Messages in this thread | | | Date | Tue, 15 Dec 2020 07:55:56 +0200 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH] x86/sgx: Synchronize encl->srcu in sgx_encl_release(). |
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On Mon, Dec 14, 2020 at 11:01:32AM -0800, Sean Christopherson wrote: > On Fri, Dec 11, 2020, Jarkko Sakkinen wrote: > > Each sgx_mmun_notifier_release() starts a grace period, which means that > > Should be sgx_mmu_notifier_release(), here and in the comment.
Thanks.
> > one extra synchronize_rcu() in sgx_encl_release(). Add it there. > > > > sgx_release() has the loop that drains the list but with bad luck the > > entry is already gone from the list before that loop processes it. > > Why not include the actual analysis that "proves" the bug? The splat that > Haitao reported would also be useful info.
True. I can include a snippet of dmesg to the commit message.
> > Fixes: 1728ab54b4be ("x86/sgx: Add a page reclaimer") > > Cc: Borislav Petkov <bp@alien8.de> > > Cc: Dave Hansen <dave.hansen@linux.intel.com> > > Reported-by: Sean Christopherson <seanjc@google.com> > > Haitao reported the bug, and for all intents and purposes provided the fix. I > just did the analysis to verify that there was a legitimate bug and that the > synchronization in sgx_encl_release() was indeed necessary.
Good and valid point. The way I see it, the tags should be:
Reported-by: Haitao Huang <haitao.huang@linux.intel.com> Suggested-by: Sean Christopherson <seanjc@google.com>
Haitao pointed out the bug but from your analysis I could resolve that this is the fix to implement, and was able to write the long description for the commit.
Does this make sense to you?
/Jarkko
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