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 #include <asm/asm-const.h>
  28
  29 #ifndef __ASSEMBLY__
  30 struct pt_regs
  31 {
  32         union {
  33                 struct user_pt_regs user_regs;
  34                 struct {
  35                         unsigned long gpr[32];
  36                         unsigned long nip;
  37                         unsigned long msr;
  38                         unsigned long orig_gpr3;
  39                         unsigned long ctr;
  40                         unsigned long link;
  41                         unsigned long xer;
  42                         unsigned long ccr;
  43 #ifdef CONFIG_PPC64
  44                         unsigned long softe;
  45 #else
  46                         unsigned long mq;
  47 #endif
  48                         unsigned long trap;
  49                         unsigned long dar;
  50                         unsigned long dsisr;
  51                         unsigned long result;
  52                 };
  53         };
  54
  55         union {
  56                 struct {
  57 #ifdef CONFIG_PPC64
  58                         unsigned long ppr;
  59 #endif
  60 #ifdef CONFIG_PPC_KUAP
  61                         unsigned long kuap;
  62 #endif
  63                 };
  64                 unsigned long __pad[2]; /* Maintain 16 byte interrupt stack alignment */
  65         };
  66 };
  67 #endif
  68
  69 #ifdef __powerpc64__
  70
  71 /*
  72  * Size of redzone that userspace is allowed to use below the stack
  73  * pointer.  This is 288 in the 64-bit big-endian ELF ABI, and 512 in
  74  * the new ELFv2 little-endian ABI, so we allow the larger amount.
  75  *
  76  * For kernel code we allow a 288-byte redzone, in order to conserve
  77  * kernel stack space; gcc currently only uses 288 bytes, and will
  78  * hopefully allow explicit control of the redzone size in future.
  79  */
  80 #define USER_REDZONE_SIZE       512
  81 #define KERNEL_REDZONE_SIZE     288
  82
  83 #define STACK_FRAME_OVERHEAD    112     /* size of minimum stack frame */
  84 #define STACK_FRAME_LR_SAVE     2       /* Location of LR in stack frame */
  85 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265)
  86 #define STACK_INT_FRAME_SIZE    (sizeof(struct pt_regs) + \
  87                                  STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)
  88 #define STACK_FRAME_MARKER      12
  89
  90 #ifdef PPC64_ELF_ABI_v2
  91 #define STACK_FRAME_MIN_SIZE    32
  92 #else
  93 #define STACK_FRAME_MIN_SIZE    STACK_FRAME_OVERHEAD
  94 #endif
  95
  96 /* Size of dummy stack frame allocated when calling signal handler. */
  97 #define __SIGNAL_FRAMESIZE      128
  98 #define __SIGNAL_FRAMESIZE32    64
  99
 100 #else /* __powerpc64__ */
 101
 102 #define USER_REDZONE_SIZE       0
 103 #define KERNEL_REDZONE_SIZE     0
 104 #define STACK_FRAME_OVERHEAD    16      /* size of minimum stack frame */
 105 #define STACK_FRAME_LR_SAVE     1       /* Location of LR in stack frame */
 106 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
 107 #define STACK_INT_FRAME_SIZE    (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
 108 #define STACK_FRAME_MARKER      2
 109 #define STACK_FRAME_MIN_SIZE    STACK_FRAME_OVERHEAD
 110
 111 /* Size of stack frame allocated when calling signal handler. */
 112 #define __SIGNAL_FRAMESIZE      64
 113
 114 #endif /* __powerpc64__ */
 115
 116 #ifndef __ASSEMBLY__
 117
 118 #define GET_IP(regs)            ((regs)->nip)
 119 #define GET_USP(regs)           ((regs)->gpr[1])
 120 #define GET_FP(regs)            (0)
 121 #define SET_FP(regs, val)
 122
 123 #ifdef CONFIG_SMP
 124 extern unsigned long profile_pc(struct pt_regs *regs);
 125 #define profile_pc profile_pc
 126 #endif
 127
 128 #include <asm-generic/ptrace.h>
 129
 130 #define kernel_stack_pointer(regs) ((regs)->gpr[1])
 131 static inline int is_syscall_success(struct pt_regs *regs)
 132 {
 133         return !(regs->ccr & 0x10000000);
 134 }
 135
 136 static inline long regs_return_value(struct pt_regs *regs)
 137 {
 138         if (is_syscall_success(regs))
 139                 return regs->gpr[3];
 140         else
 141                 return -regs->gpr[3];
 142 }
 143
 144 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 145 {
 146         regs->gpr[3] = rc;
 147 }
 148
 149 #ifdef __powerpc64__
 150 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
 151 #else
 152 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
 153 #endif
 154
 155 #define force_successful_syscall_return()   \
 156         do { \
 157                 set_thread_flag(TIF_NOERROR); \
 158         } while(0)
 159
 160 struct task_struct;
 161 extern int ptrace_get_reg(struct task_struct *task, int regno,
 162                           unsigned long *data);
 163 extern int ptrace_put_reg(struct task_struct *task, int regno,
 164                           unsigned long data);
 165
 166 #define current_pt_regs() \
 167         ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
 168 /*
 169  * We use the least-significant bit of the trap field to indicate
 170  * whether we have saved the full set of registers, or only a
 171  * partial set.  A 1 there means the partial set.
 172  * On 4xx we use the next bit to indicate whether the exception
 173  * is a critical exception (1 means it is).
 174  */
 175 #define FULL_REGS(regs)         (((regs)->trap & 1) == 0)
 176 #ifndef __powerpc64__
 177 #define IS_CRITICAL_EXC(regs)   (((regs)->trap & 2) != 0)
 178 #define IS_MCHECK_EXC(regs)     (((regs)->trap & 4) != 0)
 179 #define IS_DEBUG_EXC(regs)      (((regs)->trap & 8) != 0)
 180 #endif /* ! __powerpc64__ */
 181 #define TRAP(regs)              ((regs)->trap & ~0xF)
 182 #ifdef __powerpc64__
 183 #define NV_REG_POISON           0xdeadbeefdeadbeefUL
 184 #define CHECK_FULL_REGS(regs)   BUG_ON(regs->trap & 1)
 185 #else
 186 #define NV_REG_POISON           0xdeadbeef
 187 #define CHECK_FULL_REGS(regs)                                                 \
 188 do {                                                                          \
 189         if ((regs)->trap & 1)                                                 \
 190                 printk(KERN_CRIT "%s: partial register set\n", __func__); \
 191 } while (0)
 192 #endif /* __powerpc64__ */
 193
 194 #define arch_has_single_step()  (1)
 195 #define arch_has_block_step()   (!cpu_has_feature(CPU_FTR_601))
 196 #define ARCH_HAS_USER_SINGLE_STEP_REPORT
 197
 198 /*
 199  * kprobe-based event tracer support
 200  */
 201
 202 #include <linux/stddef.h>
 203 #include <linux/thread_info.h>
 204 extern int regs_query_register_offset(const char *name);
 205 extern const char *regs_query_register_name(unsigned int offset);
 206 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
 207
 208 /**
 209  * regs_get_register() - get register value from its offset
 210  * @regs:          pt_regs from which register value is gotten
 211  * @offset:    offset number of the register.
 212  *
 213  * regs_get_register returns the value of a register whose offset from @regs.
 214  * The @offset is the offset of the register in struct pt_regs.
 215  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 216  */
 217 static inline unsigned long regs_get_register(struct pt_regs *regs,
 218                                                 unsigned int offset)
 219 {
 220         if (unlikely(offset > MAX_REG_OFFSET))
 221                 return 0;
 222         return *(unsigned long *)((unsigned long)regs + offset);
 223 }
 224
 225 /**
 226  * regs_within_kernel_stack() - check the address in the stack
 227  * @regs:      pt_regs which contains kernel stack pointer.
 228  * @addr:      address which is checked.
 229  *
 230  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 231  * If @addr is within the kernel stack, it returns true. If not, returns false.
 232  */
 233
 234 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
 235                                                 unsigned long addr)
 236 {
 237         return ((addr & ~(THREAD_SIZE - 1))  ==
 238                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 239 }
 240
 241 /**
 242  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 243  * @regs:       pt_regs which contains kernel stack pointer.
 244  * @n:          stack entry number.
 245  *
 246  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 247  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 248  * this returns 0.
 249  */
 250 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 251                                                       unsigned int n)
 252 {
 253         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 254         addr += n;
 255         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 256                 return *addr;
 257         else
 258                 return 0;
 259 }
 260
 261 #endif /* __ASSEMBLY__ */
 262
 263 #ifndef __powerpc64__
 264 #else /* __powerpc64__ */
 265 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
 266 #define PT_VR0_32 164   /* each Vector reg occupies 4 slots in 32-bit */
 267 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
 268 #define PT_VRSAVE_32 (PT_VR0 + 33*4)
 269 #define PT_VSR0_32 300  /* each VSR reg occupies 4 slots in 32-bit */
 270 #endif /* __powerpc64__ */
 271 #endif /* _ASM_POWERPC_PTRACE_H */