Messages in this thread | | | Date | Wed, 27 Aug 2008 22:10:55 +0530 | From | Ananth N Mavinakayanahalli <> | Subject | Re: [PATCH 0/2] utrace |
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On Wed, Aug 27, 2008 at 09:54:53AM -0400, Christoph Hellwig wrote: > On Tue, Aug 26, 2008 at 08:17:12PM -0400, Frank Ch. Eigler wrote: > > Among others, utrace is an enablement layer for systemtap user-space > > probing, through another subsequent part that implements a > > kprobes-like API for user-space tasks. All this code now exists in at > > least prototype form, so if you need to see the bigger picture, look > > that way. Other users are anticipated, but first we need to get past > > the chicken-and-egg. > > As usual nothing of that stuff has any real in-kernel users so the same > argument applies here. If it did have real uses it could be merged at > the same time. But the current uprobes mess is not a reason to merge > utrace.
Uprobes is just one user of utrace. It is intended for use for simple tracing where we need a kernel+userspace look at the problem at hand. The intention is for use in simple cases (when condition x is met, what is the value of variable y, etc).
For more advanced tracing though, there are other ideas being proposed (see ntrace discussions on utrace-devel, but I guess now lkml is the right place for that discussion too).
However, there are components of uprobes such as breakpoint insertion/removal and single-stepping infrastructure that are potentially useful to other userspace debuggers. We are working on factoring those out to live independent of uprobes. You should be seeing those patches soon.
Ananth
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