Android中实现对/system/bin/surfaceflinger进程进行拦截和注入

对于Android for arm上的so注入（inject）和挂钩（hook），网上已有牛人给出了代码inject。由于实现中的ptrace函数是依赖于平台的，所以不经改动只能用于arm平台。本文将之扩展了一下，使它能够通用于Android的x86和arm平台。Arm平台部分基本重用了inject中的代码，其中因为汇编不好移植且容易出错，所以把shellcode.s用ptrace_call替换掉了，另外保留了mmap，用来传字符串参数，当然也可以通过栈来传，但栈里和其它东西混一起，一弄不好就会隔儿了，所以还是保险点好。最后注意设备要root。

还有就是要在Linux中配置一下NDK编译环境呀~~(这个可以google了~~)

首先创建目录及文件：

文件夹：jni

文件：
    inject.c
    Android.mk
    Application.mk

(说明：由于NDK编译的条件限制，所以我们需要创建的jni文件夹，当然这个文件的名字必须是jni)

注入的核心源代码：

inject.c

#include <stdio.h>    
#include <stdlib.h>    
#include <asm/user.h>    
#include <asm/ptrace.h>    
#include <sys/ptrace.h>    
#include <sys/wait.h>    
#include <sys/mman.h>    
#include <dlfcn.h>    
#include <dirent.h>    
#include <unistd.h>    
#include <string.h>    
#include <elf.h>    
#include <android/log.h>    
    
#if defined(__i386__)    
#define pt_regs         user_regs_struct    
#endif    
    
#define ENABLE_DEBUG 1    
    
#if ENABLE_DEBUG    
#define  LOG_TAG "INJECT"    
#define  LOGD(fmt, args...)  __android_log_print(ANDROID_LOG_DEBUG,LOG_TAG, fmt, ##args)    
#define DEBUG_PRINT(format,args...)     
    LOGD(format, ##args)    
#else    
#define DEBUG_PRINT(format,args...)    
#endif    
    
#define CPSR_T_MASK     ( 1u << 5 )    
    
const char *libc_path = "/system/lib/libc.so";    
const char *linker_path = "/system/bin/linker";    
    
int ptrace_readdata(pid_t pid,  uint8_t *src, uint8_t *buf, size_t size)    
{    
    uint32_t i, j, remain;    
    uint8_t *laddr;    
    
    union u {    
        long val;    
        char chars[sizeof(long)];    
    } d;    
    
    j = size / 4;    
    remain = size % 4;    
    
    laddr = buf;    
    
    for (i = 0; i < j; i ++) {    
        d.val = ptrace(PTRACE_PEEKTEXT, pid, src, 0);    
        memcpy(laddr, d.chars, 4);    
        src += 4;    
        laddr += 4;    
    }    
    
    if (remain > 0) {    
        d.val = ptrace(PTRACE_PEEKTEXT, pid, src, 0);    
        memcpy(laddr, d.chars, remain);    
    }    
    
    return 0;    
}    
    
int ptrace_writedata(pid_t pid, uint8_t *dest, uint8_t *data, size_t size)    
{    
    uint32_t i, j, remain;    
    uint8_t *laddr;    
    
    union u {    
        long val;    
        char chars[sizeof(long)];    
    } d;    
    
    j = size / 4;    
    remain = size % 4;    
    
    laddr = data;    
    
    for (i = 0; i < j; i ++) {    
        memcpy(d.chars, laddr, 4);    
        ptrace(PTRACE_POKETEXT, pid, dest, d.val);    
    
        dest  += 4;    
        laddr += 4;    
    }    
    
    if (remain > 0) {    
        d.val = ptrace(PTRACE_PEEKTEXT, pid, dest, 0);    
        for (i = 0; i < remain; i ++) {    
            d.chars[i] = *laddr ++;    
        }    
    
        ptrace(PTRACE_POKETEXT, pid, dest, d.val);    
    }    
    
    return 0;    
}    
    
#if defined(__arm__)    
int ptrace_call(pid_t pid, uint32_t addr, long *params, uint32_t num_params, struct pt_regs* regs)    
{    
    uint32_t i;    
    for (i = 0; i < num_params && i < 4; i ++) {    
        regs->uregs[i] = params[i];    
    }    
    
