ubuntu 32 位系统 12.04 LTS pstack 无法使用

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ubuntuqyt@ubuntuqyt-OptiPlex-3020:~/桌面/Code/HMC_Release$ pstack 11474
Could not attach to target 11474: Operation not permitted.
detach: No such process
ubuntuqyt@ubuntuqyt-OptiPlex-3020:~/桌面/Code/HMC_Release$ sudo pstack 11474

11474: ./HMC_ServiceApp
(No symbols found in )
(No symbols found in /lib/i386-linux-gnu/libc.so.6)
(No symbols found in /lib/ld-linux.so.2)
(No symbols found in /lib/i386-linux-gnu/libm.so.6)
(No symbols found in /lib/i386-linux-gnu/libnss_files.so.2)
crawl: Input/output error
Error tracing through process 11474


我使用的是-g 选项编译的，我GDB进入我的程序都能正常调试。这是怎么回事啊？  

我以前都用的好好的，不知道为啥现在出这个问题，