/*

 * Copyright (C) 2011 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

/* Useful ptrace() utility functions. */

#ifndef _CORKSCREW_PTRACE_H

#define _CORKSCREW_PTRACE_H

#include <corkscrew/map_info.h>

#include <corkscrew/symbol_table.h>

#include <sys/types.h>

#include <stdbool.h>

#include <stdint.h>

#ifdef __cplusplus

extern "C" {

#endif

/* Stores information about a process that is used for several different

 * ptrace() based operations. */

typedef struct {

    map_info_t* map_info_list;

} ptrace_context_t;

/* Describes how to access memory from a process. */

typedef struct {

    pid_t tid;

    const map_info_t* map_info_list;

} memory_t;

#if __i386__

/* ptrace() register context. */

typedef struct pt_regs_x86 {

    uint32_t ebx;

    uint32_t ecx;

    uint32_t edx;

    uint32_t esi;

    uint32_t edi;

    uint32_t ebp;

    uint32_t eax;

    uint32_t xds;

    uint32_t xes;

    uint32_t xfs;

    uint32_t xgs;

    uint32_t orig_eax;

    uint32_t eip;

    uint32_t xcs;

    uint32_t eflags;

    uint32_t esp;

    uint32_t xss;

} pt_regs_x86_t;

#endif

#if __mips__

/* ptrace() GET_REGS context. */

typedef struct pt_regs_mips {

    uint64_t regs[32];

    uint64_t lo;

    uint64_t hi;

    uint64_t cp0_epc;

    uint64_t cp0_badvaddr;

    uint64_t cp0_status;

    uint64_t cp0_cause;

} pt_regs_mips_t;

#endif

/*

 * Initializes a memory structure for accessing memory from this process.

 */

void init_memory(memory_t* memory, const map_info_t* map_info_list);

/*

 * Initializes a memory structure for accessing memory from another process

 * using ptrace().

 */

void init_memory_ptrace(memory_t* memory, pid_t tid);

/*

 * Reads a word of memory safely.

 * If the memory is local, ensures that the address is readable before dereferencing it.

 * Returns false and a value of 0xffffffff if the word could not be read.

 */

bool try_get_word(const memory_t* memory, uintptr_t ptr, uint32_t* out_value);

/*

 * Reads a word of memory safely using ptrace().

 * Returns false and a value of 0xffffffff if the word could not be read.

 */

bool try_get_word_ptrace(pid_t tid, uintptr_t ptr, uint32_t* out_value);

/*

 * Loads information needed for examining a remote process using ptrace().

 * The caller must already have successfully attached to the process

 * using ptrace().

 *

 * The context can be used for any threads belonging to that process

 * assuming ptrace() is attached to them before performing the actual

 * unwinding.  The context can continue to be used to decode backtraces

 * even after ptrace() has been detached from the process.

 */

ptrace_context_t* load_ptrace_context(pid_t pid);

/*

 * Frees a ptrace context.

 */

void free_ptrace_context(ptrace_context_t* context);

/*

 * Finds a symbol using ptrace.

 * Returns the containing map and information about the symbol, or

 * NULL if one or the other is not available.

 */

void find_symbol_ptrace(const ptrace_context_t* context,

        uintptr_t addr, const map_info_t** out_map_info, const symbol_t** out_symbol);

#ifdef __cplusplus

}

#endif

#endif // _CORKSCREW_PTRACE_H