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-rw-r--r--arch/microblaze/include/asm/exceptions.h5
-rw-r--r--arch/microblaze/include/asm/system.h1
-rw-r--r--arch/microblaze/include/asm/unwind.h29
-rw-r--r--arch/microblaze/kernel/Makefile2
-rw-r--r--arch/microblaze/kernel/entry-nommu.S28
-rw-r--r--arch/microblaze/kernel/entry.S27
-rw-r--r--arch/microblaze/kernel/hw_exception_handler.S4
-rw-r--r--arch/microblaze/kernel/stacktrace.c44
-rw-r--r--arch/microblaze/kernel/traps.c91
-rw-r--r--arch/microblaze/kernel/unwind.c318
10 files changed, 454 insertions, 95 deletions
diff --git a/arch/microblaze/include/asm/exceptions.h b/arch/microblaze/include/asm/exceptions.h
index 4c7b5d037c88..fa0e36657fdd 100644
--- a/arch/microblaze/include/asm/exceptions.h
+++ b/arch/microblaze/include/asm/exceptions.h
@@ -14,6 +14,11 @@
14#define _ASM_MICROBLAZE_EXCEPTIONS_H 14#define _ASM_MICROBLAZE_EXCEPTIONS_H
15 15
16#ifdef __KERNEL__ 16#ifdef __KERNEL__
17
18#ifndef CONFIG_MMU
19#define EX_HANDLER_STACK_SIZ (4*19)
20#endif
21
17#ifndef __ASSEMBLY__ 22#ifndef __ASSEMBLY__
18 23
19/* Macros to enable and disable HW exceptions in the MSR */ 24/* Macros to enable and disable HW exceptions in the MSR */
diff --git a/arch/microblaze/include/asm/system.h b/arch/microblaze/include/asm/system.h
index 48c4f0335e3f..4f8eaea21f88 100644
--- a/arch/microblaze/include/asm/system.h
+++ b/arch/microblaze/include/asm/system.h
@@ -45,7 +45,6 @@ extern struct task_struct *_switch_to(struct thread_info *prev,
45#define smp_rmb() rmb() 45#define smp_rmb() rmb()
46#define smp_wmb() wmb() 46#define smp_wmb() wmb()
47 47
48void show_trace(struct task_struct *task, unsigned long *stack);
49void __bad_xchg(volatile void *ptr, int size); 48void __bad_xchg(volatile void *ptr, int size);
50 49
51static inline unsigned long __xchg(unsigned long x, volatile void *ptr, 50static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
diff --git a/arch/microblaze/include/asm/unwind.h b/arch/microblaze/include/asm/unwind.h
new file mode 100644
index 000000000000..d248b7de4b13
--- /dev/null
+++ b/arch/microblaze/include/asm/unwind.h
@@ -0,0 +1,29 @@
1/*
2 * Backtrace support for Microblaze
3 *
4 * Copyright (C) 2010 Digital Design Corporation
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10
11#ifndef __MICROBLAZE_UNWIND_H
12#define __MICROBLAZE_UNWIND_H
13
14struct stack_trace;
15
16struct trap_handler_info {
17 unsigned long start_addr;
18 unsigned long end_addr;
19 const char *trap_name;
20};
21extern struct trap_handler_info microblaze_trap_handlers;
22
23extern const char _hw_exception_handler;
24extern const char ex_handler_unhandled;
25
26void microblaze_unwind(struct task_struct *task, struct stack_trace *trace);
27
28#endif /* __MICROBLAZE_UNWIND_H */
29
diff --git a/arch/microblaze/kernel/Makefile b/arch/microblaze/kernel/Makefile
index e51bc1520825..d66ddef53c07 100644
--- a/arch/microblaze/kernel/Makefile
+++ b/arch/microblaze/kernel/Makefile
@@ -17,7 +17,7 @@ extra-y := head.o vmlinux.lds
17obj-y += dma.o exceptions.o \ 17obj-y += dma.o exceptions.o \
18 hw_exception_handler.o init_task.o intc.o irq.o of_device.o \ 18 hw_exception_handler.o init_task.o intc.o irq.o of_device.o \
