From ba08afe8377ac72f834f8baad38e9631957b2ea8 Mon Sep 17 00:00:00 2001 From: Klaus Goger Date: Thu, 26 Apr 2018 20:18:10 +0200 Subject: [PATCH] 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 Signed-off-by: Christoph Muellner --- arch/arm/lib/memcpy.S | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S index 0ca61210da..f7fb77235c 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 @@ ENTRY(memcpy) 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 @@ ENTRY(memcpy) .endm .macro copy_abort_end - ldmfd sp!, {r4, pc} + ldmfd sp!, {r4, lr} + bx lr .endm ENDPROC(memcpy) -- 2.25.1