    //    
    // push remained params onto stack    
    //    
    if (i < num_params) {    
        regs->ARM_sp -= (num_params - i) * sizeof(long) ;    
        ptrace_writedata(pid, (void *)regs->ARM_sp, (uint8_t *)¶ms[i], (num_params - i) * sizeof(long));    
    }    
    
    regs->ARM_pc = addr;    
    if (regs->ARM_pc & 1) {    
        /* thumb */    
        regs->ARM_pc &= (~1u);    
        regs->ARM_cpsr |= CPSR_T_MASK;    
    } else {    
        /* arm */    
        regs->ARM_cpsr &= ~CPSR_T_MASK;    
    }    
    
    regs->ARM_lr = 0;        
    
    if (ptrace_setregs(pid, regs) == -1     
            || ptrace_continue(pid) == -1) {    
        printf("error
");    
        return -1;    
    }    
    
    int stat = 0;  
    waitpid(pid, &stat, WUNTRACED);  
    while (stat != 0xb7f) {  
        if (ptrace_continue(pid) == -1) {  
            printf("error
");  
            return -1;  
        }  
        waitpid(pid, &stat, WUNTRACED);  
    }  
    
    return 0;    
}    
    
#elif defined(__i386__)    
long ptrace_call(pid_t pid, uint32_t addr, long *params, uint32_t num_params, struct user_regs_struct * regs)    
{    
    regs->esp -= (num_params) * sizeof(long) ;    
    ptrace_writedata(pid, (void *)regs->esp, (uint8_t *)params, (num_params) * sizeof(long));    
    
    long tmp_addr = 0x00;    
    regs->esp -= sizeof(long);    
    ptrace_writedata(pid, regs->esp, (char *)&tmp_addr, sizeof(tmp_addr));     
    
    regs->eip = addr;    
    
    if (ptrace_setregs(pid, regs) == -1     
            || ptrace_continue( pid) == -1) {    
        printf("error
");    
        return -1;    
    }    
    
    int stat = 0;  
    waitpid(pid, &stat, WUNTRACED);  
    while (stat != 0xb7f) {  
        if (ptrace_continue(pid) == -1) {  
            printf("error
");  
            return -1;  
        }  
        waitpid(pid, &stat, WUNTRACED);  
    }  
    
    return 0;    
}    
#else     
#error "Not supported"    
#endif    
    
int ptrace_getregs(pid_t pid, struct pt_regs * regs)    
{    
    if (ptrace(PTRACE_GETREGS, pid, NULL, regs) < 0) {    
        perror("ptrace_getregs: Can not get register values");    
        return -1;    
    }    
    
    return 0;    
}    
    
int ptrace_setregs(pid_t pid, struct pt_regs * regs)    
{    
    if (ptrace(PTRACE_SETREGS, pid, NULL, regs) < 0) {    
        perror("ptrace_setregs: Can not set register values");    
        return -1;    
    }    
    
    return 0;    
}    
    
int ptrace_continue(pid_t pid)    
{    
    if (ptrace(PTRACE_CONT, pid, NULL, 0) < 0) {    
        perror("ptrace_cont");    
        return -1;    
    }    
    
    return 0;    
}    
    
int ptrace_attach(pid_t pid)    
{    
    if (ptrace(PTRACE_ATTACH, pid, NULL, 0) < 0) {    
        perror("ptrace_attach");    
        return -1;    
    }    
    
    int status = 0;    
    waitpid(pid, &status , WUNTRACED);    
    
    return 0;    
}    
    
int ptrace_detach(pid_t pid)    
{    
    if (ptrace(PTRACE_DETACH, pid, NULL, 0) < 0) {    
        perror("ptrace_detach");    
        return -1;    
    }    
    
