Re: [PATCH 1/1] x86: fix text_poke

From: Ingo Molnar
Date: Fri Apr 25 2008 - 12:23:29 EST



* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> + spin_lock_irqsave(&poke_lock, flags);
> + set_fixmap(FIX_POKE, phys);
> + memcpy((void *)(virt + offset), opcode, len);
> + spin_unlock_irqrestore(&poke_lock, flags);

hm, right now we've got a debug protection in set_fixmap() to make sure
it's only ever called once. So it's going to be a noisy bootup. (but
it's a warning only) The patch below removes that.

Ingo

------------->
Subject: x86: remove set_fixmap() warning
From: Ingo Molnar <mingo@xxxxxxx>
Date: Fri Apr 25 18:05:57 CEST 2008

set_fixmap() is safe as long as it's explicitly serialized between
all users.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/mm/init_64.c | 3 ---
1 file changed, 3 deletions(-)

Index: linux/arch/x86/mm/init_64.c
===================================================================
--- linux.orig/arch/x86/mm/init_64.c
+++ linux/arch/x86/mm/init_64.c
@@ -173,9 +173,6 @@ set_pte_phys(unsigned long vaddr, unsign
new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);

pte = pte_offset_kernel(pmd, vaddr);
- if (!pte_none(*pte) &&
- pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
- pte_ERROR(*pte);
set_pte(pte, new_pte);

/*
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