On Mon, 2012-04-23 at 12:54 +0530, Srikar Dronamraju wrote: > * Peter Zijlstra <peterz@xxxxxxxxxxxxx> [2012-04-23 09:14:00]: > > > On Fri, 2012-04-20 at 20:37 +0200, Oleg Nesterov wrote: > > > Say, a user wants to probe /sbin/init only. What if init forks? > > > We should remove breakpoints from child->mm somehow. > > > > How is that hard? dup_mmap() only copies the VMAs, this doesn't actually > > copy the breakpoint. So the child doesn't have a breakpoint to be > > removed. > > > > Because the pages are COWED, the breakpoint gets copied over to the > child. If we dont want the breakpoints to be not visible to the child, > then we would have to remove them explicitly based on the filter (i.e if > and if we had inserted breakpoints conditionally based on filter). I thought we didn't COW shared maps since the fault handler will fill in the pages right and only anon stuff gets copied. > Once we add the conditional breakpoint insertion (which is tricky), How so? > we have > to support conditional breakpoint removal in the dup_mmap() thro the > uprobe_mmap hook (which I think is not that hard). Conditional removal > of breakpoints in fork path would just be an extension of the > conditional breakpoint insertion. Right, I don't think that removal is particularly hard if needed. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href