Messages in this thread Patch in this message | | | Date | Sat, 23 Feb 2008 07:18:56 +0100 | From | Ingo Molnar <> | Subject | Re: Regression [Was: Boot hang with stack protector on x86_64] |
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James,
could you try the fix below ontop of x86.git#testing, does it solve your boot hang?
Ingo
---------------> Subject: x86: stackprotector fix: do not zap %gs From: Ingo Molnar <mingo@elte.hu> Date: Sat Feb 23 07:06:55 CET 2008
pda_init() puts 0 into %gs - that's wrong because any %gs access will fault from now on and we already have a dummy PDA set up that can be accessed just fine.
This normally does not matter because almost nothing accesses %gs this early ... but the stackprotector now does to read the canary ...
Signed-off-by: Ingo Molnar <mingo@elte.hu> --- arch/x86/kernel/setup64.c | 2 -- 1 file changed, 2 deletions(-)
Index: linux-x86.q/arch/x86/kernel/setup64.c =================================================================== --- linux-x86.q.orig/arch/x86/kernel/setup64.c +++ linux-x86.q/arch/x86/kernel/setup64.c @@ -165,8 +165,6 @@ void pda_init(int cpu) { struct x8664_pda *pda = cpu_pda(cpu); - /* Setup up data that may be needed in __get_free_pages early */ - asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0)); /* Memory clobbers used to order PDA accessed */ mb(); wrmsrl(MSR_GS_BASE, pda);
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