path: root/arch/blackfin/kernel/trace.c

/* provide some functions which dump the trace buffer, in a nice way for people
 * to read it, and understand what is going on
 *
 * Copyright 2004-2010 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later
 */

#include <linux/kernel.h>
#include <linux/hardirq.h>
#include <linux/thread_info.h>
#include <linux/mm.h>
#include <linux/oom.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/irq.h>
#include <asm/dma.h>
#include <asm/trace.h>
#include <asm/fixed_code.h>
#include <asm/traps.h>
#include <asm/irq_handler.h>
#include <asm/pda.h>

void decode_address(char *buf, unsigned long address)
{
	struct task_struct *p;
	struct mm_struct *mm;
	unsigned long offset;
	struct rb_node *n;

#ifdef CONFIG_KALLSYMS
	unsigned long symsize;
	const char *symname;
	char *modname;
	char *delim = ":";
	char namebuf[128];
#endif

	buf += sprintf(buf, "<0x%08lx> ", address);

#ifdef CONFIG_KALLSYMS
	/* look up the address and see if we are in kernel space */
	symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);

	if (symname) {
		/* yeah! kernel space! */
		if (!modname)
			modname = delim = "";
		sprintf(buf, "{ %s%s%s%s + 0x%lx }",
			delim, modname, delim, symname,
			(unsigned long)offset);
		return;
	}
#endif

	if (address >= FIXED_CODE_START && address < FIXED_CODE_END) {
		/* Problem in fixed code section? */
		strcat(buf, "/* Maybe fixed code section */");
		return;

	} else if (address < CONFIG_BOOT_LOAD) {
		/* Problem somewhere before the kernel start address */
		strcat(buf, "/* Maybe null pointer? */");
		return;

	} else if (address >= COREMMR_BASE) {
		strcat(buf, "/* core mmrs */");
		return;

	} else if (address >= SYSMMR_BASE) {
		strcat(buf, "/* system mmrs */");
		return;

	} else if (address >= L1_ROM_START && address < L1_ROM_START + L1_ROM_LENGTH) {
		strcat(buf, "/* on-chip L1 ROM */");
		return;

	} else if (address >= L1_SCRATCH_START && address < L1_SCRATCH_START + L1_SCRATCH_LENGTH) {
		strcat(buf, "/* on-chip scratchpad */");
		return;

	} else if (address >= physical_mem_end && address < ASYNC_BANK0_BASE) {
		strcat(buf, "/* unconnected memory */");
		return;

	} else if (address >= ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE && address < BOOT_ROM_START) {
		strcat(buf, "/* reserved memory */");
		return;

	} else if (address >= L1_DATA_A_START && address < L1_DATA_A_START + L1_DATA_A_LENGTH) {
		strcat(buf, "/* on-chip Data Bank A */");
		return;

	} else if (address >= L1_DATA_B_START && address < L1_DATA_B_START + L1_DATA_B_LENGTH) {
		strcat(buf, "/* on-chip Data Bank B */");
		return;
	}

	/*
	 * Don't walk any of the vmas if we are oopsing, it has been known
	 * to cause problems - corrupt vmas (kernel crashes) cause double faults
	 */
	if (oops_in_progress) {
		strcat(buf, "/* kernel dynamic memory (maybe user-space) */");
		return;
	}

	/* looks like we're off in user-land, so let's walk all the
	 * mappings of all our processes and see if we can't be a whee
	 * bit more specific
	 */
	read_lock(&tasklist_lock);
	for_each_process(p) {
		struct task_struct *t;

		t = find_lock_task_mm(p);
		if (!t)
			continue;

		mm = t->mm;
		if (!down_read_trylock(&mm->mmap_sem))
			goto __continue;

		for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
			struct vm_area_struct *vma;

			vma = rb_entry(n, struct vm_area_struct, vm_rb);

			if (address >= vma->vm_start && address < vma->vm_end) {
				char _tmpbuf[256];
				char *name = t->comm;
				struct file *file = vma->vm_file;

				if (file) {
					char *d_name = file_path(file, _tmpbuf,
						      sizeof(_tmpbuf));
					if (!IS_ERR(d_name))
						name = d_name;
				}

				/* FLAT does not have its text aligned to the start of
				 * the map while FDPIC ELF does ...
				 */

				/* before we can check flat/fdpic, we need to
				 * make sure current is valid
				 */
				if ((unsigned long)current >= FIXED_CODE_START &&
				    !((unsigned long)current & 0x3)) {
					if (current->mm &&
					    (address > current->mm->start_code) &&
					    (address < current->mm->end_code))
						offset = address - current->mm->start_code;
					else
						offset = (address - vma->vm_start) +
							 (vma->vm_pgoff << PAGE_SHIFT);

					sprintf(buf, "[ %s + 0x%lx ]", name, offset);
				} else
					sprintf(buf, "[ %s vma:0x%lx-0x%lx]",
						name, vma->vm_start, vma->vm_end);

				up_read(&mm->mmap_sem);
				task_unlock(t);

				if (buf[0] == '\0')
					sprintf(buf, "[ %s ] dynamic memory", name);

				goto done;
			}
		}

		up_read(&mm->mmap_sem);
__continue:
		task_unlock(t);
	}

	/*
	 * we were unable to find this address anywhere,
	 * or some MMs were skipped because they were in use.
	 */
	sprintf(buf, "/* kernel dynamic memory */");

done:
	read_unlock(&tasklist_lock);
}

#define EXPAND_LEN ((1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN) * 256 - 1)

/*
 * Similar to get_user, do some address checking, then dereference
 * Return true on success, false on bad address
 */
bool get_mem16(unsigned short *val,