David F Barrera
2005-Feb-25 21:02 UTC
[Xen-devel] PIC register ''bx'' clobbered in ''asm'' - xen-unstable build error
I am trying to build xen-unstable on an x86 box, but it is failing with the following message: gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I ../../tools/libxutil -I. -Wp,-MD,.xc_rrobin.opic.d -fPIC -c -o xc_rrobin.opic xc_rrobin.c gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I ../../tools/libxutil -I. -Wp,-MD,.xc_vmx_build.opic.d -fPIC -c -o xc_vmx_build.opic xc_vmx_build.c xc_vmx_build.c: In function `vmx_identify'': xc_vmx_build.c:468: error: PIC register `bx'' clobbered in `asm'' make[4]: *** [xc_vmx_build.opic] Error 1 make[4]: Leaving directory `/tmp/xen-unstable/tools/libxc'' make[3]: *** [all] Error 2 make[3]: Leaving directory `/tmp/xen-unstable/tools/libxc'' make[2]: *** [install] Error 2 make[2]: Leaving directory `/tmp/xen-unstable/tools'' make[1]: *** [tools] Error 2 make[1]: Leaving directory `/tmp/xen-unstable'' make: *** [world] Error 2 make world failed I have built xen-unstable on this machine before, so I don''t believe it is a setup problem. Has anyone else observed this? David F Barrera ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
Jerone Young
2005-Feb-25 21:17 UTC
Re: [Xen-devel] PIC register ''bx'' clobbered in ''asm'' - xen-unstable build error
The big question is why are you clobbering bx , dx registers on get
cpuid:
_asm__ __volatile__ ("cpuid"
: "=a" (eax), "=c" (ecx)
: "0" (1)
: "bx", "dx");
You can change this to:
_asm__ __volatile__ ("cpuid"
: "=a" (eax), "=c" (ecx)
: "0" (1)
);
But I am not sure why this is there?
On Fri, 2005-02-25 at 15:02 -0600, David F Barrera
wrote:> I am trying to build xen-unstable on an x86 box, but it is failing with
> the following message:
>
> gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I
> ../../tools/libxutil -I. -Wp,-MD,.xc_rrobin.opic.d -fPIC -c -o
> xc_rrobin.opic xc_rrobin.c
> gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I
> ../../tools/libxutil -I. -Wp,-MD,.xc_vmx_build.opic.d -fPIC -c -o
> xc_vmx_build.opic xc_vmx_build.c
> xc_vmx_build.c: In function `vmx_identify'':
> xc_vmx_build.c:468: error: PIC register `bx'' clobbered in
`asm''
> make[4]: *** [xc_vmx_build.opic] Error 1
> make[4]: Leaving directory `/tmp/xen-unstable/tools/libxc''
> make[3]: *** [all] Error 2
> make[3]: Leaving directory `/tmp/xen-unstable/tools/libxc''
> make[2]: *** [install] Error 2
> make[2]: Leaving directory `/tmp/xen-unstable/tools''
> make[1]: *** [tools] Error 2
> make[1]: Leaving directory `/tmp/xen-unstable''
> make: *** [world] Error 2
> make world failed
>
> I have built xen-unstable on this machine before, so I don''t
believe it
> is a setup problem. Has anyone else observed this?
>
> David F Barrera
>
>
>
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT Products from real
users.
> Discover which products truly live up to the hype. Start reading now.
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>
--
Jerone Young
Open Virtualization
IBM Linux Technology Center
jyoung5@us.ibm.com
512-838-1157 (T/L: 678-1157)
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Bin Ren
2005-Feb-25 21:21 UTC
Re: [Xen-devel] PIC register ''bx'' clobbered in ''asm'' - xen-unstable build error
A patch has been proposed by Vincent Hanquez. I''ve already pushed it
into the unstable tree. The problem happens with gcc 3.4
Bin
--- xeno-unstable.bk/tools/libxc/xc_vmx_build.c.orig 2005-02-09
13:50:48 +0100
+++ xeno-unstable.bk/tools/libxc/xc_vmx_build.c 2005-02-09 13:51:33 +0100
@@ -426,10 +426,10 @@
{
int eax, ecx;
- __asm__ __volatile__ ("cpuid"
+ __asm__ __volatile__ ("pushl %%ebx; cpuid; popl %%ebx"
: "=a" (eax), "=c" (ecx)
: "0" (1)
- : "bx", "dx");
+ : "dx");
if (!(ecx & VMX_FEATURE_FLAG)) {
return -1;
}
On Fri, 25 Feb 2005 15:02:30 -0600, David F Barrera <dfbp@us.ibm.com>
wrote:> I am trying to build xen-unstable on an x86 box, but it is failing with
> the following message:
>
> gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I
> ../../tools/libxutil -I. -Wp,-MD,.xc_rrobin.opic.d -fPIC -c -o
> xc_rrobin.opic xc_rrobin.c
> gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I
> ../../tools/libxutil -I. -Wp,-MD,.xc_vmx_build.opic.d -fPIC -c -o
> xc_vmx_build.opic xc_vmx_build.c
> xc_vmx_build.c: In function `vmx_identify'':
> xc_vmx_build.c:468: error: PIC register `bx'' clobbered in
`asm''
> make[4]: *** [xc_vmx_build.opic] Error 1
> make[4]: Leaving directory `/tmp/xen-unstable/tools/libxc''
> make[3]: *** [all] Error 2
> make[3]: Leaving directory `/tmp/xen-unstable/tools/libxc''
> make[2]: *** [install] Error 2
> make[2]: Leaving directory `/tmp/xen-unstable/tools''
> make[1]: *** [tools] Error 2
> make[1]: Leaving directory `/tmp/xen-unstable''
> make: *** [world] Error 2
> make world failed
>
> I have built xen-unstable on this machine before, so I don''t
believe it
> is a setup problem. Has anyone else observed this?