    return 0;    
}    
    
void* get_module_base(pid_t pid, const char* module_name)    
{    
    FILE *fp;    
    long addr = 0;    
    char *pch;    
    char filename[32];    
    char line[1024];    
    
    if (pid < 0) {    
        /* self process */    
        snprintf(filename, sizeof(filename), "/proc/self/maps", pid);    
    } else {    
        snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);    
    }    
    
    fp = fopen(filename, "r");    
    
    if (fp != NULL) {    
        while (fgets(line, sizeof(line), fp)) {    
            if (strstr(line, module_name)) {    
                pch = strtok( line, "-" );    
                addr = strtoul( pch, NULL, 16 );    
    
                if (addr == 0x8000)    
                    addr = 0;    
    
                break;    
            }    
        }    
    
        fclose(fp) ;    
    }    
    
    return (void *)addr;    
}    
    
void* get_remote_addr(pid_t target_pid, const char* module_name, void* local_addr)    
{    
    void* local_handle, *remote_handle;    
    
    local_handle = get_module_base(-1, module_name);    
    remote_handle = get_module_base(target_pid, module_name);    
    
    DEBUG_PRINT("[+] get_remote_addr: local[%x], remote[%x]
", local_handle, remote_handle);    
    
    void * ret_addr = (void *)((uint32_t)local_addr + (uint32_t)remote_handle - (uint32_t)local_handle);    
    
#if defined(__i386__)    
    if (!strcmp(module_name, libc_path)) {    
        ret_addr += 2;    
    }    
#endif    
    return ret_addr;    
}    
    
int find_pid_of(const char *process_name)    
{    
    int id;    
    pid_t pid = -1;    
    DIR* dir;    
    FILE *fp;    
    char filename[32];    
    char cmdline[256];    
    
    struct dirent * entry;    
    
    if (process_name == NULL)    
        return -1;    
    
    dir = opendir("/proc");    
    if (dir == NULL)    
        return -1;    
    
    while((entry = readdir(dir)) != NULL) {    
        id = atoi(entry->d_name);    
        if (id != 0) {    
            sprintf(filename, "/proc/%d/cmdline", id);    
            fp = fopen(filename, "r");    
            if (fp) {    
                fgets(cmdline, sizeof(cmdline), fp);    
                fclose(fp);    
    
                if (strcmp(process_name, cmdline) == 0) {    
                    /* process found */    
                    pid = id;    
                    break;    
                }    
            }    
        }    
    }    
    
    closedir(dir);    
    return pid;    
}    
    
long ptrace_retval(struct pt_regs * regs)    
{    
#if defined(__arm__)    
    return regs->ARM_r0;    
#elif defined(__i386__)    
    return regs->eax;    
#else    
#error "Not supported"    
#endif    
}    
    
long ptrace_ip(struct pt_regs * regs)    
{    
#if defined(__arm__)    
    return regs->ARM_pc;    
#elif defined(__i386__)    
    return regs->eip;    
#else    
#error "Not supported"    
#endif    
}    
    
int ptrace_call_wrapper(pid_t target_pid, const char * func_name, void * func_addr, long * parameters, int param_num, struct pt_regs * regs)     
{    
    DEBUG_PRINT("[+] Calling %s in target process.
", func_name);    
    if (ptrace_call(target_pid, (uint32_t)func_addr, parameters, param_num, regs) == -1)    
        return -1;    
    
    if (ptrace_getregs(target_pid, regs) == -1)    
        return -1;    
    DEBUG_PRINT("[+] Target process returned from %s, return value=%x, pc=%x 
",     
            func_name, ptrace_retval(regs), ptrace_ip(regs));    
    return 0;    
}    
    
