1 files changed, 58 insertions, 16 deletions

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 47454ee143df..416aea2c6719 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -43,6 +43,10 @@
 #include <asm/stacktrace.h>
 #include <asm/exception.h>
 #include <asm/system_misc.h>
+#include <asm/esr.h>
+#include <asm/edac.h>
+
+#include <trace/events/exception.h>
 
 static const char *handler[]= {
 	"Synchronous Abort",
@@ -151,7 +155,7 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 	unsigned long irq_stack_ptr;
 	int skip;
 
-	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
+	pr_debug("%s(regs = %pK tsk = %pK)\n", __func__, regs, tsk);
 
 	if (!tsk)
 		tsk = current;
@@ -267,9 +271,6 @@ static int __die(const char *str, int err, struct pt_regs *regs)
 		 end_of_stack(tsk));
 
 	if (!user_mode(regs) || in_interrupt()) {
-		dump_mem(KERN_EMERG, "Stack: ", regs->sp,
-			 THREAD_SIZE + (unsigned long)task_stack_page(tsk),
-			 compat_user_mode(regs));
 		dump_backtrace(regs, tsk);
 		dump_instr(KERN_EMERG, regs);
 	}
@@ -277,40 +278,73 @@ static int __die(const char *str, int err, struct pt_regs *regs)
 	return ret;
 }
 
-static DEFINE_RAW_SPINLOCK(die_lock);
+static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
+static int die_owner = -1;
+static unsigned int die_nest_count;
 
-/*
- * This function is protected against re-entrancy.
- */
-void die(const char *str, struct pt_regs *regs, int err)
+static unsigned long oops_begin(void)
 {
-	int ret;
+	int cpu;
 	unsigned long flags;
 
-	raw_spin_lock_irqsave(&die_lock, flags);
-
 	oops_enter();
 
+	/* racy, but better than risking deadlock. */
+	raw_local_irq_save(flags);
+	cpu = smp_processor_id();
+	if (!arch_spin_trylock(&die_lock)) {
+		if (cpu == die_owner)
+			/* nested oops. should stop eventually */;
+		else
+			arch_spin_lock(&die_lock);
+	}
+	die_nest_count++;
+	die_owner = cpu;
 	console_verbose();
 	bust_spinlocks(1);
-	ret = __die(str, err, regs);
+	return flags;
+}
 
+static void oops_end(unsigned long flags, struct pt_regs *regs, int notify)
+{
 	if (regs && kexec_should_crash(current))
 		crash_kexec(regs);
 
 	bust_spinlocks(0);
+	die_owner = -1;
 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+	die_nest_count--;
+	if (!die_nest_count)
+		/* Nest count reaches zero, release the lock. */
+		arch_spin_unlock(&die_lock);
+	raw_local_irq_restore(flags);
 	oops_exit();
 
 	if (in_interrupt())
 		panic("Fatal exception in interrupt");
 	if (panic_on_oops)
 		panic("Fatal exception");
+	if (notify != NOTIFY_STOP)
+		do_exit(SIGSEGV);
+}
 
-	raw_spin_unlock_irqrestore(&die_lock, flags);
+/*
+ * This function is protected against re-entrancy.
+ */
+void die(const char *str, struct pt_regs *regs, int err)
+{
+	enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
+	unsigned long flags = oops_begin();
+	int ret;
 
-	if (ret != NOTIFY_STOP)
-		do_exit(SIGSEGV);
+	if (!user_mode(regs))
+		bug_type = report_bug(regs->pc, regs);
+	if (bug_type != BUG_TRAP_TYPE_NONE)
+		str = "Oops - BUG";
+
+	ret = __die(str, err, regs);
+
+	oops_end(flags, regs, ret);
 }
 
 void arm64_notify_die(const char *str, struct pt_regs *regs,
@@ -400,6 +434,8 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
 	if (call_undef_hook(regs) == 0)
 		return;
 
+	trace_undef_instr(regs, (void *)pc);
+
 	if (unhandled_signal(current, SIGILL) && show_unhandled_signals_ratelimited()) {
 		pr_info("%s[%d]: undefined instruction: pc=%p\n",
 			current->comm, task_pid_nr(current), pc);
@@ -518,6 +554,12 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
 	pr_crit("Bad mode in %s handler detected, code 0x%08x -- %s\n",
 		handler[reason], esr, esr_get_class_string(esr));
 
+	if (esr >> ESR_ELx_EC_SHIFT == ESR_ELx_EC_SERROR) {
+		pr_crit("System error detected. ESR.ISS = %08x\n",
+			esr & 0xffffff);
+		arm64_check_cache_ecc(NULL);
+	}
+
 	local_irq_disable();
 	panic("bad mode");
 }