projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 40a8b421 DP |
1 | /* |
| 2 | * SH specific backtracing code for oprofile | |
| 3 | * | |
| 4 | * Copyright 2007 STMicroelectronics Ltd. | |
| 5 | * | |
| 6 | * Author: Dave Peverley <dpeverley@mpc-data.co.uk> | |
| 7 | * | |
| 8 | * Based on ARM oprofile backtrace code by Richard Purdie and in turn, i386 | |
| 9 | * oprofile backtrace code by John Levon, David Smith | |
| 10 | * | |
| 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. | |
| 14 | * | |
| 15 | */ | |
| 16 | #include <linux/oprofile.h> | |
| 17 | #include <linux/sched.h> | |
| 18 | #include <linux/kallsyms.h> | |
| 19 | #include <linux/mm.h> | |
| 20 | #include <asm/ptrace.h> | |
| 21 | #include <asm/uaccess.h> | |
| 22 | #include <asm/sections.h> | |
| 4e14dfc7 MF |
23 | #include <asm/stacktrace.h> |
| 24 | ||
| 25 | static void backtrace_warning_symbol(void *data, char *msg, | |
| 26 | unsigned long symbol) | |
| 27 | { | |
| 28 | /* Ignore warnings */ | |
| 29 | } | |
| 30 | ||
| 31 | static void backtrace_warning(void *data, char *msg) | |
| 32 | { | |
| 33 | /* Ignore warnings */ | |
| 34 | } | |
| 35 | ||
| 36 | static int backtrace_stack(void *data, char *name) | |
| 37 | { | |
| 38 | /* Yes, we want all stacks */ | |
| 39 | return 0; | |
| 40 | } | |
| 41 | ||
| 42 | static void backtrace_address(void *data, unsigned long addr, int reliable) | |
| 43 | { | |
| 44 | unsigned int *depth = data; | |
| 45 | ||
| 46 | if ((*depth)--) | |
| 47 | oprofile_add_trace(addr); | |
| 48 | } | |
| 49 | ||
| 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, | |
| 55 | }; | |
| 40a8b421 DP |
56 | |
| 57 | /* Limit to stop backtracing too far. */ | |
| 58 | static int backtrace_limit = 20; | |
| 59 | ||
| 60 | static unsigned long * | |
| 61 | user_backtrace(unsigned long *stackaddr, struct pt_regs *regs) | |
| 62 | { | |
| 63 | unsigned long buf_stack; | |
| 64 | ||
| 65 | /* Also check accessibility of address */ | |
| 66 | if (!access_ok(VERIFY_READ, stackaddr, sizeof(unsigned long))) | |
| 67 | return NULL; | |
| 68 | ||
| 69 | if (__copy_from_user_inatomic(&buf_stack, stackaddr, sizeof(unsigned long))) | |
| 70 | return NULL; | |
| 71 | ||
| 72 | /* Quick paranoia check */ | |
| 73 | if (buf_stack & 3) | |
| 74 | return NULL; | |
| 75 | ||
| 76 | oprofile_add_trace(buf_stack); | |
| 77 | ||
| 78 | stackaddr++; | |
| 79 | ||
| 80 | return stackaddr; | |
| 81 | } | |
| 82 | ||
| 83 | /* | |
| 84 | * | | /\ Higher addresses | |
| 85 | * | | | |
| 86 | * --------------- stack base (address of current_thread_info) | |
| 87 | * | thread info | | |
| 88 | * . . | |
| 89 | * | stack | | |
| 90 | * --------------- saved regs->regs[15] value if valid | |
| 91 | * . . | |
| 92 | * --------------- struct pt_regs stored on stack (struct pt_regs *) | |
| 93 | * | | | |
| 94 | * . . | |
| 95 | * | | | |
| 96 | * --------------- ??? | |
| 97 | * | | | |
| 98 | * | | \/ Lower addresses | |
| 99 | * | |
| 100 | * Thus, &pt_regs <-> stack base restricts the valid(ish) fp values | |
| 101 | */ | |
| 102 | static int valid_kernel_stack(unsigned long *stackaddr, struct pt_regs *regs) | |
| 103 | { | |
| 104 | unsigned long stack = (unsigned long)regs; | |
| 105 | unsigned long stack_base = (stack & ~(THREAD_SIZE - 1)) + THREAD_SIZE; | |
| 106 | ||
| 107 | return ((unsigned long)stackaddr > stack) && ((unsigned long)stackaddr < stack_base); | |
| 108 | } | |
| 109 | ||
| 40a8b421 DP |
110 | void sh_backtrace(struct pt_regs * const regs, unsigned int depth) |
| 111 | { | |
| 112 | unsigned long *stackaddr; | |
| 113 | ||
| 114 | /* | |
| 115 | * Paranoia - clip max depth as we could get lost in the weeds. | |
| 116 | */ | |
| 117 | if (depth > backtrace_limit) | |
| 118 | depth = backtrace_limit; | |
| 119 | ||
| 120 | stackaddr = (unsigned long *)regs->regs[15]; | |
| 121 | if (!user_mode(regs)) { | |
| 4e14dfc7 MF |
122 | if (depth) |
| 123 | dump_trace(NULL, regs, stackaddr, | |
| 124 | &backtrace_ops, &depth); | |
| 40a8b421 DP |
125 | return; |
| 126 | } | |
| 127 | ||
| 128 | while (depth-- && (stackaddr != NULL)) | |
| 129 | stackaddr = user_backtrace(stackaddr, regs); | |
| 130 | } |