From: Dave Martin Date: Wed, 26 Jan 2011 17:34:26 +0000 (+0100) Subject: ARM: 6640/1: Thumb-2: Symbol manipulation macros for function body copying X-Git-Tag: v2.6.39-rc1~463^2~3^5~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5756e9dd0de6d5c307773f8f734c0684b3098fdd;p=pandora-kernel.git ARM: 6640/1: Thumb-2: Symbol manipulation macros for function body copying In low-level board support code, there is sometimes a need to copy a function body to another location at run-time. A straightforward call to memcpy doesn't work in Thumb-2, because bit 0 of external Thumb function symbols is set to 1, indicating that the function is Thumb. Without corrective measures, this will cause an off-by-one copy, and the copy may be called using the wrong instruction set. This patch adds an fncpy() macro to help with such copies. Particular care is needed, because C doesn't guarantee any defined behaviour when casting a function pointer to any other type. This has been observed to lead to strange optimisation side-effects when doing the arithmetic which is required in order to copy/move function bodies correctly in Thumb-2. Thanks to Russell King and Nicolas Pitre for their input on this patch. Signed-off-by: Dave Martin Tested-by: Jean Pihet Tested-by: Tony Lindgren Tested-by: Kevin Hilman Signed-off-by: Russell King --- Reading git-diff-tree failed