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Date: Sat, 11 Dec 2004 18:07:00 -0000
From: "Eli Zaretskii" <eliz@gnu.org>
To: Daniel Jacobowitz <drow@false.org>
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CC: kettenis@gnu.org, jjohnstn@redhat.com, gdb-patches@sources.redhat.com
In-reply-to: <20041211173757.GB15506@nevyn.them.org> (message from Daniel
	Jacobowitz on Sat, 11 Dec 2004 12:37:57 -0500)
Subject: Re: [RFA]: Modified Watchthreads Patch
Reply-to: Eli Zaretskii <eliz@gnu.org>
References: <41B8E16D.6070505@redhat.com> <20041210191015.GA18430@nevyn.them.org> <01c4df0c$Blat.v2.2.2$244dda20@zahav.net.il> <20041210230603.GA23419@nevyn.them.org> <01c4df10$Blat.v2.2.2$6f63d1a0@zahav.net.il> <20041210233700.GA24439@nevyn.them.org> <01c4df73$Blat.v2.2.2$5e13b740@zahav.net.il> <200412111433.iBBEXqpN007235@elgar.sibelius.xs4all.nl> <20041211163652.GB13865@nevyn.them.org> <01c4dfa6$Blat.v2.2.2$d4763ba0@zahav.net.il> <20041211173757.GB15506@nevyn.them.org>
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> Date: Sat, 11 Dec 2004 12:37:57 -0500
> From: Daniel Jacobowitz <drow@false.org>
> Cc: kettenis@gnu.org, jjohnstn@redhat.com, gdb-patches@sources.redhat.com
> 
> For the Linux kernel, it doesn't matter what you set in that bit.  It
> has to clear the registers at task switch anyway, for security reasons.

This might mean that, in practice, we will need to have some GDB code
to produce an illusion of thread-specific watchpoints on the x86.
That is, the hardware will stop the inferior whenever _any_ thread
hits the watchtpoint, and then GDB will take control, and figure out
whether it needs to stop or continue.