| commit | 5febe8f5748ea5923d6465791c344a3a6138dee4 | |
| author | Matthew Dillon <dillon@apollo.backplane.com> | |
| Fri, 2 Oct 2009 22:53:17 +0000 (2 15:53 -0700) | ||
| committer | Matthew Dillon <dillon@apollo.backplane.com> | |
| Fri, 2 Oct 2009 23:00:59 +0000 (2 16:00 -0700) | ||
| tree | 9c769345f4b5098d9cf0f986906f0f211db82910 | treesnapshot (tar.gz zip) |
| parent | ec61b2892719413e2fd52a677fc9a1d05d09d59a | commitdiff |
vkernel - Fix FP corruption from preemptive thread switch
* Recent work on the vkernel enabled preemptive interrupt thread switching.
This introduced a race where the floating point state could change
out from under the vkernel's go_user() function, causing the FP state
in the virtual user process to become corrupt.
* Fixed by introducing a critical section which essentially defers any
preemptive thread switches inside go_user().
Reported-by: YONETANI Tomokazu <qhwt+dfly@les.ath.cx>
Test-cases-by: YONETANI Tomokazu <qhwt+dfly@les.ath.cx>
* Recent work on the vkernel enabled preemptive interrupt thread switching.
This introduced a race where the floating point state could change
out from under the vkernel's go_user() function, causing the FP state
in the virtual user process to become corrupt.
* Fixed by introducing a critical section which essentially defers any
preemptive thread switches inside go_user().
Reported-by: YONETANI Tomokazu <qhwt+dfly@les.ath.cx>
Test-cases-by: YONETANI Tomokazu <qhwt+dfly@les.ath.cx>
| sys/platform/vkernel/i386/trap.c | diffblobblamehistory |