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#define isa_mode(regs) \
  31        ((((regs)->ARM_cpsr & PSR_J_BIT) >> 23) | \
  32         (((regs)->ARM_cpsr & PSR_T_BIT) >> 5))
  33
  34#define processor_mode(regs) \
  35        ((regs)->ARM_cpsr & MODE_MASK)
  36
  37#define interrupts_enabled(regs) \
  38        (!((regs)->ARM_cpsr & PSR_I_BIT))
  39
  40#define fast_interrupts_enabled(regs) \
  41        (!((regs)->ARM_cpsr & PSR_F_BIT))
  42
  43/* Are the current registers suitable for user mode?
  44 * (used to maintain security in signal handlers)
  45 */
  46static inline int valid_user_regs(struct pt_regs *regs)
  47{
  48#ifndef CONFIG_CPU_V7M
  49        unsigned long mode = regs->ARM_cpsr & MODE_MASK;
  50
  51        /*
  52         * Always clear the F (FIQ) and A (delayed abort) bits
  53         */
  54        regs->ARM_cpsr &= ~(PSR_F_BIT | PSR_A_BIT);
  55
  56        if ((regs->ARM_cpsr & PSR_I_BIT) == 0) {
  57                if (mode == USR_MODE)
  58                        return 1;
  59                if (elf_hwcap & HWCAP_26BIT && mode == USR26_MODE)
  60                        return 1;
  61        }
  62
  63        /*
  64         * Force CPSR to something logical...
  65         */
  66        regs->ARM_cpsr &= PSR_f | PSR_s | PSR_x | PSR_T_BIT | MODE32_BIT;
  67        if (!(elf_hwcap & HWCAP_26BIT))
  68                regs->ARM_cpsr |= USR_MODE;
  69
  70        return 0;
  71#else /* ifndef CONFIG_CPU_V7M */
  72        return 1;
  73#endif
  74}
  75
  76static inline long regs_return_value(struct pt_regs *regs)
  77{
  78        return regs->ARM_r0;
  79}
  80
  81#define instruction_pointer(regs)       (regs)->ARM_pc
  82
  83#ifdef CONFIG_SMP
  84extern unsigned long profile_pc(struct pt_regs *regs);
  85#else
  86#define profile_pc(regs) instruction_pointer(regs)
  87#endif
  88
  89#define predicate(x)            ((x) & 0xf0000000)
  90#define PREDICATE_ALWAYS        0xe0000000
  91
  92/*
  93 * True if instr is a 32-bit thumb instruction. This works if instr
  94 * is the first or only half-word of a thumb instruction. It also works
  95 * when instr holds all 32-bits of a wide thumb instruction if stored
  96 * in the form (first_half<<16)|(second_half)
  97 */
  98#define is_wide_instruction(instr)      ((unsigned)(instr) >= 0xe800)
  99
 100/*
 101 * kprobe-based event tracer support
 102 */
 103#include <linux/stddef.h>
 104#include <linux/types.h>
 105#define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0))
 106
 107extern int regs_query_register_offset(const char *name);
 108extern const char *regs_query_register_name(unsigned int offset);
 109extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
 110extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 111                                               unsigned int n);
 112
 113/**
 114 * regs_get_register() - get register value from its offset
 115 * @regs:          pt_regs from which register value is gotten
 116 * @offset:    offset number of the register.
 117 *
 118 * regs_get_register returns the value of a register whose offset from @regs.
 119 * The @offset is the offset of the register in struct pt_regs.
 120 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 121 */
 122static inline unsigned long regs_get_register(struct pt_regs *regs,
 123                                              unsigned int offset)
 124{
 125        if (unlikely(offset > MAX_REG_OFFSET))
 126                return 0;
 127        return *(unsigned long *)((unsigned long)regs + offset);
 128}
 129
 130/* Valid only for Kernel mode traps. */
 131static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 132{
 133        return regs->ARM_sp;
 134}
 135
 136static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 137{
 138        return regs->ARM_sp;
 139}
 140
 141#define current_pt_regs(void) ({                                \
 142        register unsigned long sp asm ("sp");                   \
 143        (struct pt_regs *)((sp | (THREAD_SIZE - 1)) - 7) - 1;   \
 144})
 145
 146#endif /* __ASSEMBLY__ */
 147#endif
 148