[uml-devel] Testing requested - [PATCH] Fixing SKAS0 compilation problem / TT mode bug report

[uml-devel] Testing requested - [PATCH] Fixing SKAS0 compilation problem / TT mode bug report

[Blaisorblade]

[-- Attachment #1: Type: text/plain, Size: 1780 bytes --]

The attached patch is a (hacky) proposal, alternative to Jeff's 
fix-stub-syscall6, to fix the SKAS0 compilation problem.

In fact, Jeff's patch makes the problem appear on my system (where I never 
reproduced it).

I'm going to stick this in -bs2, as it makes kernels compiled for me work 
better. So please test compiling -bs2.

As an aside, I saw this code crashing at shutdown in TT mode, from 
fs/proc/array.c:do_task_stat() :

        if (mm) {
                vsize = task_vsize(mm);
                eip = KSTK_EIP(task);
                esp = KSTK_ESP(task);
        }

Went looking and guess what? There is full crap (starting from 2.6.14, due to 
the fixes for sysrq-t IIRC):

include/asm-um/processor-i386.h

#define KSTK_EIP(tsk) KSTK_REG(tsk, EIP)
#define KSTK_ESP(tsk) KSTK_REG(tsk, UESP)
#define KSTK_EBP(tsk) KSTK_REG(tsk, EBP)

include/asm-um/processor-generic.h

#ifdef CONFIG_MODE_SKAS
#define KSTK_REG(tsk, reg) \
        ({ union uml_pt_regs regs; \
           get_thread_regs(&regs, tsk->thread.mode.skas.switch_buf); \
           UPT_REG(&regs, reg); })
#else
#define KSTK_REG(tsk, reg) (0xbadbabe)
#endif

I didn't fully realize the amount of crap in the patch when I reviewed it at 
that time (but I do remember complaining about 0xbadbabe rather than 
0xdeadbeef, so I'm guilty too).

I'll restore for TT mode the 2.6.13 content (which is wrong and kills sysrq-t, 
but is better than crap).

And there's no reason for letting TT mode bitrot so much, sorry. Making UML 
work for everybody, plus having a SMP testing mode, still means keeping it 
working.
-- 
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade

[-- Attachment #2: uml-use-asm-preventing-ebp.diff --]
[-- Type: text/x-diff, Size: 738 bytes --]

Index: linux-2.6.14/arch/um/kernel/skas/clone.c
===================================================================
--- linux-2.6.14.orig/arch/um/kernel/skas/clone.c
+++ linux-2.6.14/arch/um/kernel/skas/clone.c
@@ -1,5 +1,6 @@
 #include <sched.h>
 #include <signal.h>
+#include <stddef.h>
 #include <sys/mman.h>
 #include <sys/time.h>
 #include <asm/unistd.h>
@@ -39,6 +40,10 @@ stub_clone_handler(void)
 			    from->fd, from->offset);
  out:
 	/* save current result. Parent: pid; child: retcode of mmap */
+#if defined(UML_CONFIG_UML_X86) && !defined(UML_CONFIG_64BIT)
+	__asm__("movl %0, %1": : "r" (err), "g" (*(long*) (UML_CONFIG_STUB_DATA + offsetof(struct stub_data, err))));
+#else
 	from->err = err;
+#endif
 	trap_myself();
 }

[uml-devel] Blaisorblade's UML binaries - MORE MORE... please give us an x86_64 UML

[UML]

Hi Paolo,

Please create an x86_64 binary so I can play with different 64 bit distros.

Thanks in advance (I know you have lots of spare time on your hands....)

Cheers
Phill.

P.S. the 32 bit binary is wonderful! It does absolutely everything I need.


-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Blaisorblade's UML binaries - MORE MORE... please give us an x86_64 UML

[Phill Wombat]

Hi Paolo,

x86_64 binary.

So far so good!

I have managed to create an FC4/x86_64 rootfs from the very impressive
(and amazingly simple) shell script on umlwiki where the entire distro
is installed via yum. Had some trouble with gpg keys though.

The rootfs starts up and hangs at the usual places to do with consoles
etc. I'll get to doing some hacks on the rootfs to get things going.

Thanks again
Phill.

