[PATCH 5/5] x86/traps: Clean up diagnostics

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

do{_reserved,}_trap() should use fatal_trap() rather than opencoding part of
it.  This lets the remote stack trace logic work in more fatal error
conditions.

With do_trap() converted, there is only one single user of trapstr()
remaining.  Tweak the formatting in pv_inject_event(), and remove trapstr()
entirely.

Take the opportunity of exporting vec_name() to improve the diagnostics in
stub_selftest().

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
---
 xen/arch/x86/extable.c      |  8 +++++---
 xen/arch/x86/pv/traps.c     |  6 +++---
 xen/arch/x86/traps.c        | 25 +++----------------------
 xen/include/asm-x86/traps.h |  2 +-
 4 files changed, 12 insertions(+), 29 deletions(-)

diff --git a/xen/arch/x86/extable.c b/xen/arch/x86/extable.c
index 109ab7da9811..3cb0352abe5f 100644
--- a/xen/arch/x86/extable.c
+++ b/xen/arch/x86/extable.c
@@ -124,6 +124,8 @@ search_exception_table(const struct cpu_user_regs *regs)
 }
 
 #ifndef NDEBUG
+#include <asm/traps.h>
+
 static int __init stub_selftest(void)
 {
     static const struct {
@@ -172,10 +174,10 @@ static int __init stub_selftest(void)
         if ( res.raw != tests[i].res.raw )
         {
             printk("Selftest %u failed: Opc %*ph "
-                   "expected %u[%04x], got %u[%04x]\n",
+                   "expected %s[%04x], got %s[%04x]\n",
                    i, (int)ARRAY_SIZE(tests[i].opc), tests[i].opc,
-                   tests[i].res.fields.trapnr, tests[i].res.fields.ec,
-                   res.fields.trapnr, res.fields.ec);
+                   vec_name(tests[i].res.fields.trapnr), 
tests[i].res.fields.ec,
+                   vec_name(res.fields.trapnr), res.fields.ec);
 
             fail = true;
         }
diff --git a/xen/arch/x86/pv/traps.c b/xen/arch/x86/pv/traps.c
index 1e05a9f1cdad..1d1cb0784c98 100644
--- a/xen/arch/x86/pv/traps.c
+++ b/xen/arch/x86/pv/traps.c
@@ -89,9 +89,9 @@ void pv_inject_event(const struct x86_event *event)
 
     if ( unlikely(null_trap_bounce(curr, tb)) )
     {
-        gprintk(XENLOG_WARNING,
-                "Unhandled %s fault/trap [#%d, ec=%04x]\n",
-                trapstr(vector), vector, error_code);
+        gprintk(XENLOG_ERR,
+                "Unhandled: vec %u, %s[%04x]\n",
+                vector, vec_name(vector), error_code);
 
         if ( vector == TRAP_page_fault )
             show_page_walk(event->cr2);
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index e82ab007abcf..7a178f030c73 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -759,21 +759,7 @@ static int nmi_show_execution_state(const struct 
cpu_user_regs *regs, int cpu)
     return 1;
 }
 
-const char *trapstr(unsigned int trapnr)
-{
-    static const char * const strings[] = {
-        "divide error", "debug", "nmi", "bkpt", "overflow", "bounds",
-        "invalid opcode", "device not available", "double fault",
-        "coprocessor segment", "invalid tss", "segment not found",
-        "stack error", "general protection fault", "page fault",
-        "spurious interrupt", "coprocessor error", "alignment check",
-        "machine check", "simd error", "virtualisation exception"
-    };
-
-    return trapnr < ARRAY_SIZE(strings) ? strings[trapnr] : "???";
-}
-
-static const char *vec_name(unsigned int vec)
+const char *vec_name(unsigned int vec)
 {
     static const char names[][4] = {
 #define P(x) [X86_EXC_ ## x] = "#" #x
@@ -858,9 +844,7 @@ void do_unhandled_trap(struct cpu_user_regs *regs)
     if ( debugger_trap_fatal(trapnr, regs) )
         return;
 
-    show_execution_state(regs);
-    panic("FATAL RESERVED TRAP: vec %u, %s[%04x]\n",
-          trapnr, vec_name(trapnr), regs->error_code);
+    fatal_trap(regs, false);
 }
 
 static void fixup_exception_return(struct cpu_user_regs *regs,
@@ -970,10 +954,7 @@ void do_trap(struct cpu_user_regs *regs)
     if ( debugger_trap_fatal(trapnr, regs) )
         return;
 
-    show_execution_state(regs);
-    panic("FATAL TRAP: vector = %d (%s)\n"
-          "[error_code=%04x]\n",
-          trapnr, trapstr(trapnr), regs->error_code);
+    fatal_trap(regs, false);
 }
 
 int guest_rdmsr_xen(const struct vcpu *v, uint32_t idx, uint64_t *val)
diff --git a/xen/include/asm-x86/traps.h b/xen/include/asm-x86/traps.h
index ec23d3a70b36..3c5feac5e4b1 100644
--- a/xen/include/asm-x86/traps.h
+++ b/xen/include/asm-x86/traps.h
@@ -19,7 +19,7 @@
 #ifndef ASM_TRAP_H
 #define ASM_TRAP_H
 
-const char *trapstr(unsigned int trapnr);
+const char *vec_name(unsigned int vec);
 
 #endif /* ASM_TRAP_H */
 
-- 
2.11.0