linux.git/drivers/lguest, branch v2.6.23

fix modules oopsing in lguest guests

2007-09-25T15:51:04+00:00

The assembly templates for lguest guest patching are in the .init.text
section.  This means that modules get patched with "cc cc cc cc" or similar
junk.

Signed-off-by: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lguest: Fix guest crash when CONFIG_X86_USE_3DNOW=y

2007-09-12T19:19:46+00:00

One of the very first things lguest_init() does is a memcpy.  On
Athlon/Duron/K7 or CyrixIII/VIA-C3 or Geode GX/LX, this tries to use
MMX.

memcpy -> _mmx_memcpy -> kernel_fpu_begin -> clts -> paravirt_ops.clts

But we haven't set paravirt_ops.clts yet, so we do the native version
and crash.  The simplest solution is to use __memcpy.

Thanks to Michael Rasenberger for the bug report.

Signed-off-by: Rusty Russell 
Signed-off-by: Linus Torvalds

Fix lguest page-pinning logic ("lguest: bad stack page 0xc057a000")

2007-08-30T16:58:22+00:00

If the stack pointer is 0xc057a000, then the first stack page is at
0xc0579000 (the stack pointer is decremented before use).  Not
calculating this correctly caused guests with CONFIG_DEBUG_PAGEALLOC=y
to be killed with a "bad stack page" message: the initial kernel stack
was just proceeding the .smp_locks section which
CONFIG_DEBUG_PAGEALLOC marks read-only when freeing.

Thanks to Frederik Deweerdt for the bug report!

Signed-off-by: Rusty Russell 
Signed-off-by: Linus Torvalds

lguest should depend on CONFIG_FUTEX

2007-08-24T04:23:33+00:00

It uses get_futex_key().

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Rusty Russell 
Signed-off-by: Linus Torvalds

i386: Make patching more robust, fix paravirt issue

2007-08-11T22:58:13+00:00

Commit 19d36ccdc34f5ed444f8a6af0cbfdb6790eb1177 "x86: Fix alternatives
and kprobes to remap write-protected kernel text" uses code which is
being patched for patching.

In particular, paravirt_ops does patching in two stages: first it
calls paravirt_ops.patch, then it fills any remaining instructions
with nop_out().  nop_out calls text_poke() which calls
lookup_address() which calls pgd_val() (aka paravirt_ops.pgd_val):
that call site is one of the places we patch.

If we always do patching as one single call to text_poke(), we only
need make sure we're not patching the memcpy in text_poke itself.
This means the prototype to paravirt_ops.patch needs to change, to
marshal the new code into a buffer rather than patching in place as it
does now.  It also means all patching goes through text_poke(), which
is known to be safe (apply_alternatives is also changed to make a
single patch).

AK: fix compilation on x86-64 (bad rusty!)
AK: fix boot on x86-64 (sigh)
AK: merged with other patches

Signed-off-by: Rusty Russell 
Signed-off-by: Andi Kleen 
Signed-off-by: Linus Torvalds

lguest files should explicitly include asm/paravirt.h

2007-08-11T22:47:42+00:00

Files using bits from paravirt.h should explicitly include it rather than
relying on it being pulled in by something else.

Signed-off-by: Jes Sorensen 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lguest: Fix Malicious Guest GDT Host Crash

2007-08-09T15:14:56+00:00

If a Guest makes hypercall which sets a GDT entry to not present, we
currently set any segment registers using that GDT entry to 0.
Unfortunately, this is not sufficient: there are other ways of
altering GDT entries which will cause a fault.

The correct solution to do what Linux does: let them set any GDT value
they want and handle the #GP when popping causes a fault.  This has
the added benefit of making our Switcher slightly more robust in the
case of any other bugs which cause it to fault.

We kill the Guest if it causes a fault in the Switcher: it's the
Guest's responsibility to make sure it's not using segments when it
changes them.

Signed-off-by: Rusty Russell 
Signed-off-by: Linus Torvalds

Fix non-TSC guest clocksource lockup

2007-08-09T15:14:56+00:00

lguest uses a host-supplied wallclock-based clocksource when the TSC
is not reliable.  As this is already in nanoseconds, I naively used a
multiplier of 1 and a shift of 0.

But update_wall_time() in its infinite wisdom decides to adjust the
clock a little (where does it think it's getting a more accurate time
from?)

It will happily tweak the multiplier... to 0, then -1.

So the "fix" is to use a shift of 22 like everyone else, and a
multiplier of 1 << 22.

Signed-off-by: Rusty Russell 
Signed-off-by: Linus Torvalds

Enable lguest drivers in Kconfig

2007-08-07T01:21:15+00:00

Lguest drivers need to default to "Y" otherwise they're never selected
for new builds.  (We don't bother prompting, because they're less than
4k combined, and implied by selecting lguest support).

Signed-off-by: Rusty Russell 
Signed-off-by: Linus Torvalds

Make lguest compile with CONFIG_BLOCK=n and CONFIG_NET=n

2007-07-30T00:37:45+00:00

Gabriel C reports lguest doesn't compile with CONFIG_BLOCK=n.  Fix this
by introducing a config var for the block device, which depends on
LGUEST && BLOCK.  Do the same for the net driver, rather then depending
gratuitously on CONFIG_NET.

Signed-off-by: Rusty Russell 
Cc: Gabriel C 
Signed-off-by: Linus Torvalds