On Mon, 2005-11-28 at 11:47 +1100, UML wrote:
> Hi Paolo,
> 
> Please create an x86_64 binary so I can play with different 64 bit distros.
> 
> Thanks in advance (I know you have lots of spare time on your hands....)
> 
> Cheers
> Phill.
> 
> P.S. the 32 bit binary is wonderful! It does absolutely everything I need.
> 




-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Blaisorblade's UML binaries - MORE MORE... please give us an x86_64 UML

[Blaisorblade]

On Tuesday 29 November 2005 13:22, Phill Wombat wrote:
> Hi Paolo,
>
> x86_64 binary.
>
> So far so good!

Thanks, I have no 64-bit FS to test it. Btw, there's also some other site with 
binaries:

http://uml.harlowhill.com/index.php/PrecompiledKernels

http://uml.nagafix.co.uk/

> I have managed to create an FC4/x86_64 rootfs from the very impressive
> (and amazingly simple) shell script on umlwiki where the entire distro
> is installed via yum. Had some trouble with gpg keys though.

> The rootfs starts up and hangs at the usual places to do with consoles
> etc. I'll get to doing some hacks on the rootfs to get things going.

> Thanks again
> Phill.

-- 
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade

	

	
		
___________________________________ 
Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB 
http://mail.yahoo.it



-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Blaisorblade's UML binaries - MORE MORE... please give us an x86_64 UML

[Phill Wombat]

Hi Paolo,

Use this to create a new FC4/x86_64 rootfs (modified from umlwiki post).

#!/bin/bash

RPM_INSTALL_CHR=./INSTALL

echo " --> Setting up chroot env in $RPM_INSTALL_CHR"

if [ `id -u` = "0" ] ; then
        mkdir -p \
                $RPM_INSTALL_CHR/etc \
                $RPM_INSTALL_CHR/dev \
                $RPM_INSTALL_CHR/proc \
                $RPM_INSTALL_CHR/sys \
                $RPM_INSTALL_CHR/var/tmp \
                $RPM_INSTALL_CHR/var/cache/yum
        touch $RPM_INSTALL_CHR/etc/fstab
        mknod $RPM_INSTALL_CHR/dev/null c 1 3
        chmod 666 $RPM_INSTALL_CHR/dev/null
        mount --bind /proc $RPM_INSTALL_CHR/proc
        mount --bind /sys $RPM_INSTALL_CHR/sys
#       rpm \
#               --root $PWD/$RPM_INSTALL_CHR \
#               --import http://fedora.redhat.com/about/security/4F2A6FD2.txt
        rpm \
                --root $PWD/$RPM_INSTALL_CHR \
                -Uvh \
                --nodeps \
                --force \
                http://download.fedora.redhat.com/pub/fedora/linux/core/4/x86_64/os/Fedora/RPMS/fedora-release-4-2.noarch.rpm
        yum \
                -y \
                -C \
                --installroot=$PWD/$RPM_INSTALL_CHR \
                groupinstall "Base"
        umount $RPM_INSTALL_CHR/proc
        umount $RPM_INSTALL_CHR/sys
else
        echo " *** Sorry, you must be root to setup a chroot environment"
        exit 1
fi

This is the gpg key installed instead of the commented lines (I couldn't
find the right key on the fedora web site). It comes from the live
FC4/x86_64 host with rpm -qa gpg-pubkeys*; rpm -qi gpg-pubkey-db42a60e


Name        : gpg-pubkey                   Relocations: (not relocatable)
Version     : db42a60e                          Vendor: (none)
Release     : 37ea5438                      Build Date: Thu 25 Aug 2005 02:28:19 PM EST
Install Date: Thu 25 Aug 2005 02:28:19 PM EST      Build Host: localhost
Group       : Public Keys                   Source RPM: (none)
Size        : 0                                License: pubkey
Signature   : (none)
Summary     : gpg(Red Hat, Inc <security@redhat.com>)
Description :
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: rpm-4.4.1 (beecrypt-3.0.0)
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=3AHZ
-----END PGP PUBLIC KEY BLOCK-----



