gdb如何在Linux上访问另一个进程虚拟内存？这一切都是通过/ proc完成的吗？
答案 0 :(得分：10)
gdb如何在Linux上访问另一个进程虚拟内存？这一切都是通过/ proc完成的吗？
在Linux上阅读内存：
1）如果要读取的字节数小于3 * sizeof (long)或文件系统/proc不可用或从/proc/PID/mem读取不成功，则ptrace与{一起使用} {1}}读取数据。
这些是函数PTRACE_PEEKTEXT中的条件：
linux_proc_xfer_partial() 2）如果要读取的字节数大于或等于3 * sizeof（long）且 /* Don't bother for one word. */
if (len < 3 * sizeof (long))
return 0;
/* We could keep this file open and cache it - possibly one per
thread. That requires some juggling, but is even faster. */
xsnprintf (filename, sizeof filename, "/proc/%d/mem",
ptid_get_pid (inferior_ptid));
fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0);
if (fd == -1)
return 0;
可用，则/proc或（pread64和lseek()使用：
read()在Linux上编写内存：
1）static LONGEST
linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
const char *annex, gdb_byte *readbuf,
const gdb_byte *writebuf,
ULONGEST offset, LONGEST len)
{
.....
/* If pread64 is available, use it. It's faster if the kernel
supports it (only one syscall), and it's 64-bit safe even on
32-bit platforms (for instance, SPARC debugging a SPARC64
application). */
#ifdef HAVE_PREAD64
if (pread64 (fd, readbuf, len, offset) != len)
#else
if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
#endif
ret = 0;
else
ret = len;
close (fd);
return ret;
}
使用ptrace或PTRACE_POKETEXT。
<小时/> 至于你的第二个问题：
在哪里可以找到有关...设置硬件观察点的信息
gdb，Internals Watchpoint：s http://sourceware.org/gdb/wiki/Internals%20Watchpoints
参考：