diff options
Diffstat (limited to 'arch/blackfin/kernel/dumpstack.c')
| -rw-r--r-- | arch/blackfin/kernel/dumpstack.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/dumpstack.c b/arch/blackfin/kernel/dumpstack.c new file mode 100644 index 00000000000..5cfbaa29821 --- /dev/null +++ b/arch/blackfin/kernel/dumpstack.c @@ -0,0 +1,174 @@ +/* Provide basic stack dumping functions + * + * Copyright 2004-2009 Analog Devices Inc. + * + * Licensed under the GPL-2 or later + */ + +#include <linux/kernel.h> +#include <linux/thread_info.h> +#include <linux/mm.h> +#include <linux/uaccess.h> +#include <linux/module.h> +#include <asm/trace.h> + +/* + * Checks to see if the address pointed to is either a + * 16-bit CALL instruction, or a 32-bit CALL instruction + */ +static bool is_bfin_call(unsigned short *addr) +{ + unsigned int opcode; + + if (!get_instruction(&opcode, addr)) + return false; + + if ((opcode >= 0x0060 && opcode <= 0x0067) || + (opcode >= 0x0070 && opcode <= 0x0077) || + (opcode >= 0xE3000000 && opcode <= 0xE3FFFFFF)) + return true; + + return false; + +} + +void show_stack(struct task_struct *task, unsigned long *stack) +{ +#ifdef CONFIG_PRINTK + unsigned int *addr, *endstack, *fp = 0, *frame; + unsigned short *ins_addr; + char buf[150]; + unsigned int i, j, ret_addr, frame_no = 0; + + /* + * If we have been passed a specific stack, use that one otherwise + * if we have been passed a task structure, use that, otherwise + * use the stack of where the variable "stack" exists + */ + + if (stack == NULL) { + if (task) { + /* We know this is a kernel stack, so this is the start/end */ + stack = (unsigned long *)task->thread.ksp; + endstack = (unsigned int *)(((unsigned int)(stack) & ~(THREAD_SIZE - 1)) + THREAD_SIZE); + } else { + /* print out the existing stack info */ + stack = (unsigned long *)&stack; + endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack); + } + } else + endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack); + + printk(KERN_NOTICE "Stack info:\n"); + decode_address(buf, (unsigned int)stack); + printk(KERN_NOTICE " SP: [0x%p] %s\n", stack, buf); + + if (!access_ok(VERIFY_READ, stack, (unsigned int)endstack - (unsigned int)stack)) { + printk(KERN_NOTICE "Invalid stack pointer\n"); + return; + } + + /* First thing is to look for a frame pointer */ + for (addr = (unsigned int *)((unsigned int)stack & ~0xF); addr < endstack; addr++) { + if (*addr & 0x1) + continue; + ins_addr = (unsigned short *)*addr; + ins_addr--; + if (is_bfin_call(ins_addr)) + fp = addr - 1; + + if (fp) { + /* Let's check to see if it is a frame pointer */ + while (fp >= (addr - 1) && fp < endstack + && fp && ((unsigned int) fp & 0x3) == 0) + fp = (unsigned int *)*fp; + if (fp == 0 || fp == endstack) { + fp = addr - 1; + break; + } + fp = 0; + } + } + if (fp) { + frame = fp; + printk(KERN_NOTICE " FP: (0x%p)\n", fp); + } else + frame = 0; + + /* + * Now that we think we know where things are, we + * walk the stack again, this time printing things out + * incase there is no frame pointer, we still look for + * valid return addresses + */ + + /* First time print out data, next time, print out symbols */ + for (j = 0; j <= 1; j++) { + if (j) + printk(KERN_NOTICE "Return addresses in stack:\n"); + else + printk(KERN_NOTICE " Memory from 0x%08lx to %p", ((long unsigned int)stack & ~0xF), endstack); + + fp = frame; + frame_no = 0; + + for (addr = (unsigned int *)((unsigned int)stack & ~0xF), i = 0; + addr < endstack; addr++, i++) { + + ret_addr = 0; + if (!j && i % 8 == 0) + printk(KERN_NOTICE "%p:", addr); + + /* if it is an odd address, or zero, just skip it */ + if (*addr & 0x1 || !*addr) + goto print; + + ins_addr = (unsigned short *)*addr; + + /* Go back one instruction, and see if it is a CALL */ + ins_addr--; + ret_addr = is_bfin_call(ins_addr); + print: + if (!j && stack == (unsigned long *)addr) + printk("[%08x]", *addr); + else if (ret_addr) + if (j) { + decode_address(buf, (unsigned int)*addr); + if (frame == addr) { + printk(KERN_NOTICE " frame %2i : %s\n", frame_no, buf); + continue; + } + printk(KERN_NOTICE " address : %s\n", buf); + } else + printk("<%08x>", *addr); + else if (fp == addr) { + if (j) + frame = addr+1; + else + printk("(%08x)", *addr); + + fp = (unsigned int *)*addr; + frame_no++; + + } else if (!j) + printk(" %08x ", *addr); + } + if (!j) + printk("\n"); + } +#endif +} +EXPORT_SYMBOL(show_stack); + +void dump_stack(void) +{ + unsigned long stack; +#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON + int tflags; +#endif + trace_buffer_save(tflags); + dump_bfin_trace_buffer(); + show_stack(current, &stack); + trace_buffer_restore(tflags); +} +EXPORT_SYMBOL(dump_stack); |