Messages in this thread | | | Date | Sat, 26 Feb 2011 04:59:01 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH 1/1] ptrace: make sure do_wait() won't hang after PTRACE_ATTACH |
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On Mon 2011-02-14 10:03:56, Jan Kratochvil wrote: > On Mon, 14 Feb 2011 00:01:47 +0100, Denys Vlasenko wrote: > > * sleep runs in nanosleep > > * SIGSTOP arrives, strace sees it > > * strace logs it and allows it via ptrace(PTRACE_SYSCALL, ..., SIGSTOP) > > * sleep process enters group-stop > > The last point breaks the documented behavior of ptrace: > If data is nonzero and not SIGSTOP, it is interpreted as a signal to > be delivered to the child; otherwise, no signal is delivered. > > I do not see it would affect gdb. strace will change its behavior when > SIGSTOP is sent to its tracee although the new behavior may be OK. > > It is more a subject of apps compatibility testing with such a kernel change.
apps compatibility testing?
No, we don't change kernel APIs like that -- those are called regressions.
Just make ptrace(PTRACE_SYSCALL_2, ...) with fixed semantics. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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