[MIPS] lockdep: Add STACKTRACE_SUPPORT and enable LOCKDEP_SUPPORT

Implement stacktrace interface by using unwind_stack() and enable lockdep support in Kconfig. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] lockdep: Add STACKTRACE_SUPPORT and enable LOCKDEP_SUPPORT
Implement stacktrace interface by using unwind_stack() and enable lockdep support in Kconfig. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Atsushi Nemoto · Ralf Baechle
1 parent eae6c0da9d
Showing 6 changed files with 168 additions and 34 deletions Side-by-side Diff
arch/mips/Kconfig
arch/mips/kernel/Makefile
arch/mips/kernel/process.c
arch/mips/kernel/stacktrace.c
arch/mips/kernel/traps.c
include/asm-mips/stacktrace.h
@@ -1841,6 +1841,14 @@
 	bool
 	default y
  
+config LOCKDEP_SUPPORT
+	bool
+	default y
+
+config STACKTRACE_SUPPORT
+	bool
+	default y
+
 source "init/Kconfig"
  
 menu "Bus options (PCI, PCMCIA, EISA, ISA, TC)"
@@ -11,6 +11,7 @@
 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
@@ -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);
+/*
+ * 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 int skip, unsigned long reg29)
+{
+	unsigned long *sp = (unsigned long *)reg29;
+	unsigned long addr;
+
+	while (!kstack_end(sp)) {
+		addr = *sp++;
+		if (__kernel_text_address(addr)) {
+			if (!skip)
+				trace->entries[trace->nr_entries++] = addr;
+			else
+				skip--;
+			if (trace->nr_entries >= trace->max_entries)
+				break;
+		}
+	}
+}
+
+static struct pt_regs * save_context_stack(struct stack_trace *trace,
+	unsigned int skip, 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;
+	extern void ret_from_irq(void);
+
+	if (raw_show_trace || !__kernel_text_address(pc)) {
+		save_raw_context_stack(trace, skip, sp);
+		return NULL;
+	}
+	do {
+		if (!skip)
+			trace->entries[trace->nr_entries++] = pc;
+		else
+			skip--;
+		if (trace->nr_entries >= trace->max_entries)
+			break;
+		/*
+		 * If we reached the bottom of interrupt context,
+		 * return saved pt_regs.
+		 */
+		if (pc == (unsigned long)ret_from_irq) {
+			unsigned long stack_page =
+				(unsigned long)task_stack_page(task);
+			if (!stack_page ||
+			    sp < stack_page ||
+			    sp > stack_page + THREAD_SIZE - 32)
+				break;
+			return (struct pt_regs *)sp;
+		}
+		pc = unwind_stack(task, &sp, pc, ra);
+		ra = 0;
+	} while (pc);
+#else
+	save_raw_context_stack(sp);
+#endif
+
+	return NULL;
+}
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ * If all_contexts is set, all contexts (hardirq, softirq and process)
+ * are saved. If not set then only the current context is saved.
+ */
+void save_stack_trace(struct stack_trace *trace,
+		      struct task_struct *task, int all_contexts,
+		      unsigned int skip)
+{
+	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);
+	}
+
+	while (1) {
+		regs = save_context_stack(trace, skip, task, regs);
+		if (!all_contexts || !regs ||
+		    trace->nr_entries >= trace->max_entries)
+			break;
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+		if (trace->nr_entries >= trace->max_entries)
+			break;
+		skip = 0;
+	}
+}
@@ -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);
  
