patch from Vince Weaver for review

Information
Submitter:	Lisa Hsu
Repository:	gem5
Branch:
Bugs:
Depends On:
Reviewers
Groups:	Default
People:	ali, gblack, nate, stever

Description

X86:  SE syscalls: patch from Vince Weaver for review

Testing Done

I've done minimal testing on these, i.e. I've pushed them to a clean tree and run X86 SPEC2k6 binaries on them, some of which didn't work prior to the patches but now do.  Others remain broken.  Vince, however, has done lots of testing and basically needed these to run SPEC2K workloads to completion for his thesis.  In other words, I bet these patches are good, but not complete for the purposes of running SPEC2k6.

It seems like we should be able to emulate the access system call fairly easily. It basically just checks if a file can be accessed in certain ways, I think. We could do that on the real file descriptor, rearrange the result if necessary, and pass it back. The other syscall changes here look ok.

Lisa Hsu March 31, 2011, 3:17 a.m. (March 31, 2011, 3:17 a.m.)

Would you object to committing/pushing as is and emulating access() if it ever becomes necessary in the future?  It's not something I'm going to commit to doing, and I wouldn't want everything else to get held up because of it.

Gabe Black April 3, 2011, 9:11 a.m. (April 3, 2011, 9:11 a.m.)

How is access() being used right now? It would be dangerous to assume just because it didn't seem to cause a problem by ignoring it that it's actually safe to do so, and it must be used by something or that line wouldn't be necessary. I would rather we did this safely than expediently. This change, or at least that line, should be independent of any other change as far as I've seen and shouldn't hold anything else up.

Ali Saidi April 3, 2011, 11:03 a.m. (April 3, 2011, 11:03 a.m.)

well... all it seems like you would need to do is return 0 when it's called. That means you can access the file and I doubt we would ever have a case where you couldn't.

Gabe Black April 3, 2011, 11:08 a.m. (April 3, 2011, 11:08 a.m.)

That sounds about right, and that should be really easy to implement. We should make sure we put a comment in there explaining why we're always returning 0.

Ali Saidi Feb. 12, 2012, 7:13 a.m. (Feb. 12, 2012, 7:13 a.m.)
```
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```

Steve Reinhardt Feb. 12, 2012, 8:56 p.m. (Feb. 12, 2012, 8:56 p.m.)

Actually printing a warning and returning zero is exactly what ignoreFunc does, so I don't see much reason to create a special implementation for access() that does the same thing.

You have a pending review.

Review Board 2.0.15

This change has been marked as submitted.

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Status: Closed (submitted)