Red Hat Bugzilla – Bug 75299
sys_call_table not exported; no alternate mechanism provided for registering sys calls from modules with reserved table entries
Last modified: 2008-08-01 12:22:52 EDT
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.9) Gecko/20020513 Description of problem: OpenAFS uses the reserved AFS sys call. De-exporting sys_call_table precludes registration. Additionally, get/setgroups are replaced to allow insertion and maintence of extra groups. Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1.Install RedHat 8.0 2.Build OpenAFS 3.Observe that kernel module gets undefined symbol. Actual Results: Nothing exciting. Expected Results: I should have been able to read my files. Additional info: You should if you wish to modify (arguably break, but given the state of 2.5 I can see the other side) provide a mechanism to register handlers for reserved syscalls. OpenAFS should provide a different mechanism of managing pags which does not require auxiliary groups and thus maintaining them in the face of e.g. initgroups(), but I don't believe task ornaments have been implemented yet, so if you have suggestions for that, I'd be glad to hear them.
>I don't believe task ornaments have been implemented yet should say "in your kernels"; You get the idea.
the OpenAFS people know for over a year that this was going away, on lkml they even agreed to provide the patch for the registration code.... no patch seen so far.
I'm an OpenAFS people. This is news to me. Likewise to our RedHat port maintainer, the other 2 gatekeepers, and pretty much everyone else. Can you provide a reference? I'm wondering who that probably isn't qualified to do so promised to provide something on our behalf.
The only thing relevant I find is this: http://www.cs.helsinki.fi/linux/linux-kernel/2002-14/0050.html I don't see who it was a reply to, but Alan certainly isn't an OpenAFS person. I see you replied to him. I would have assumed based on what I see (now) of that exchange that he or you were going to handle it on the basis of what's there.
And incidentally, we did know it was coming... in 2.5. We didn't expect to see it yet, and apparently Alan didn't expect us to either: http://www.cs.helsinki.fi/linux/linux-kernel/2002-14/0068.html
Ok, since you haven't commented on the above assertions that you were mistaken, you indicated that you expected OpenAFS to provide a registration function. Does that translate to willingness to accept and use it if it exists? Further, are you willing to provide task ornament support? If so, this problem can be made to go away otherwise, despite the above indications that it should not have yet existed in the first place.
I will accept a proper registration function. Check what the LiS folks are doing, they're just about there wrt registration interface.
Ok, that leaves us with the PAG problem. Linux Security Modules was integrated in 2.5 recently, so since the problem was created by pulling up this change from 2.5, perhaps you'd be willing to pull up Linux Security Modules as well? Currently PAGs work by adding extra groups to the group list, which requires replacing setgroups to not wipe them. The correct way of doing this in the post-LSM universe appears to be with a Linux Security module providing task_ elements to maintain appropriate mappings. I have a sys call registration function for the AFS syscall which I'm going to send to linux-kernel as a followup to the (now many months old) discussion; After I know that we have something "final" I will submit the result to you.
This isn't related to OpenAFS, but not exporting sys_call_table also breaks the ATI Linux drivers for the Radeon 8500 card.
This isn't also related to OpenAFS, but not exporting sys_call_table also breaks the AVFS virtual filesystem (http://sourceforge.net/projects/avf) redir.o kernel module.
*** Bug 64014 has been marked as a duplicate of this bug. ***
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