LXR linux/arch/mips/include/asm/ptrace.h

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000 by Ralf Baechle
   7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8 */
   9#ifndef _ASM_PTRACE_H
  10#define _ASM_PTRACE_H
  11
  12
  13#include <linux/compiler.h>
  14#include <linux/linkage.h>
  15#include <linux/types.h>
  16#include <asm/isadep.h>
  17#include <asm/page.h>
  18#include <asm/thread_info.h>
  19#include <uapi/asm/ptrace.h>
  20
  21/*
  22 * This struct defines the way the registers are stored on the stack during a
  23 * system call/exception. As usual the registers k0/k1 aren't being saved.
  24 *
  25 * If you add a register here, also add it to regoffset_table[] in
  26 * arch/mips/kernel/ptrace.c.
  27 */
  28struct pt_regs {
  29#ifdef CONFIG_32BIT
  30        /* Pad bytes for argument save space on the stack. */
  31        unsigned long pad0[8];
  32#endif
  33
  34        /* Saved main processor registers. */
  35        unsigned long regs[32];
  36
  37        /* Saved special registers. */
  38        unsigned long cp0_status;
  39        unsigned long hi;
  40        unsigned long lo;
  41#ifdef CONFIG_CPU_HAS_SMARTMIPS
  42        unsigned long acx;
  43#endif
  44        unsigned long cp0_badvaddr;
  45        unsigned long cp0_cause;
  46        unsigned long cp0_epc;
  47#ifdef CONFIG_CPU_CAVIUM_OCTEON
  48        unsigned long long mpl[6];        /* MTM{0-5} */
  49        unsigned long long mtp[6];        /* MTP{0-5} */
  50#endif
  51        unsigned long __last[0];
  52} __aligned(8);
  53
  54static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
  55{
  56        return regs->regs[31];
  57}
  58
  59/*
  60 * Don't use asm-generic/ptrace.h it defines FP accessors that don't make
  61 * sense on MIPS.  We rather want an error if they get invoked.
  62 */
  63
  64static inline void instruction_pointer_set(struct pt_regs *regs,
  65                                           unsigned long val)
  66{
  67        regs->cp0_epc = val;
  68}
  69
  70/* Query offset/name of register from its name/offset */
  71extern int regs_query_register_offset(const char *name);
  72#define MAX_REG_OFFSET (offsetof(struct pt_regs, __last))
  73
  74/**
  75 * regs_get_register() - get register value from its offset
  76 * @regs:       pt_regs from which register value is gotten.
  77 * @offset:     offset number of the register.
  78 *
  79 * regs_get_register returns the value of a register. The @offset is the
  80 * offset of the register in struct pt_regs address which specified by @regs.
  81 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
  82 */
  83static inline unsigned long regs_get_register(struct pt_regs *regs,
  84                                              unsigned int offset)
  85{
  86        if (unlikely(offset > MAX_REG_OFFSET))
  87                return 0;
  88
  89        return *(unsigned long *)((unsigned long)regs + offset);
  90}
  91
  92/**
  93 * regs_within_kernel_stack() - check the address in the stack
  94 * @regs:       pt_regs which contains kernel stack pointer.
  95 * @addr:       address which is checked.
  96 *
  97 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
  98 * If @addr is within the kernel stack, it returns true. If not, returns false.
  99 */
 100static inline int regs_within_kernel_stack(struct pt_regs *regs,
 101                                           unsigned long addr)
 102{
 103        return ((addr & ~(THREAD_SIZE - 1))  ==
 104                (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 105}
 106
 107/**
 108 * regs_get_kernel_stack_nth() - get Nth entry of the stack
 109 * @regs:       pt_regs which contains kernel stack pointer.
 110 * @n:          stack entry number.
 111 *
 112 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 113 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 114 * this returns 0.
 115 */
 116static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 117                                                      unsigned int n)
 118{
 119        unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 120
 121        addr += n;
 122        if (regs_within_kernel_stack(regs, (unsigned long)addr))
 123                return *addr;
 124        else
 125                return 0;
 126}
 127
 128struct task_struct;
 129
 130extern int ptrace_getregs(struct task_struct *child,
 131        struct user_pt_regs __user *data);
 132extern int ptrace_setregs(struct task_struct *child,
 133        struct user_pt_regs __user *data);
 134
 135extern int ptrace_getfpregs(struct task_struct *child, __u32 __user *data);
 136extern int ptrace_setfpregs(struct task_struct *child, __u32 __user *data);
 137
 138extern int ptrace_get_watch_regs(struct task_struct *child,
 139        struct pt_watch_regs __user *addr);
 140extern int ptrace_set_watch_regs(struct task_struct *child,
 141        struct pt_watch_regs __user *addr);
 142
 143/*
 144 * Does the process account for user or for system time?
 145 */
 146#define user_mode(regs) (((regs)->cp0_status & KU_MASK) == KU_USER)
 147
 148static inline int is_syscall_success(struct pt_regs *regs)
 149{
 150        return !regs->regs[7];
 151}
 152
 153static inline long regs_return_value(struct pt_regs *regs)
 154{
 155        if (is_syscall_success(regs) || !user_mode(regs))
 156                return regs->regs[2];
 157        else
 158                return -regs->regs[2];
 159}
 160
 161#define instruction_pointer(regs) ((regs)->cp0_epc)
 162#define profile_pc(regs) instruction_pointer(regs)
 163
 164extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall);
 165extern asmlinkage void syscall_trace_leave(struct pt_regs *regs);
 166
 167extern void die(const char *, struct pt_regs *) __noreturn;
 168
 169static inline void die_if_kernel(const char *str, struct pt_regs *regs)
 170{
 171        if (unlikely(!user_mode(regs)))
 172                die(str, regs);
 173}
 174
 175#define current_pt_regs()                                               \
 176({                                                                      \
 177        unsigned long sp = (unsigned long)__builtin_frame_address(0);   \
 178        (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1;      \
 179})
 180
 181/* Helpers for working with the user stack pointer */
 182
 183static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 184{
 185        return regs->regs[29];
 186}
 187
 188static inline void user_stack_pointer_set(struct pt_regs *regs,
 189        unsigned long val)
 190{
 191        regs->regs[29] = val;
 192}
 193
 194#endif /* _ASM_PTRACE_H */
 195