The runtime offset has to be added to the memcpy source address and
substracted from the return address. This should have been changed in
a43e2bbc46 which changed from returning the negative runtime offset
into changing the positive runtime offset. Instead a43e2bbc46 only
changed a zero substraction ("subs r4, r0, #0") into a zero addition
("adds r4, r0, #0") which was used as a equal to zero test and changed
nothing. This part is reverted here.
Fixes wrong copy / return locations when setup_c is called with
different runtime and link addresses.
fixes: a43e2bbc46 ("ARM: return positive offset in get_runtime_offset()")
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
arch/arm/cpu/setupc.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm/cpu/setupc.S b/arch/arm/cpu/setupc.S
index 717500cfff..a5f311b8ec 100644
--- a/arch/arm/cpu/setupc.S
+++ b/arch/arm/cpu/setupc.S
@@ -15,13 +15,13 @@ ENTRY(setup_c)
push {r4, r5}
mov r5, lr
bl get_runtime_offset
- adds r4, r0, #0
+ subs r4, r0, #0
beq 1f /* skip memcpy if already at correct address */
ldr r0,=_text
ldr r2,=__bss_start
sub r2, r2, r0
- sub r1, r0, r4
- bl memcpy /* memcpy(_text, _text - offset, __bss_start - _text) */
+ add r1, r0, r4
+ bl memcpy /* memcpy(_text, _text + offset, __bss_start - _text) */
1: ldr r0, =__bss_start
mov r1, #0
ldr r2, =__bss_stop
@@ -32,7 +32,7 @@ ENTRY(setup_c)
#endif
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 /* flush icache */
- add lr, r5, r4 /* adjust return address to new location */
+ sub lr, r5, r4 /* adjust return address to new location */
pop {r4, r5}
mov pc, lr
ENDPROC(setup_c)
--
2.19.1
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