int inject_remote_process(pid_t target_pid, const char *library_path, const char *function_name, const char *param, size_t param_size)    
{    
    int ret = -1;    
    void *mmap_addr, *dlopen_addr, *dlsym_addr, *dlclose_addr, *dlerror_addr;    
    void *local_handle, *remote_handle, *dlhandle;    
    uint8_t *map_base = 0;    
    uint8_t *dlopen_param1_ptr, *dlsym_param2_ptr, *saved_r0_pc_ptr, *inject_param_ptr, *remote_code_ptr, *local_code_ptr;    
    
    struct pt_regs regs, original_regs;    
    extern uint32_t _dlopen_addr_s, _dlopen_param1_s, _dlopen_param2_s, _dlsym_addr_s,     
        _dlsym_param2_s, _dlclose_addr_s, _inject_start_s, _inject_end_s, _inject_function_param_s,     
        _saved_cpsr_s, _saved_r0_pc_s;    
    
    uint32_t code_length;    
    long parameters[10];    
    
    DEBUG_PRINT("[+] Injecting process: %d
", target_pid);    
    
    if (ptrace_attach(target_pid) == -1)    
        goto exit;    
    
    if (ptrace_getregs(target_pid, &regs) == -1)    
        goto exit;    
    
    /* save original registers */    
    memcpy(&original_regs, &regs, sizeof(regs));    
    
    mmap_addr = get_remote_addr(target_pid, libc_path, (void *)mmap);    
    DEBUG_PRINT("[+] Remote mmap address: %x
", mmap_addr);    
    
    /* call mmap */    
    parameters[0] = 0;  // addr    
    parameters[1] = 0x4000; // size    
    parameters[2] = PROT_READ | PROT_WRITE | PROT_EXEC;  // prot    
    parameters[3] =  MAP_ANONYMOUS | MAP_PRIVATE; // flags    
    parameters[4] = 0; //fd    
    parameters[5] = 0; //offset    
    
    if (ptrace_call_wrapper(target_pid, "mmap", mmap_addr, parameters, 6, &regs) == -1)    
        goto exit;    
    
    map_base = ptrace_retval(&regs);    
    
    dlopen_addr = get_remote_addr( target_pid, linker_path, (void *)dlopen );    
    dlsym_addr = get_remote_addr( target_pid, linker_path, (void *)dlsym );    
    dlclose_addr = get_remote_addr( target_pid, linker_path, (void *)dlclose );    
    dlerror_addr = get_remote_addr( target_pid, linker_path, (void *)dlerror );    
    
    DEBUG_PRINT("[+] Get imports: dlopen: %x, dlsym: %x, dlclose: %x, dlerror: %x
",    
            dlopen_addr, dlsym_addr, dlclose_addr, dlerror_addr);    
    
    printf("library path = %s
", library_path);    
    ptrace_writedata(target_pid, map_base, library_path, strlen(library_path) + 1);    
    
    parameters[0] = map_base;       
    parameters[1] = RTLD_NOW| RTLD_GLOBAL;     
    
    if (ptrace_call_wrapper(target_pid, "dlopen", dlopen_addr, parameters, 2, &regs) == -1)    
        goto exit;    
    
    void * sohandle = ptrace_retval(&regs);    
    
#define FUNCTION_NAME_ADDR_OFFSET       0x100    
    ptrace_writedata(target_pid, map_base + FUNCTION_NAME_ADDR_OFFSET, function_name, strlen(function_name) + 1);    
    parameters[0] = sohandle;       
    parameters[1] = map_base + FUNCTION_NAME_ADDR_OFFSET;     
    
    if (ptrace_call_wrapper(target_pid, "dlsym", dlsym_addr, parameters, 2, &regs) == -1)    
        goto exit;    
    
    void * hook_entry_addr = ptrace_retval(&regs);    
    DEBUG_PRINT("hook_entry_addr = %p
", hook_entry_addr);    
    
