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    SubjectRe: [PATCH] x86: fix virt_addr_valid() with CONFIG_DEBUG_VIRTUAL=y
    On 10/01/2008 12:47 PM, Vegard Nossum wrote:
    > Hi,
    >
    > Fix for tip/x86/mm-debug (commit 59ea746337c69f6a5f1bc4d5e8544b3cbf12f801).
    > I'm not sure if choice of names/structure is entirely correct, comments are
    > appreciated.


    > From 01613a1949de51c7ab9d0acaaa9a5444722a5cfa Mon Sep 17 00:00:00 2001
    > From: Vegard Nossum <vegardno@ben.ifi.uio.no>
    > Date: Wed, 1 Oct 2008 12:36:34 +0200
    > Subject: [PATCH] x86: fix virt_addr_valid() with CONFIG_DEBUG_VIRTUAL=y
    >
    > virt_addr_valid() calls __pa(), which calls __phys_addr(). With
    > CONFIG_DEBUG_VIRTUAL=y, __phys_addr() will kill the kernel if the
    > address *isn't* valid. That's clearly wrong for virt_addr_valid().
    >
    > Cc: Jiri Slaby <jirislaby@gmail.com>
    > Cc: Andi Kleen <andi@firstfloor.org>
    > Signed-off-by: Vegard Nossum <vegardno@ben.ifi.uio.no>
    > ---
    > diff --git a/arch/x86/kernel/doublefault_32.c b/arch/x86/kernel/doublefault_32.c
    > index 395acb1..1580e0b 100644
    > --- a/arch/x86/kernel/doublefault_32.c
    > +++ b/arch/x86/kernel/doublefault_32.c
    > @@ -66,6 +66,6 @@ struct tss_struct doublefault_tss __cacheline_aligned = {
    > .ds = __USER_DS,
    > .fs = __KERNEL_PERCPU,
    >
    > - .__cr3 = __phys_addr_const((unsigned long)swapper_pg_dir)
    > + .__cr3 = __phys_addr_nodebug((unsigned long)swapper_pg_dir)

    Now, this may be switched back to __pa: __pa_nodebug(swapper_pg_dir);

    > }
    > };
    [...]
    > --- a/include/asm-x86/page_64.h
    > +++ b/include/asm-x86/page_64.h
    > @@ -69,6 +69,7 @@ extern unsigned long max_pfn;
    > extern unsigned long phys_base;
    >
    > extern unsigned long __phys_addr(unsigned long);
    > +#define __phys_addr_nodebug(x) __phys_addr(x)
    > #define __phys_reloc_hide(x) (x)

    x86_64 is screwed in the same way, isn't it?


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