arm: Make arch specific memcpy thumb-safe.
The current arch implementation of memcpy cannot be called
from thumb code, because it does not use bx instructions on return.
This patch addresses that. Note, that this patch does not touch
the hot loop of memcpy, so performance is not affected.
Tested on MXS (arm926ejs) with and without thumb-mode enabled.
Signed-off-by: Klaus Goger <klaus.goger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S
index 0ca6121..f7fb772 100644
--- a/arch/arm/lib/memcpy.S
+++ b/arch/arm/lib/memcpy.S
@@ -59,7 +59,7 @@
#endif
ENTRY(memcpy)
cmp r0, r1
- moveq pc, lr
+ bxeq lr
enter r4, lr
@@ -147,7 +147,8 @@
str1b r0, r4, cs, abort=21f
str1b r0, ip, cs, abort=21f
- exit r4, pc
+ exit r4, lr
+ bx lr
9: rsb ip, ip, #4
cmp ip, #2
@@ -256,7 +257,8 @@
.endm
.macro copy_abort_end
- ldmfd sp!, {r4, pc}
+ ldmfd sp!, {r4, lr}
+ bx lr
.endm
ENDPROC(memcpy)