#define FUNCTION_PARAM_ADDR_OFFSET      0x200    
    ptrace_writedata(target_pid, map_base + FUNCTION_PARAM_ADDR_OFFSET, param, strlen(param) + 1);    
    parameters[0] = map_base + FUNCTION_PARAM_ADDR_OFFSET;      
  
    if (ptrace_call_wrapper(target_pid, "hook_entry", hook_entry_addr, parameters, 1, &regs) == -1)    
        goto exit;        
    
    printf("Press enter to dlclose and detach
");    
    getchar();    
    parameters[0] = sohandle;       
    
    if (ptrace_call_wrapper(target_pid, "dlclose", dlclose, parameters, 1, &regs) == -1)    
        goto exit;    
    
    /* restore */    
    ptrace_setregs(target_pid, &original_regs);    
    ptrace_detach(target_pid);    
    ret = 0;    
    
exit:    
    return ret;    
}    
    
int main(int argc, char** argv) {    
    pid_t target_pid;    
    target_pid = find_pid_of("/system/bin/surfaceflinger");    
    if (-1 == target_pid) {  
        printf("Can't find the process
");  
        return -1;  
    }  
    //target_pid = find_pid_of("/data/test");    
    inject_remote_process(target_pid, "/data/libhello.so", "hook_entry",  "I'm parameter!", strlen("I'm parameter!"));    
    return 0;  
} 

注意上面的/system/bin/surfaceflinger进程我随手写的，你的设备上不一定有。没有的话挑其它的也行，前提是ps命令里能找到。

Android.mk:

LOCAL_PATH := $(call my-dir)  
include $(CLEAR_VARS)  
LOCAL_MODULE := inject   
LOCAL_SRC_FILES := inject.c   
#shellcode.s   
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog   
#LOCAL_FORCE_STATIC_EXECUTABLE := true  
include $(BUILD_EXECUTABLE)  

Application.mk:

APP_ABI := x86 armeabi-v7a  

运行nkd-build编译成生x86和arm平台下的可执行文件：


再来生成要注入的so，创建目录及文件：
jni
    suf.c
    Android.mk

    Application.mk

suf.c:

#include <unistd.h>  
#include <stdio.h>  
#include <stdlib.h>  
#include <android/log.h>  
#include <elf.h>  
#include <fcntl.h>  
  
#define LOG_TAG "DEBUG"  
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, fmt, ##args)    
  
int hook_entry(char * a){  
    LOGD("Hook success, pid = %d
", getpid());  
    LOGD("Hello %s
", a);  
    return 0;  
}  

Android.mk:

LOCAL_PATH := $(call my-dir)  
include $(CLEAR_VARS)  
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog   
#LOCAL_ARM_MODE := arm  
LOCAL_MODULE    := suf  
LOCAL_SRC_FILES := suf.c  
include $(BUILD_SHARED_LIBRARY)  

Application.mk:

APP_ABI := x86 armeabi-v7a  

运行nkd-build编译成生x86和arm平台下的so：


然后就可以跑起来试试了，连接root过的Android设备或者打开模拟器。将inject和libhello.so拷入设备，设执行权限，执行：
先看看被注入进程（surfaceflinger）的mmap，可以看到我们的so已经被加载了，紧接着的那一块就是我们mmap出来的：

从logcat中也可以看到so注入成功，并且以被注入进程的身份执行了so中的代码.

将编译好的文件拷贝到设备的data目录(这里不一定要拷贝到data目录下面，这个可以看自己的需要了)下面：

adb push inject /data/

adb push libsuf.so /data/

然后修改一下文件的权限

chmod 777 inject

然后运行inject,同时我们可以查询一下/system/bin/surfaceflinger进程信息，可以看到，我们将libsuf.so注入到了此进程中.

