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[PATCH] reset tss->io_bitmap_owner in sys_ioperm()

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my patch "x86: initialise tss->io_bitmap_owner to something" (commit ID
d5cd4aadd3d220afac8e3e6d922e333592551f7d) introduced a problem with a
program (DOSEMU) that called ioperm after already doing some port i/o.

The problem is that a process switch return causes tss->io_bitmap_base
to be set to IO_BITMAP_OFFSET so that the fault (that *really* sets the
io bitmap) never triggers.

This fixes that regression.

Signed-off-by: Bart Oldeman <bartoldeman@users.sourceforge.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Bart Oldeman 2005-11-06 12:54:07 +13:00 committed by Linus Torvalds
parent 88dcb6c411
commit f912696ab3
1 changed files with 3 additions and 0 deletions
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3
arch/i386/kernel/ioport.c
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@ -108,8 +108,11 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
/* /*
* Sets the lazy trigger so that the next I/O operation will * Sets the lazy trigger so that the next I/O operation will
* reload the correct bitmap. * reload the correct bitmap.
* Reset the owner so that a process switch will not set
* tss->io_bitmap_base to IO_BITMAP_OFFSET.
*/ */
tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY; tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
tss->io_bitmap_owner = NULL;
put_cpu(); put_cpu();