ARM: 8225/1: Add unwinding support for memory copy functions
The memory copy functions(memcpy, __copy_from_user, __copy_to_user)
never had unwinding annotations added. Currently, when accessing
invalid pointer by these functions occurs the backtrace shown will
stop at these functions or some completely unrelated function.
Add unwinding annotations in hopes of getting a more useful backtrace
in following cases:
1. die on accessing invalid pointer by these functions
2. kprobe trapped at any instruction within these functions
3. interrupted at any instruction within these functions
Signed-off-by: Lin Yongting <linyongting@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/lib/copy_from_user.S b/arch/arm/lib/copy_from_user.S
index 66a477a..7a235b9 100644
--- a/arch/arm/lib/copy_from_user.S
+++ b/arch/arm/lib/copy_from_user.S
@@ -12,6 +12,7 @@
#include <linux/linkage.h>
#include <asm/assembler.h>
+#include <asm/unwind.h>
/*
* Prototype:
@@ -77,6 +78,10 @@
stmdb sp!, {r0, r2, r3, \reg1, \reg2}
.endm
+ .macro usave reg1 reg2
+ UNWIND( .save {r0, r2, r3, \reg1, \reg2} )
+ .endm
+
.macro exit reg1 reg2
add sp, sp, #8
ldmfd sp!, {r0, \reg1, \reg2}