[PATCH 4/7] ARM: KVM: enforce page alignment for identity mapped code

[Marc Zyngier]

We're about to move to a init procedure where we rely on the
fact that the init code fits in a single page. Make sure we
align the idmap text on a page boundary, and that the code is
not bigger than a single page.

Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
 arch/arm/kernel/vmlinux.lds.S | 2 +-
 arch/arm/kvm/init.S           | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index b571484..d9dd265 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -20,7 +20,7 @@
 	VMLINUX_SYMBOL(__idmap_text_start) = .;				\
 	*(.idmap.text)							\
 	VMLINUX_SYMBOL(__idmap_text_end) = .;				\
-	ALIGN_FUNCTION();						\
+	. = ALIGN(PAGE_SIZE);						\
 	VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;			\
 	*(.hyp.idmap.text)						\
 	VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;
diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index 9f37a79..35a463f 100644
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -111,4 +111,11 @@ __do_hyp_init:
 	.globl __kvm_hyp_init_end
 __kvm_hyp_init_end:
 
+	/*
+	 * The above code *must* fit in a single page for the trampoline
+	 * madness to work. Whoever decides to change it must make sure
+	 * we map the right amount of memory for the trampoline to work.
+	 * The line below ensures any breakage will get noticed.
+	 */
+	.org	__kvm_hyp_init + PAGE_SIZE
 	.popsection
-- 
1.8.1.4