Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
kstack.h
Go to the documentation of this file.
1 #ifndef _KSTACK_H
2 #define _KSTACK_H
3 
4 #include <linux/thread_info.h>
5 #include <linux/sched.h>
6 #include <asm/ptrace.h>
7 #include <asm/irq.h>
8 
9 /* SP must be STACK_BIAS adjusted already. */
10 static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
11 {
12  unsigned long base = (unsigned long) tp;
13 
14  /* Stack pointer must be 16-byte aligned. */
15  if (sp & (16UL - 1))
16  return false;
17 
18  if (sp >= (base + sizeof(struct thread_info)) &&
19  sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
20  return true;
21 
22  if (hardirq_stack[tp->cpu]) {
23  base = (unsigned long) hardirq_stack[tp->cpu];
24  if (sp >= base &&
25  sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
26  return true;
27  base = (unsigned long) softirq_stack[tp->cpu];
28  if (sp >= base &&
29  sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
30  return true;
31  }
32  return false;
33 }
34 
35 /* Does "regs" point to a valid pt_regs trap frame? */
36 static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *regs)
37 {
38  unsigned long base = (unsigned long) tp;
39  unsigned long addr = (unsigned long) regs;
40 
41  if (addr >= base &&
42  addr <= (base + THREAD_SIZE - sizeof(*regs)))
43  goto check_magic;
44 
45  if (hardirq_stack[tp->cpu]) {
46  base = (unsigned long) hardirq_stack[tp->cpu];
47  if (addr >= base &&
48  addr <= (base + THREAD_SIZE - sizeof(*regs)))
49  goto check_magic;
50  base = (unsigned long) softirq_stack[tp->cpu];
51  if (addr >= base &&
52  addr <= (base + THREAD_SIZE - sizeof(*regs)))
53  goto check_magic;
54  }
55  return false;
56 
57 check_magic:
58  if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC)
59  return true;
60  return false;
61 
62 }
63 
64 static inline __attribute__((always_inline)) void *set_hardirq_stack(void)
65 {
66  void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
67 
68  __asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
69  if (orig_sp < sp ||
70  orig_sp > (sp + THREAD_SIZE)) {
71  sp += THREAD_SIZE - 192 - STACK_BIAS;
72  __asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
73  }
74 
75  return orig_sp;
76 }
77 
78 static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
79 {
80  __asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
81 }
82 
83 #endif /* _KSTACK_H */