  
@@ -92,17 +93,15 @@
 }
  
 #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);
+#endif
  
-extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
-				  unsigned long pc, unsigned long ra);
-
 static void show_backtrace(struct task_struct *task, struct pt_regs *regs)
 {
 	unsigned long sp = regs->regs[29];
@@ -121,9 +120,6 @@
 	} 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 +154,6 @@
 	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 +180,6 @@
 {
 	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);
 }
+#ifndef _ASM_STACKTRACE_H
+#define _ASM_STACKTRACE_H
+
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_KALLSYMS
+extern int raw_show_trace;
+extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
+				  unsigned long pc, unsigned long ra);
+#else
+#define raw_show_trace 1
+#define unwind_stack(task, sp, pc, ra)	0
+#endif
+
+static __always_inline void prepare_frametrace(struct pt_regs *regs)
+{
+#ifndef CONFIG_KALLSYMS
+	/*
+	 * Remove any garbage that may be in regs (specially func
+	 * addresses) to avoid show_raw_backtrace() to report them
+	 */
+	memset(regs, 0, sizeof(*regs));
+#endif
+	__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 $31, %2\n\t"
+#endif
+		".set pop\n\t"
+		: "=m" (regs->cp0_epc),
+		"=m" (regs->regs[29]), "=m" (regs->regs[31])
+		: : "memory");
+}
+
+#endif /* _ASM_STACKTRACE_H */
...	...	@@ -1841,6 +1841,14 @@
1841	1841	bool
1842	1842	default y
1843	1843
	1844	+config LOCKDEP_SUPPORT
	1845	+ bool
	1846	+ default y
	1847	+
	1848	+config STACKTRACE_SUPPORT
	1849	+ bool
	1850	+ default y
	1851	+
1844	1852	source "init/Kconfig"
1845	1853
1846	1854	menu "Bus options (PCI, PCMCIA, EISA, ISA, TC)"
...	...	@@ -11,6 +11,7 @@
11	11	binfmt_irix-objs := irixelf.o irixinv.o irixioctl.o irixsig.o \
12	12	irix5sys.o sysirix.o
13	13
	14	+obj-$(CONFIG_STACKTRACE) += stacktrace.o
14	15	obj-$(CONFIG_MODULES) += mips_ksyms.o module.o
15	16
16	17	obj-$(CONFIG_APM) += apm.o
...	...	@@ -40,6 +40,7 @@
40	40	#include <asm/elf.h>
41	41	#include <asm/isadep.h>
42	42	#include <asm/inst.h>
	43	+#include <asm/stacktrace.h>
43	44	#ifdef CONFIG_MIPS_MT_SMTC
44	45	#include <asm/mipsmtregs.h>
45	46	extern void smtc_idle_loop_hook(void);
	1	+/*
	2	+ * arch/mips/kernel/stacktrace.c
	3	+ *
	4	+ * Stack trace management functions
	5	+ *
	6	+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	7	+ */
	8	+#include <linux/sched.h>
	9	+#include <linux/stacktrace.h>
	10	+#include <asm/stacktrace.h>
	11	+
	12	+/*
	13	+ * Save stack-backtrace addresses into a stack_trace buffer:
	14	+ */
	15	+static void save_raw_context_stack(struct stack_trace *trace,
	16	+ unsigned int skip, unsigned long reg29)
	17	+{
	18	+ unsigned long sp = (unsigned long )reg29;
	19	+ unsigned long addr;
	20	+
	21	+ while (!kstack_end(sp)) {
	22	+ addr = *sp++;
	23	+ if (__kernel_text_address(addr)) {
	24	+ if (!skip)
	25	+ trace->entries[trace->nr_entries++] = addr;
	26	+ else
	27	+ skip--;
	28	+ if (trace->nr_entries >= trace->max_entries)
	29	+ break;
	30	+ }
	31	+ }
	32	+}
	33	+
	34	+static struct pt_regs * save_context_stack(struct stack_trace *trace,
	35	+ unsigned int skip, struct task_struct task, struct pt_regs regs)
	36	+{
	37	+ unsigned long sp = regs->regs[29];
	38	+#ifdef CONFIG_KALLSYMS
	39	+ unsigned long ra = regs->regs[31];
	40	+ unsigned long pc = regs->cp0_epc;
	41	+ extern void ret_from_irq(void);
	42	+
	43	+ if (raw_show_trace \|\| !__kernel_text_address(pc)) {
	44	+ save_raw_context_stack(trace, skip, sp);
	45	+ return NULL;
	46	+ }
	47	+ do {
	48	+ if (!skip)
	49	+ trace->entries[trace->nr_entries++] = pc;
	50	+ else
	51	+ skip--;
	52	+ if (trace->nr_entries >= trace->max_entries)
	53	+ break;
	54	+ /*
	55	+ * If we reached the bottom of interrupt context,
	56	+ * return saved pt_regs.
	57	+ */
	58	+ if (pc == (unsigned long)ret_from_irq) {
	59	+ unsigned long stack_page =
	60	+ (unsigned long)task_stack_page(task);
	61	+ if (!stack_page \|\|
	62	+ sp < stack_page \|\|
	63	+ sp > stack_page + THREAD_SIZE - 32)
	64	+ break;
	65	+ return (struct pt_regs *)sp;
	66	+ }
	67	+ pc = unwind_stack(task, &sp, pc, ra);
	68	+ ra = 0;
	69	+ } while (pc);
	70	+#else
	71	+ save_raw_context_stack(sp);
	72	+#endif
	73	+
	74	+ return NULL;
	75	+}
	76	+
	77	+/*
	78	+ * Save stack-backtrace addresses into a stack_trace buffer.
	79	+ * If all_contexts is set, all contexts (hardirq, softirq and process)