简单的注入成功，现在我们再来做一个实验，就是应用这套机制来截获surfaceflinger中的eglSwapBuffers调用，然后用我们自己的函数来替换掉原来的eglSwapBuffers调用。关于截系统中的函数调用网上有例子，这里依葫芦画瓢。首先将suf.c改下：

#include <unistd.h>  
#include <stdio.h>  
#include <stdlib.h>  
#include <android/log.h>  
#include <EGL/egl.h>  
#include <GLES/gl.h>  
#include <elf.h>  
#include <fcntl.h>  
#include <sys/mman.h>  
  
#define LOG_TAG "DEBUG"  
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, fmt, ##args)    
  
EGLBoolean (*old_eglSwapBuffers)(EGLDisplay dpy, EGLSurface surf) = -1;  
  
EGLBoolean new_eglSwapBuffers(EGLDisplay dpy, EGLSurface surface)  
{  
    LOGD("New eglSwapBuffers
");  
    if (old_eglSwapBuffers == -1)  
        LOGD("error
");  
    return old_eglSwapBuffers(dpy, surface);  
}  
  
void* get_module_base(pid_t pid, const char* module_name)  
{  
    FILE *fp;  
    long addr = 0;  
    char *pch;  
    char filename[32];  
    char line[1024];  
  
    if (pid < 0) {  
        /* self process */  
        snprintf(filename, sizeof(filename), "/proc/self/maps", pid);  
    } else {  
        snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);  
    }  
  
    fp = fopen(filename, "r");  
  
    if (fp != NULL) {  
        while (fgets(line, sizeof(line), fp)) {  
            if (strstr(line, module_name)) {  
                pch = strtok( line, "-" );  
                addr = strtoul( pch, NULL, 16 );  
  
                if (addr == 0x8000)  
                    addr = 0;  
  
                break;  
            }  
        }  
  
        fclose(fp) ;  
    }  
  
    return (void *)addr;  
}  
  
#define LIBSF_PATH  "/system/lib/libsurfaceflinger.so"    
int hook_eglSwapBuffers()    
{    
    old_eglSwapBuffers = eglSwapBuffers;    
    LOGD("Orig eglSwapBuffers = %p
", old_eglSwapBuffers);    
    void * base_addr = get_module_base(getpid(), LIBSF_PATH);    
    LOGD("libsurfaceflinger.so address = %p
", base_addr);    
  
    int fd;    
    fd = open(LIBSF_PATH, O_RDONLY);    
    if (-1 == fd) {    
        LOGD("error
");    
        return -1;    
    }    
  
    Elf32_Ehdr ehdr;    
    read(fd, &ehdr, sizeof(Elf32_Ehdr));    
  
    unsigned long shdr_addr = ehdr.e_shoff;      
    int shnum = ehdr.e_shnum;      
    int shent_size = ehdr.e_shentsize;      
    unsigned long stridx = ehdr.e_shstrndx;      
  
    Elf32_Shdr shdr;    
    lseek(fd, shdr_addr + stridx * shent_size, SEEK_SET);      
    read(fd, &shdr, shent_size);      
  
    char * string_table = (char *)malloc(shdr.sh_size);      
    lseek(fd, shdr.sh_offset, SEEK_SET);      
    read(fd, string_table, shdr.sh_size);    
    lseek(fd, shdr_addr, SEEK_SET);      
  
    int i;      
    uint32_t out_addr = 0;    
    uint32_t out_size = 0;    
    uint32_t got_item = 0;  
    int32_t got_found = 0;    
  
    for (i = 0; i < shnum; i++) {      
        read(fd, &shdr, shent_size);      
        if (shdr.sh_type == SHT_PROGBITS) {    
            int name_idx = shdr.sh_name;      
            if (strcmp(&(string_table[name_idx]), ".got.plt") == 0   
                    || strcmp(&(string_table[name_idx]), ".got") == 0) {      
                out_addr = base_addr + shdr.sh_addr;      
                out_size = shdr.sh_size;      
                LOGD("out_addr = %lx, out_size = %lx
", out_addr, out_size);    
  
                for (i = 0; i < out_size; i += 4) {      
                    got_item = *(uint32_t *)(out_addr + i);    
                    if (got_item  == old_eglSwapBuffers) {      
                        LOGD("Found eglSwapBuffers in got
");    
                        got_found = 1;  
  
