Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Andi Kleen]

Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

> > > Is it impossible to handle unaligned access traps properly on
> > > parisc?  If so, well you have some problems...
> > 
> > No, we just haven't bothered to implement it yet.  Not many people
> > use IPX these days.
> 
> You also need unaligned trap fixups for
> 
> AX.25, NetROM, LAPB, X.25, Appletalk, PPP, Anything over 802.2LLC, Linus
> NFS code for some NFS mount options (although not the -ac NFS code)

And also everybody connected to the internet needs them, because you can 
create arbitarily unaligned TCP/UDP/ICMP headers using IP option byte sized 
NOPs. 

-Andi

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[David S. Miller]

   From: Andi Kleen <ak@suse.de>
   Date: 03 Sep 2001 09:29:12 +0200
   
   And also everybody connected to the internet needs them, because you can 
   create arbitarily unaligned TCP/UDP/ICMP headers using IP option byte sized 
   NOPs. 

IP header length is measured in octets, so how is this possible?
:-)

Later,
David S. Miller
davem@redhat.com

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Andi Kleen]

On Mon, Sep 03, 2001 at 01:15:30AM -0700, David S. Miller wrote:
>    From: Andi Kleen <ak@suse.de>
>    Date: 03 Sep 2001 09:29:12 +0200
>    
>    And also everybody connected to the internet needs them, because you can 
>    create arbitarily unaligned TCP/UDP/ICMP headers using IP option byte sized 
>    NOPs. 
> 
> IP header length is measured in octets, so how is this possible?
> :-)

Sorry that came out wrong. You can in theory generate unaligned IP options this way, but the 
kernel handles this correctly using memcpy. What it doesn't handle is unaligned TCP options
(e.g. timestamps); which you can create using TCP option byte fillers.

Also the 4 byte alignment of the header doesn't help much when the driver didn't cooperate.

-Andi

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Hans Reiser]

Ok, so the sum of this is that Jeff's patches work on the platforms he wrote
them for, and we need one more fix for PA-RISC.

So, we can reasonably send Jeff's patches to Linus, and test and then put the
PA-RISC patch into the AC tree, any disagreement?

Hans

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Matthew Wilcox]

On Mon, Sep 03, 2001 at 02:48:24PM +0400, Hans Reiser wrote:
> Ok, so the sum of this is that Jeff's patches work on the platforms he wrote
> them for, and we need one more fix for PA-RISC.
> 
> So, we can reasonably send Jeff's patches to Linus, and test and then put the
> PA-RISC patch into the AC tree, any disagreement?

If you don't align on sparc, alpha, et al, then it will be slower than
it could be; don't you want to fix that first?

-- 
Revolutions do not require corporate support.

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Horst von Brand]

"David S. Miller" <davem@redhat.com> said:
> IP header length is measured in octets, so how is this possible?
> :-)

1 octet == 8 bits in RFC-speak. "Byte" is the name given to character
units.  There were machines around with non-8-bit bytes. AFAIR, DEC PDP-10
had the options of 6, 7, or 8 bits/byte in 36 bit words. Purely historical
now, since (AFAIK) everybody has agreed with IBM (S/360?) that 1 byte == 8
bits. As Brian Reid (IIRC) used to say: "It is spelled 'o-c-t-e-t' and
pronounced 'byte'"
-- 
Horst von Brand                             vonbrand@sleipnir.valparaiso.cl
Casilla 9G, Vin~a del Mar, Chile                               +56 32 672616

documented Oops running big-endian reiserfs on parisc architecture

[thunder7]

Well, I watched the number of files in /lost+found grow every time I
had to pull the plug from my HP C200, so I added a 'sync' option in
/etc/fstab and tried to get reiserfs working.

I patched my 2.4.9-pa13 kernel with

endian-safe-reiserfs-for-2.4.8.patch

which went without warnings or errors. A patched
reiserfs-progs-3.x.0k-pre9 also built well (despite what the configure
scripts says, you _need_ automake).

Creating a reiserfs-partition went without a hitch.

running bonnie -s 128 on it did this:

Adding Swap: 1041400k swap-space (priority -1)
eth0: Setting half-duplex based on MII#1 link partner capability of 0021.
reiserfs: checking transaction log (device 08:03) ...
Using r5 hash to sort names
ReiserFS version 3.6.25
bonnie[163]: Unaligned data reference 28

     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00000000000001001111111100001110
r0-3     00000000 102ec550 10197d0c 26f24838
r4-7     26f24848 27054e40 00000011 00000020
r8-11    0000000a 26f06580 00000020 26f247a0
r12-15   27088d1c ffffffff 26f24838 00000001
r16-19   26f24708 faf02c68 0006a248 26f24852
r20-23   0000000f 00000003 03000000 00000002
r24-27   0000000a 0000000a 26f24848 102d4010
r28-31   26f24848 01000000 26f24b40 10196fc8
sr0-3    00000000 00000004 00000000 00000004
sr4-7    00000000 00000000 00000000 00000000

