1 files changed, 147 insertions, 76 deletions

diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c
index fcc3a69831ad..959a917c989d 100644
--- a/arch/csky/kernel/traps.c
+++ b/arch/csky/kernel/traps.c
@@ -15,6 +15,8 @@
 #include <linux/rtc.h>
 #include <linux/uaccess.h>
 #include <linux/kprobes.h>
+#include <linux/kdebug.h>
+#include <linux/sched/debug.h>
 
 #include <asm/setup.h>
 #include <asm/traps.h>
@@ -27,6 +29,8 @@
 #include <abi/fpu.h>
 #endif
 
+int show_unhandled_signals = 1;
+
 /* Defined in entry.S */
 asmlinkage void csky_trap(void);
 
@@ -77,117 +81,184 @@ void __init trap_init(void)
 #endif
 }
 
-void die_if_kernel(char *str, struct pt_regs *regs, int nr)
+static DEFINE_SPINLOCK(die_lock);
+
+void die(struct pt_regs *regs, const char *str)
 {
-	if (user_mode(regs))
-		return;
+	static int die_counter;
+	int ret;
 
+	oops_enter();
+
+	spin_lock_irq(&die_lock);
 	console_verbose();
-	pr_err("%s: %08x\n", str, nr);
+	bust_spinlocks(1);
+
+	pr_emerg("%s [#%d]\n", str, ++die_counter);
+	print_modules();
 	show_regs(regs);
+	show_stack(current, (unsigned long *)regs->regs[4], KERN_INFO);
+
+	ret = notify_die(DIE_OOPS, str, regs, 0, trap_no(regs), SIGSEGV);
+
+	bust_spinlocks(0);
 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
-	do_exit(SIGSEGV);
+	spin_unlock_irq(&die_lock);
+	oops_exit();
+
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+	if (panic_on_oops)
+		panic("Fatal exception");
+	if (ret != NOTIFY_STOP)
+		do_exit(SIGSEGV);
 }
 
-void buserr(struct pt_regs *regs)
+void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
 {
-#ifdef CONFIG_CPU_CK810
-	static unsigned long prev_pc;
+	struct task_struct *tsk = current;
 
-	if ((regs->pc == prev_pc) && prev_pc != 0) {
-		prev_pc = 0;
-	} else {
-		prev_pc = regs->pc;
-		return;
+	if (show_unhandled_signals && unhandled_signal(tsk, signo)
+	    && printk_ratelimit()) {
+		pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x%08lx",
+			tsk->comm, task_pid_nr(tsk), signo, code, addr);
+		print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
+		pr_cont("\n");
+		show_regs(regs);
 	}
-#endif
 
-	die_if_kernel("Kernel mode BUS error", regs, 0);
+	force_sig_fault(signo, code, (void __user *)addr);
+}
 
-	pr_err("User mode Bus Error\n");
-	show_regs(regs);
+static void do_trap_error(struct pt_regs *regs, int signo, int code,
+	unsigned long addr, const char *str)
+{
+	current->thread.trap_no = trap_no(regs);
 
-	force_sig_fault(SIGSEGV, 0, (void __user *)regs->pc);
+	if (user_mode(regs)) {
+		do_trap(regs, signo, code, addr);
+	} else {
+		if (!fixup_exception(regs))
+			die(regs, str);
+	}
 }
 
-asmlinkage void trap_c(struct pt_regs *regs)
-{
-	int sig;
-	unsigned long vector;
-	siginfo_t info;
-	struct task_struct *tsk = current;
+#define DO_ERROR_INFO(name, signo, code, str)				\
+asmlinkage __visible void name(struct pt_regs *regs)			\
+{									\
+	do_trap_error(regs, signo, code, regs->pc, "Oops - " str);	\
+}
 
-	vector = (regs->sr >> 16) & 0xff;
+DO_ERROR_INFO(do_trap_unknown,
+	SIGILL, ILL_ILLTRP, "unknown exception");
+DO_ERROR_INFO(do_trap_zdiv,
+	SIGFPE, FPE_INTDIV, "error zero div exception");
+DO_ERROR_INFO(do_trap_buserr,
+	SIGSEGV, ILL_ILLADR, "error bus error exception");
 