>
> David F Barrera
>
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT Products from real
users.
> Discover which products truly live up to the hype. Start reading now.
> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/xen-devel
>
--
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- Pablo Picasso
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Anthony Liguori
2005-Feb-25 21:44 UTC
Re: [Xen-devel] PIC register ''bx'' clobbered in ''asm'' - xen-unstable build error
Jerone Young wrote:>The big question is why are you clobbering bx , dx registers on get >cpuid: > >CPUID returns information in eax, ebx, ecx, and edx. With -fPIC you have to push ebx onto the stack before calling cpuid and pop it afterward as Bin points out is what the patch to xen-unstable does. Regards,> _asm__ __volatile__ ("cpuid" > : "=a" (eax), "=c" (ecx) > : "0" (1) > : "bx", "dx"); > >You can change this to: > > _asm__ __volatile__ ("cpuid" > : "=a" (eax), "=c" (ecx) > : "0" (1) > ); > >But I am not sure why this is there? > > > >On Fri, 2005-02-25 at 15:02 -0600, David F Barrera wrote: > > >>I am trying to build xen-unstable on an x86 box, but it is failing with >>the following message: >> >>gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I >>../../tools/libxutil -I. -Wp,-MD,.xc_rrobin.opic.d -fPIC -c -o >>xc_rrobin.opic xc_rrobin.c >>gcc -DPIC -m32 -march=i686 -Wall -Werror -O3 -fno-strict-aliasing -I >>../../tools/libxutil -I. -Wp,-MD,.xc_vmx_build.opic.d -fPIC -c -o >>xc_vmx_build.opic xc_vmx_build.c >>xc_vmx_build.c: In function `vmx_identify'': >>xc_vmx_build.c:468: error: PIC register `bx'' clobbered in `asm'' >>make[4]: *** [xc_vmx_build.opic] Error 1 >>make[4]: Leaving directory `/tmp/xen-unstable/tools/libxc'' >>make[3]: *** [all] Error 2 >>make[3]: Leaving directory `/tmp/xen-unstable/tools/libxc'' >>make[2]: *** [install] Error 2 >>make[2]: Leaving directory `/tmp/xen-unstable/tools'' >>make[1]: *** [tools] Error 2 >>make[1]: Leaving directory `/tmp/xen-unstable'' >>make: *** [world] Error 2 >>make world failed >> >>I have built xen-unstable on this machine before, so I don''t believe it >>is a setup problem. Has anyone else observed this? >> >>David F Barrera >> >> >> >>------------------------------------------------------- >>SF email is sponsored by - The IT Product Guide >>Read honest & candid reviews on hundreds of IT Products from real users. >>Discover which products truly live up to the hype. Start reading now. >>http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >>_______________________________________________ >>Xen-devel mailing list >>Xen-devel@lists.sourceforge.net >>https://lists.sourceforge.net/lists/listinfo/xen-devel >> >> >>------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
Arun Sharma
2005-Feb-25 23:19 UTC
Re: [Xen-devel] PIC register ''bx'' clobbered in ''asm'' - xen-unstable build error
On 2/25/2005 1:44 PM, Anthony Liguori wrote:> Jerone Young wrote: > >> The big question is why are you clobbering bx , dx registers on get >> cpuid: >> >> > CPUID returns information in eax, ebx, ecx, and edx. With -fPIC you > have to push ebx onto the stack before calling cpuid and pop it > afterward as Bin points out is what the patch to xen-unstable does.The compiler used to generate the push/pop just fine for gcc-3.3. This is an issue specific to gcc-3.4. gcc-3.3 code: (gdb) disassemble vmx_identify Dump of assembler code for function vmx_identify: 0x00000000 <vmx_identify+0>: push %ebp 0x00000001 <vmx_identify+1>: mov $0x1,%eax 0x00000006 <.LC23+3>: mov %esp,%ebp 0x00000008 <.LC23+5>: push %ebx 0x00000009 <.LC23+6>: cpuid 0x0000000b <.LC23+8>: pop %ebx 0x0000000c <.LC23+9>: xor %eax,%eax 0x0000000e <.LC23+11>: test $0x20,%cl 0x00000011 <.LC23+14>: setne %al 0x00000014 <.LC23+17>: pop %ebp 0x00000015 <.LC23+18>: dec %eax 0x00000016 <.LC23+19>: ret 0x00000017 <.LC23+20>: mov %esi,%esi 0x00000019 <.LC23+22>: lea 0x0(%edi),%edi End of assembler dump. I''m following up with compiler people here to understand why the compiler thinks this is a bug. BTW <asm-i386/processor.h> has similar code. -Arun ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel