diff options
| -rw-r--r-- | arch/microblaze/include/asm/exceptions.h | 5 | ||||
| -rw-r--r-- | arch/microblaze/include/asm/system.h | 1 | ||||
| -rw-r--r-- | arch/microblaze/include/asm/unwind.h | 29 | ||||
| -rw-r--r-- | arch/microblaze/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/microblaze/kernel/entry-nommu.S | 28 | ||||
| -rw-r--r-- | arch/microblaze/kernel/entry.S | 27 | ||||
| -rw-r--r-- | arch/microblaze/kernel/hw_exception_handler.S | 4 | ||||
| -rw-r--r-- | arch/microblaze/kernel/stacktrace.c | 44 | ||||
| -rw-r--r-- | arch/microblaze/kernel/traps.c | 91 | ||||
| -rw-r--r-- | arch/microblaze/kernel/unwind.c | 318 |
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 @@ #define _ASM_MICROBLAZE_EXCEPTIONS_H #ifdef __KERNEL__ + +#ifndef CONFIG_MMU +#define EX_HANDLER_STACK_SIZ (4*19) +#endif + #ifndef __ASSEMBLY__ /* 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, #define smp_rmb() rmb() #define smp_wmb() wmb() -void show_trace(struct task_struct *task, unsigned long *stack); void __bad_xchg(volatile void *ptr, int size); static 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 @@ +/* + * Backtrace support for Microblaze + * + * Copyright (C) 2010 Digital Design Corporation + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#ifndef __MICROBLAZE_UNWIND_H +#define __MICROBLAZE_UNWIND_H + +struct stack_trace; + +struct trap_handler_info { + unsigned long start_addr; + unsigned long end_addr; + const char *trap_name; +}; +extern struct trap_handler_info microblaze_trap_handlers; + +extern const char _hw_exception_handler; +extern const char ex_handler_unhandled; + +void microblaze_unwind(struct task_struct *task, struct stack_trace *trace); + +#endif /* __MICROBLAZE_UNWIND_H */ + 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 obj-y += dma.o exceptions.o \ hw_exception_handler.o init_task.o intc.o irq.o of_device.o \ of_platform.o process.o prom.o prom_parse.o ptrace.o \ - setup.o signal.o sys_microblaze.o timer.o traps.o reset.o + reset.o setup.o signal.o sys_microblaze.o timer.o traps.o unwind.o obj-y += cpu/ 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: #include "syscall_table.S" syscall_table_size=(.-sys_call_table) + +type_SYSCALL: + .ascii "SYSCALL\0" +type_IRQ: + .ascii "IRQ\0" +type_IRQ_PREEMPT: + .ascii "IRQ (PREEMPTED)\0" +type_SYSCALL_PREEMPT: + .ascii " SYSCALL (PREEMPTED)\0" + + /* + * Trap decoding for stack unwinder + * Tuples are (start addr, end addr, string) + * If return address lies on [start addr, end addr], + * unwinder displays 'string' + */ + + .align 4 +.global microblaze_trap_handlers +microblaze_trap_handlers: + /* Exact matches come first */ + .word ret_to_user ; .word ret_to_user ; .word type_SYSCALL + .word ret_from_intr; .word ret_from_intr ; .word type_IRQ + /* Fuzzy matches go here */ + .word ret_from_intr; .word no_intr_resched; .word type_IRQ_PREEMPT + .word work_pending ; .word no_work_pending; .word type_SYSCALL_PREEMPT + /* End of table */ + .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) syscall_table_size=(.-sys_call_table) +type_SYSCALL: + .ascii "SYSCALL\0" +type_IRQ: + .ascii "IRQ\0" +type_IRQ_PREEMPT: + .ascii "IRQ (PREEMPTED)\0" +type_SYSCALL_PREEMPT: + .ascii " SYSCALL (PREEMPTED)\0" + + /* + * Trap decoding for stack unwinder + * Tuples are (start addr, end addr, string) + * If return address lies on [start addr, end addr], + * unwinder displays 'string' + */ + + .align 4 +.global microblaze_trap_handlers +microblaze_trap_handlers: + /* Exact matches come first */ + .word ret_from_trap; .word ret_from_trap ; .word type_SYSCALL + .word ret_from_irq ; .word ret_from_irq ; .word type_IRQ + /* Fuzzy matches go here */ + .word ret_from_irq ; .word no_intr_resched ; .word type_IRQ_PREEMPT + .word ret_from_trap; .word TRAP_return ; .word type_SYSCALL_PREEMPT + /* End of table */ + .