提交 f912696a 编写于 作者: B Bart Oldeman 提交者: Linus Torvalds

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

my patch "x86: initialise tss->io_bitmap_owner to something" (commit ID
d5cd4aad) 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: NBart Oldeman <bartoldeman@users.sourceforge.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 88dcb6c4
......@@ -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
* 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_owner = NULL;
put_cpu();
......
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