Re: [Qemu-devel] Unknown symbol __PAGE_KERNEL_EXEC

[Fabrice Bellard <fabrice@bellard.org>]

Hi,

I propose this patch:

--- kqemu-linux.c       25 Apr 2005 22:14:39 -0000      1.4
+++ kqemu-linux.c       25 Jul 2005 22:17:34 -0000
@@ -28,7 +28,13 @@
  #define pfn_to_page(pfn) (mem_map + (pfn))
  #endif

-#ifndef PAGE_KERNEL_EXEC
+#ifdef PAGE_KERNEL_EXEC
+#if defined(__i386__)
+/* problem : i386 kernels usually don't export __PAGE_KERNEL_EXEC */
+#undef PAGE_KERNEL_EXEC
+#define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL & ~_PAGE_NX)
+#endif
+#else
  #define PAGE_KERNEL_EXEC PAGE_KERNEL
  #endif

Is it working with all kernels and x86/x86_64 ?

Fabrice.

Pascal Terjan wrote:
> On 7/26/05, Darryl Dixon <esrever_otua@pythonhacker.is-a-geek.net> wrote:
> 
>>Hi All, Fabrice,
>>
>>    Compiling the new kqemu-0.7.1 on Fedora Core 4 with kernel
>>2.6.12-1.1398_FC4 gives this error:
>>
>>-------------8<-------------------
>>[dixond@unixadmindazfc2 kqemu]$ make
>>make -C /lib/modules/2.6.12-1.1398_FC4/build M=`pwd` modules
>>make[1]: Entering directory `/usr/src/kernels/2.6.12-1.1398_FC4-i686'
>>  CC [M]  /opt/src/qemu-0.7.1/kqemu/kqemu-linux.o
>>cp /opt/src/qemu-0.7.1/kqemu/kqemu-mod-i386.o /opt/src/qemu-0.7.1/kqemu/kqemu-mod.o
>>  LD [M]  /opt/src/qemu-0.7.1/kqemu/kqemu.o
>>  Building modules, stage 2.
>>  MODPOST
>>Warning: could not find /opt/src/qemu-0.7.1/kqemu/.kqemu-mod.o.cmd
>>for /opt/src/qemu-0.7.1/kqemu/kqemu-mod.o
>>*** Warning: "__PAGE_KERNEL_EXEC" [/opt/src/qemu-0.7.1/kqemu/kqemu.ko]
>>undefined!
>>  CC      /opt/src/qemu-0.7.1/kqemu/kqemu.mod.o
>>  LD [M]  /opt/src/qemu-0.7.1/kqemu/kqemu.ko
>>make[1]: Leaving directory `/usr/src/kernels/2.6.12-1.1398_FC4-i686'
> 
> 
> My understanding of the problem :
> on i386, in pgtable.h we have
> extern unsigned long long __PAGE_KERNEL, __PAGE_KERNEL_EXEC;
> #define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC)
> 
> an there is EXPORT_SYMBOL(__PAGE_KERNEL) but not for __PAGE_KERNEL_EXEC
> 
> on x86_64 :
> #define __PAGE_KERNEL_EXEC \
>         (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
> #define MAKE_GLOBAL(x) __pgprot((x) | _PAGE_GLOBAL)
> #define PAGE_KERNEL_EXEC MAKE_GLOBAL(__PAGE_KERNEL_EXEC)
> 
> So, on i386 __PAGE_KERNEL_EXEC is an extern variable wich is not
> exported and not a macro.
> 
> I wrote a patch on
> http://www.zarb.org/cgi-bin/viewcvs.cgi/plf/SPECS/non-free/dkms-kqemu/kqemu-0.7.1-PAGE_KERNEL_EXEC.patch?rev=1.1&view=markup
> but I don't know much kernel stuff so I have no idea how much it is
> broken :-)
> 
> 
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