19 of_platform.o process.o prom.o prom_parse.o ptrace.o \ 19 of_platform.o process.o prom.o prom_parse.o ptrace.o \
20 setup.o signal.o sys_microblaze.o timer.o traps.o reset.o 20 reset.o setup.o signal.o sys_microblaze.o timer.o traps.o unwind.o
21 21
22obj-y += cpu/ 22obj-y += cpu/
23 23
diff --git a/arch/microblaze/kernel/entry-nommu.S b/arch/microblaze/kernel/entry-nommu.S
index 8cc18cd2cce6..ca84368570b6 100644
--- a/arch/microblaze/kernel/entry-nommu.S
+++ b/arch/microblaze/kernel/entry-nommu.S
@@ -588,3 +588,31 @@ sys_rt_sigsuspend_wrapper:
588#include "syscall_table.S" 588#include "syscall_table.S"
589 589
590syscall_table_size=(.-sys_call_table) 590syscall_table_size=(.-sys_call_table)
591
592type_SYSCALL:
593 .ascii "SYSCALL\0"
594type_IRQ:
595 .ascii "IRQ\0"
596type_IRQ_PREEMPT:
597 .ascii "IRQ (PREEMPTED)\0"
598type_SYSCALL_PREEMPT:
599 .ascii " SYSCALL (PREEMPTED)\0"
600
601 /*
602 * Trap decoding for stack unwinder
603 * Tuples are (start addr, end addr, string)
604 * If return address lies on [start addr, end addr],
605 * unwinder displays 'string'
606 */
607
608 .align 4
609.global microblaze_trap_handlers
610microblaze_trap_handlers:
611 /* Exact matches come first */
612 .word ret_to_user ; .word ret_to_user ; .word type_SYSCALL
613 .word ret_from_intr; .word ret_from_intr ; .word type_IRQ
614 /* Fuzzy matches go here */
615 .word ret_from_intr; .word no_intr_resched; .word type_IRQ_PREEMPT
616 .word work_pending ; .word no_work_pending; .word type_SYSCALL_PREEMPT
617 /* End of table */
618 .word 0 ; .word 0 ; .word 0
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index 077377a5d0ca..7a19d8910e3b 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -1127,3 +1127,30 @@ ENTRY(_break)
1127 1127
1128syscall_table_size=(.-sys_call_table) 1128syscall_table_size=(.-sys_call_table)
1129 1129
1130type_SYSCALL:
1131 .ascii "SYSCALL\0"
1132type_IRQ:
1133 .ascii "IRQ\0"
1134type_IRQ_PREEMPT:
1135 .ascii "IRQ (PREEMPTED)\0"
1136type_SYSCALL_PREEMPT:
1137 .ascii " SYSCALL (PREEMPTED)\0"
1138
1139 /*
1140 * Trap decoding for stack unwinder
1141 * Tuples are (start addr, end addr, string)
1142 * If return address lies on [start addr, end addr],
1143 * unwinder displays 'string'
1144 */
1145
1146 .align 4
1147.global microblaze_trap_handlers
1148microblaze_trap_handlers:
1149 /* Exact matches come first */
1150 .word ret_from_trap; .word ret_from_trap ; .word type_SYSCALL
1151 .word ret_from_irq ; .word ret_from_irq ; .word type_IRQ
1152 /* Fuzzy matches go here */
1153 .word ret_from_irq ; .word no_intr_resched ; .word type_IRQ_PREEMPT
1154 .word ret_from_trap; .word TRAP_return ; .word type_SYSCALL_PREEMPT
1155 /* End of table */
1156 .word 0 ; .word 0 ; .word 0
diff --git a/arch/microblaze/kernel/hw_exception_handler.S b/arch/microblaze/kernel/hw_exception_handler.S
index 995a2123635b..781195438ee6 100644
--- a/arch/microblaze/kernel/hw_exception_handler.S
+++ b/arch/microblaze/kernel/hw_exception_handler.S
@@ -78,9 +78,6 @@
78#include <asm/asm-offsets.h> 78#include <asm/asm-offsets.h>
79 79
80/* Helpful Macros */ 80/* Helpful Macros */
81#ifndef CONFIG_MMU
82#define EX_HANDLER_STACK_SIZ (4*19)
83#endif
84#define NUM_TO_REG(num) r ## num 81#define NUM_TO_REG(num) r ## num
85 82
86#ifdef CONFIG_MMU 83#ifdef CONFIG_MMU