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 @@ #include <asm/asm-offsets.h> /* Helpful Macros */ -#ifndef CONFIG_MMU -#define EX_HANDLER_STACK_SIZ (4*19) -#endif #define NUM_TO_REG(num) r ## num #ifdef CONFIG_MMU @@ -988,6 +985,7 @@ ex_unaligned_fixup: .end _unaligned_data_exception #endif /* CONFIG_MMU */ +.global ex_handler_unhandled ex_handler_unhandled: /* FIXME add handle function for unhandled exception - dump register */ 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 @@ #include <linux/thread_info.h> #include <linux/ptrace.h> #include <linux/module.h> +#include <asm/unwind.h> -/* FIXME initial support */ void save_stack_trace(struct stack_trace *trace) { - unsigned long *sp; - unsigned long addr; - asm("addik %0, r1, 0" : "=r" (sp)); - - 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; - } - } + /* Exclude our helper functions from the trace*/ + trace->skip += 2; + microblaze_unwind(NULL, trace); } EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { - unsigned int *sp; - unsigned long addr; - - struct thread_info *ti = task_thread_info(tsk); - - if (tsk == current) - asm("addik %0, r1, 0" : "=r" (sp)); - else - sp = (unsigned int *)ti->cpu_context.r1; - - 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; - } - } + microblaze_unwind(tsk, trace); } EXPORT_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 @@ #include <asm/exceptions.h> #include <asm/system.h> +#include <asm/unwind.h> void trap_init(void) { __enable_hw_exceptions(); } -static unsigned long kstack_depth_to_print = 24; +static unsigned long kstack_depth_to_print; /* 0 == entire stack */ static int __init kstack_setup(char *s) { @@ -30,31 +31,47 @@ static int __init kstack_setup(char *s) } __setup("kstack=", kstack_setup); -void show_trace(struct task_struct *task, unsigned long *stack) +void show_stack(struct task_struct *task, unsigned long *sp) { - unsigned long addr; - - if (!stack) - stack = (unsigned long *)&stack; + unsigned long words_to_show; + u32 fp = (u32) sp; + + if (fp == 0) { + if (task) { + fp = ((struct thread_info *) + (task->stack))->cpu_context.r1; + } else { + /* Pick up caller of dump_stack() */ + fp = (u32)&sp - 8; + } + } - printk(KERN_NOTICE "Call Trace: "); -#ifdef CONFIG_KALLSYMS - printk(KERN_NOTICE "\n"); -#endif - while (!kstack_end(stack)) { - addr = *stack++; - /* - * If the address is either in the text segment of the - * kernel, or in the region which contains vmalloc'ed - * memory, it *may* be the address of a calling - * routine; if so, print it so that someone tracing - * down the cause of the crash will be able to figure - * out the call path that was taken. - */ - if (kernel_text_address(addr)) - print_ip_sym(addr); + words_to_show = (THREAD_SIZE - (fp & (THREAD_SIZE - 1))) >> 2; + if (kstack_depth_to_print && (words_to_show > kstack_depth_to_print)) + words_to_show = kstack_depth_to_print; + + pr_info("Kernel Stack:\n"); + + /* + * Make the first line an 'odd' size if necessary to get + * remaining lines to start at an address multiple of 0x10 + */ + if (fp & 0xF) { + unsigned long line1_words = (0x10 - (fp & 0xF)) >> 2; + if (line1_words < words_to_show) { + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 32, + 4, (void *)fp, line1_words << 2, 0); + fp += line1_words << 2; + words_to_show -= line1_words; + } } - printk(KERN_NOTICE "\n"); + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 32, 4, (void *)fp, + words_to_show << 2, 0); + printk(KERN_INFO "\n\n"); + + pr_info("Call Trace:\n"); + microblaze_unwind(task, NULL); + pr_info("\n"); if (!task) task = current; @@ -62,34 +79,6 @@ void show_trace(struct task_struct *task, unsigned long *stack) debug_show_held_locks(task); } -void show_stack(struct task_struct *task, unsigned long *sp) -{ - unsigned long *stack; - int i; - - if (sp == NULL) { - if (task) - sp = (unsigned long *) ((struct thread_info *) - (task->stack))->cpu_context.r1; - else - sp = (unsigned long *)&sp; - } - - stack = sp; - - printk(KERN_INFO "\nStack:\n "); - - for (i = 0; i < kstack_depth_to_print; i++) { - if (kstack_end(sp)) - break; - if (i && ((i % 8) == 0)) - printk("\n "); - printk("%08lx ", *sp++); - } - printk("\n"); - show_trace(task, stack); -} - void dump_stack(void) { 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 @@ +/* + * Backtrace support for Microblaze + * + * Copyright (C) 2010 Digital Design Corporation + * + * Based on arch/sh/kernel/cpu/sh5/unwind.c code which is: + * Copyright (C) 2004 Paul Mundt + * Copyright (C) 2004 Richard Curnow + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +/* #define DEBUG 1 */ +#include <linux/kallsyms.