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authorThomas Gleixner <tglx@linutronix.de>2008-02-15 17:29:12 +0100
committerThomas Gleixner <tglx@linutronix.de>2008-02-18 20:54:14 +0100
commit31eedd823c1bf3650c450346a0d0c39431034eb9 (patch)
treeaf65f4c77b88f5d907aa54ff1e67b1bdf1488d67 /arch/x86/kernel/head64.c
parentc31c7d4844ea4817692ae16bf70f9c96c05a50eb (diff)
downloadop-kernel-dev-31eedd823c1bf3650c450346a0d0c39431034eb9.zip
op-kernel-dev-31eedd823c1bf3650c450346a0d0c39431034eb9.tar.gz
x86: zap invalid and unused pmds in early boot
The early boot code maps KERNEL_TEXT_SIZE (currently 40MB) starting from __START_KERNEL_map. The kernel itself only needs _text to _end mapped in the high alias. On relocatible kernels the ASM setup code adjusts the compile time created high mappings to the relocation. This creates invalid pmd entries for negative offsets: 0xffffffff80000000 -> pmd entry: ffffffffff2001e3 It points outside of the physical address space and is marked present. This starts at the virtual address __START_KERNEL_map and goes up to the point where the first valid physical address (0x0) is mapped. Zap the mappings before _text and after _end right away in early boot. This removes also the invalid entries. Furthermore it simplifies the range check for high aliases. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/head64.c')
-rw-r--r--arch/x86/kernel/head64.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 24dbf56..ad24408 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -88,6 +88,9 @@ void __init x86_64_start_kernel(char * real_mode_data)
/* Make NULL pointers segfault */
zap_identity_mappings();
+ /* Cleanup the over mapped high alias */
+ cleanup_highmap();
+
for (i = 0; i < IDT_ENTRIES; i++) {
#ifdef CONFIG_EARLY_PRINTK
set_intr_gate(i, &early_idt_handlers[i]);
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