                        uint32_t page_size = getpagesize();  
                        uint32_t entry_page_start = (out_addr + i) & (~(page_size - 1));  
                        mprotect((uint32_t *)entry_page_start, page_size, PROT_READ | PROT_WRITE);  
                        *(uint32_t *)(out_addr + i) = new_eglSwapBuffers;    
  
                        break;      
                    } else if (got_item == new_eglSwapBuffers) {      
                        LOGD("Already hooked
");    
                        break;      
                    }      
                }     
                if (got_found)   
                    break;  
            }     
        }      
    }      
  
    free(string_table);      
    close(fd);    
}    
  
int hook_entry(char * a){  
    LOGD("Hook success
");  
    LOGD("Start hooking
");  
    hook_eglSwapBuffers();    
    return 0;  
}  

其实这种查找方法有点简单粗暴，要是正式应用的话可以在动态符号表中查找这个符号的got地址。
接着Android.mk改为：

LOCAL_PATH := $(call my-dir)  
include $(CLEAR_VARS)  
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog -lEGL  
#LOCAL_ARM_MODE := arm  
LOCAL_MODULE    := hello  
LOCAL_SRC_FILES := hello.c  
include $(BUILD_SHARED_LIBRARY) 

Application.mk :

APP_ABI := x86 armeabi-v7a    
APP_PLATFORM := android-14  

运行ndk-build编译
和上面一样运行，查看logcat，我们可以看到surfaceflinger中调用eglSwapBuffers的地址已被替换成我们的版本：
D/INJECT  ( 2231): [+] Injecting process: 1728  
D/INJECT  ( 2231): [+] get_remote_addr: local[b7e4f000], remote[b7e73000]  
D/INJECT  ( 2231): [+] Remote mmap address: b7e9fe32  
D/INJECT  ( 2231): [+] Calling mmap in target process.  
D/INJECT  ( 2231): [+] Target process returned from mmap, return value=b4f1c000, pc=0   
D/INJECT  ( 2231): [+] get_remote_addr: local[b7f00000], remote[b7f7e000]  
D/INJECT  ( 2231): [+] get_remote_addr: local[b7f00000], remote[b7f7e000]  
D/INJECT  ( 2231): [+] get_remote_addr: local[b7f00000], remote[b7f7e000]  
D/INJECT  ( 2231): [+] get_remote_addr: local[b7f00000], remote[b7f7e000]  
D/INJECT  ( 2231): [+] Get imports: dlopen: b7f84f50, dlsym: b7f84fd0, dlclose: b7f84de0, dlerror: b7f84dc0  
D/INJECT  ( 2231): [+] Calling dlopen in target process.  
D/INJECT  ( 2231): [+] Target process returned from dlopen, return value=b7f995ec, pc=0   
D/INJECT  ( 2231): [+] Calling dlsym in target process.  
D/INJECT  ( 2231): [+] Target process returned from dlsym, return value=b4f17e10, pc=0   
D/INJECT  ( 2231): hook_entry_addr = 0xb4f17e10  
D/DEBUG   ( 1728): Hook success  
D/DEBUG   ( 1728): Start hooking  
D/DEBUG   ( 1728): Orig eglSwapBuffers = 0xb7d4a9c0  
D/DEBUG   ( 1728): libsurfaceflinger.so address = 0xb7f22000  
D/DEBUG   ( 1728): out_addr = b7f7aff4, out_size = 624  
D/DEBUG   ( 1728): Found eglSwapBuffers in got  
...  
D/DEBUG   ( 1728): New eglSwapBuffers  
D/DEBUG   ( 1728): New eglSwapBuffers  
D/DEBUG   ( 1728): New eglSwapBuffers  
...  

Demo下载地址：http://download.csdn.net/detail/jiangwei0910410003/7926427

这篇文章就简单介绍了如何将对surfaceflinger进程进行注入和拦截的操作。这个还是很有用的，后续我们还会对system_process进程进行注入和拦截，那时候还会参考这篇文章。。