使用正在运行的进程的共享内存收集核心转储

Posted 2023-02-22

【中文标题】使用正在运行的进程的共享内存收集核心转储

【英文标题】：Collect core dump with shared memory of running process

【发布时间】：2016-02-18 09:55:57

【问题描述】：

核心转储只收集进程空间，但不收集为进程间通信创建的共享内存。如何使核心转储也包含正在运行的进程的共享内存？

【参考方案1】：

在/proc/PID/coredump_filter per http://man7.org/linux/man-pages/man5/core.5.html 中设置核心文件过滤器：

控制将哪些映射写入核心转储

   Since kernel 2.6.23, the Linux-specific /proc/PID/coredump_filter
   file can be used to control which memory segments are written to the
   core dump file in the event that a core dump is performed for the
   process with the corresponding process ID.

   The value in the file is a bit mask of memory mapping types (see
   mmap(2)).  If a bit is set in the mask, then memory mappings of the
   corresponding type are dumped; otherwise they are not dumped.  The
   bits in this file have the following meanings:

       bit 0  Dump anonymous private mappings.
       bit 1  Dump anonymous shared mappings.
       bit 2  Dump file-backed private mappings.
       bit 3  Dump file-backed shared mappings.
       bit 4 (since Linux 2.6.24)
              Dump ELF headers.
       bit 5 (since Linux 2.6.28)
              Dump private huge pages.
       bit 6 (since Linux 2.6.28)
              Dump shared huge pages.
       bit 7 (since Linux 4.4)
              Dump private DAX pages.
       bit 8 (since Linux 4.4)
              Dump shared DAX pages.

   By default, the following bits are set: 0, 1, 4 (if the
   CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS kernel configuration option is
   enabled), and 5.  This default can be modified at boot time using the
   coredump_filter boot option.

【讨论】：

这有帮助，我使用了 sprintf(cmd, "echo 0xff > /proc/%d/coredump_filter",getpid() );系统（cmd）；它奏效了。谢谢安德鲁！

【参考方案2】：

核心文件捕获完整的进程地址空间，包括共享内存。您可以通过在 Linux 上使用 gcore 命令生成核心文件，然后在核心文件中检查您存储在共享内存中的特定内容来检查。

【讨论】：

我试过了，共享内存无法访问。必须有一种方法可以使用共享内存启用核心转储。请帮忙

你是从root用户生成core文件的吗？

是的，我们需要在 coredump_filter 上启用一点。