From: Ian Campbell <ian.campbell@citrix.com>
Date: Mon, 21 Jul 2014 12:59:59 +0000 (+0100)
Subject: xen: arm: ensure that the boot code is <4K in size
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~4612
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=6d848a95df61a76bdf9069b4ba9286d6358784d8;p=xen.git

xen: arm: ensure that the boot code is <4K in size

This avoids having to deal with the 1:1 boot mapping crossing a
section or page boundary.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.grall@linaro.org>
---

diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index 0a95b68b56..2547ce1d6d 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -457,6 +457,8 @@ fail:   PRINT("- Boot failed -\r\n")
 1:      wfe
         b     1b
 
+GLOBAL(_end_boot)
+
 /* Copy Xen to new location and switch TTBR
  * r1:r0       ttbr
  * r2          source address
diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
index 4f0ea2dca2..b71b6f0812 100644
--- a/xen/arch/arm/arm64/head.S
+++ b/xen/arch/arm/arm64/head.S
@@ -487,6 +487,8 @@ fail:   PRINT("- Boot failed -\r\n")
 1:      wfe
         b     1b
 
+GLOBAL(_end_boot)
+
 /* Copy Xen to new location and switch TTBR
  * x0    ttbr
  * x1    source address
diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
index be55dad4da..079e0851c7 100644
--- a/xen/arch/arm/xen.lds.S
+++ b/xen/arch/arm/xen.lds.S
@@ -178,3 +178,9 @@ SECTIONS
   .stab.indexstr 0 : { *(.stab.indexstr) }
   .comment 0 : { *(.comment) }
 }
+
+/*
+ * We require that Xen is loaded at a 4K boundary, so this ensures that any
+ * code running on the boot time identity map cannot cross a section boundary.
+ */
+ASSERT( _end_boot - start <= PAGE_SIZE, "Boot code is larger than 4K")