On Tue, 2005-11-29 at 17:52 +0100, Blaisorblade wrote:
> On Tuesday 29 November 2005 13:22, Phill Wombat wrote:
> > Hi Paolo,
> >
> > x86_64 binary.
> >
> > So far so good!
> 
> Thanks, I have no 64-bit FS to test it. Btw, there's also some other site with 
> binaries:
> 
> http://uml.harlowhill.com/index.php/PrecompiledKernels
> 
> http://uml.nagafix.co.uk/
> 
> > I have managed to create an FC4/x86_64 rootfs from the very impressive
> > (and amazingly simple) shell script on umlwiki where the entire distro
> > is installed via yum. Had some trouble with gpg keys though.
> 
> > The rootfs starts up and hangs at the usual places to do with consoles
> > etc. I'll get to doing some hacks on the rootfs to get things going.
> 
> > Thanks again
> > Phill.
> 



-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Blaisorblade's UML binaries - MORE MORE... please give us an x86_64 UML

[Blaisorblade]

On Wednesday 30 November 2005 21:32, Phill Wombat wrote:
> Hi Paolo,
>
> Use this to create a new FC4/x86_64 rootfs (modified from umlwiki post).
Can that be added there too? Doing collaborative editing is the Wiki purpose.

> #!/bin/bash
>
> RPM_INSTALL_CHR=./INSTALL
>
> echo " --> Setting up chroot env in $RPM_INSTALL_CHR"
>
> if [ `id -u` = "0" ] ; then
>         mkdir -p \
>                 $RPM_INSTALL_CHR/etc \
>                 $RPM_INSTALL_CHR/dev \
>                 $RPM_INSTALL_CHR/proc \
>                 $RPM_INSTALL_CHR/sys \
>                 $RPM_INSTALL_CHR/var/tmp \
>                 $RPM_INSTALL_CHR/var/cache/yum
>         touch $RPM_INSTALL_CHR/etc/fstab
>         mknod $RPM_INSTALL_CHR/dev/null c 1 3
>         chmod 666 $RPM_INSTALL_CHR/dev/null
>         mount --bind /proc $RPM_INSTALL_CHR/proc
>         mount --bind /sys $RPM_INSTALL_CHR/sys
> #       rpm \
> #               --root $PWD/$RPM_INSTALL_CHR \
> #               --import
> http://fedora.redhat.com/about/security/4F2A6FD2.txt rpm \
>                 --root $PWD/$RPM_INSTALL_CHR \
>                 -Uvh \
>                 --nodeps \
>                 --force \
>                
> http://download.fedora.redhat.com/pub/fedora/linux/core/4/x86_64/os/Fedora/
>RPMS/fedora-release-4-2.noarch.rpm yum \
>                 -y \
>                 -C \
>                 --installroot=$PWD/$RPM_INSTALL_CHR \
>                 groupinstall "Base"
>         umount $RPM_INSTALL_CHR/proc
>         umount $RPM_INSTALL_CHR/sys
> else
>         echo " *** Sorry, you must be root to setup a chroot environment"
>         exit 1
> fi
>
> This is the gpg key installed instead of the commented lines (I couldn't
> find the right key on the fedora web site). It comes from the live
> FC4/x86_64 host with rpm -qa gpg-pubkeys*; rpm -qi gpg-pubkey-db42a60e
>
>
> Name        : gpg-pubkey                   Relocations: (not relocatable)
> Version     : db42a60e                          Vendor: (none)
