[patch 27/59] x86: Work around gcc 4.2 over aggressive optimizer

[Chris Wright]

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

From: Andi Kleen <ak@xxxxxxx>

The new PDA code uses a dummy _proxy_pda variable to describe
memory references to the PDA. It is never referenced
in inline assembly, but exists as input/output arguments.
gcc 4.2 in some cases can CSE references to this which causes
unresolved symbols.  Define it to zero to avoid this.

Signed-off-by: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---
 arch/i386/kernel/vmlinux.lds.S   |    1 +
 arch/x86_64/kernel/vmlinux.lds.S |    1 +
 2 files changed, 2 insertions(+)

--- linux-2.6.19.2.orig/arch/i386/kernel/vmlinux.lds.S
+++ linux-2.6.19.2/arch/i386/kernel/vmlinux.lds.S
@@ -13,6 +13,7 @@ OUTPUT_FORMAT("elf32-i386", "elf32-i386"
 OUTPUT_ARCH(i386)
 ENTRY(phys_startup_32)
 jiffies = jiffies_64;
+_proxy_pda = 0;
 
 PHDRS {
 	text PT_LOAD FLAGS(5);	/* R_E */
--- linux-2.6.19.2.orig/arch/x86_64/kernel/vmlinux.lds.S
+++ linux-2.6.19.2/arch/x86_64/kernel/vmlinux.lds.S
@@ -13,6 +13,7 @@ OUTPUT_FORMAT("elf64-x86-64", "elf64-x86
 OUTPUT_ARCH(i386:x86-64)
 ENTRY(phys_startup_64)
 jiffies_64 = jiffies;
+_proxy_pda = 0;
 PHDRS {
 	text PT_LOAD FLAGS(5);	/* R_E */
 	data PT_LOAD FLAGS(7);	/* RWE */

--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/