	80	+ * are saved. If not set then only the current context is saved.
	81	+ */
	82	+void save_stack_trace(struct stack_trace *trace,
	83	+ struct task_struct *task, int all_contexts,
	84	+ unsigned int skip)
	85	+{
	86	+ struct pt_regs dummyregs;
	87	+ struct pt_regs *regs = &dummyregs;
	88	+
	89	+ WARN_ON(trace->nr_entries \|\| !trace->max_entries);
	90	+
	91	+ if (task && task != current) {
	92	+ regs->regs[29] = task->thread.reg29;
	93	+ regs->regs[31] = 0;
	94	+ regs->cp0_epc = task->thread.reg31;
	95	+ } else {
	96	+ if (!task)
	97	+ task = current;
	98	+ prepare_frametrace(regs);
	99	+ }
	100	+
	101	+ while (1) {
	102	+ regs = save_context_stack(trace, skip, task, regs);
	103	+ if (!all_contexts \|\| !regs \|\|
	104	+ trace->nr_entries >= trace->max_entries)
	105	+ break;
	106	+ trace->entries[trace->nr_entries++] = ULONG_MAX;
	107	+ if (trace->nr_entries >= trace->max_entries)
	108	+ break;
	109	+ skip = 0;
	110	+ }
	111	+}
...	...	@@ -41,6 +41,7 @@
41	41	#include <asm/mmu_context.h>
42	42	#include <asm/watch.h>
43	43	#include <asm/types.h>
	44	+#include <asm/stacktrace.h>
44	45
45	46	extern asmlinkage void handle_int(void);
46	47	extern asmlinkage void handle_tlbm(void);
47	48
48	49
...	...	@@ -92,17 +93,15 @@
92	93	}
93	94
94	95	#ifdef CONFIG_KALLSYMS
95		-static int raw_show_trace;
	96	+int raw_show_trace;
96	97	static int __init set_raw_show_trace(char *str)
97	98	{
98	99	raw_show_trace = 1;
99	100	return 1;
100	101	}
101	102	__setup("raw_show_trace", set_raw_show_trace);
	103	+#endif
102	104
103		-extern unsigned long unwind_stack(struct task_struct task, unsigned long sp,
104		- unsigned long pc, unsigned long ra);
105		-
106	105	static void show_backtrace(struct task_struct task, struct pt_regs regs)
107	106	{
108	107	unsigned long sp = regs->regs[29];
...	...	@@ -121,9 +120,6 @@
121	120	} while (pc);
122	121	printk("\n");
123	122	}
124		-#else
125		-#define show_backtrace(task, r) show_raw_backtrace((r)->regs[29]);
126		-#endif
127	123
128	124	/*
129	125	* This routine abuses get_user()/put_user() to reference pointers
...	...	@@ -158,28 +154,6 @@
158	154	show_backtrace(task, regs);
159	155	}
160	156
161		-static __always_inline void prepare_frametrace(struct pt_regs *regs)
162		-{
163		- __asm__ __volatile__(
164		- ".set push\n\t"
165		- ".set noat\n\t"
166		-#ifdef CONFIG_64BIT
167		- "1: dla $1, 1b\n\t"
168		- "sd $1, %0\n\t"
169		- "sd $29, %1\n\t"
170		- "sd $31, %2\n\t"
171		-#else
172		- "1: la $1, 1b\n\t"
173		- "sw $1, %0\n\t"
174		- "sw $29, %1\n\t"
175		- "sw $31, %2\n\t"
176		-#endif
177		- ".set pop\n\t"
178		- : "=m" (regs->cp0_epc),
179		- "=m" (regs->regs[29]), "=m" (regs->regs[31])
180		- : : "memory");
181		-}
182		-
183	157	void show_stack(struct task_struct task, unsigned long sp)
184	158	{
185	159	struct pt_regs regs;
...	...	@@ -206,11 +180,6 @@
206	180	{
207	181	struct pt_regs regs;
208	182
209		- /*
210		- * Remove any garbage that may be in regs (specially func
211		- * addresses) to avoid show_raw_backtrace() to report them
212		- */
213		- memset(&regs, 0, sizeof(regs));
214	183	prepare_frametrace(&regs);
215	184	show_backtrace(current, &regs);
216	185	}
	1	+#ifndef _ASM_STACKTRACE_H
	2	+#define _ASM_STACKTRACE_H
	3	+
	4	+#include <asm/ptrace.h>
	5	+
	6	+#ifdef CONFIG_KALLSYMS
	7	+extern int raw_show_trace;
	8	+extern unsigned long unwind_stack(struct task_struct task, unsigned long sp,
	9	+ unsigned long pc, unsigned long ra);
	10	+#else
	11	+#define raw_show_trace 1
	12	+#define unwind_stack(task, sp, pc, ra) 0
	13	+#endif
	14	+
	15	+static __always_inline void prepare_frametrace(struct pt_regs *regs)
	16	+{
	17	+#ifndef CONFIG_KALLSYMS
	18	+ /*
	19	+ * Remove any garbage that may be in regs (specially func
	20	+ * addresses) to avoid show_raw_backtrace() to report them
	21	+ */
	22	+ memset(regs, 0, sizeof(*regs));
	23	+#endif
	24	+ __asm__ __volatile__(
	25	+ ".set push\n\t"
	26	+ ".set noat\n\t"
	27	+#ifdef CONFIG_64BIT
	28	+ "1: dla $1, 1b\n\t"
	29	+ "sd $1, %0\n\t"
	30	+ "sd $29, %1\n\t"
	31	+ "sd $31, %2\n\t"
	32	+#else
	33	+ "1: la $1, 1b\n\t"
	34	+ "sw $1, %0\n\t"
	35	+ "sw $29, %1\n\t"
	36	+ "sw $31, %2\n\t"
	37	+#endif
	38	+ ".set pop\n\t"
	39	+ : "=m" (regs->cp0_epc),
	40	+ "=m" (regs->regs[29]), "=m" (regs->regs[31])
	41	+ : : "memory");
	42	+}
	43	+
	44	+#endif /* _ASM_STACKTRACE_H */