Module Name: src
Committed By: matt
Date: Mon Feb 13 17:07:45 UTC 2012
Modified Files:
src/sys/arch/arm/include: mcontext.h
Log Message:
Modify __lwp_getprivate_fast to call _lwp_getprivate if the mrc instruction
returns 0 (some ARM cores are broken and don't raise an undefined exception
when encountering an unknown or privileged mrc instruction in user mode).
To generate a diff of this commit:
cvs rdiff -u -r1.9 -r1.10 src/sys/arch/arm/include/mcontext.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/arm/include/mcontext.h
diff -u src/sys/arch/arm/include/mcontext.h:1.9 src/sys/arch/arm/include/mcontext.h:1.10
--- src/sys/arch/arm/include/mcontext.h:1.9 Thu Apr 7 10:20:29 2011
+++ src/sys/arch/arm/include/mcontext.h Mon Feb 13 17:07:45 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: mcontext.h,v 1.9 2011/04/07 10:20:29 matt Exp $ */
+/* $NetBSD: mcontext.h,v 1.10 2012/02/13 17:07:45 matt Exp $ */
/*-
* Copyright (c) 2001, 2002 The NetBSD Foundation, Inc.
@@ -112,9 +112,18 @@ typedef struct {
static __inline void *
__lwp_getprivate_fast(void)
{
+ extern void *_lwp_getprivate(void);
void *rv;
__asm("mrc p15, 0, %0, c13, c0, 3" : "=r"(rv));
- return rv;
+ if (__predict_true(rv))
+ return rv;
+ /*
+ * Some ARM cores are broken and don't raise an undefined fault when an
+ * unrecogized mrc instruction is encountered, but just return zero.
+ * To do deal with that, if we get a zero we (re-)fetch the value using
+ * syscall.
+ */
+ return _lwp_getprivate();
}
#endif /* !_ARM_MCONTEXT_H_ */
