ARM: make cr_alignment read-only #ifndef CONFIG_CPU_CP15
This makes cr_alignment a constant 0 to break code that tries to modify
the value as it's likely that it's built on wrong assumption when
CONFIG_CPU_CP15 isn't defined. For code that is only reading the value 0
is more or less a fine value to report.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1358413196-5609-2-git-send-email-u.kleine-koenig@pengutronix.de (v8)
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index 854bd22..5b391a6 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -98,8 +98,9 @@
str r9, [r4] @ Save processor ID
str r1, [r5] @ Save machine type
str r2, [r6] @ Save atags pointer
- bic r4, r0, #CR_A @ Clear 'A' bit
- stmia r7, {r0, r4} @ Save control register values
+ cmp r7, #0
+ bicne r4, r0, #CR_A @ Clear 'A' bit
+ stmneia r7, {r0, r4} @ Save control register values
b start_kernel
ENDPROC(__mmap_switched)
@@ -113,7 +114,11 @@
.long processor_id @ r4
.long __machine_arch_type @ r5
.long __atags_pointer @ r6
+#ifdef CONFIG_CPU_CP15
.long cr_alignment @ r7
+#else
+ .long 0 @ r7
+#endif
.long init_thread_union + THREAD_START_SP @ sp
.size __mmap_switched_data, . - __mmap_switched_data