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/stacktrace.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/io.h> +#include <asm/sections.h> +#include <asm/exceptions.h> +#include <asm/unwind.h> + +struct stack_trace; + +/* + * On Microblaze, finding the previous stack frame is a little tricky. + * At this writing (3/2010), Microblaze does not support CONFIG_FRAME_POINTERS, + * and even if it did, gcc (4.1.2) does not store the frame pointer at + * a consistent offset within each frame. To determine frame size, it is + * necessary to search for the assembly instruction that creates or reclaims + * the frame and extract the size from it. + * + * Microblaze stores the stack pointer in r1, and creates a frame via + * + * addik r1, r1, -FRAME_SIZE + * + * The frame is reclaimed via + * + * addik r1, r1, FRAME_SIZE + * + * Frame creation occurs at or near the top of a function. + * Depending on the compiler, reclaim may occur at the end, or before + * a mid-function return. + * + * A stack frame is usually not created in a leaf function. + * + */ + +/** + * get_frame_size - Extract the stack adjustment from an + * "addik r1, r1, adjust" instruction + * @instr : Microblaze instruction + * + * Return - Number of stack bytes the instruction reserves or reclaims + */ +inline long get_frame_size(unsigned long instr) +{ + return abs((s16)(instr & 0xFFFF)); +} + +/** + * find_frame_creation - Search backward to find the instruction that creates + * the stack frame (hopefully, for the same function the + * initial PC is in). + * @pc : Program counter at which to begin the search + * + * Return - PC at which stack frame creation occurs + * NULL if this cannot be found, i.e. a leaf function + */ +static unsigned long *find_frame_creation(unsigned long *pc) +{ + int i; + + /* NOTE: Distance to search is arbitrary + * 250 works well for most things, + * 750 picks up things like tcp_recvmsg(), + * 1000 needed for fat_fill_super() + */ + for (i = 0; i < 1000; i++, pc--) { + unsigned long instr; + s16 frame_size; + + if (!kernel_text_address((unsigned long) pc)) + return NULL; + + instr = *pc; + + /* addik r1, r1, foo ? */ + if ((instr & 0xFFFF0000) != 0x30210000) + continue; /* No */ + + frame_size = get_frame_size(instr); + if ((frame_size < 8) || (frame_size & 3)) { + pr_debug(" Invalid frame size %d at 0x%p\n", + frame_size, pc); + return NULL; + } + + pr_debug(" Found frame creation at 0x%p, size %d\n", pc, + frame_size); + return pc; + } + + return NULL; +} + +/** + * lookup_prev_stack_frame - Find the stack frame of the previous function. + * @fp : Frame (stack) pointer for current function + * @pc : Program counter within current function + * @leaf_return : r15 value within current function. If the current function + * is a leaf, this is the caller's return address. + * @pprev_fp : On exit, set to frame (stack) pointer for previous function + * @pprev_pc : On exit, set to current function caller's return address + * + * Return - 0 on success, -EINVAL if the previous frame cannot be found + */ +static int lookup_prev_stack_frame(unsigned long fp, unsigned long pc, + unsigned long leaf_return, + unsigned long *pprev_fp, + unsigned long *pprev_pc) +{ + unsigned long *prologue = NULL; + + /* _switch_to is a special leaf function */ + if (pc != (unsigned long) &_switch_to) + prologue = find_frame_creation((unsigned long *)pc); + + if (prologue) { + long frame_size = get_frame_size(*prologue); + + *pprev_fp = fp + frame_size; + *pprev_pc = *(unsigned long *)fp; + } else { + if (!leaf_return) + return -EINVAL; + *pprev_pc = leaf_return; + *pprev_fp = fp; + } + + /* NOTE: don't check kernel_text_address here, to allow display + * of userland return address + */ + return (!