linux-toradex.git/drivers/lguest/x86, branch v2.6.33.2

percpu: make misc percpu symbols unique

2009-10-29T13:34:14+00:00

This patch updates misc percpu related symbols such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* drivers/crypto/padlock-aes.c: s/last_cword/paes_last_cword/

* drivers/lguest/x86/core.c: s/last_cpu/lg_last_cpu/

* drivers/s390/net/netiucv.c: rename the variable used in a macro to
  avoid clashing with percpu symbol

* arch/mn10300/kernel/kprobes.c: replace current_ prefix with cur_ for
  static variables.  Please note that percpu symbol current_kprobe
  can't be changed as it's used by generic code.

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo 
Reviewed-by: Christoph Lameter 
Cc: Rusty Russell 
Cc: Herbert Xu 
Cc: Chuck Ebbert 
Cc: David Howells 
Cc: Koichi Yasutake 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Cc: Masami Hiramatsu 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux390@de.ibm.com

lguest: update commentry

2009-07-30T06:33:46+00:00

Every so often, after code shuffles, I need to go through and unbitrot
the Lguest Journey (see drivers/lguest/README).  Since we now use RCU in
a simple form in one place I took the opportunity to expand that explanation.

Signed-off-by: Rusty Russell 
Cc: Ingo Molnar 
Cc: Paul McKenney

lguest: fix comment style

2009-07-30T06:33:45+00:00

I don't really notice it (except to begrudge the extra vertical
space), but Ingo does.  And he pointed out that one excuse of lguest
is as a teaching tool, it should set a good example.

Signed-off-by: Rusty Russell 
Cc: Ingo Molnar

lguest: fix on Intel when KVM loaded (unhandled trap 13)

2009-05-26T19:13:11+00:00

When KVM is loaded, and hence VT set up, the vmcall instruction in an
lguest guest causes a #GP, not #UD.

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

lguest: fix guest crash on non-linear addresses in gdt pvops

2009-04-19T13:44:01+00:00

Fixes guest crash 'lguest: bad read address 0x4800000 len 256'

The new per-cpu allocator ends up handing a non-linear address to
write_gdt_entry.  We do __pa() on it, and hand it to the host, which
kills us.

I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT
code, but had no pressing reason until now.

Signed-off-by: Rusty Russell 
Cc: lguest@ozlabs.org

lguest: fix crash on vmlinux images

2009-04-19T13:44:00+00:00

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

vmlinux guests were broken by 4cd8b5e2a159f18a1507f1187b44a1acbfa6341b
'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 
Tested-by: Patrick McHardy

lguest: use KVM hypercalls

2009-03-30T11:25:24+00:00

Impact: cleanup

This patch allow us to use KVM hypercalls

Signed-off-by: Matias Zabaljauregui 
Signed-off-by: Rusty Russell

lguest: use cpu capability accessors

2008-07-28T23:58:34+00:00

To support my little make-x86-bitops-use-proper-typechecking projectlet.

Cc: Thomas Gleixner 
Cc: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Acked-by: Ingo Molnar 
Signed-off-by: Rusty Russell

on_each_cpu(): kill unused 'retry' parameter

2008-06-26T09:24:38+00:00

It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.

Acked-by: Jeremy Fitzhardinge 
Reviewed-by: Paul E. McKenney 
Signed-off-by: Jens Axboe

x86: fix NULL pointer deref in __switch_to

2008-06-20T11:26:18+00:00

I am able to reproduce the oops reported by Simon in __switch_to() with
lguest.

My debug showed that there is at least one lguest specific
issue (which should be present in 2.6.25 and before aswell) and it got
exposed with a kernel oops with the recent fpu dynamic allocation patches.

In addition to the previous possible scenario (with fpu_counter), in the
presence of lguest, it is possible that the cpu's TS bit it still set and the
lguest launcher task's thread_info has TS_USEDFPU still set.

This is because of the way the lguest launcher handling the guest's TS bit.
(look at lguest_set_ts() in lguest_arch_run_guest()). This can result
in a DNA fault while doing unlazy_fpu() in __switch_to(). This will
end up causing a DNA fault in the context of new process thats
getting context switched in (as opossed to handling DNA fault in the context
of lguest launcher/helper process).

This is wrong in both pre and post 2.6.25 kernels. In the recent
2.6.26-rc series, this is showing up as NULL pointer dereferences or
sleeping function called from atomic context(__switch_to()), as
we free and dynamically allocate the FPU context for the newly
created threads. Older kernels might show some FPU corruption for processes
running inside of lguest.

With the appended patch, my test system is running for more than 50 mins
now. So atleast some of your oops (hopefully all!) should get fixed.
Please give it a try. I will spend more time with this fix tomorrow.

Reported-by: Simon Holm Thøgersen 
Reported-by: Patrick McHardy 
Signed-off-by: Suresh Siddha 
Signed-off-by: Ingo Molnar