arch/powerpc/include/asm/ptrace.h

   1 /*
   2  * Copyright (C) 2001 PPC64 Team, IBM Corp
   3  *
   4  * This struct defines the way the registers are stored on the
   5  * kernel stack during a system call or other kernel entry.
   6  *
   7  * this should only contain volatile regs
   8  * since we can keep non-volatile in the thread_struct
   9  * should set this up when only volatiles are saved
  10  * by intr code.
  11  *
  12  * Since this is going on the stack, *CARE MUST BE TAKEN* to insure
  13  * that the overall structure is a multiple of 16 bytes in length.
  14  *
  15  * Note that the offsets of the fields in this struct correspond with
  16  * the PT_* values below.  This simplifies arch/powerpc/kernel/ptrace.c.
  17  *
  18  * This program is free software; you can redistribute it and/or
  19  * modify it under the terms of the GNU General Public License
  20  * as published by the Free Software Foundation; either version
  21  * 2 of the License, or (at your option) any later version.
  22  */
  23 #ifndef _ASM_POWERPC_PTRACE_H
  24 #define _ASM_POWERPC_PTRACE_H
  25
  26 #include <uapi/asm/ptrace.h>
  27
  28
  29 #ifdef __powerpc64__
  30
  31 #define STACK_FRAME_OVERHEAD    112     /* size of minimum stack frame */
  32 #define STACK_FRAME_LR_SAVE     2       /* Location of LR in stack frame */
  33 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265)
  34 #define STACK_INT_FRAME_SIZE    (sizeof(struct pt_regs) + \
  35                                         STACK_FRAME_OVERHEAD + 288)
  36 #define STACK_FRAME_MARKER      12
  37
  38 /* Size of dummy stack frame allocated when calling signal handler. */
  39 #define __SIGNAL_FRAMESIZE      128
  40 #define __SIGNAL_FRAMESIZE32    64
  41
  42 #else /* __powerpc64__ */
  43
  44 #define STACK_FRAME_OVERHEAD    16      /* size of minimum stack frame */
  45 #define STACK_FRAME_LR_SAVE     1       /* Location of LR in stack frame */
  46 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
  47 #define STACK_INT_FRAME_SIZE    (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
  48 #define STACK_FRAME_MARKER      2
  49
  50 /* Size of stack frame allocated when calling signal handler. */
  51 #define __SIGNAL_FRAMESIZE      64
  52
  53 #endif /* __powerpc64__ */
  54
  55 #ifndef __ASSEMBLY__
  56
  57 #define GET_IP(regs)            ((regs)->nip)
  58 #define GET_USP(regs)           ((regs)->gpr[1])
  59 #define GET_FP(regs)            (0)
  60 #define SET_FP(regs, val)
  61
  62 #ifdef CONFIG_SMP
  63 extern unsigned long profile_pc(struct pt_regs *regs);
  64 #define profile_pc profile_pc
  65 #endif
  66
  67 #include <asm-generic/ptrace.h>
  68
  69 #define kernel_stack_pointer(regs) ((regs)->gpr[1])
  70 static inline int is_syscall_success(struct pt_regs *regs)
  71 {
  72         return !(regs->ccr & 0x10000000);
  73 }
  74
  75 static inline long regs_return_value(struct pt_regs *regs)
  76 {
  77         if (is_syscall_success(regs))
  78                 return regs->gpr[3];
  79         else
  80                 return -regs->gpr[3];
  81 }
  82
  83 #ifdef __powerpc64__
  84 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
  85 #else
  86 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
  87 #endif
  88
  89 #define force_successful_syscall_return()   \
  90         do { \
  91                 set_thread_flag(TIF_NOERROR); \
  92         } while(0)
  93
  94 struct task_struct;
  95 extern unsigned long ptrace_get_reg(struct task_struct *task, int regno);
  96 extern int ptrace_put_reg(struct task_struct *task, int regno,
  97                           unsigned long data);
  98
  99 #define current_pt_regs() \
 100         ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
 101 /*
 102  * We use the least-significant bit of the trap field to indicate
 103  * whether we have saved the full set of registers, or only a
 104  * partial set.  A 1 there means the partial set.