> Release     : 37ea5438                      Build Date: Thu 25 Aug 2005
> 02:28:19 PM EST Install Date: Thu 25 Aug 2005 02:28:19 PM EST      Build
> Host: localhost Group       : Public Keys                   Source RPM:
> (none)
> Size        : 0                                License: pubkey
> Signature   : (none)
> Summary     : gpg(Red Hat, Inc <security@redhat.com>)
> Description :
> -----BEGIN PGP PUBLIC KEY BLOCK-----
> Version: rpm-4.4.1 (beecrypt-3.0.0)
>
> mQGiBDfqVDgRBADBKr3Bl6PO8BQ0H8sJoD6p9U7Yyl7pjtZqioviPwXP+DCWd4u8HQzcxAZ5
> 7m8ssA1LK1Fx93coJhDzM130+p5BG9mYSWShLabR3N1KXdXQYYcowTOMGxdwYRGr1Spw8Qyd
> LhjVfU1VSl4xt6bupPbWJbyjkg5Z3P7BlUOUJmrx3wCgobNVEDGaWYJcch5z5B1of/41G8kE
> AKii6q7Gu/vhXXnLS6m15oNnPVybyngiw/23dKjSZVG7rKANEK2mxg1VB+vc/uUc4k49UxJJ
> fCZg1gu1sPFV3GSa+Y/7jsiLktQvCiLPlncQt1dV+ENmHR5BdIDPWDzKBVbgWnSDnqQ6KrZ7
> T6AlZ74VMpjGxxkWU6vV2xsWXCLPA/9P/vtImA8CZN3jxGgtK5GGtDNJ/cMhhuv5tnfwFg4b
> /VGo2Jr8mhLUqoIbE6zeGAmZbUpdckDco8D5fiFmqTf5+++pCEpJLJkkzel/32N2w4qzPrcR
> MCiBURESPjCLd4Y5rPoU8E4kOHc/4BuHN903tiCsCPloCrWsQZ7UdxfQ5LQiUmVkIEhhdCwg
> SW5jIDxzZWN1cml0eUByZWRoYXQuY29tPohVBBMRAgAVBQI36lQ4AwsKAwMVAwIDFgIBAheA
> AAoJECGRgM3bQqYOsBQAnRVtg7B25Hm11PHcpa8FpeddKiq2AJ9aO8sBXmLDmPOEFI75mpTr
> KYHF6rkCDQQ36lRyEAgAokgI2xJ+3bZsk8jRA8ORIX8DH05UlMH27qFYzLbT6npXwXYIOtVn
> 0K2/iMDj+oEB1Aa2au4OnddYaLWp06v3d+XyS0t+5ab2ZfIQzdh7wCwxqRkzR+/H5TLYbMG+
> hvtTdylfqIX0WEfoOXMtWEGSVwyUsnM3Jy3LOi48rQQSCKtCAUdV20FoIGWhwnb/gHU1BnmE
> S6UdQujFBE6EANqPhp0coYoIhHJ2oIO8ujQItvvNaU88j/s/izQv5e7MXOgVSjKe/WX3s2Jt
> B/tW7utpy12wh1J+JsFdbLV/t8CozUTpJgx5mVA3RKlxjTA+On+1IEUWioB+iVfT7Ov/0kcA
> zwADBQf9E4SKCWRand8K0XloMYgmipxMhJNnWDMLkokvbMNTUoNpSfRoQJ9EheXDxwMpTPwK
> ti/PYrrL2J11P2ed0x7zm8v3gLrY0cue1iSba+8glY+p31ZPOr5ogaJw7ZARgoS8BwjyRymX
> Qp+8Dete0TELKOL2/itDOPGHW07SsVWOR6cmX4VlRRcWB5KejaNvdrE54XFtOd04NMgWI63u
> qZc4zkRa+kwEZtmbz3tHSdRCCE+Y7YVP6IUf/w6YPQFQriWYFiA6fD10eB+BlIUqIw80Vgjs
> BKmCwvKkn4jg8kibXgj4/TzQSx77uYokw1EqQ2wkOZoaEtcubsNMquuLCMWijYhGBBgRAgAG
> BQI36lRyAAoJECGRgM3bQqYOhyYAnj7hVDY/FJAGqmtZpwVp9IlitW5tAJ4xQApr/jNFZCTk
> snI+4O1765F7tA==
> =3AHZ
> -----END PGP PUBLIC KEY BLOCK-----
>
> On Tue, 2005-11-29 at 17:52 +0100, Blaisorblade wrote:
> > On Tuesday 29 November 2005 13:22, Phill Wombat wrote:
> > > Hi Paolo,
> > >
> > > x86_64 binary.
> > >
> > > So far so good!
> >
> > Thanks, I have no 64-bit FS to test it. Btw, there's also some other site
> > with binaries:
> >
> > http://uml.harlowhill.com/index.php/PrecompiledKernels
> >
> > http://uml.nagafix.co.uk/
> >
> > > I have managed to create an FC4/x86_64 rootfs from the very impressive
> > > (and amazingly simple) shell script on umlwiki where the entire distro
> > > is installed via yum. Had some trouble with gpg keys though.
> > >
> > > The rootfs starts up and hangs at the usual places to do with consoles
> > > etc. I'll get to doing some hacks on the rootfs to get things going.
> > >
> > > Thanks again
> > > Phill.