@@ -988,6 +985,7 @@ ex_unaligned_fixup:
988.end _unaligned_data_exception 985.end _unaligned_data_exception
989#endif /* CONFIG_MMU */ 986#endif /* CONFIG_MMU */
990 987
988.global ex_handler_unhandled
991ex_handler_unhandled: 989ex_handler_unhandled:
992/* FIXME add handle function for unhandled exception - dump register */ 990/* FIXME add handle function for unhandled exception - dump register */
993 bri 0 991 bri 0
diff --git a/arch/microblaze/kernel/stacktrace.c b/arch/microblaze/kernel/stacktrace.c
index 123692f22647..84bc6686102c 100644
--- a/arch/microblaze/kernel/stacktrace.c
+++ b/arch/microblaze/kernel/stacktrace.c
@@ -14,52 +14,18 @@
14#include <linux/thread_info.h> 14#include <linux/thread_info.h>
15#include <linux/ptrace.h> 15#include <linux/ptrace.h>
16#include <linux/module.h> 16#include <linux/module.h>
17#include <asm/unwind.h>
17 18
18/* FIXME initial support */
19void save_stack_trace(struct stack_trace *trace) 19void save_stack_trace(struct stack_trace *trace)
20{ 20{
21 unsigned long *sp; 21 /* Exclude our helper functions from the trace*/
22 unsigned long addr; 22 trace->skip += 2;
23 asm("addik %0, r1, 0" : "=r" (sp)); 23 microblaze_unwind(NULL, trace);
24
25 while (!kstack_end(sp)) {
26 addr = *sp++;
27 if (__kernel_text_address(addr)) {
28 if (trace->skip > 0)
29 trace->skip--;
30 else
31 trace->entries[trace->nr_entries++] = addr;
32
33 if (trace->nr_entries >= trace->max_entries)
34 break;
35 }
36 }
37} 24}
38EXPORT_SYMBOL_GPL(save_stack_trace); 25EXPORT_SYMBOL_GPL(save_stack_trace);
39 26
40void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 27void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
41{ 28{
42 unsigned int *sp; 29 microblaze_unwind(tsk, trace);
43 unsigned long addr;
44
45 struct thread_info *ti = task_thread_info(tsk);
46
47 if (tsk == current)
48 asm("addik %0, r1, 0" : "=r" (sp));
49 else
50 sp = (unsigned int *)ti->cpu_context.r1;
51
52 while (!kstack_end(sp)) {
53 addr = *sp++;
54 if (__kernel_text_address(addr)) {
55 if (trace->skip > 0)
56 trace->skip--;
57 else
58 trace->entries[trace->nr_entries++] = addr;
59
60 if (trace->nr_entries >= trace->max_entries)
61 break;
62 }
63 }
64} 30}
65EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 31EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
diff --git a/arch/microblaze/kernel/traps.c b/arch/microblaze/kernel/traps.c
index 75e49202a5ed..ba034d421ec2 100644
--- a/arch/microblaze/kernel/traps.c
+++ b/arch/microblaze/kernel/traps.c
@@ -16,13 +16,14 @@
16 16
17#include <asm/exceptions.h> 17#include <asm/exceptions.h>
18#include <asm/system.h> 18#include <asm/system.h>
19#include <asm/unwind.h>
19 20
20void trap_init(void) 21void trap_init(void)
21{ 22{
22 __enable_hw_exceptions(); 23 __enable_hw_exceptions();
23} 24}
24 25
25static unsigned long kstack_depth_to_print = 24; 26static unsigned long kstack_depth_to_print; /* 0 == entire stack */
26 27
27static int __init kstack_setup(char *s) 28static int __init kstack_setup(char *s)
28{ 29{
@@ -30,31 +31,47 @@ static int __init kstack_setup(char *s)
30} 31}
31__setup("kstack=", kstack_setup); 32__setup("kstack=", kstack_setup);
32 33
33void show_trace(struct task_struct *task, unsigned long *stack) 34void show_stack(struct task_struct *task, unsigned long *sp)
