Page MenuHomeFreeBSD

Xen: Make gnttab_list_lock a recursive lock
ClosedPublic

Authored by pratyush on Jul 30 2018, 10:35 AM.
Tags
None
Referenced Files
Unknown Object (File)
Wed, Oct 15, 4:29 AM
Unknown Object (File)
Mon, Oct 13, 2:21 AM
Unknown Object (File)
Sun, Oct 12, 8:09 AM
Unknown Object (File)
Thu, Sep 25, 7:25 AM
Unknown Object (File)
Wed, Sep 17, 8:51 PM
Unknown Object (File)
Sep 13 2025, 10:03 PM
Unknown Object (File)
Sep 3 2025, 3:00 AM
Unknown Object (File)
Sep 1 2025, 2:16 PM
Subscribers

Details

Summary

This fixes the panic caused by lock recursion when the grant-table free callbacks are used.

The cause of the recursion is: check_free_callbacks() is always called with the lock gnttab_list_lock held. So, the callback function is called with the lock held. So, when the client uses any of the grant reference allocation methods get_free_entries() is called, which tries to acquire gnttab_list_lock, causing a recursion on the non-recursive lock.

Diff Detail

Repository
rS FreeBSD src repository - subversion
Lint
Lint Not Applicable
Unit
Tests Not Applicable

Event Timeline

This revision is now accepted and ready to land.Jul 30 2018, 11:36 AM
This revision was automatically updated to reflect the committed changes.