Initial import

1 files changed, 175 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/dumpstack.c b/arch/blackfin/kernel/dumpstack.c
new file mode 100644
index 000000000..95ba6d9e9
--- /dev/null
+++ b/arch/blackfin/kernel/dumpstack.c
@@ -0,0 +1,175 @@
+/* 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();
+	dump_stack_print_info(KERN_DEFAULT);
+	show_stack(current, &stack);
+	trace_buffer_restore(tflags);
+}
+EXPORT_SYMBOL(dump_stack);