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Subject[PATCH] [66/223] um: remove PAGE_SIZE alignment in linker script causing kernel segfault.
Date
2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Richard Weinberger <richard@nod.at>

commit 6915e04f8847bea16d0890f559694ad8eedd026c upstream.

The linker script cleanup that I did in commit 5d150a97f93 ("um: Clean up
linker script using standard macros.") (2.6.32) accidentally introduced an
ALIGN(PAGE_SIZE) when converting to use INIT_TEXT_SECTION; Richard
Weinberger reported that this causes the kernel to segfault with
CONFIG_STATIC_LINK=y.

I'm not certain why this extra alignment is a problem, but it seems likely
it is because previously

__init_begin = _stext = _text = _sinittext

and with the extra ALIGN(PAGE_SIZE), _sinittext becomes different from the
rest. So there is likely a bug here where something is assuming that
_sinittext is the same as one of those other symbols. But reverting the
accidental change fixes the regression, so it seems worth committing that
now.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Reported-by: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested by: Antoine Martin <antoine@nagafix.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/um/kernel/uml.lds.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/arch/um/kernel/uml.lds.S
===================================================================
--- linux.orig/arch/um/kernel/uml.lds.S
+++ linux/arch/um/kernel/uml.lds.S
@@ -22,7 +22,7 @@ SECTIONS
_text = .;
_stext = .;
__init_begin = .;
- INIT_TEXT_SECTION(PAGE_SIZE)
+ INIT_TEXT_SECTION(0)
. = ALIGN(PAGE_SIZE);

.text :

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