2002-02-17 14:56:46

by Juan Cespedes

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Subject: ptrace() bug

Hi,

I am the author of "ltrace" and unfortunatelly it does not work in 2.4
kernels, due to a bug in the kernel. Unfortunately, I don't know when
did this behaviour started and what could have caused it...

Summary: if I use ptrace() witth a process that does fork(), and after
the fork I modify with PTRACE_POKETEXT some of the code in the parent,
the same modification is observed in the child.

I need to modify the .text in order to introduce breakpoints, but with
this bug ltrace does not work with any process which forks.

The attached little program shows the bug: the child should not see the
content of "sync" modified after it is alive.

Thanks for your help,

--
.+'''+. .+'''+. .+'''+. .+'''+. .+''
Juan Cespedes / \ / \ [email protected]
.+' `+...+' `+...+' `+...+' `+...+'


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