[PATCH 1/3] ARM: debug.S: move hexbuf to a writable section
Nicolas Pitre
nicolas.pitre at linaro.org
Sun Oct 1 19:06:16 PDT 2017
This was located in .text which is meant to be read-only. And in the XIP
case this shortcut simply doesn't work and may trigger a Flash controller
mode switch and crash the kernel. Move it to the .bss area.
Signed-off-by: Nicolas Pitre <nico at linaro.org>
---
arch/arm/kernel/debug.S | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S
index ea9646cc2a..423f443258 100644
--- a/arch/arm/kernel/debug.S
+++ b/arch/arm/kernel/debug.S
@@ -55,7 +55,9 @@ ENDPROC(printhex4)
ENTRY(printhex2)
mov r1, #2
-printhex: adr r2, hexbuf
+printhex: adr r2, hexbuf_rel
+ ldr r3, [r2]
+ add r2, r2, r3
add r3, r2, r1
mov r1, #0
strb r1, [r3]
@@ -71,7 +73,11 @@ printhex: adr r2, hexbuf
b printascii
ENDPROC(printhex2)
-hexbuf: .space 16
+ .pushsection .bss
+hexbuf_addr: .space 16
+ .popsection
+ .align
+hexbuf_rel: .long hexbuf_addr - .
.ltorg
@@ -120,7 +126,9 @@ ENTRY(printascii)
ENDPROC(printascii)
ENTRY(printch)
- adr r1, hexbuf
+ adr r1, hexbuf_rel
+ ldr r2, [r1]
+ add r1, r1, r2
strb r0, [r1]
mov r0, #0x03 @ SYS_WRITEC
ARM( svc #0x123456 )
--
2.9.5
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