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>
If the virtual 86 machine reaches an instruction which raises a General
Protection Fault (such as CLI or STI), the instruction is emulated (in
handle_vm86_fault). However, the emulation ignored the TF bit, so the
hardware debug interrupt was not invoked after such an emulated instruction
(and the DOS debugger missed it).
This patch fixes the problem by emulating the hardware debug interrupt as
the last action before control is returned to the VM86 program.
Signed-off-by: Petr Tesarik <kernel@tesarici.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There were still a few comments left refering to verify_area, and two
functions, verify_area_skas & verify_area_tt that just wrap corresponding
access_ok_skas & access_ok_tt functions, just like verify_area does for
access_ok - deprecate those.
There was also a few places that still used verify_area in commented-out
code, fix those up to use access_ok.
After applying this one there should not be anything left but finally
removing verify_area completely, which will happen after a kernel release
or two.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch solves VM86 interrupt emulation deadlock on SMP systems. The VM86
interrupt emulation has been heavily tested and works well on UP systems
after last update, but it seems to deadlock when we have used it on SMP/HT
boxes now.
It seems, that disable_irq() cannot be called from interrupts, because it
waits until disabled interrupt handler finishes
(/kernel/irq/manage.c:synchronize_irq():while(IRQ_INPROGRESS);). This
blocks one CPU after another. Solved by use disable_irq_nosync.
There is the second problem. If IRQ source is fast, it is possible, that
interrupt is sometimes processed and re-enabled by the second CPU, before
it is disabled by the first one, but negative IRQ disable depths are not
allowed. The spinlocking and disabling IRQs over call to
disable_irq_nosync/enable_irq is the only solution found reliable till now.
Signed-off-by: Michal Sojka <sojkam1@control.felk.cvut.cz>
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The new i386/x86_64 assemblers no longer accept instructions for moving
between a segment register and a 32bit memory location, i.e.,
movl (%eax),%ds
movl %ds,(%eax)
To generate instructions for moving between a segment register and a
16bit memory location without the 16bit operand size prefix, 0x66,
mov (%eax),%ds
mov %ds,(%eax)
should be used. It will work with both new and old assemblers. The
assembler starting from 2.16.90.0.1 will also support
movw (%eax),%ds
movw %ds,(%eax)
without the 0x66 prefix. I am enclosing patches for 2.4 and 2.6 kernels
here. The resulting kernel binaries should be unchanged as before, with
old and new assemblers, if gcc never generates memory access for
unsigned gsindex;
asm volatile("movl %%gs,%0" : "=g" (gsindex));
If gcc does generate memory access for the code above, the upper bits
in gsindex are undefined and the new assembler doesn't allow it.
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!
