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Re: status of Linux ptrace on amd64?

On Dec 2, 10:06pm, (Alexander Nasonov) wrote:
-- Subject: Re: status of Linux ptrace on amd64?

| Alexander Nasonov wrote:
| > Christos Zoulas wrote:
| > > Should not be that hard, but what is that tool reading from PEEKUSER?
| > > Registers?
| > 
| > In both cases it reads from user_regs_struct, if I understand everything
| > correctly. But it's the first step, the tool would definitely try other
| > things if PEEKUSER didn't fail. In fact, I'm not sure that thing would
| > work at all because it's a dynamic instrumentation tool called Pin. It
| > updates code on the fly.
| OK, I implemented reading orig_ax by PEEKUSER. It fixed ptrace failure
| but it added two problems:
| 1. I had to disable compat_linux32 to fix compilation. I need
|    to make linux_sys_ptrace_arch multiarch-aware.
| 2. PEEKUSER didn't change anything. The tool still detaches its child
|    and exits. I can't debug to see what's going on, gdb receives SIGUSR1
|    from the tool. I suspect PEEKUSER returns unexpected value.

Have you tried porting "the tool" to NetBSD? What is involved?


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