Messages in this thread | | | Date | Thu, 1 Dec 2011 18:54:06 +0530 | From | Srikar Dronamraju <> | Subject | Re: [PATCH v7 3.2-rc2 4/30] uprobes: Define hooks for mmap/munmap. |
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> > I was following the general convention being used within the kernel to not > > bother about the area that we are going to unmap. For example: If a ptraced > > area were to be unmapped or remapped, I dont see the breakpoint being > > removed and added back. Also if a ptrace process is exitting, we dont go > > about removing the installed breakpoints. > > > > Also we would still need the check for EEXIST and read_opcode for handling > > the fork() case. So even if we add extra line to remove the actual > > breakpoint in munmap, It doesnt make the code any more simpler. > > Not adding the counter now does though. The whole mm->mm_uprobes_count > thing itself is basically an optimization. > > Without it we'll get to uprobe_notify_resume() too often, but who cares. > And not having to worry about it removes a lot of this complexity. > > Then in the patch where you introduce this optimization you can list all > the nitty gritty details of mremap/fork and counter balancing. >
Okay, I will move the optimization parts into a separate patch and keep it at the end of the patchset.
> Another point, maybe add some comments on how the generic bits of > uprobe_notify_resume()/uprobe_bkpt_notifier()/uprobe_post_notifier() etc > hang together and what the arch stuff should do. > > Currently I have to flip back and forth between those to figure out what > happens. > > Having that information also helps validate that x86 does indeed do what > is expected and helps other arch maintainers write their code without > having to grok wtf x86 does. >
Okay, will work towards this.
-- Thanks and Regards Srikar
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