2 * SH specific backtracing code for oprofile
4 * Copyright 2007 STMicroelectronics Ltd.
6 * Author: Dave Peverley <dpeverley@mpc-data.co.uk>
8 * Based on ARM oprofile backtrace code by Richard Purdie and in turn, i386
9 * oprofile backtrace code by John Levon, David Smith
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #include <linux/oprofile.h>
17 #include <linux/sched.h>
18 #include <linux/kallsyms.h>
20 #include <asm/ptrace.h>
21 #include <asm/uaccess.h>
22 #include <asm/sections.h>
23 #include <asm/stacktrace.h>
25 static void backtrace_warning_symbol(void *data, char *msg,
31 static void backtrace_warning(void *data, char *msg)
36 static int backtrace_stack(void *data, char *name)
38 /* Yes, we want all stacks */
42 static void backtrace_address(void *data, unsigned long addr, int reliable)
44 unsigned int *depth = data;
47 oprofile_add_trace(addr);
50 static struct stacktrace_ops backtrace_ops = {
51 .warning = backtrace_warning,
52 .warning_symbol = backtrace_warning_symbol,
53 .stack = backtrace_stack,
54 .address = backtrace_address,
57 /* Limit to stop backtracing too far. */
58 static int backtrace_limit = 20;
60 static unsigned long *
61 user_backtrace(unsigned long *stackaddr, struct pt_regs *regs)
63 unsigned long buf_stack;
65 /* Also check accessibility of address */
66 if (!access_ok(VERIFY_READ, stackaddr, sizeof(unsigned long)))
69 if (__copy_from_user_inatomic(&buf_stack, stackaddr, sizeof(unsigned long)))
72 /* Quick paranoia check */
76 oprofile_add_trace(buf_stack);
84 * | | /\ Higher addresses
86 * --------------- stack base (address of current_thread_info)
90 * --------------- saved regs->regs[15] value if valid
92 * --------------- struct pt_regs stored on stack (struct pt_regs *)
98 * | | \/ Lower addresses
100 * Thus, &pt_regs <-> stack base restricts the valid(ish) fp values
102 static int valid_kernel_stack(unsigned long *stackaddr, struct pt_regs *regs)
104 unsigned long stack = (unsigned long)regs;
105 unsigned long stack_base = (stack & ~(THREAD_SIZE - 1)) + THREAD_SIZE;
107 return ((unsigned long)stackaddr > stack) && ((unsigned long)stackaddr < stack_base);
110 void sh_backtrace(struct pt_regs * const regs, unsigned int depth)
112 unsigned long *stackaddr;
115 * Paranoia - clip max depth as we could get lost in the weeds.
117 if (depth > backtrace_limit)
118 depth = backtrace_limit;
120 stackaddr = (unsigned long *)regs->regs[15];
121 if (!user_mode(regs)) {
123 dump_trace(NULL, regs, stackaddr,
124 &backtrace_ops, &depth);
128 while (depth-- && (stackaddr != NULL))
129 stackaddr = user_backtrace(stackaddr, regs);