*pprev_pc || (*pprev_pc & 3)) ? -EINVAL : 0; +} + +static void microblaze_unwind_inner(struct task_struct *task, + unsigned long pc, unsigned long fp, + unsigned long leaf_return, + struct stack_trace *trace); + +/** + * unwind_trap - Unwind through a system trap, that stored previous state + * on the stack. + */ +#ifdef CONFIG_MMU +static inline void unwind_trap(struct task_struct *task, unsigned long pc, + unsigned long fp, struct stack_trace *trace) +{ + /* To be implemented */ +} +#else +static inline void unwind_trap(struct task_struct *task, unsigned long pc, + unsigned long fp, struct stack_trace *trace) +{ + const struct pt_regs *regs = (const struct pt_regs *) fp; + microblaze_unwind_inner(task, regs->pc, regs->r1, regs->r15, trace); +} +#endif + +/** + * microblaze_unwind_inner - Unwind the stack from the specified point + * @task : Task whose stack we are to unwind (may be NULL) + * @pc : Program counter from which we start unwinding + * @fp : Frame (stack) pointer from which we start unwinding + * @leaf_return : Value of r15 at pc. If the function is a leaf, this is + * the caller's return address. + * @trace : Where to store stack backtrace (PC values). + * NULL == print backtrace to kernel log + */ +void microblaze_unwind_inner(struct task_struct *task, + unsigned long pc, unsigned long fp, + unsigned long leaf_return, + struct stack_trace *trace) +{ + int ofs = 0; + + pr_debug(" Unwinding with PC=%p, FP=%p\n", (void *)pc, (void *)fp); + if (!pc || !fp || (pc & 3) || (fp & 3)) { + pr_debug(" Invalid state for unwind, aborting\n"); + return; + } + for (; pc != 0;) { + unsigned long next_fp, next_pc = 0; + unsigned long return_to = pc + 2 * sizeof(unsigned long); + const struct trap_handler_info *handler = + µblaze_trap_handlers; + + /* Is previous function the HW exception handler? */ + if ((return_to >= (unsigned long)&_hw_exception_handler) + &&(return_to < (unsigned long)&ex_handler_unhandled)) { + /* + * HW exception handler doesn't save all registers, + * so we open-code a special case of unwind_trap() + */ +#ifndef CONFIG_MMU + const struct pt_regs *regs = + (const struct pt_regs *) fp; +#endif + pr_info("HW EXCEPTION\n"); +#ifndef CONFIG_MMU + microblaze_unwind_inner(task, regs->r17 - 4, + fp + EX_HANDLER_STACK_SIZ, + regs->r15, trace); +#endif + return; + } + + /* Is previous function a trap handler? */ + for (; handler->start_addr; ++handler) { + if ((return_to >= handler->start_addr) + && (return_to <= handler->end_addr)) { + if (!trace) + pr_info("%s\n", handler->trap_name); + unwind_trap(task, pc, fp, trace); + return; + } + } + pc -= ofs; + + if (trace) { +#ifdef CONFIG_STACKTRACE + if (trace->skip > 0) + trace->skip--; + else + trace->entries[trace->nr_entries++] = pc; + + if (trace->nr_entries >= trace->max_entries) + break; +#endif + } else { + /* Have we reached userland? */ + if (unlikely(pc == task_pt_regs(task)->pc)) { + pr_info("[<%p>] PID %lu [%s]\n", + (void *) pc, + (unsigned long) task->pid, + task->comm); + break; + } else + print_ip_sym(pc); + } + + /* Stop when we reach anything not part of the kernel */ + if (!kernel_text_address(pc)) + break; + + if (lookup_prev_stack_frame(fp, pc, leaf_return, &next_fp, + &next_pc) == 0) { + ofs = sizeof(unsigned long); + pc = next_pc & ~3; + fp = next_fp; + leaf_return = 0; + } else { + pr_debug(" Failed to find previous stack frame\n"); + break; + } + + pr_debug(" Next PC=%p, next FP=%p\n", + (void *)next_pc, (void *)next_fp); + } +} + +/** + * microblaze_unwind - Stack unwinder for Microblaze (external entry point) + * @task : Task whose stack we are to unwind (NULL == current) + * @trace : Where to store stack backtrace (PC values). + * NULL == print backtrace to kernel log + */ +void microblaze_unwind(struct task_struct *task, struct stack_trace *trace) +{ + if (task) { + if (task == current) { + const struct pt_regs *regs = task_pt_regs(task); + microblaze_unwind_inner(task, regs->pc, regs->r1, + regs->r15, trace); + } else { + struct thread_info *thread_info = + (struct thread_info *)(task->stack); + const struct cpu_context *cpu_context = + &thread_info->cpu_context; + + microblaze_unwind_inner(task, + (unsigned long) &_switch_to, + cpu_context->r1, + cpu_context->r15, trace); + } + } else { + unsigned long pc, fp; + + __asm__ __volatile__ ("or %0, r1, r0" : "=r" (fp)); + + __asm__ __volatile__ ( + "brlid %0, 0f;" + "nop;" + "0:" + : "=r" (pc) + ); + + /* Since we are not a leaf function, use leaf_return = 0 */ + microblaze_unwind_inner(current, pc, fp, 0, trace); + } +} + |