-- 
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade

	

	
		
___________________________________ 
Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB 
http://mail.yahoo.it



-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Testing requested - [PATCH] Fixing SKAS0 compilation problem / TT mode bug report

[Jeff Dike]

On Sun, Nov 27, 2005 at 09:59:37PM +0100, Blaisorblade wrote:
> The attached patch is a (hacky) proposal, alternative to Jeff's 
> fix-stub-syscall6, to fix the SKAS0 compilation problem.

Bleah :-)

> In fact, Jeff's patch makes the problem appear on my system (where I never 
> reproduced it).

What assembly did you end up with, with my patch?

> As an aside, I saw this code crashing at shutdown in TT mode, from 
> fs/proc/array.c:do_task_stat() :
> 
>         if (mm) {
>                 vsize = task_vsize(mm);
>                 eip = KSTK_EIP(task);
>                 esp = KSTK_ESP(task);
>         }
> 
> Went looking and guess what? There is full crap (starting from 2.6.14, due to 
> the fixes for sysrq-t IIRC):
> 
> include/asm-um/processor-i386.h
> 
> #define KSTK_EIP(tsk) KSTK_REG(tsk, EIP)
> #define KSTK_ESP(tsk) KSTK_REG(tsk, UESP)
> #define KSTK_EBP(tsk) KSTK_REG(tsk, EBP)
> 
> include/asm-um/processor-generic.h
> 
> #ifdef CONFIG_MODE_SKAS
> #define KSTK_REG(tsk, reg) \
>         ({ union uml_pt_regs regs; \
>            get_thread_regs(&regs, tsk->thread.mode.skas.switch_buf); \
>            UPT_REG(&regs, reg); })
> #else
> #define KSTK_REG(tsk, reg) (0xbadbabe)
> #endif

Oops, needs fixing.

				Jeff


-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Testing requested - [PATCH] Fixing SKAS0 compilation problem / TT mode bug report

[Blaisorblade]

On Monday 28 November 2005 05:23, Jeff Dike wrote:
> On Sun, Nov 27, 2005 at 09:59:37PM +0100, Blaisorblade wrote:
> > The attached patch is a (hacky) proposal, alternative to Jeff's
> > fix-stub-syscall6, to fix the SKAS0 compilation problem.

> Bleah :-)

Yep :-).

> > In fact, Jeff's patch makes the problem appear on my system (where I
> > never reproduced it).

> What assembly did you end up with, with my patch?

Actually, looking at it today, it's a different story than the usual one:

====working (from the .s output rather than disassembly):

#APP
        push %ebp ; movl %eax,%ebp ; movl $192,%eax ; int $0x80 ; pop %ebp
#NO_APP
        movl    %eax, %edi
.L4:
        movl    %edi, -1073745896
#APP
        int3

====not-working:

#APP
        push %ebp ; movl %eax,%ebp ; movl $192,%eax ; int $0x80 ; pop %ebp
#NO_APP
        movl    %eax, -16(%ebp)
.L4:
        movl    -16(%ebp), %eax
        movl    %eax, -1073745896
#APP
        int3

Command line for GCC:

  gcc -Wp,-MD,arch/um/kernel/skas/.clone.s.d -Wall -Wundef -Wstrict-prototypes 
-Wno-trigraphs -fno-strict-aliasing -fno-common -ffreestanding -O2 
-fno-omit-frame-pointer -fno-optimize-sibling-calls -D__arch_um__ 
-DSUBARCH=\"i386\" -Dvmap=kernel_vmap 
-Din6addr_loopback=kernel_in6addr_loopback -Iarch/um/include 
-I/home/paolo/Admin/kernel/6/VCS/linux-2.6.14/arch/um/include  
-I/home/paolo/Admin/kernel/6/VCS/linux-2.6.14/arch/um/kernel/tt/include  
-I/home/paolo/Admin/kernel/6/VCS/linux-2.6.14/arch/um/kernel/skas/include 
-D_FILE_OFFSET_BITS=64 -m32 -D_GNU_SOURCE -D_LARGEFILE64_SOURCE  -S -o 
arch/um/kernel/skas/clone.s /home/paolo/Admin/kernel/6/VCS/linux-2.6.14/arch/um/kernel/skas/clone.c

As you see, what's moved is the scratch pid location, put in %edi register 
normally and in the stack on the faulty assembly (btw, I'm puzzled why GCC 
should do this puzzling around).

