LXR linux/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#if defined(_CALL_ELF) && _CALL_ELF == 2
  51#define STACK_FRAME_MIN_SIZE    32
  52#else
  53#define STACK_FRAME_MIN_SIZE    STACK_FRAME_OVERHEAD
  54#endif
  55
  56/* Size of dummy stack frame allocated when calling signal handler. */
  57#define __SIGNAL_FRAMESIZE      128
  58#define __SIGNAL_FRAMESIZE32    64
  59
  60#else /* __powerpc64__ */
  61
  62#define USER_REDZONE_SIZE       0
  63#define KERNEL_REDZONE_SIZE     0
  64#define STACK_FRAME_OVERHEAD    16      /* size of minimum stack frame */
  65#define STACK_FRAME_LR_SAVE     1       /* Location of LR in stack frame */
  66#define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
  67#define STACK_INT_FRAME_SIZE    (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
  68#define STACK_FRAME_MARKER      2
  69#define STACK_FRAME_MIN_SIZE    STACK_FRAME_OVERHEAD
  70
  71/* Size of stack frame allocated when calling signal handler. */
  72#define __SIGNAL_FRAMESIZE      64
  73
  74#endif /* __powerpc64__ */
  75
  76#ifndef __ASSEMBLY__
  77
  78#define GET_IP(regs)            ((regs)->nip)
  79#define GET_USP(regs)           ((regs)->gpr[1])
  80#define GET_FP(regs)            (0)
  81#define SET_FP(regs, val)
  82
  83#ifdef CONFIG_SMP
  84extern unsigned long profile_pc(struct pt_regs *regs);
  85#define profile_pc profile_pc
  86#endif
  87
  88#include <asm-generic/ptrace.h>
  89
  90#define kernel_stack_pointer(regs) ((regs)->gpr[1])
  91static inline int is_syscall_success(struct pt_regs *regs)
  92{
  93        return !(regs->ccr & 0x10000000);
  94}
  95
  96static inline long regs_return_value(struct pt_regs *regs)
  97{
  98        if (is_syscall_success(regs))
  99                return regs->gpr[3];
 100        else
 101                return -regs->gpr[3];
 102}
 103
 104#ifdef __powerpc64__
 105#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
 106#else
 107#define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
 108#endif
 109
 110#define force_successful_syscall_return()   \
 111        do { \
 112                set_thread_flag(TIF_NOERROR); \
 113        } while(0)
 114
 115struct task_struct;
 116extern int ptrace_get_reg(struct task_struct *task, int regno,
 117                          unsigned long *data);
 118extern int ptrace_put_reg(struct task_struct *task, int regno,
 119                          unsigned long data);
 120
 121#define current_pt_regs() \
 122        ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
 123/*
 124 * We use the least-significant bit of the trap field to indicate
 125 * whether we have saved the full set of registers, or only a
 126 * partial set.  A 1 there means the partial set.
 127 * On 4xx we use the next bit to indicate whether the exception
 128 * is a critical exception (1 means it is).
 129 */
 130#define FULL_REGS(regs)         (((regs)->trap & 1) == 0)
 131#ifndef __powerpc64__
 132#define IS_CRITICAL_EXC(regs)   (((regs)->trap & 2) != 0)
 133#define IS_MCHECK_EXC(regs)     (((regs)->trap & 4) != 0)
 134#define IS_DEBUG_EXC(regs)      (((regs)->trap & 8) != 0)
 135#endif /* ! __powerpc64__ */
 136#define TRAP(regs)              ((regs)->trap & ~0xF)
 137#ifdef __powerpc64__
 138#define NV_REG_POISON           0xdeadbeefdeadbeefUL
 139#define CHECK_FULL_REGS(regs)   BUG_ON(regs->trap & 1)
 140#else
 141#define NV_REG_POISON           0xdeadbeef
 142#define CHECK_FULL_REGS(regs)                                                 \
 143do {                                                                          \
 144        if ((regs)->trap & 1)                                                 \
 145                printk(KERN_CRIT "%s: partial register set\n", __func__); \
 146} while (0)
 147#endif /* __powerpc64__ */
 148
 149#define arch_has_single_step()  (1)
 150#define arch_has_block_step()   (!cpu_has_feature(CPU_FTR_601))
 151#define ARCH_HAS_USER_SINGLE_STEP_INFO
 152
 153/*
 154 * kprobe-based event tracer support
 155 */
 156
 157#include <linux/stddef.h>
 158#include <linux/thread_info.h>
 159extern int regs_query_register_offset(const char *name);
 160extern const char *regs_query_register_name(unsigned int offset);
 161#define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
 162
 163/**
 164 * regs_get_register() - get register value from its offset
 165 * @regs:          pt_regs from which register value is gotten
 166 * @offset:    offset number of the register.
 167 *
 168 * regs_get_register returns the value of a register whose offset from @regs.
 169 * The @offset is the offset of the register in struct pt_regs.
 170 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 171 */
 172static inline unsigned long regs_get_register(struct pt_regs *regs,
 173                                                unsigned int offset)
 174{
 175        if (unlikely(offset > MAX_REG_OFFSET))
 176                return 0;
 177        return *(unsigned long *)((unsigned long)regs + offset);
 178}
 179
 180/**
 181 * regs_within_kernel_stack() - check the address in the stack
 182 * @regs:      pt_regs which contains kernel stack pointer.
 183 * @addr:      address which is checked.
 184 *
 185 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 186 * If @addr is within the kernel stack, it returns true. If not, returns false.
 187 */
 188
 189static inline bool regs_within_kernel_stack(struct pt_regs *regs,
 190                                                unsigned long addr)
 191{
 192        return ((addr & ~(THREAD_SIZE - 1))  ==
 193                (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 194}
 195
 196/**
 197 * regs_get_kernel_stack_nth() - get Nth entry of the stack
 198 * @regs:       pt_regs which contains kernel stack pointer.
 199 * @n:          stack entry number.
 200 *
 201 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 202 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 203 * this returns 0.
 204 */
 205static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 206                                                      unsigned int n)
 207{
 208        unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 209        addr += n;
 210        if (regs_within_kernel_stack(regs, (unsigned long)addr))
 211                return *addr;
 212        else
 213                return 0;
 214}
 215
 216#endif /* __ASSEMBLY__ */
 217
 218#ifndef __powerpc64__
 219#else /* __powerpc64__ */
 220#define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
 221#define PT_VR0_32 164   /* each Vector reg occupies 4 slots in 32-bit */
 222#define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
 223#define PT_VRSAVE_32 (PT_VR0 + 33*4)
 224#define PT_VSR0_32 300  /* each VSR reg occupies 4 slots in 32-bit */
 225#endif /* __powerpc64__ */
 226#endif /* _ASM_POWERPC_PTRACE_H */
 227