atmel_serial: fix bugs in probe() error path and remove()
[pv_ops_mirror.git] / arch / x86 / oprofile / backtrace.c
blobe2095cba409f200b5b25e9b5bcdbce0ed6288492
1 /**
2 * @file backtrace.c
4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
7 * @author John Levon
8 * @author David Smith
9 */
11 #include <linux/oprofile.h>
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <asm/ptrace.h>
15 #include <asm/uaccess.h>
16 #include <asm/stacktrace.h>
18 static void backtrace_warning_symbol(void *data, char *msg,
19 unsigned long symbol)
21 /* Ignore warnings */
24 static void backtrace_warning(void *data, char *msg)
26 /* Ignore warnings */
29 static int backtrace_stack(void *data, char *name)
31 /* Yes, we want all stacks */
32 return 0;
35 static void backtrace_address(void *data, unsigned long addr, int reliable)
37 unsigned int *depth = data;
39 if ((*depth)--)
40 oprofile_add_trace(addr);
43 static struct stacktrace_ops backtrace_ops = {
44 .warning = backtrace_warning,
45 .warning_symbol = backtrace_warning_symbol,
46 .stack = backtrace_stack,
47 .address = backtrace_address,
50 struct frame_head {
51 struct frame_head *bp;
52 unsigned long ret;
53 } __attribute__((packed));
55 static struct frame_head *
56 dump_user_backtrace(struct frame_head * head)
58 struct frame_head bufhead[2];
60 /* Also check accessibility of one struct frame_head beyond */
61 if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
62 return NULL;
63 if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
64 return NULL;
66 oprofile_add_trace(bufhead[0].ret);
68 /* frame pointers should strictly progress back up the stack
69 * (towards higher addresses) */
70 if (head >= bufhead[0].bp)
71 return NULL;
73 return bufhead[0].bp;
76 void
77 x86_backtrace(struct pt_regs * const regs, unsigned int depth)
79 struct frame_head *head = (struct frame_head *)frame_pointer(regs);
80 unsigned long stack = kernel_trap_sp(regs);
82 if (!user_mode_vm(regs)) {
83 if (depth)
84 dump_trace(NULL, regs, (unsigned long *)stack, 0,
85 &backtrace_ops, &depth);
86 return;
89 while (depth-- && head)
90 head = dump_user_backtrace(head);