[Patch v3 3/4] x86/stack: Change show_stack_overflow() to use frame pointers if available

[Andrew Cooper <andrew.cooper3@citrix.com>]

Pass a full set of cpu_user_regs, and defer the hand-coded stack printing to
__show_trace(), which will correctly use frame pointers if available.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <JBeulich@suse.com>
CC: Tim Deegan <tim@xen.org>
---
 xen/arch/x86/traps.c            |   14 ++++----------
 xen/arch/x86/x86_64/traps.c     |    2 +-
 xen/include/asm-x86/processor.h |    2 +-
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index d68f93c..67be3c4 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -316,11 +316,11 @@ void show_stack(struct cpu_user_regs *regs)
     show_trace(regs);
 }
 
-void show_stack_overflow(unsigned int cpu, unsigned long esp)
+void show_stack_overflow(unsigned int cpu, const struct cpu_user_regs *regs)
 {
 #ifdef MEMORY_GUARD
+    unsigned long esp = regs->rsp;
     unsigned long esp_top, esp_bottom;
-    unsigned long *stack, addr;
 
     esp_bottom = (esp | (STACK_SIZE - 1)) + 1;
     esp_top    = esp_bottom - PRIMARY_STACK_SIZE;
@@ -340,16 +340,10 @@ void show_stack_overflow(unsigned int cpu, unsigned long esp)
     if ( esp < esp_top )
         esp = esp_top;
 
-    printk("Xen stack overflow (dumping trace %p-%p):\n   ",
+    printk("Xen stack overflow (dumping trace %p-%p):\n",
            (void *)esp, (void *)esp_bottom);
 
-    stack = (unsigned long *)esp;
-    while ( ((long)stack & (STACK_SIZE-BYTES_PER_LONG)) != 0 )
-    {
-        addr = *stack++;
-        if ( is_active_kernel_text(addr) )
-            printk("%p: [<%p>] %pS\n", stack, _p(addr), _p(addr));
-    }
+    __show_trace(esp, regs->rbp);
 
     printk("\n");
 #endif
diff --git a/xen/arch/x86/x86_64/traps.c b/xen/arch/x86/x86_64/traps.c
index 8e6a7c1..bcf72b6 100644
--- a/xen/arch/x86/x86_64/traps.c
+++ b/xen/arch/x86/x86_64/traps.c
@@ -248,7 +248,7 @@ void do_double_fault(struct cpu_user_regs *regs)
 
     printk("CPU:    %d\n", cpu);
     _show_registers(regs, crs, CTXT_hypervisor, NULL);
-    show_stack_overflow(cpu, regs->rsp);
+    show_stack_overflow(cpu, regs);
 
     panic("DOUBLE FAULT -- system shutdown\n");
 }
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index 73a3202..c120460 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -509,7 +509,7 @@ extern always_inline void prefetchw(const void *x)
 #endif
 
 void show_stack(struct cpu_user_regs *regs);
-void show_stack_overflow(unsigned int cpu, unsigned long esp);
+void show_stack_overflow(unsigned int cpu, const struct cpu_user_regs *regs);
 void show_registers(struct cpu_user_regs *regs);
 void show_execution_state(struct cpu_user_regs *regs);
 #define dump_execution_state() run_in_exception_handler(show_execution_state)
-- 
1.7.10.4