34{ 35{
35 unsigned long addr; 36 unsigned long words_to_show;
36 37 u32 fp = (u32) sp;
37 if (!stack) 38
38 stack = (unsigned long *)&stack; 39 if (fp == 0) {
40 if (task) {
41 fp = ((struct thread_info *)
42 (task->stack))->cpu_context.r1;
43 } else {
44 /* Pick up caller of dump_stack() */
45 fp = (u32)&sp - 8;
46 }
47 }
39 48
40 printk(KERN_NOTICE "Call Trace: "); 49 words_to_show = (THREAD_SIZE - (fp & (THREAD_SIZE - 1))) >> 2;
41#ifdef CONFIG_KALLSYMS 50 if (kstack_depth_to_print && (words_to_show > kstack_depth_to_print))
42 printk(KERN_NOTICE "\n"); 51 words_to_show = kstack_depth_to_print;
43#endif 52
44 while (!kstack_end(stack)) { 53 pr_info("Kernel Stack:\n");
45 addr = *stack++; 54
46 /* 55 /*
47 * If the address is either in the text segment of the 56 * Make the first line an 'odd' size if necessary to get
48 * kernel, or in the region which contains vmalloc'ed 57 * remaining lines to start at an address multiple of 0x10
49 * memory, it *may* be the address of a calling 58 */
50 * routine; if so, print it so that someone tracing 59 if (fp & 0xF) {
51 * down the cause of the crash will be able to figure 60 unsigned long line1_words = (0x10 - (fp & 0xF)) >> 2;
52 * out the call path that was taken. 61 if (line1_words < words_to_show) {
53 */ 62 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 32,
54 if (kernel_text_address(addr)) 63 4, (void *)fp, line1_words << 2, 0);
55 print_ip_sym(addr); 64 fp += line1_words << 2;
65 words_to_show -= line1_words;
66 }
56 } 67 }
57 printk(KERN_NOTICE "\n"); 68 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 32, 4, (void *)fp,
69 words_to_show << 2, 0);
70 printk(KERN_INFO "\n\n");
71
72 pr_info("Call Trace:\n");
73 microblaze_unwind(task, NULL);
74 pr_info("\n");
58 75
59 if (!task) 76 if (!task)
60 task = current; 77 task = current;
@@ -62,34 +79,6 @@ void show_trace(struct task_struct *task, unsigned long *stack)
62 debug_show_held_locks(task); 79 debug_show_held_locks(task);
63} 80}
64 81
65void show_stack(struct task_struct *task, unsigned long *sp)
66{
67 unsigned long *stack;
68 int i;
69
70 if (sp == NULL) {
71 if (task)
72 sp = (unsigned long *) ((struct thread_info *)
73 (task->stack))->cpu_context.r1;
74 else
75 sp = (unsigned long *)&sp;
76 }
77
78 stack = sp;
79
80 printk(KERN_INFO "\nStack:\n ");
81
82 for (i = 0; i < kstack_depth_to_print; i++) {
83 if (kstack_end(sp))
84 break;
85 if (i && ((i % 8) == 0))
86 printk("\n ");
87 printk("%08lx ", *sp++);
88 }
89 printk("\n");
90 show_trace(task, stack);
91}
92
93void dump_stack(void) 82void dump_stack(void)
94{ 83{
95 show_stack(NULL, NULL); 84 show_stack(NULL, NULL);
diff --git a/arch/microblaze/kernel/unwind.c b/arch/microblaze/kernel/unwind.c
new file mode 100644
index 000000000000..fefac5c33586
--- /dev/null
+++ b/arch/microblaze/kernel/unwind.c
@@ -0,0 +1,318 @@
1/*
2 * Backtrace support for Microblaze
3 *
4 * Copyright (C) 2010 Digital Design Corporation
5 *
6 * Based on arch/sh/kernel/cpu/sh5/unwind.c code which is:
7 * Copyright (C) 2004 Paul Mundt
8 * Copyright (C) 2004 Richard Curnow
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file "COPYING" in the main directory of this archive
12 * for more details.
