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Re: More bad backtraces through nanosleep
- From: Daniel Jacobowitz <drow at mvista dot com>
- To: gdb at sources dot redhat dot com, libc-alpha at sources dot redhat dot com
- Date: Sun, 7 Sep 2003 15:23:45 -0400
- Subject: Re: More bad backtraces through nanosleep
- References: <20030907192232.GA3951@nevyn.them.org>
Er, ah, I meant to send this to libc-alpha also of course.
On Sun, Sep 07, 2003 at 03:22:32PM -0400, Daniel Jacobowitz wrote:
> This is a little unfortunate...
> Glibc with NPTL uses DWARF-2 unwind information to describe syscall
> wrappers, because the NPTL implementation of cancellation uses dwarf2
> unwinding. However, glibc with LinuxThreads does not. So if you're running
> a multi-threaded LinuxThreads application, when we hit a syscall we're
> likely to get completely lost. We can't reasonably expect GDB's prologue
> unwinder to figure out nanosleep; the function has no prologue, and then
> pushes things onto the stack inside CENABLE/CDISABLE.
> Libc folks, would there be any disadvantages besides space to adding unwind
> info to the cancellable syscall wrappers in LT also? How would you feel
> about such a patch?
MontaVista Software Debian GNU/Linux Developer