So, indeed, with your patch GCC understands that the variable is at a known 
location, but becomes silly for other reasons.

So, again: can we finally rewrite clone.c in assembly? Or, otherwise, to use a 
unique assembly macro joining mmap, the return and trap_myself?

It could be nicer to have it in C, but hey, GCC won, we lost. So let gcc suck 
and work without it.

It's fundamentally hacky to get GCC not to use the stack, it's not written for 
that. Either you say "ok, let's copy the whole stack content when remapping" 
a-la switcheroo() or we agree on ASM.

> > #ifdef CONFIG_MODE_SKAS
> > #define KSTK_REG(tsk, reg) \
> >         ({ union uml_pt_regs regs; \
> >            get_thread_regs(&regs, tsk->thread.mode.skas.switch_buf); \
> >            UPT_REG(&regs, reg); })
> > #else
> > #define KSTK_REG(tsk, reg) (0xbadbabe)
> > #endif

> Oops, needs fixing.

Btw, the old code was probably uncorrect but didn't crash except for sysrq-t.

Actually,  in TT mode we possibly don't have the right location (do we save 
the stack pointer before entering the kernel)? Let's just use the old code as 
fallback for that, it's not worth implementing such a feature for TT mode.

-- 
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade

	

	
		
___________________________________ 
Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB 
http://mail.yahoo.it



-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Testing requested - [PATCH] Fixing SKAS0 compilation problem / TT mode bug report

[Jeff Dike]

On Tue, Nov 29, 2005 at 05:28:56PM +0100, Blaisorblade wrote:
> So, again: can we finally rewrite clone.c in assembly? Or, otherwise, to use a 
> unique assembly macro joining mmap, the return and trap_myself?

I would favor the second, although I would just join the mmap and storing of 
the error value.  The stack switching is at the heart of our recent problems
here, so some asm which hides that should be OK.  I think the rest is OK with
the pseudo-C, right?

				Jeff


-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Testing requested - [PATCH] Fixing SKAS0 compilation problem / TT mode bug report

[Blaisorblade]

On Tuesday 29 November 2005 18:55, Jeff Dike wrote:
> On Tue, Nov 29, 2005 at 05:28:56PM +0100, Blaisorblade wrote:
> > So, again: can we finally rewrite clone.c in assembly? Or, otherwise, to
> > use a unique assembly macro joining mmap, the return and trap_myself?
>
> I would favor the second, although I would just join the mmap and storing
> of the error value.
I want to add the int3 too - that's the only way to be deterministically sure 
that GCC doesn't use %ebp after the unmap.

> The stack switching is at the heart of our recent 
> problems here, so some asm which hides that should be OK.  I think the rest
> is OK with the pseudo-C, right?
Yes, mostly.... there is also the problem with hardened toolchains (two 
different reports), which makes inline syscalls bleach (hardened toolchains 
use PIE code and need to have %EBX reserved for GOT/PLT handling), but I 
currently I do not consider fixing it before I can reproduce it.
-- 
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade


		
___________________________________ 
Yahoo! Messenger: chiamate gratuite in tutto il mondo 
http://it.messenger.yahoo.com



-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Testing requested - [PATCH] Fixing SKAS0 compilation problem / TT mode bug report

[Jeff Dike]

On Fri, Dec 02, 2005 at 01:18:27AM +0100, Blaisorblade wrote:
> I want to add the int3 too - that's the only way to be deterministically 
> sure that GCC doesn't use %ebp after the unmap.

Well, my current patch branches to the int3.  gcc will have to be pretty
imaginative to involve ebp in a branch.

> Yes, mostly.... there is also the problem with hardened toolchains (two 
> different reports), which makes inline syscalls bleach (hardened toolchains 
> use PIE code and need to have %EBX reserved for GOT/PLT handling), but I 
> currently I do not consider fixing it before I can reproduce it.

Yeah, I encountered this in a different context.

				Jeff


-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems?  Stop!  Download the new AJAX search engine that makes
searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel