Re: [osol-discuss] Tracing programs on opensolaris
I'm under the impression that dtrace is read-only, for security reasons. On Sat, Jul 11, 2009 at 4:50 PM, Rafael Cunha de Almeidaalmeida...@gmail.com wrote: Hello, I have been studying ptrace(2) on the Unix systems (I have studied it on Debian and OpenBSD so far). On all the systems I have tried there is a request flag that allows for a given process to attach itself to some other running process (given that other process is not setuid and has the same uid as the attacher). Opensolaris' manual pages doesn't say anything about such a request. Opensolaris' ptrace(3C) manual page says that ptrace isn't even a system call in solaris. It is build using some /proc interface. Further investigation showed me that gdb is able to attach itself to a running process (actually, two gdbs are able to attach itself to the same process, something that's impossible on Linux and OpenBSD). Where can I read up on that /proc interface? So, it allows for more than one process attach to a single process? On a related topic, is it possible to change the behaviour of programs using dtrace (like you can with ptrace) or is it read-only? Does it use those /proc features as well? ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
Re: [osol-discuss] Tracing programs on opensolaris
I have been studying ptrace(2) on the Unix systems (I have studied it on Debian and OpenBSD so far). On all the systems I have tried there is a request flag that allows for a given process to attach itself to some other running process (given that other process is not setuid and has the same uid as the attacher). Opensolaris' manual pages doesn't say anything about such a request. Ptrace is dead in Solaris; truss doesn't use ptrace neither does mdb/dbx. Opensolaris' ptrace(3C) manual page says that ptrace isn't even a system call in solaris. It is build using some /proc interface. Further investigation showed me that gdb is able to attach itself to a running process (actually, two gdbs are able to attach itself to the same process, something that's impossible on Linux and OpenBSD). Where can I read up on that /proc interface? So, it allows for more than one process attach to a single process? See proc(4). You open the appropriate files under /proc/pid, particularly, ctl and /proc/pid/lwp/tid/lwpctl On a related topic, is it possible to change the behaviour of programs using dtrace (like you can with ptrace) or is it read-only? Does it use those /proc features as well? Use /proc which doesn't require any privileges; dtrace, especially when you want to modify data, requires privileges. Modifying data is easy through the as file; to change registers you'll need to write a specific control message. Casper ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
[osol-discuss] Tracing programs on opensolaris
Hello, I have been studying ptrace(2) on the Unix systems (I have studied it on Debian and OpenBSD so far). On all the systems I have tried there is a request flag that allows for a given process to attach itself to some other running process (given that other process is not setuid and has the same uid as the attacher). Opensolaris' manual pages doesn't say anything about such a request. Opensolaris' ptrace(3C) manual page says that ptrace isn't even a system call in solaris. It is build using some /proc interface. Further investigation showed me that gdb is able to attach itself to a running process (actually, two gdbs are able to attach itself to the same process, something that's impossible on Linux and OpenBSD). Where can I read up on that /proc interface? So, it allows for more than one process attach to a single process? On a related topic, is it possible to change the behaviour of programs using dtrace (like you can with ptrace) or is it read-only? Does it use those /proc features as well? ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