13 */
14
15/* #define DEBUG 1 */
16#include <linux/kallsyms.h>
17#include <linux/kernel.h>
18#include <linux/sched.h>
19#include <linux/stacktrace.h>
20#include <linux/types.h>
21#include <linux/errno.h>
22#include <linux/module.h>
23#include <linux/io.h>
24#include <asm/sections.h>
25#include <asm/exceptions.h>
26#include <asm/unwind.h>
27
28struct stack_trace;
29
30/*
31 * On Microblaze, finding the previous stack frame is a little tricky.
32 * At this writing (3/2010), Microblaze does not support CONFIG_FRAME_POINTERS,
33 * and even if it did, gcc (4.1.2) does not store the frame pointer at
34 * a consistent offset within each frame. To determine frame size, it is
35 * necessary to search for the assembly instruction that creates or reclaims
36 * the frame and extract the size from it.
37 *
38 * Microblaze stores the stack pointer in r1, and creates a frame via
39 *
40 * addik r1, r1, -FRAME_SIZE
41 *
42 * The frame is reclaimed via
43 *
44 * addik r1, r1, FRAME_SIZE
45 *
46 * Frame creation occurs at or near the top of a function.
47 * Depending on the compiler, reclaim may occur at the end, or before
48 * a mid-function return.
49 *
50 * A stack frame is usually not created in a leaf function.
51 *
52 */
53
54/**
55 * get_frame_size - Extract the stack adjustment from an
56 * "addik r1, r1, adjust" instruction
57 * @instr : Microblaze instruction
58 *
59 * Return - Number of stack bytes the instruction reserves or reclaims
60 */
61inline long get_frame_size(unsigned long instr)
62{
63 return abs((s16)(instr & 0xFFFF));
64}
65
66/**
67 * find_frame_creation - Search backward to find the instruction that creates
68 * the stack frame (hopefully, for the same function the
69 * initial PC is in).
70 * @pc : Program counter at which to begin the search
71 *
72 * Return - PC at which stack frame creation occurs
73 * NULL if this cannot be found, i.e. a leaf function
74 */
75static unsigned long *find_frame_creation(unsigned long *pc)
76{
77 int i;
78
79 /* NOTE: Distance to search is arbitrary
80 * 250 works well for most things,
81 * 750 picks up things like tcp_recvmsg(),
82 * 1000 needed for fat_fill_super()
83 */
84 for (i = 0; i < 1000; i++, pc--) {
85 unsigned long instr;
86 s16 frame_size;
87
88 if (!kernel_text_address((unsigned long) pc))
89 return NULL;
90
91 instr = *pc;
92
93 /* addik r1, r1, foo ? */
94 if ((instr & 0xFFFF0000) != 0x30210000)
95 continue; /* No */
96
97 frame_size = get_frame_size(instr);
98 if ((frame_size < 8) || (frame_size & 3)) {
99 pr_debug(" Invalid frame size %d at 0x%p\n",
100 frame_size, pc);
101 return NULL;
102 }
103
104 pr_debug(" Found frame creation at 0x%p, size %d\n", pc,
105 frame_size);
106 return pc;
107 }
108
109 return NULL;
110}
111
112/**
113 * lookup_prev_stack_frame - Find the stack frame of the previous function.
