Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Remove unused galileo-boars header files
  [MIPS] Rename SERIAL_PORT_DEFNS for EV64120
  [MIPS] Add UART IRQ number for EV64120
  [MIPS] Remove excite_flash.c
  [MIPS] Update i8259 resources.
  [MIPS] Make unwind_stack() can dig into interrupted context
  [MIPS] Stacktrace build-fix and improvement
  [MIPS] QEMU: Add support for little endian mips
  [MIPS] Remove __flush_icache_page
  [MIPS] lockdep: update defconfigs
  [MIPS] lockdep: Add STACKTRACE_SUPPORT and enable LOCKDEP_SUPPORT
  [MIPS] lockdep: fix TRACE_IRQFLAGS_SUPPORT

arch/mips/kernel/Makefile

@@ -11,6 +11,7 @@ obj-y		+= cpu-probe.o branch.o entry.o genex.o irq.o process.o \
 binfmt_irix-objs	:= irixelf.o irixinv.o irixioctl.o irixsig.o	\
 			   irix5sys.o sysirix.o
 
+obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_MODULES)		+= mips_ksyms.o module.o
 
 obj-$(CONFIG_APM)		+= apm.o

arch/mips/kernel/genex.S

@@ -220,8 +220,8 @@ NESTED(except_vec_vi_handler, 0, sp)
 	CLI
 	TRACE_IRQS_OFF
 	move	a0, sp
-	jalr	v0
-	j	ret_from_irq
+	PTR_LA	ra, ret_from_irq
+	jr	v0
 	END(except_vec_vi_handler)
 
 /*
@@ -349,8 +349,8 @@ NESTED(nmi_handler, PT_SIZE, sp)
 	.set	at
 	__BUILD_\verbose \exception
 	move	a0, sp
-	jal	do_\handler
-	j	ret_from_exception
+	PTR_LA	ra, ret_from_exception
+	j	do_\handler
 	END(handle_\exception)
 	.endm
 

arch/mips/kernel/i8259.c

@@ -302,11 +302,11 @@ static struct irqaction irq2 = {
 };
 
 static struct resource pic1_io_resource = {
-	.name = "pic1", .start = 0x20, .end = 0x3f, .flags = IORESOURCE_BUSY
+	.name = "pic1", .start = 0x20, .end = 0x21, .flags = IORESOURCE_BUSY
 };
 
 static struct resource pic2_io_resource = {
-	.name = "pic2", .start = 0xa0, .end = 0xbf, .flags = IORESOURCE_BUSY
+	.name = "pic2", .start = 0xa0, .end = 0xa1, .flags = IORESOURCE_BUSY
 };
 
 /*

arch/mips/kernel/process.c

@@ -40,6 +40,7 @@
 #include <asm/elf.h>
 #include <asm/isadep.h>
 #include <asm/inst.h>
+#include <asm/stacktrace.h>
 #ifdef CONFIG_MIPS_MT_SMTC
 #include <asm/mipsmtregs.h>
 extern void smtc_idle_loop_hook(void);
@@ -398,7 +399,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 #ifdef CONFIG_KALLSYMS
 /* used by show_backtrace() */
 unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
-			   unsigned long pc, unsigned long ra)
+			   unsigned long pc, unsigned long *ra)
 {
 	unsigned long stack_page;
 	struct mips_frame_info info;
@@ -406,18 +407,42 @@ unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
 	char namebuf[KSYM_NAME_LEN + 1];
 	unsigned long size, ofs;
 	int leaf;
+	extern void ret_from_irq(void);
+	extern void ret_from_exception(void);
 
 	stack_page = (unsigned long)task_stack_page(task);
 	if (!stack_page)
 		return 0;
 
+	/*
+	 * If we reached the bottom of interrupt context,
+	 * return saved pc in pt_regs.
+	 */
+	if (pc == (unsigned long)ret_from_irq ||
+	    pc == (unsigned long)ret_from_exception) {
+		struct pt_regs *regs;
+		if (*sp >= stack_page &&
+		    *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) {
+			regs = (struct pt_regs *)*sp;
+			pc = regs->cp0_epc;
+			if (__kernel_text_address(pc)) {
+				*sp = regs->regs[29];
+				*ra = regs->regs[31];
+				return pc;
+			}
+		}
+		return 0;
+	}
 	if (!kallsyms_lookup(pc, &size, &ofs, &modname, namebuf))
 		return 0;
 	/*
 	 * Return ra if an exception occured at the first instruction
 	 */
-	if (unlikely(ofs == 0))
-		return ra;
+	if (unlikely(ofs == 0)) {
+		pc = *ra;
+		*ra = 0;
+		return pc;
+	}
 
