File 551d1dbf-arm-Factor-out-psr_mode_is_user.patch of Package xen.8005

Subject: xen: arm: Factor out psr_mode_is_user
From: Ian Campbell ian.campbell@citrix.com Mon Mar 30 12:12:22 2015 +0100
Date: Thu Apr 2 11:45:19 2015 +0100:
Git: fe6bc7d95bc9c518ef3b0faaf899a3294c456c4b

This embodies the logic on arm64 that userspace can be either 32-bit
or 64-bit. It will be used in other places shortly.

Note that the logic differs slightly because the original (in
inject_abt64_exception) knew that the kernel was 64-bit and could
therefore assume that any 32-bit mode was userspace. Instead the
refactored code explicitly checks for usr mode.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
(cherry picked from commit 9e1342cf1aabf5841293d32c918f59ffee01ec67)

Index: xen-4.4.4-testing/xen/arch/arm/traps.c
===================================================================
--- xen-4.4.4-testing.orig/xen/arch/arm/traps.c
+++ xen-4.4.4-testing/xen/arch/arm/traps.c
@@ -451,14 +451,7 @@ static void inject_abt64_exception(struc
         .len = instr_len,
     };
 
-    /*
-     * Trap may have been taken from EL0, which might be in AArch32
-     * mode (PSR_MODE_BIT set), or in AArch64 mode (PSR_MODE_EL0t).
-     *
-     * Since we know the kernel must be 64-bit any trap from a 32-bit
-     * mode must have been from EL0.
-     */
-    if ( psr_mode_is_32bit(regs->cpsr) || psr_mode(regs->cpsr,PSR_MODE_EL0t) )
+    if ( psr_mode_is_user(regs) )
         esr.ec = prefetch
             ? HSR_EC_INSTR_ABORT_LOWER_EL : HSR_EC_DATA_ABORT_LOWER_EL;
     else
Index: xen-4.4.4-testing/xen/include/asm-arm/regs.h
===================================================================
--- xen-4.4.4-testing.orig/xen/include/asm-arm/regs.h
+++ xen-4.4.4-testing/xen/include/asm-arm/regs.h
@@ -24,9 +24,17 @@
 
 #ifdef CONFIG_ARM_32
 #define hyp_mode(r)     psr_mode((r)->cpsr,PSR_MODE_HYP)
+#define psr_mode_is_user(r) usr_mode(r)
 #else
 #define hyp_mode(r)     (psr_mode((r)->cpsr,PSR_MODE_EL2h) || \
                          psr_mode((r)->cpsr,PSR_MODE_EL2t))
+
+/*
+ * Trap may have been taken from EL0, which might be in AArch32 usr
+ * mode, or in AArch64 mode (PSR_MODE_EL0t).
+ */
+#define psr_mode_is_user(r) \
+    (psr_mode((r)->cpsr,PSR_MODE_EL0t) || usr_mode(r))
 #endif
 
 #define guest_mode(r)                                                         \