alistair23-linux

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Matias Zabaljauregui 88df781afb lguest: fix crash on vmlinux images Typical message: 'lguest: unhandled trap 6 at 0x418726 (0x0)' vmlinux guests were broken by `4cd8b5e2a1` 'lguest: use KVM hypercalls', which rewrites guest text from kvm hypercalls to trap 31. The Launcher mmaps the kernel image. The Guest executes and immediately faults in the first text page (read-only). Then it hits a hypercall, and we rewrite that hypercall, causing a copy-on-write. But the Guest pagetables still refer to the old page: we fault again, but as Host we see the hypercall already rewritten, and pass the fault back to the Guest. The Guest hasn't set up an IDT yet, so we kill it. This doesn't happen with bzImages: they unpack themselves and so the text pages are already read-write. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Tested-by: Patrick McHardy <kaber@trash.net>	2009-04-19 23:14:00 +09:30
..
core.c	lguest: fix crash on vmlinux images	2009-04-19 23:14:00 +09:30
switcher_32.S

Matias Zabaljauregui 88df781afb lguest: fix crash on vmlinux images

Typical message: 'lguest: unhandled trap 6 at 0x418726 (0x0)'

vmlinux guests were broken by 4cd8b5e2a1
'lguest: use KVM hypercalls', which rewrites guest text from kvm hypercalls
to trap 31.

The Launcher mmaps the kernel image.  The Guest executes and
immediately faults in the first text page (read-only).  Then it hits a
hypercall, and we rewrite that hypercall, causing a copy-on-write.
But the Guest pagetables still refer to the old page: we fault again,
but as Host we see the hypercall already rewritten, and pass the fault
back to the Guest.  The Guest hasn't set up an IDT yet, so we kill it.

This doesn't happen with bzImages: they unpack themselves and so the
text pages are already read-write.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Patrick McHardy <kaber@trash.net>

2009-04-19 23:14:00 +09:30

core.c lguest: fix crash on vmlinux images 2009-04-19 23:14:00 +09:30

switcher_32.S