 105  * On 4xx we use the next bit to indicate whether the exception
 106  * is a critical exception (1 means it is).
 107  */
 108 #define FULL_REGS(regs)         (((regs)->trap & 1) == 0)
 109 #ifndef __powerpc64__
 110 #define IS_CRITICAL_EXC(regs)   (((regs)->trap & 2) != 0)
 111 #define IS_MCHECK_EXC(regs)     (((regs)->trap & 4) != 0)
 112 #define IS_DEBUG_EXC(regs)      (((regs)->trap & 8) != 0)
 113 #endif /* ! __powerpc64__ */
 114 #define TRAP(regs)              ((regs)->trap & ~0xF)
 115 #ifdef __powerpc64__
 116 #define NV_REG_POISON           0xdeadbeefdeadbeefUL
 117 #define CHECK_FULL_REGS(regs)   BUG_ON(regs->trap & 1)
 118 #else
 119 #define NV_REG_POISON           0xdeadbeef
 120 #define CHECK_FULL_REGS(regs)                                                 \
 121 do {                                                                          \
 122         if ((regs)->trap & 1)                                                 \
 123                 printk(KERN_CRIT "%s: partial register set\n", __func__); \
 124 } while (0)
 125 #endif /* __powerpc64__ */
 126
 127 #define arch_has_single_step()  (1)
 128 #define arch_has_block_step()   (!cpu_has_feature(CPU_FTR_601))
 129 #define ARCH_HAS_USER_SINGLE_STEP_INFO
 130
 131 /*
 132  * kprobe-based event tracer support
 133  */
 134
 135 #include <linux/stddef.h>
 136 #include <linux/thread_info.h>
 137 extern int regs_query_register_offset(const char *name);
 138 extern const char *regs_query_register_name(unsigned int offset);
 139 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
 140
 141 /**
 142  * regs_get_register() - get register value from its offset
 143  * @regs:          pt_regs from which register value is gotten
 144  * @offset:    offset number of the register.
 145  *
 146  * regs_get_register returns the value of a register whose offset from @regs.
 147  * The @offset is the offset of the register in struct pt_regs.
 148  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 149  */
 150 static inline unsigned long regs_get_register(struct pt_regs *regs,
 151                                                 unsigned int offset)
 152 {
 153         if (unlikely(offset > MAX_REG_OFFSET))
 154                 return 0;
 155         return *(unsigned long *)((unsigned long)regs + offset);
 156 }
 157
 158 /**
 159  * regs_within_kernel_stack() - check the address in the stack
 160  * @regs:      pt_regs which contains kernel stack pointer.
 161  * @addr:      address which is checked.
 162  *
 163  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 164  * If @addr is within the kernel stack, it returns true. If not, returns false.
 165  */
 166
 167 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
 168                                                 unsigned long addr)
 169 {
 170         return ((addr & ~(THREAD_SIZE - 1))  ==
 171                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 172 }
 173
 174 /**
 175  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 176  * @regs:       pt_regs which contains kernel stack pointer.
 177  * @n:          stack entry number.
 178  *
 179  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 180  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 181  * this returns 0.
 182  */
 183 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 184                                                       unsigned int n)
 185 {
 186         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 187         addr += n;
 188         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 189                 return *addr;
 190         else
 191                 return 0;
 192 }
 193
 194 #endif /* __ASSEMBLY__ */
 195
 196 #ifndef __powerpc64__
 197 #else /* __powerpc64__ */
 198 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
 199 #define PT_VR0_32 164   /* each Vector reg occupies 4 slots in 32-bit */
 200 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
 201 #define PT_VRSAVE_32 (PT_VR0 + 33*4)
 202 #define PT_VSR0_32 300  /* each VSR reg occupies 4 slots in 32-bit */
 203 #endif /* __powerpc64__ */
 204 #endif /* _ASM_POWERPC_PTRACE_H */