The new percpu code has apparently broken the doublefault handler
when CONFIG_DEBUG_SPINLOCK is set. Doublefault is handled by
a hardware task, making the check
SPIN_BUG_ON(lock->owner == current, lock, "recursion");
fault because it uses the FS register to access the percpu data
for current, and that register is zero in the new TSS. (The trace
I saw was on 2.6.20 where it was GS, but it looks like this will
still happen with FS on 2.6.22.)
Initializing FS in the doublefault_tss should fix it.
AK: Also fix broken ptr_ok() and turn printks into KERN_EMERG
AK: And add a PANIC prefix to make clear the system will hang
AK: (e.g. x86-64 will recover)
Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On Thu, 2007-03-29 at 13:16 +0200, Andi Kleen wrote:
> Please clean it up properly with two structs.
Not sure about this, now I've done it. Running it here.
If you like it, I can do x86-64 as well.
==
lguest defines its own TSS struct because the "struct tss_struct"
contains linux-specific additions. Andi asked me to split the struct
in processor.h.
Unfortunately it makes usage a little awkward.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Add cpu_relax() to infinite loops in crash.c and doublefault.c. This is
the safest change.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
i386 inline assembler cleanup.
This change encapsulates descriptor and task register management. Also,
it is possible to improve assembler generation in two cases; savesegment
may store the value in a register instead of a memory location, which
allows GCC to optimize stack variables into registers, and MOV MEM, SEG
is always a 16-bit write to memory, making the casting in math-emu
unnecessary.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Thomas Gleixner