ARM: KVM: enforce maximum size for identity mapped code

We're about to move to an 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 vector alignment, and that the code is
not bigger than a single page.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index b571484e9f03..a871b8e00fca 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(32);                                                  \
         VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;                     \
         *(.hyp.idmap.text)                                              \
         VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;
@@ -315,3 +315,8 @@ SECTIONS
  */
 ASSERT((__proc_info_end - __proc_info_begin), "missing CPU support")
 ASSERT((__arch_info_end - __arch_info_begin), "no machine record defined")
+/*
+ * The HYP init code can't be more than a page long.
+ * The above comment applies as well.
+ */
+ASSERT(((__hyp_idmap_text_end - __hyp_idmap_text_start) <= PAGE_SIZE), "HYP init code too big")