From 476c6c11a9ee4610ff0e4941e3851729f7caf062 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 1 Jan 2008 21:48:36 +1100 Subject: [PATCH] fix lguest rmmod "bad pgd" After 17d57a9206b4de6ad082ac9f2d2346985abbd2aa ("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 Signed-off-by: Linus Torvalds --- arch/x86/kernel/head_32.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index ac0637a6d7..fbad51fce6 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -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) */ -- 2.39.5