114 * @fp : Frame (stack) pointer for current function
115 * @pc : Program counter within current function
116 * @leaf_return : r15 value within current function. If the current function
117 * is a leaf, this is the caller's return address.
118 * @pprev_fp : On exit, set to frame (stack) pointer for previous function
119 * @pprev_pc : On exit, set to current function caller's return address
120 *
121 * Return - 0 on success, -EINVAL if the previous frame cannot be found
122 */
123static int lookup_prev_stack_frame(unsigned long fp, unsigned long pc,
124 unsigned long leaf_return,
125 unsigned long *pprev_fp,
126 unsigned long *pprev_pc)
127{
128 unsigned long *prologue = NULL;
129
130 /* _switch_to is a special leaf function */
131 if (pc != (unsigned long) &_switch_to)
132 prologue = find_frame_creation((unsigned long *)pc);
133
134 if (prologue) {
135 long frame_size = get_frame_size(*prologue);
136
137 *pprev_fp = fp + frame_size;
138 *pprev_pc = *(unsigned long *)fp;
139 } else {
140 if (!leaf_return)
141 return -EINVAL;
142 *pprev_pc = leaf_return;
143 *pprev_fp = fp;
144 }
145
146 /* NOTE: don't check kernel_text_address here, to allow display
147 * of userland return address
148 */
149 return (!*pprev_pc || (*pprev_pc & 3)) ? -EINVAL : 0;
150}
151
152static void microblaze_unwind_inner(struct task_struct *task,
153 unsigned long pc, unsigned long fp,
154 unsigned long leaf_return,
155 struct stack_trace *trace);
156
157/**
158 * unwind_trap - Unwind through a system trap, that stored previous state
159 * on the stack.
160 */
161#ifdef CONFIG_MMU
162static inline void unwind_trap(struct task_struct *task, unsigned long pc,
163 unsigned long fp, struct stack_trace *trace)
164{
165 /* To be implemented */
166}
167#else
168static inline void unwind_trap(struct task_struct *task, unsigned long pc,
169 unsigned long fp, struct stack_trace *trace)
170{
171 const struct pt_regs *regs = (const struct pt_regs *) fp;
172 microblaze_unwind_inner(task, regs->pc, regs->r1, regs->r15, trace);
173}
174#endif
175
176/**
177 * microblaze_unwind_inner - Unwind the stack from the specified point
178 * @task : Task whose stack we are to unwind (may be NULL)
179 * @pc : Program counter from which we start unwinding
180 * @fp : Frame (stack) pointer from which we start unwinding
181 * @leaf_return : Value of r15 at pc. If the function is a leaf, this is
182 * the caller's return address.
183 * @trace : Where to store stack backtrace (PC values).
