fc9 /firmware/libc
parentf444ae70ebe9c978818bf473d176538244b4559e (diff)
Make errno a thread-local variable.
errno is supposed to be thread local and we do that here in a rather makeshift way by implementing a function that returns a pointer to the __errno variable in the thread block. If more serious TLS is required, perhaps it would be worthwhile implementing it using the linker and the "__thread" storage attribute. That's a bit overkill just for this. I'm also not liking what I saw the compiler producing. Change-Id: I03bc0bd6a89f6e3d6bae7653284ee01054614f9a Reviewed-on: Reviewed-by: Michael Sevakis <> Tested: Michael Sevakis <>
Diffstat (limited to 'firmware/libc')
2 files changed, 9 insertions, 3 deletions
diff --git a/firmware/libc/errno.c b/firmware/libc/errno.c
index 6e7bb62b51..2e3cd9083e 100644
--- a/firmware/libc/errno.c
+++ b/firmware/libc/errno.c
@@ -1 +1,5 @@
-int errno;
+#include "thread.h"
+int * __errno(void)
+ return &thread_self_entry()->__errno;
diff --git a/firmware/libc/include/errno.h b/firmware/libc/include/errno.h
index 6a24a1938f..9df261db9f 100644
--- a/firmware/libc/include/errno.h
+++ b/firmware/libc/include/errno.h
@@ -10,10 +10,12 @@
#ifndef _SYS_ERRNO_H_
+extern int * __errno(void);
#ifdef PLUGIN
-#define errno (*rb->__errno)
+#define errno (*rb->__errno())
-extern int errno;
+#define errno (*__errno())
#define EPERM 1 /* Not super-user */