Re: [PATCH v3 2.6.39-rc1-tip 12/26] 12: uprobes: slot allocation for uprobes

From: Frank Ch. Eigler
Date: Wed Apr 20 2011 - 10:52:42 EST



eparis wrote:

> [...]
> Now how to fix the problems you were seeing. If you run a modern
> system with a GUI I'm willing to bet the pop-up window told you
> exactly how to fix your problem. [...]
>
> 1) chcon -t unconfined_execmem_t /path/to/your/binary
> 2) setsebool -P allow_execmem 1
> [...]
> I believe there was a question about how JIT's work with SELinux
> systems. They work mostly by method #1.

Actually, that's a solution to a different problem. Here, it's not
particular /path/to/your/binaries that want/need selinux provileges.
It's a kernel-driven debugging facility that needs it temporarily for
arbitrary processes.

It's not like JITs, with known binary names. It's not like GDB, which
simply overwrites existing instructions in the text segment. To make
uprobes work fast (single-step-out-of-line), one needs one or emore
temporary pages with unusual mapping permissions.

- FChE
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