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  */
  28 struct 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
  54 static 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
  64 static 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 */
  71 extern 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  */
  83 static 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  */
 100 static 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  */
 116 static 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
 128 struct task_struct;
 129
 130 extern int ptrace_getregs(struct task_struct *child,
 131         struct user_pt_regs __user *data);
 132 extern int ptrace_setregs(struct task_struct *child,
 133         struct user_pt_regs __user *data);
 134
 135 extern int ptrace_getfpregs(struct task_struct *child, __u32 __user *data);
 136 extern int ptrace_setfpregs(struct task_struct *child, __u32 __user *data);
 137
 138 extern int ptrace_get_watch_regs(struct task_struct *child,
 139         struct pt_watch_regs __user *addr);
 140 extern 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
 148 static inline int is_syscall_success(struct pt_regs *regs)
 149 {
 150         return !regs->regs[7];
 151 }
 152
 153 static inline long regs_return_value(struct pt_regs *regs)
 154 {
 155         if (is_syscall_success(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
 164 extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall);
 165 extern asmlinkage void syscall_trace_leave(struct pt_regs *regs);
 166
 167 extern void die(const char *, struct pt_regs *) __noreturn;
 168
 169 static 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
 183 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 184 {
 185         return regs->regs[29];
 186 }
 187
 188 static 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 */