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__
  16 struct 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  */
  46 static 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
  76 static 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
  84 extern 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
 107 extern int regs_query_register_offset(const char *name);
 108 extern const char *regs_query_register_name(unsigned int offset);
 109 extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
 110 extern 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  */
 122 static 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. */
 131 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 132 {
 133         return regs->ARM_sp;
 134 }
 135
 136 static 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