IASQ: 00000000 00000000 IAOQ: 10197d10 10197d14
 IIR: 0c7c1093    ISR: 00000000  IOR: 26f24846
 ORIG_R28: 00000000
pa8200:/var/log#

After reading in the archives about ksymoops, I looked up this part of
my System.map:

101979e0 T reiserfs_lookup
101979e0 t .L1432
10197ad4 t reiserfs_add_entry
10197e50 t .L1512
10197f28 t .L1510
10198068 T reiserfs_create

objdump -d /boot/linux-2.4.9-pa13 revealed:

10197cbc:       d6 d6 0b 18     depw,z r22,7,8,r22
10197cc0:       d6 b5 0a 10     depw,z r21,15,16,r21
10197cc4:       41 33 01 fe     ldb ff(sr0,r9),r19
10197cc8:       0a d5 02 75     or r21,r22,r21
10197ccc:       d6 94 09 08     depw,z r20,23,24,r20
10197cd0:       0a b4 02 74     or r20,r21,r20
10197cd4:       0a 93 02 73     or r19,r20,r19
10197cd8:       d2 75 18 f8     extrw,u r19,7,8,r21
10197cdc:       d2 74 19 f8     extrw,u r19,15,8,r20
10197ce0:       0c 73 12 16     stb  r19,b(sr0,r3)
10197ce4:       d2 73 1a f8     extrw,u r19,23,8,r19
10197ce8:       0c 75 12 10     stb  r21,8(sr0,r3)
10197cec:       0c 74 12 12     stb  r20,9(sr0,r3)
10197cf0:       e8 86 a9 e4     b,l 102a51e8 <memcpy>,%r2
10197cf4:       0c 73 12 14     stb  r19,a(sr0,r3)
10197cf8:       08 06 02 59     copy r6,r25
10197cfc:       08 04 02 5a     copy r4,r26
10197d00:       d7 20 1c 1d     depwi 0,31,3,r25
10197d04:       e8 0d a5 d8     call 101b1ff8 <padd_item>
10197d08:       08 08 02 58     copy r8,r24
10197d0c:       00 01 0e 74     rsm 1,r20
10197d10:       0c 7c 10 93     ldw  e(sr0,r3),r19
10197d14:       d6 60 1f 1f     depwi 0,7,1,r19
10197d18:       0c 73 12 9c     stw  r19,e(sr0,r3)
10197d1c:       00 14 18 60     mtsm r20
10197d20:       85 e0 26 32     cmpib,=,n 0,r15,10198040 <.L1510+0x118>
10197d24:       00 01 0e 74     rsm 1,r20
10197d28:       0c 7c 10 93     ldw  e(sr0,r3),r19
10197d2c:       d6 7f 1f 5f     depwi -1,5,1,r19
10197d30:       0c 73 12 9c     stw  r19,e(sr0,r3)
10197d34:       00 14 18 60     mtsm r20
10197d38:       08 00 02 54     copy r0,r20
10197d3c:       08 00 02 55     copy r0,r21
10197d40:       37 c6 3e 51     ldo -d8(sp),r6
10197d44:       37 cd 3d c1     ldo -120(sp),r13
10197d48:       6b d4 3e 51     stw r20,-d8(sr0,sp)
10197d4c:       6b d5 3e 59     stw r21,-d4(sr0,sp)
10197d50:       6b d4 3e 61     stw r20,-d0(sr0,sp)
10197d54:       6b d5 3e 69     stw r21,-cc(sr0,sp)
10197d58:       08 0c 02 59     copy r12,r25
10197d5c:       6b c6 3e 01     stw r6,-100(sr0,sp)
10197d60:       6b cd 3f 99     stw r13,-34(sr0,sp)
10197d64:       08 08 02 58     copy r8,r24
10197d68:       08 05 02 5a     copy r5,r26
10197d6c:       eb ff b4 4d     b,l 10197798 <reiserfs_find_entry>,%r2

which makes the error somewhere around here in 
fs/reiserfs/namei.c, function reiserfs_add_entry, after call to
padd_item, before call to reiserfs_find_entry:

    /* copy name */
    memcpy ((char *)(deh + 1), name, namelen);
    /* padd by 0s to the 4 byte boundary */
    padd_item ((char *)(deh + 1), ROUND_UP (namelen), namelen);

    /* entry is ready to be pasted into tree, set 'visibility' and 'stat data in entry' attributes */
    mark_de_without_sd (deh);
    visible ? mark_de_visible (deh) : mark_de_hidden (deh);

    /* find the proper place for the new entry */
    memset (bit_string, 0, sizeof (bit_string));
    de.de_gen_number_bit_string = (char *)bit_string;
    retval = reiserfs_find_entry (dir, name, namelen, &path, &de);


And there I'm stuck. I'm sending this to the parisc-list to document the
failure, and to linux-kernel to reach some reiserfs-experts, perhaps.

