aboutsummaryrefslogtreecommitdiff
path: root/arch/blackfin/kernel/dumpstack.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/blackfin/kernel/dumpstack.c')
-rw-r--r--arch/blackfin/kernel/dumpstack.c174
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);