On Wed, 6 Apr 2011 17:09:04 +0200, "Roland Vossen" <rvossen@xxxxxxxxxxxx> wrote: > Hello Rusty, > > I would like to make a change to module.c and noticed with 'git blame' > that you were the last person who touched these specific lines in module.c: > > http://lxr.linux.no/#linux+v2.6.38/kernel/module.c#L2792 > > ===== Corresponding commit for your reference: > > commit 811d66a0e1e99902d365497eec7884113a2665bd > Author: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > Date: Thu Aug 5 12:59:12 2010 -0600 > > module: group post-relocation functions into post_relocation() > > This simply hoists more code out of load_module; we also put the > identification of the extable and dynamic debug table in with the > others in find_module_sections(). > > We move the taint check to the actual add/remove of the dynamic debug > info: this is certain (find_module_sections is too early). > > Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > Cc: Yehuda Sadeh <yehuda@xxxxxxxxxxxxxxx> > > ============== > > > Can you tell me if the following proposed code change in module.c is ok > with you: > > /* This has to be done once we're sure module name is unique. */ > if (!mod->taints || mod->taints == (1U << TAINT_CRAP)) > dynamic_debug_setup(info.debug, info.num_debug); > > Thanks, Roland. > > > -------- Original Message -------- > Subject: Re: Why is dynamic debug disabled for staging drivers ? > Date: Wed, 6 Apr 2011 07:13:29 -0700 > From: Greg KH <greg@xxxxxxxxx> > To: Roland Vossen <rvossen@xxxxxxxxxxxx> > CC: devel@xxxxxxxxxxxxxxxxxxxxxx <devel@xxxxxxxxxxxxxxxxxxxxxx> > > On Wed, Apr 06, 2011 at 03:54:37PM +0200, Roland Vossen wrote: > > Hi, > > > > I want to replace the proprietary logging mechanism in brcm80211 > > with a Linux mechanism. 'Dynamic debug' seemed to be a good fit. > > But, to my disappointment, I discovered that dynamic debugging is > > not supported for drivers from the staging dir: > > > > - staging drivers are marked tainted (ref: > > http://lxr.linux.no/#linux+v2.6.38/kernel/module.c#L2417) > > > > - subsequently tainted drivers don't get dynamic debug goodies (ref: > > http://lxr.linux.no/#linux+v2.6.38/kernel/module.c#L2792) > > > > I wonder if this is intentional behavior. Does anybody know ? > > Ah, no it isn't. I didn't realize that tainted modules didn't get > dynamic debug stuff, that's not nice. I'd be glad to take a fix that > allows drivers tainted with the TAINT_CRAP flag to be able to use > dynamic debug. > > In looking at that check, it probably can be fixed to just make sure > that the module name is unique (i.e. only a specific taint flag check) > which is the real goal of that check in module.c. That's a red herring. I think it was originally to do with avoiding hooks for proprietary modules, but it'd take some serious archeology to find that discussion. (BTW, is there a simple way of doing a git blame on an older version of a particular file, when the first git blame refers to a refactoring patch and you want to dig deeper?) But a slightly neater change would seem to be: /* If tainted for any reason other than staging, don't touch it... */ if ((mod->taints & ~(1U << TAINT_CRAP) == 0) dynamic_debug_setup(info.debug, info.num_debug); Thanks, Rusty. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
