Commit 476c6c11 authored Jan 01, 2008 by Rusty Russell Committed by Linus Torvalds Jan 01, 2008

fix lguest rmmod "bad pgd"



After 17d57a92 ("x86: fix x86-32 early
fixmap initialization.") removing lg.ko caused a printk from vunmap:

	mm/memory.c:115: bad pgd 004b3027.

On the second use after module load, the kernel crashes.

This fixes the immediate problem (accessed and dirty bits not set as
expected in pmd_none_or_clear_bad).  I can't see why this would cause
a crash, but I haven't been able to reproduce it once this is applied.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e697789d

arch/x86/kernel/head_32.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -196,7 +196,7 @@ default_entry:
		/* Do an early initialization of the fixmap area */
		movl $(swapper_pg_dir - __PAGE_OFFSET), %edx
		movl $(swapper_pg_pmd - __PAGE_OFFSET), %eax
		addl $0x007, %eax /* 0x007 = PRESENT+RW+USER */
		addl $0x67, %eax /* 0x67 == _PAGE_TABLE */
		movl %eax, 4092(%edx)

		xorl %ebx,%ebx /* This is the boot CPU (BSP) */

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