[PATCH v2] x86: remove NX from video bios area
From: wangyanqing
Date: Thu Nov 17 2011 - 03:28:08 EST
5bd5a452662bc37c54fb6828db1a3faf87e6511c make area
between BIOS_BEGIN and BIOS_END NX when boot machine
with ACPI enable.
It make my machine can't boot, system hang with black
screen very early.
The more detail, please see:
https://lkml.org/lkml/2011/11/16/84
This patch try to resolve it. Any comment is welcome.
Signed-off-by: Wang YanQing <Udknight@xxxxxxxxx>
---
arch/x86/include/asm/e820.h | 4 ++++
arch/x86/mm/pageattr.c | 6 ++++++
2 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h
index 908b969..1adc26e 100644
--- a/arch/x86/include/asm/e820.h
+++ b/arch/x86/include/asm/e820.h
@@ -72,6 +72,10 @@ struct e820map {
#define BIOS_BEGIN 0x000a0000
#define BIOS_END 0x00100000
+/*we hope this the right video bios range*/
+#define VIDEO_BIOS_BEGIN 0x000c0000
+#define VIDEO_BIOS_END 0x000c7fff
+
#define BIOS_ROM_BASE 0xffe00000
#define BIOS_ROM_END 0xffffffff
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index f9e5267..c4e5100 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -263,6 +263,12 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
if (pcibios_enabled && within(pfn, BIOS_BEGIN >> PAGE_SHIFT, BIOS_END >> PAGE_SHIFT))
pgprot_val(forbidden) |= _PAGE_NX;
#endif
+ /*The video bios area needs to be executable for
+ *some programs(like v86d for uvesafb) to execute
+ *video bios functions
+ */
+ if (!pcibios_enable && within(pfn, VIDEO_BIOS_BEGIN >> PAGE_SHIFT, VIDEO_BIOS_END >> PAGE_SHIFT))
+ pgprot_val(forbidden) |= _PAGE_NX;
/*
* The kernel text needs to be executable for obvious reasons
--
1.7.3.4
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