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 /*
  32  * Size of redzone that userspace is allowed to use below the stack
  33  * pointer.  This is 288 in the 64-bit big-endian ELF ABI, and 512 in
  34  * the new ELFv2 little-endian ABI, so we allow the larger amount.
  35  *
  36  * For kernel code we allow a 288-byte redzone, in order to conserve
  37  * kernel stack space; gcc currently only uses 288 bytes, and will
  38  * hopefully allow explicit control of the redzone size in future.
  39  */
  40 #define USER_REDZONE_SIZE       512
  41 #define KERNEL_REDZONE_SIZE     288
  42
  43 #define STACK_FRAME_OVERHEAD    112     /* size of minimum stack frame */
  44 #define STACK_FRAME_LR_SAVE     2       /* Location of LR in stack frame */
  45 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265)
  46 #define STACK_INT_FRAME_SIZE    (sizeof(struct pt_regs) + \
  47                                  STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)
  48 #define STACK_FRAME_MARKER      12
  49
  50 /* Size of dummy stack frame allocated when calling signal handler. */
  51 #define __SIGNAL_FRAMESIZE      128
  52 #define __SIGNAL_FRAMESIZE32    64
  53
  54 #else /* __powerpc64__ */
  55
  56 #define USER_REDZONE_SIZE       0
  57 #define KERNEL_REDZONE_SIZE     0
  58 #define STACK_FRAME_OVERHEAD    16      /* size of minimum stack frame */
  59 #define STACK_FRAME_LR_SAVE     1       /* Location of LR in stack frame */
  60 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
  61 #define STACK_INT_FRAME_SIZE    (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
  62 #define STACK_FRAME_MARKER      2
  63
  64 /* Size of stack frame allocated when calling signal handler. */
  65 #define __SIGNAL_FRAMESIZE      64
  66
  67 #endif /* __powerpc64__ */
  68
  69 #ifndef __ASSEMBLY__
  70
  71 #define GET_IP(regs)            ((regs)->nip)
  72 #define GET_USP(regs)           ((regs)->gpr[1])
  73 #define GET_FP(regs)            (0)
  74 #define SET_FP(regs, val)
  75
  76 #ifdef CONFIG_SMP
  77 extern unsigned long profile_pc(struct pt_regs *regs);
  78 #define profile_pc profile_pc
  79 #endif
  80
  81 #include <asm-generic/ptrace.h>
  82
  83 #define kernel_stack_pointer(regs) ((regs)->gpr[1])
  84 static inline int is_syscall_success(struct pt_regs *regs)
  85 {
  86         return !(regs->ccr & 0x10000000);
  87 }
  88
  89 static inline long regs_return_value(struct pt_regs *regs)
  90 {
  91         if (is_syscall_success(regs))
  92                 return regs->gpr[3];
  93         else
  94                 return -regs->gpr[3];
  95 }
  96
  97 #ifdef __powerpc64__
  98 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
  99 #else
 100 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
 101 #endif
 102
 103 #define force_successful_syscall_return()   \
 104         do { \
 105                 set_thread_flag(TIF_NOERROR); \
 106         } while(0)
 107
 108 struct task_struct;
 109 extern int ptrace_get_reg(struct task_struct *task, int regno,
 110                           unsigned long *data);
 111 extern int ptrace_put_reg(struct task_struct *task, int regno,
 112                           unsigned long data);
 113
 114 #define current_pt_regs() \
 115         ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
 116 /*
 117  * We use the least-significant bit of the trap field to indicate
 118  * whether we have saved the full set of registers, or only a
 119  * partial set.  A 1 there means the partial set.
 120  * On 4xx we use the next bit to indicate whether the exception
 121  * is a critical exception (1 means it is).
 122  */
 123 #define FULL_REGS(regs)         (((regs)->trap & 1) == 0)
 124 #ifndef __powerpc64__
 125 #define IS_CRITICAL_EXC(regs)   (((regs)->trap & 2) != 0)
 126 #define IS_MCHECK_EXC(regs)     (((regs)->trap & 4) != 0)
 127 #define IS_DEBUG_EXC(regs)      (((regs)->trap & 8) != 0)
 128 #endif /* ! __powerpc64__ */
 129 #define TRAP(regs)              ((regs)->trap & ~0xF)
 130 #ifdef __powerpc64__
 131 #define NV_REG_POISON           0xdeadbeefdeadbeefUL
 132 #define CHECK_FULL_REGS(regs)   BUG_ON(regs->trap & 1)
 133 #else
 134 #define NV_REG_POISON           0xdeadbeef
 135 #define CHECK_FULL_REGS(regs)                                                 \
 136 do {                                                                          \
 137         if ((regs)->trap & 1)                                                 \
 138                 printk(KERN_CRIT "%s: partial register set\n", __func__); \
 139 } while (0)
 140 #endif /* __powerpc64__ */
 141
 142 #define arch_has_single_step()  (1)
 143 #define arch_has_block_step()   (!cpu_has_feature(CPU_FTR_601))
 144 #define ARCH_HAS_USER_SINGLE_STEP_INFO
 145
 146 /*
 147  * kprobe-based event tracer support
 148  */
 149
 150 #include <linux/stddef.h>
 151 #include <linux/thread_info.h>
 152 extern int regs_query_register_offset(const char *name);
 153 extern const char *regs_query_register_name(unsigned int offset);
 154 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
 155
 156 /**
 157  * regs_get_register() - get register value from its offset
 158  * @regs:          pt_regs from which register value is gotten
 159  * @offset:    offset number of the register.
 160  *
 161  * regs_get_register returns the value of a register whose offset from @regs.
 162  * The @offset is the offset of the register in struct pt_regs.
 163  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 164  */
 165 static inline unsigned long regs_get_register(struct pt_regs *regs,
 166                                                 unsigned int offset)
 167 {
 168         if (unlikely(offset > MAX_REG_OFFSET))
 169                 return 0;
 170         return *(unsigned long *)((unsigned long)regs + offset);
 171 }
 172
 173 /**
 174  * regs_within_kernel_stack() - check the address in the stack
 175  * @regs:      pt_regs which contains kernel stack pointer.
 176  * @addr:      address which is checked.
 177  *
 178  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 179  * If @addr is within the kernel stack, it returns true. If not, returns false.
 180  */
 181
 182 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
 183                                                 unsigned long addr)
 184 {
 185         return ((addr & ~(THREAD_SIZE - 1))  ==
 186                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 187 }
 188
 189 /**
 190  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 191  * @regs:       pt_regs which contains kernel stack pointer.
 192  * @n:          stack entry number.
 193  *
 194  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 195  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 196  * this returns 0.
 197  */
 198 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 199                                                       unsigned int n)
 200 {
 201         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 202         addr += n;
 203         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 204                 return *addr;
 205         else
 206                 return 0;
 207 }
 208
 209 #endif /* __ASSEMBLY__ */
 210
 211 #ifndef __powerpc64__
 212 #else /* __powerpc64__ */
 213 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
 214 #define PT_VR0_32 164   /* each Vector reg occupies 4 slots in 32-bit */
 215 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
 216 #define PT_VRSAVE_32 (PT_VR0 + 33*4)
 217 #define PT_VSR0_32 300  /* each VSR reg occupies 4 slots in 32-bit */
 218 #endif /* __powerpc64__ */
 219 #endif /* _ASM_POWERPC_PTRACE_H */