[PATCH 063/173] x86: Use u32 instead of long to set reset vector back to 0

[Willy Tarreau]

2.6.27.59-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Don Zickus <dzickus@xxxxxxxxxx>

commit 299c56966a72b9109d47c71a6db52097098703dd upstream.

A customer of ours, complained that when setting the reset
vector back to 0, it trashed other data and hung their box.
They noticed when only 4 bytes were set to 0 instead of 8,
everything worked correctly.

Mathew pointed out:

 |
 | We're supposed to be resetting trampoline_phys_low and
 | trampoline_phys_high here, which are two 16-bit values.
 | Writing 64 bits is definitely going to overwrite space
 | that we're not supposed to be touching.
 |

So limit the area modified to u32.

Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
Acked-by: Matthew Garrett <mjg@xxxxxxxxxx>
LKML-Reference: <1297139100-424-1-git-send-email-dzickus@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/x86/include/asm/smpboot_hooks.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: longterm-2.6.27/include/asm-x86/mach-default/smpboot_hooks.h
===================================================================
--- longterm-2.6.27.orig/include/asm-x86/mach-default/smpboot_hooks.h	2011-04-25 15:10:35.000000000 +0200
+++ longterm-2.6.27/include/asm-x86/mach-default/smpboot_hooks.h	2011-04-25 15:10:44.035278651 +0200
@@ -32,7 +32,7 @@
 	 */
 	CMOS_WRITE(0, 0xf);
 
-	*((volatile long *) phys_to_virt(0x467)) = 0;
+	*((volatile u32 *) phys_to_virt(0x467)) = 0;
 }
 
 static inline void __init smpboot_setup_io_apic(void)


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