 	info.func = (void *)(pc - ofs);
 	info.func_size = ofs;	/* analyze from start to ofs */
@@ -436,11 +461,12 @@ unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
 		 * one. In that cases avoid to return always the
 		 * same value.
 		 */
-		pc = pc != ra ? ra : 0;
+		pc = pc != *ra ? *ra : 0;
 	else
 		pc = ((unsigned long *)(*sp))[info.pc_offset];
 
 	*sp += info.frame_size;
+	*ra = 0;
 	return __kernel_text_address(pc) ? pc : 0;
 }
 #endif
@@ -453,6 +479,7 @@ unsigned long get_wchan(struct task_struct *task)
 	unsigned long pc = 0;
 #ifdef CONFIG_KALLSYMS
 	unsigned long sp;
+	unsigned long ra = 0;
 #endif
 
 	if (!task || task == current || task->state == TASK_RUNNING)
@@ -466,7 +493,7 @@ unsigned long get_wchan(struct task_struct *task)
 	sp = task->thread.reg29 + schedule_mfi.frame_size;
 
 	while (in_sched_functions(pc))
-		pc = unwind_stack(task, &sp, pc, 0);
+		pc = unwind_stack(task, &sp, pc, &ra);
 #endif
 
 out:

arch/mips/kernel/scall32-o32.S

@@ -28,18 +28,7 @@
 NESTED(handle_sys, PT_SIZE, sp)
 	.set	noat
 	SAVE_SOME
-#ifdef CONFIG_TRACE_IRQFLAGS
-	TRACE_IRQS_ON
-#ifdef CONFIG_64BIT
-	LONG_L	$8, PT_R8(sp)
-	LONG_L	$9, PT_R9(sp)
-#endif
-	LONG_L	$7, PT_R7(sp)
-	LONG_L	$6, PT_R6(sp)
-	LONG_L	$5, PT_R5(sp)
-	LONG_L	$4, PT_R4(sp)
-	LONG_L	$2, PT_R2(sp)
-#endif
+	TRACE_IRQS_ON_RELOAD
 	STI
 	.set	at
 

arch/mips/kernel/scall64-64.S

@@ -34,7 +34,7 @@ NESTED(handle_sys64, PT_SIZE, sp)
 	 */
 	.set	noat
 	SAVE_SOME
-	TRACE_IRQS_ON
+	TRACE_IRQS_ON_RELOAD
 	STI
 	.set	at
 #endif

arch/mips/kernel/scall64-n32.S

@@ -33,7 +33,7 @@ NESTED(handle_sysn32, PT_SIZE, sp)
 #ifndef CONFIG_MIPS32_O32
 	.set	noat
 	SAVE_SOME
-	TRACE_IRQS_ON
+	TRACE_IRQS_ON_RELOAD
 	STI
 	.set	at
 #endif

arch/mips/kernel/scall64-o32.S

@@ -28,7 +28,7 @@
 NESTED(handle_sys, PT_SIZE, sp)
 	.set	noat
 	SAVE_SOME
-	TRACE_IRQS_ON
+	TRACE_IRQS_ON_RELOAD
 	STI
 	.set	at
 	ld	t1, PT_EPC(sp)		# skip syscall on return

