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Patch is attached now.. ----- Original Message ----- From: rsmadhvesh@vsnl.net Date: Thursday, January 18, 2007 2:22 pm Subject: Re: Kprobes Support for ARM arch To: systemtap@sources.redhat.com Cc: madhvesh.s@ap.sony.com, satish.v@ap.sony.com > Hi All, > > The attached patch addresses the branch instructions > check for ARM kprobes last week release and avoids > unexpected crash when probe is placed for branch > type instructions. If any one finds issues, please let > me know. > > Regards > Madhvesh > > ----- Original Message ----- > From: Ananth N Mavinakayanahalli <ananth@in.ibm.com> > Date: Friday, January 12, 2007 11:02 am > Subject: Re: Kprobes Support for ARM arch > To: rsmadhvesh@vsnl.net > Cc: systemtap@sources.redhat.com, madhvesh.s@ap.sony.com, > lubna@ap.sony.com, satish.v@ap.sony.com > > > On Thu, Jan 11, 2007 at 07:58:07PM +0500, rsmadhvesh@vsnl.net wrote: > > > > Hi Madhvesh, > > > > > Hi All, > > > > > > Recently we completed the kprobes support for ARM architecture > > > targetted at 2.6.16 kernel. I have uploaded these patches in the > > > below CELF wiki page along with few test programs. > > > This implementation is tested using 2.6.16-24 kernel for > > > OMAP5912 OSK reference platform. > > > > I am not familiar with the ARM architecture details... the following > > comments are from a quick glance at the patch. > > > > > The patch is available in the below CELF wiki page > > > http://tree.celinuxforum.org/CelfPubWiki/PatchArchive > > > > > > The patch can be downloaded directly from here > > > > > > http://tree.celinuxforum.org/CelfPubWiki/PatchArchive?action=AttachFile&do=get&target=kprobes-arm-patches-2.6.16.24.tgz > > > > > > This implementation supports only kprobes and doesnot > > > support any other variants like jprobes, kretprobes etc. > > > Also it doesnot support branch/jump instructions probing. > > > > How are you ensuring that a kprobe register request on a branch/jump > > instruction fails? I don't see any profiling done to verify what the > > underlying instruction is. > > > > See arch_prepare_kprobe() from the powerpc port as to how we fail > > kproberegistration on certain instructions. > > > > > I noticed some discussions regarding ARM kprobes in the > > > archive. We are open to suggestions and how this implementation > can> > be improved. > > > > Given that quite a bit of the kprobes code for any platform is > > architecture specific, its important that your code gets reviewed > > by the > > ARM kernel gurus/maintainers, if you intend that the patch be > included> in the mainline Linux kernels. > > > > Also, you may want to port the patch to the latest kernel. There > have> been some interface changes: > > - kprobe modules are more portable with the addition of in-kernel > > symbol lookup. > > - The page fault case gets its own notifier so there isn't a > > penalty paid > > when kprobes aren't in use. > > > > Good work! > > > > Ananth > > >
Attachment:
kprobes-arm-2.6.16.24-1-branch-check.patch
Description: Text document
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