Commit 32f3bf67 authored Nov 12, 2019 by Thomas Gleixner

x86/ioperm: Avoid bitmap allocation if no permissions are set



If ioperm() is invoked the first time and the @turn_on argument is 0, then
there is no point to allocate a bitmap just to clear permissions which are
not set.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent ae31cea8

arch/x86/kernel/ioport.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,9 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on)
		*/
		bitmap = t->io_bitmap_ptr;
		if (!bitmap) {
		/* No point to allocate a bitmap just to clear permissions */
		if (!turn_on)
		return 0;
		bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
		if (!bitmap)
		return -ENOMEM;

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