arch/mips/kernel/stacktrace.c

@@ -0,0 +1,85 @@
+/*
+ * arch/mips/kernel/stacktrace.c
+ *
+ * Stack trace management functions
+ *
+ *  Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ */
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <asm/stacktrace.h>
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer:
+ */
+static void save_raw_context_stack(struct stack_trace *trace,
+	unsigned long reg29)
+{
+	unsigned long *sp = (unsigned long *)reg29;
+	unsigned long addr;
+
+	while (!kstack_end(sp)) {
+		addr = *sp++;
+		if (__kernel_text_address(addr)) {
+			if (trace->skip > 0)
+				trace->skip--;
+			else
+				trace->entries[trace->nr_entries++] = addr;
+			if (trace->nr_entries >= trace->max_entries)
+				break;
+		}
+	}
+}
+
+static void save_context_stack(struct stack_trace *trace,
+	struct task_struct *task, struct pt_regs *regs)
+{
+	unsigned long sp = regs->regs[29];
+#ifdef CONFIG_KALLSYMS
+	unsigned long ra = regs->regs[31];
+	unsigned long pc = regs->cp0_epc;
+
+	if (raw_show_trace || !__kernel_text_address(pc)) {
+		unsigned long stack_page =
+			(unsigned long)task_stack_page(task);
+		if (stack_page && sp >= stack_page &&
+		    sp <= stack_page + THREAD_SIZE - 32)
+			save_raw_context_stack(trace, sp);
+		return;
+	}
+	do {
+		if (trace->skip > 0)
+			trace->skip--;
+		else
+			trace->entries[trace->nr_entries++] = pc;
+		if (trace->nr_entries >= trace->max_entries)
+			break;
+		pc = unwind_stack(task, &sp, pc, &ra);
+	} while (pc);
+#else
+	save_raw_context_stack(sp);
+#endif
+}
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
+{
+	struct pt_regs dummyregs;
+	struct pt_regs *regs = &dummyregs;
+
+	WARN_ON(trace->nr_entries || !trace->max_entries);
+
+	if (task && task != current) {
+		regs->regs[29] = task->thread.reg29;
+		regs->regs[31] = 0;
+		regs->cp0_epc = task->thread.reg31;
+	} else {
+		if (!task)
+			task = current;
+		prepare_frametrace(regs);
+	}
+
+	save_context_stack(trace, task, regs);
+}

arch/mips/kernel/traps.c

@@ -41,6 +41,7 @@
 #include <asm/mmu_context.h>
 #include <asm/watch.h>
 #include <asm/types.h>
+#include <asm/stacktrace.h>
 
 extern asmlinkage void handle_int(void);
 extern asmlinkage void handle_tlbm(void);
@@ -92,16 +93,14 @@ static void show_raw_backtrace(unsigned long reg29)
 }
 
 #ifdef CONFIG_KALLSYMS
-static int raw_show_trace;
+int raw_show_trace;
 static int __init set_raw_show_trace(char *str)
 {
 	raw_show_trace = 1;
 	return 1;
 }
 __setup("raw_show_trace", set_raw_show_trace);
-
-extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
-				  unsigned long pc, unsigned long ra);
+#endif
 
 static void show_backtrace(struct task_struct *task, struct pt_regs *regs)
 {
@@ -116,14 +115,10 @@ static void show_backtrace(struct task_struct *task, struct pt_regs *regs)
 	printk("Call Trace:\n");
 	do {
 		print_ip_sym(pc);
-		pc = unwind_stack(task, &sp, pc, ra);
-		ra = 0;
+		pc = unwind_stack(task, &sp, pc, &ra);
 	} while (pc);
 	printk("\n");
 }
-#else
-#define show_backtrace(task, r) show_raw_backtrace((r)->regs[29]);
-#endif
 
 /*
  * This routine abuses get_user()/put_user() to reference pointers
@@ -158,28 +153,6 @@ static void show_stacktrace(struct task_struct *task, struct pt_regs *regs)
 	show_backtrace(task, regs);
 }
 
-static __always_inline void prepare_frametrace(struct pt_regs *regs)
-{
-	__asm__ __volatile__(
-		".set push\n\t"
-		".set noat\n\t"
-#ifdef CONFIG_64BIT
-		"1: dla $1, 1b\n\t"
-		"sd $1, %0\n\t"
-		"sd $29, %1\n\t"
-		"sd $31, %2\n\t"
-#else
-		"1: la $1, 1b\n\t"
-		"sw $1, %0\n\t"
-		"sw $29, %1\n\t"
-		"sw $31, %2\n\t"
-#endif
-		".set pop\n\t"
-		: "=m" (regs->cp0_epc),
-		"=m" (regs->regs[29]), "=m" (regs->regs[31])
-		: : "memory");
-}
-
 void show_stack(struct task_struct *task, unsigned long *sp)
 {
 	struct pt_regs regs;
@@ -206,11 +179,6 @@ void dump_stack(void)
 {
 	struct pt_regs regs;
 
-	/*
-	 * Remove any garbage that may be in regs (specially func
-	 * addresses) to avoid show_raw_backtrace() to report them
-	 */
-	memset(&regs, 0, sizeof(regs));
 	prepare_frametrace(&regs);
 	show_backtrace(current, &regs);
 }