xen/arm32: entry: Add missing trap_reset entry

At the moment, the reset vector is defined as .word 0 (e.g andeq r0, r0,
r0).

This is rather unintuitive and will result to execute the trap
undefined. Instead introduce trap helpers for reset and will generate an
error message in the unlikely case that reset will be called.

This is part of XSA-254.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 00268cc91270c7b0aa3a1906bf7e7702db9c61c1)

Conflicts:
	xen/arch/arm/arm32/traps.c

diff --git a/xen/arch/arm/arm32/entry.S b/xen/arch/arm/arm32/entry.S
index e1e60c278c5a9614b3ee3789481f64194b719ad0..c5fec60e440d78bbaa96ae0399c2a3d71b768e73 100644 (file)
--- a/xen/arch/arm/arm32/entry.S
+++ b/xen/arch/arm/arm32/entry.S
@@ -125,7 +125,7 @@ trap_##trap:                                                            \
 
         .align 5
 GLOBAL(hyp_traps_vector)
-        .word 0                         /* 0x00 - Reset */
+        b trap_reset                    /* 0x00 - Reset */
         b trap_undefined_instruction    /* 0x04 - Undefined Instruction */
         b trap_supervisor_call          /* 0x08 - Supervisor Call */
         b trap_prefetch_abort           /* 0x0c - Prefetch Abort */
@@ -134,6 +134,7 @@ GLOBAL(hyp_traps_vector)
         b trap_irq                      /* 0x18 - IRQ */
         b trap_fiq                      /* 0x1c - FIQ */
 
+DEFINE_TRAP_ENTRY(reset)
 DEFINE_TRAP_ENTRY(undefined_instruction)
 DEFINE_TRAP_ENTRY(supervisor_call)
 DEFINE_TRAP_ENTRY(prefetch_abort)

diff --git a/xen/arch/arm/arm32/traps.c b/xen/arch/arm/arm32/traps.c
index 7bfc5ffe9d4a52b2cfad5c0a90dafb8afa85b41b..cd38dfaaf30cb7dac749091752dac674b6c4454b 100644 (file)
--- a/xen/arch/arm/arm32/traps.c
+++ b/xen/arch/arm/arm32/traps.c
@@ -24,6 +24,11 @@
 
 #include <asm/processor.h>
 
+asmlinkage void do_trap_reset(struct cpu_user_regs *regs)
+{
+    do_unexpected_trap("Reset", regs);
+}
+
 asmlinkage void do_trap_undefined_instruction(struct cpu_user_regs *regs)
 {
     uint32_t pc = regs->pc;