Re: [Qemu-devel] Unknown symbol __PAGE_KERNEL_EXEC

[Pascal Terjan]

On 7/26/05, Pascal Terjan <address@hidden> wrote:
> On 7/26/05, Darryl Dixon <address@hidden> 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<-------------------
> > address@hidden 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 :-)
> 
after think to what I wrote, as PAGE_KERNEL is OK, a simpler and
better patch may be to use & ~_PAGE_NX