I'm willing to test anything!

Good luck,
Jurriaan
-- 
"I have seen her. That is enough, perhaps."
Pug smiled. "You are a rare man."
	Raymond E Feist - The King's Buccaneer
GNU/Linux 2.4.9-ac5 SMP/ReiserFS 2x1402 bogomips load av: 0.04 0.01 0.06

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Matthew Wilcox]

On Sun, Sep 02, 2001 at 10:55:38AM +0200, thunder7@xs4all.nl wrote:
> ReiserFS version 3.6.25
> bonnie[163]: Unaligned data reference 28

As it says, an unaligned data reference.

> r0-3     00000000 102ec550 10197d0c 26f24838

> IASQ: 00000000 00000000 IAOQ: 10197d10 10197d14

In kernel mode.

> 10197d10:       0c 7c 10 93     ldw  e(sr0,r3),r19

r3 is 26f24838, and offset `e' from that is unaligned.

> which makes the error somewhere around here in 
> fs/reiserfs/namei.c, function reiserfs_add_entry, after call to
> padd_item, before call to reiserfs_find_entry:
> 
>     /* copy name */
>     memcpy ((char *)(deh + 1), name, namelen);
>     /* padd by 0s to the 4 byte boundary */
>     padd_item ((char *)(deh + 1), ROUND_UP (namelen), namelen);
> 
>     /* entry is ready to be pasted into tree, set 'visibility' and 'stat data in entry' attributes */
>     mark_de_without_sd (deh);
>     visible ? mark_de_visible (deh) : mark_de_hidden (deh);
> 
>     /* find the proper place for the new entry */
>     memset (bit_string, 0, sizeof (bit_string));
>     de.de_gen_number_bit_string = (char *)bit_string;
>     retval = reiserfs_find_entry (dir, name, namelen, &path, &de);

I suspect mark_de_without_sd is an inlined function/macro and this will
be where the unaligned data reference is happening.

-- 
Revolutions do not require corporate support.

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[David S. Miller]

   From: Matthew Wilcox <willy@debian.org>
   Date: Sun, 2 Sep 2001 15:00:23 +0100

   On Sun, Sep 02, 2001 at 10:55:38AM +0200, thunder7@xs4all.nl wrote:
   > ReiserFS version 3.6.25
   > bonnie[163]: Unaligned data reference 28
   
   As it says, an unaligned data reference.
   
BTW, you should not be OOPSing on this as unaligned references are
defined as completely normal, especially in the networking.

Is it impossible to handle unaligned access traps properly on
parisc?  If so, well you have some problems...

Later,
David S. Miller
davem@redhat.com

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Matthew Wilcox]

On Sun, Sep 02, 2001 at 04:04:41PM -0700, David S. Miller wrote:
>    From: Matthew Wilcox <willy@debian.org>
>    Date: Sun, 2 Sep 2001 15:00:23 +0100
> 
>    On Sun, Sep 02, 2001 at 10:55:38AM +0200, thunder7@xs4all.nl wrote:
>    > ReiserFS version 3.6.25
>    > bonnie[163]: Unaligned data reference 28
>    
>    As it says, an unaligned data reference.
>    
> BTW, you should not be OOPSing on this as unaligned references are
> defined as completely normal, especially in the networking.
> 
> Is it impossible to handle unaligned access traps properly on
> parisc?  If so, well you have some problems...

No, we just haven't bothered to implement it yet.  Not many people
use IPX these days.

-- 
Revolutions do not require corporate support.

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[David S. Miller]

   From: Matthew Wilcox <willy@debian.org>
   Date: Mon, 3 Sep 2001 00:25:14 +0100
   
   No, we just haven't bothered to implement it yet.  Not many people
   use IPX these days.
   
IPX is not the only way this can happen.  Normal IPv4 can get
it with some ethernet cards on receive.

Later,
David S. Miller
davem@redhat.com

Re: [parisc-linux] documented Oops running big-endian reiserfs on parisc architecture

[Alan Cox]

> > Is it impossible to handle unaligned access traps properly on
> > parisc?  If so, well you have some problems...
> 
> No, we just haven't bothered to implement it yet.  Not many people
> use IPX these days.

You also need unaligned trap fixups for

AX.25, NetROM, LAPB, X.25, Appletalk, PPP, Anything over 802.2LLC, Linus
NFS code for some NFS mount options (although not the -ac NFS code)

Alan