184 * NULL == print backtrace to kernel log
185 */
186void microblaze_unwind_inner(struct task_struct *task,
187 unsigned long pc, unsigned long fp,
188 unsigned long leaf_return,
189 struct stack_trace *trace)
190{
191 int ofs = 0;
192
193 pr_debug(" Unwinding with PC=%p, FP=%p\n", (void *)pc, (void *)fp);
194 if (!pc || !fp || (pc & 3) || (fp & 3)) {
195 pr_debug(" Invalid state for unwind, aborting\n");
196 return;
197 }
198 for (; pc != 0;) {
199 unsigned long next_fp, next_pc = 0;
200 unsigned long return_to = pc + 2 * sizeof(unsigned long);
201 const struct trap_handler_info *handler =
202 &microblaze_trap_handlers;
203
204 /* Is previous function the HW exception handler? */
205 if ((return_to >= (unsigned long)&_hw_exception_handler)
206 &&(return_to < (unsigned long)&ex_handler_unhandled)) {
207 /*
208 * HW exception handler doesn't save all registers,
209 * so we open-code a special case of unwind_trap()
210 */
211#ifndef CONFIG_MMU
212 const struct pt_regs *regs =
213 (const struct pt_regs *) fp;
214#endif
215 pr_info("HW EXCEPTION\n");
216#ifndef CONFIG_MMU
217 microblaze_unwind_inner(task, regs->r17 - 4,
218 fp + EX_HANDLER_STACK_SIZ,
219 regs->r15, trace);
220#endif
221 return;
222 }
223
224 /* Is previous function a trap handler? */
225 for (; handler->start_addr; ++handler) {
226 if ((return_to >= handler->start_addr)
227 && (return_to <= handler->end_addr)) {
228 if (!trace)
229 pr_info("%s\n", handler->trap_name);
230 unwind_trap(task, pc, fp, trace);
231 return;
232 }
233 }
234 pc -= ofs;
235
236 if (trace) {
237#ifdef CONFIG_STACKTRACE
238 if (trace->skip > 0)
239 trace->skip--;
240 else
241 trace->entries[trace->nr_entries++] = pc;
242
243 if (trace->nr_entries >= trace->max_entries)
244 break;
245#endif
246 } else {
247 /* Have we reached userland? */
248 if (unlikely(pc == task_pt_regs(task)->pc)) {
249 pr_info("[<%p>] PID %lu [%s]\n",
250 (void *) pc,
251 (unsigned long) task->pid,
252 task->comm);
253 break;
254 } else
255 print_ip_sym(pc);
256 }
257
258 /* Stop when we reach anything not part of the kernel */
259 if (!kernel_text_address(pc))
260 break;
261
262 if (lookup_prev_stack_frame(fp, pc, leaf_return, &next_fp,
263 &next_pc) == 0) {
264 ofs = sizeof(unsigned long);
265 pc = next_pc & ~3;
266 fp = next_fp;
267 leaf_return = 0;
268 } else {
269 pr_debug(" Failed to find previous stack frame\n");
270 break;
271 }
272
273 pr_debug(" Next PC=%p, next FP=%p\n",
274 (void *)next_pc, (void *)next_fp);
275 }
276}
277
278/**
279 * microblaze_unwind - Stack unwinder for Microblaze (external entry point)
280 * @task : Task whose stack we are to unwind (NULL == current)
281 * @trace : Where to store stack backtrace (PC values).
282 * NULL == print backtrace to kernel log
283 */
284void microblaze_unwind(struct task_struct *task, struct stack_trace *trace)
285{
286 if (task) {
287 if (task == current) {
288 const struct pt_regs *regs = task_pt_regs(task);
289 microblaze_unwind_inner(task, regs->pc, regs->r1,
290 regs->r15, trace);
291 } else {
292 struct thread_info *thread_info =
293 (struct thread_info *)(task->stack);
294 const struct cpu_context *cpu_context =
295 &thread_info->cpu_context;
296
297 microblaze_unwind_inner(task,
298 (unsigned long) &_switch_to,
299 cpu_context->r1,
300 cpu_context->r15, trace);
301 }
302 } else {
303 unsigned long pc, fp;
304
305 __asm__ __volatile__ ("or %0, r1, r0" : "=r" (fp));
306
307 __asm__ __volatile__ (
308 "brlid %0, 0f;"
309 "nop;"
310 "0:"
311 : "=r" (pc)
312 );
313
314 /* Since we are not a leaf function, use leaf_return = 0 */
315 microblaze_unwind_inner(current, pc, fp, 0, trace);
316 }
317}
318
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-29 18:43:57 -0500