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

   1/*
   2 *  arch/arm/include/asm/ptrace.h
   3 *
   4 *  Copyright (C) 1996-2003 Russell King
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 */
  10#ifndef __ASM_ARM_PTRACE_H
  11#define __ASM_ARM_PTRACE_H
  12
  13#include <uapi/asm/ptrace.h>
  14
  15#ifndef __ASSEMBLY__
  16struct pt_regs {
  17        unsigned long uregs[18];
  18};
  19
  20#define user_mode(regs) \
  21        (((regs)->ARM_cpsr & 0xf) == 0)
  22
  23#ifdef CONFIG_ARM_THUMB
  24#define thumb_mode(regs) \
  25        (((regs)->ARM_cpsr & PSR_T_BIT))
  26#else
  27#define thumb_mode(regs) (0)
  28#endif
  29
  30#ifndef CONFIG_CPU_V7M
  31#define isa_mode(regs) \
  32        ((((regs)->ARM_cpsr & PSR_J_BIT) >> (__ffs(PSR_J_BIT) - 1)) | \
  33         (((regs)->ARM_cpsr & PSR_T_BIT) >> (__ffs(PSR_T_BIT))))
  34#else
  35#define isa_mode(regs) 1 /* Thumb */
  36#endif
  37
  38#define processor_mode(regs) \
  39        ((regs)->ARM_cpsr & MODE_MASK)
  40
  41#define interrupts_enabled(regs) \
  42        (!((regs)->ARM_cpsr & PSR_I_BIT))
  43
  44#define fast_interrupts_enabled(regs) \
  45        (!((regs)->ARM_cpsr & PSR_F_BIT))
  46
  47/* Are the current registers suitable for user mode?
  48 * (used to maintain security in signal handlers)
  49 */
  50static inline int valid_user_regs(struct pt_regs *regs)
  51{
  52#ifndef CONFIG_CPU_V7M
  53        unsigned long mode = regs->ARM_cpsr & MODE_MASK;
  54
  55        /*
  56         * Always clear the F (FIQ) and A (delayed abort) bits
  57         */
  58        regs->ARM_cpsr &= ~(PSR_F_BIT | PSR_A_BIT);
  59
  60        if ((regs->ARM_cpsr & PSR_I_BIT) == 0) {
  61                if (mode == USR_MODE)
  62                        return 1;
  63                if (elf_hwcap & HWCAP_26BIT && mode == USR26_MODE)
  64                        return 1;
  65        }
  66
  67        /*
  68         * Force CPSR to something logical...
  69         */
  70        regs->ARM_cpsr &= PSR_f | PSR_s | PSR_x | PSR_T_BIT | MODE32_BIT;
  71        if (!(elf_hwcap & HWCAP_26BIT))
  72                regs->ARM_cpsr |= USR_MODE;
  73
  74        return 0;
  75#else /* ifndef CONFIG_CPU_V7M */
  76        return 1;
  77#endif
  78}
  79
  80static inline long regs_return_value(struct pt_regs *regs)
  81{
  82        return regs->ARM_r0;
  83}
  84
  85#define instruction_pointer(regs)       (regs)->ARM_pc
  86
  87#ifdef CONFIG_THUMB2_KERNEL
  88#define frame_pointer(regs) (regs)->ARM_r7
  89#else
  90#define frame_pointer(regs) (regs)->ARM_fp
  91#endif
  92
  93static inline void instruction_pointer_set(struct pt_regs *regs,
  94                                           unsigned long val)
  95{
  96        instruction_pointer(regs) = val;
  97}
  98
  99#ifdef CONFIG_SMP
 100extern unsigned long profile_pc(struct pt_regs *regs);
 101#else
 102#define profile_pc(regs) instruction_pointer(regs)
 103#endif
 104
 105#define predicate(x)            ((x) & 0xf0000000)
 106#define PREDICATE_ALWAYS        0xe0000000
 107
 108/*
 109 * True if instr is a 32-bit thumb instruction. This works if instr
 110 * is the first or only half-word of a thumb instruction. It also works
 111 * when instr holds all 32-bits of a wide thumb instruction if stored
 112 * in the form (first_half<<16)|(second_half)
 113 */
 114#define is_wide_instruction(instr)      ((unsigned)(instr) >= 0xe800)
 115
 116/*
 117 * kprobe-based event tracer support
 118 */
 119#include <linux/stddef.h>
 120#include <linux/types.h>
 121#define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0))
 122
 123extern int regs_query_register_offset(const char *name);
 124extern const char *regs_query_register_name(unsigned int offset);
 125extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
 126extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 127                                               unsigned int n);
 128
 129/**
 130 * regs_get_register() - get register value from its offset
 131 * @regs:          pt_regs from which register value is gotten
 132 * @offset:    offset number of the register.
 133 *
 134 * regs_get_register returns the value of a register whose offset from @regs.
 135 * The @offset is the offset of the register in struct pt_regs.
 136 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 137 */
 138static inline unsigned long regs_get_register(struct pt_regs *regs,
 139                                              unsigned int offset)
 140{
 141        if (unlikely(offset > MAX_REG_OFFSET))
 142                return 0;
 143        return *(unsigned long *)((unsigned long)regs + offset);
 144}
 145
 146/* Valid only for Kernel mode traps. */
 147static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 148{
 149        return regs->ARM_sp;
 150}
 151
 152static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 153{
 154        return regs->ARM_sp;
 155}
 156
 157#define current_pt_regs(void) ({ (struct pt_regs *)                     \
 158                ((current_stack_pointer | (THREAD_SIZE - 1)) - 7) - 1;  \
 159})
 160
 161#endif /* __ASSEMBLY__ */
 162#endif
 163