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author | Andrew Cooper <andrew.cooper3@citrix.com> | 2012-05-10 11:04:32 +0100 |
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committer | Andrew Cooper <andrew.cooper3@citrix.com> | 2012-05-10 11:04:32 +0100 |
commit | d47e6a744e16d47d97033e36f07ddc108500aa8e (patch) | |
tree | a283c4efb8b4b0b1db6752d9a0320c9c5d7773c4 /tools/blktap2 | |
parent | f0b5db91de01bff8346e0d9da929c0f3ff60874d (diff) | |
download | xen-d47e6a744e16d47d97033e36f07ddc108500aa8e.tar.gz xen-d47e6a744e16d47d97033e36f07ddc108500aa8e.tar.bz2 xen-d47e6a744e16d47d97033e36f07ddc108500aa8e.zip |
x86_64: Fix off-by-one error setting up the Interrupt Stack Tables
The Interrupt Stack Table entries in a 64bit TSS are a 1 based data
structure as far as hardware is concerned. As a result, the code
setting up stacks in subarch_percpu_traps_init() fills in the wrong
IST entries.
The result is that the MCE handler executes on the stack set up for
NMIs; the NMI handler executes on a stack set up for Double Faults,
and Double Faults are executed with a stack pointer set to 0.
Once the #DF handler starts to execute, it will usually take a page
fault looking up the address at 0xfffffffffffffff8, which will cause a
triple fault. If a guest has mapped a page in that location, then it
will have some state overwritten, but as the #DF handler always calls
panic(), this is not a problem the guest will have time to care about.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Committed-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'tools/blktap2')
0 files changed, 0 insertions, 0 deletions