-	switch (vector) {
-	case VEC_ZERODIV:
-		die_if_kernel("Kernel mode ZERO DIV", regs, vector);
-		sig = SIGFPE;
-		break;
-	/* ptrace */
-	case VEC_TRACE:
+asmlinkage void do_trap_misaligned(struct pt_regs *regs)
+{
+#ifdef CONFIG_CPU_NEED_SOFTALIGN
+	csky_alignment(regs);
+#else
+	current->thread.trap_no = trap_no(regs);
+	do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->pc,
+		      "Oops - load/store address misaligned");
+#endif
+}
+
+asmlinkage void do_trap_bkpt(struct pt_regs *regs)
+{
 #ifdef CONFIG_KPROBES
-		if (kprobe_single_step_handler(regs))
-			return;
+	if (kprobe_single_step_handler(regs))
+		return;
 #endif
 #ifdef CONFIG_UPROBES
-		if (uprobe_single_step_handler(regs))
-			return;
+	if (uprobe_single_step_handler(regs))
+		return;
 #endif
-		info.si_code = TRAP_TRACE;
-		sig = SIGTRAP;
-		break;
-	case VEC_ILLEGAL:
-		tsk->thread.trap_no = vector;
+	if (user_mode(regs)) {
+		send_sig(SIGTRAP, current, 0);
+		return;
+	}
+
+	do_trap_error(regs, SIGILL, ILL_ILLTRP, regs->pc,
+		      "Oops - illegal trap exception");
+}
+
+asmlinkage void do_trap_illinsn(struct pt_regs *regs)
+{
+	current->thread.trap_no = trap_no(regs);
+
 #ifdef CONFIG_KPROBES
-		if (kprobe_breakpoint_handler(regs))
-			return;
+	if (kprobe_breakpoint_handler(regs))
+		return;
 #endif
 #ifdef CONFIG_UPROBES
-		if (uprobe_breakpoint_handler(regs))
-			return;
+	if (uprobe_breakpoint_handler(regs))
+		return;
 #endif
-		die_if_kernel("Kernel mode ILLEGAL", regs, vector);
 #ifndef CONFIG_CPU_NO_USER_BKPT
-		if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT)
+	if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT) {
+		send_sig(SIGTRAP, current, 0);
+		return;
+	}
 #endif
-		{
-			sig = SIGILL;
-			break;
-		}
-	/* gdbserver  breakpoint */
+
+	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,
+		      "Oops - illegal instruction exception");
+}
+
+asmlinkage void do_trap_fpe(struct pt_regs *regs)
+{
+#ifdef CONFIG_CPU_HAS_FP
+	return fpu_fpe(regs);
+#else
+	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,
+		      "Oops - fpu instruction exception");
+#endif
+}
+
+asmlinkage void do_trap_priv(struct pt_regs *regs)
+{
+#ifdef CONFIG_CPU_HAS_FP
+	if (user_mode(regs) && fpu_libc_helper(regs))
+		return;
+#endif
+	do_trap_error(regs, SIGILL, ILL_PRVOPC, regs->pc,
+		      "Oops - illegal privileged exception");
+}
+
+asmlinkage void trap_c(struct pt_regs *regs)
+{
+	switch (trap_no(regs)) {
+	case VEC_ZERODIV:
+		do_trap_zdiv(regs);
+		break;
+	case VEC_TRACE:
+		do_trap_bkpt(regs);
+		break;
+	case VEC_ILLEGAL:
+		do_trap_illinsn(regs);
+		break;
 	case VEC_TRAP1:
-	/* jtagserver breakpoint */
 	case VEC_BREAKPOINT:
-		die_if_kernel("Kernel mode BKPT", regs, vector);
-		info.si_code = TRAP_BRKPT;
-		sig = SIGTRAP;
+		do_trap_bkpt(regs);
 		break;
 	case VEC_ACCESS:
-		tsk->thread.trap_no = vector;
-		return buserr(regs);
-#ifdef CONFIG_CPU_NEED_SOFTALIGN
+		do_trap_buserr(regs);
+		break;
 	case VEC_ALIGN:
-		tsk->thread.trap_no = vector;
-		return csky_alignment(regs);
-#endif
-#ifdef CONFIG_CPU_HAS_FPU
+		do_trap_misaligned(regs);
+		break;
 	case VEC_FPE:
-		tsk->thread.trap_no = vector;
-		die_if_kernel("Kernel mode FPE", regs, vector);
-		return fpu_fpe(regs);
+		do_trap_fpe(regs);
+		break;
 	case VEC_PRIV:
-		tsk->thread.trap_no = vector;
-		die_if_kernel("Kernel mode PRIV", regs, vector);
-		if (fpu_libc_helper(regs))
-			return;
-#endif
+		do_trap_priv(regs);
+		break;
 	default:
-		sig = SIGSEGV;
+		do_trap_unknown(regs);
 		break;
 	}
-
-	tsk->thread.trap_no = vector;
-
-	send_sig(sig, current, 0);
 }