x86/ioperm: Remove bitmap if all permissions dropped

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If ioperm() results in a bitmap with all bits set (no permissions to any
I/O port), then handling that bitmap on context switch and exit to user
mode is pointless. Drop it.

Move the bitmap exit handling to the ioport code and reuse it for both the
thread exit path and dropping it. This allows to reuse this code for the
upcoming iopl() emulation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>

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This commit is contained in:

Thomas Gleixner 2019-11-11 23:03:24 +01:00

parent 22fe5b0439

commit ea5f1cd7ab

3 changed files with 23 additions and 15 deletions

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2

arch/x86/include/asm/io_bitmap.h

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19

arch/x86/kernel/ioport.c

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15

arch/x86/kernel/process.c

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