This Oops appears on 2.5.74+ kernels (including 2.6.0-test4) when
I'm trying to read /proc/net/igmp with 'less', 'cat' displays
the file content without oops:
LILO boot: linux init=/bin/bash
...
[snip]
...
bash# mount /proc
bash# cat /proc/net/igmp
Idx Device : Count Querier Group Users Timer Reporter
bash# less /proc/net/igmp
Idx Device : Count Querier Group Users Timer Reporter
bash# ifup -a
bash# cat /proc/net/igmp
Idx Device : Count Querier Group Users Timer Reporter
1 lo : 0 V2
010000E0 1 0:FFFA22F0 0
bash# less /proc/net/igmp
Unable to handle kernel paging request at virtual address 08051be0
printing eip:
08051be0
*pde = 0fb66067
*pfe = 00000000
Oops: 0004 [#1]
CPU: 0
EIP: 0073:[<08051be0>] Not tainted
EFLAGS: 00010246
EIP is at 0x8051be0
eax: 0805fb68 ebx: 00000001 ecx: 00000000 edx: 00000019
esi: 08060649 edi: 08057543 ebp: bffffd8c esp: bfffda50
ds: 007b es: 007b ss: 007b
Process less (pid 20, threadinfo = cfab6000 task = c13560cd)
<0>Kernel panic: Fatal exception in interrupt
In interrupt handler - not syncing
EIP points to the begin of the function clr_linenum() in
less-374/linenum.c:78 (instruction 'push %ebp').
Kernel is compiled by gcc-2.95.4 (20011002) from Debian woody.
Less is from woody and also from the original sources.
--
Marcel Sebek
jabber: [email protected] ICQ: 279852819
linux user number: 307850 GPG ID: 5F88735E
GPG FP: 0F01 BAB8 3148 94DB B95D 1FCA 8B63 CA06 5F88 735E
Hi Marcel,
I don't have the kernel, I didn't try it also, but I have faced
a similar problem sometimes back so I feel that it might be the same
problem. I have posted a similar question sometimes back on this list.
If you do an strace of both 'cat' and 'less' you will see that 'cat' does
not maintain the offset into the file in the application. It just believes
that subsequent reads will give data after the point it has read, 'less'(
as well as brother 'more')
on the other hand does an lseek(fd, last_read_return_value, SEEK_SET)
after every read, then it issues a read call.
Now if you see proc_file_read() in the kernel source, you will see that to
support proc files which are more than PAGE_SIZE long, they have a hack
that it allows the caller to interpret the offset not as byte offsets but
as anything, mostly number of records read ..
I feel ur /proc/net/igmp file is more than a PAGE_SIZE long, because that
is when this problem is more likely to happen, but it can happen otherwise
also if things are not handled properly.
The problem is probably in the proc_read function of /proc/net/igmp
Thanx
tomar
On Mon, 25 Aug 2003, Marcel Sebek wrote:
> This Oops appears on 2.5.74+ kernels (including 2.6.0-test4) when
> I'm trying to read /proc/net/igmp with 'less', 'cat' displays
> the file content without oops:
>
> LILO boot: linux init=/bin/bash
> ...
> [snip]
> ...
> bash# mount /proc
> bash# cat /proc/net/igmp
> Idx Device : Count Querier Group Users Timer Reporter
> bash# less /proc/net/igmp
> Idx Device : Count Querier Group Users Timer Reporter
> bash# ifup -a
> bash# cat /proc/net/igmp
> Idx Device : Count Querier Group Users Timer Reporter
> 1 lo : 0 V2
> 010000E0 1 0:FFFA22F0
> 0
> bash# less /proc/net/igmp
> Unable to handle kernel paging request at virtual address 08051be0
> printing eip:
> 08051be0
> *pde = 0fb66067
> *pfe = 00000000
> Oops: 0004 [#1]
> CPU: 0
> EIP: 0073:[<08051be0>] Not tainted
> EFLAGS: 00010246
> EIP is at 0x8051be0
> eax: 0805fb68 ebx: 00000001 ecx: 00000000 edx: 00000019
> esi: 08060649 edi: 08057543 ebp: bffffd8c esp: bfffda50
> ds: 007b es: 007b ss: 007b
> Process less (pid 20, threadinfo = cfab6000 task = c13560cd)
> <0>Kernel panic: Fatal exception in interrupt
> In interrupt handler - not syncing
>
>
> EIP points to the begin of the function clr_linenum() in
> less-374/linenum.c:78 (instruction 'push %ebp').
>
> Kernel is compiled by gcc-2.95.4 (20011002) from Debian woody.
> Less is from woody and also from the original sources.
>
>
>
Hello.
In article <[email protected]> (at Mon, 25 Aug 2003 18:32:06 +0200), Marcel Sebek <[email protected]> says:
> This Oops appears on 2.5.74+ kernels (including 2.6.0-test4) when
> I'm trying to read /proc/net/igmp with 'less', 'cat' displays
> the file content without oops:
:
> [snip]
> ...
> bash# mount /proc
> bash# cat /proc/net/igmp
> Idx Device : Count Querier Group Users Timer Reporter
> bash# less /proc/net/igmp
> Idx Device : Count Querier Group Users Timer Reporter
> bash# ifup -a
> bash# cat /proc/net/igmp
> Idx Device : Count Querier Group Users Timer Reporter
> 1 lo : 0 V2
> 010000E0 1 0:FFFA22F0 0
> bash# less /proc/net/igmp
> Unable to handle kernel paging request at virtual address 08051be0
> printing eip:
> 08051be0
> *pde = 0fb66067
> *pfe = 00000000
> Oops: 0004 [#1]
> CPU: 0
> EIP: 0073:[<08051be0>] Not tainted
> EFLAGS: 00010246
> EIP is at 0x8051be0
> eax: 0805fb68 ebx: 00000001 ecx: 00000000 edx: 00000019
> esi: 08060649 edi: 08057543 ebp: bffffd8c esp: bfffda50
> ds: 007b es: 007b ss: 007b
> Process less (pid 20, threadinfo = cfab6000 task = c13560cd)
> <0>Kernel panic: Fatal exception in interrupt
> In interrupt handler - not syncing
I could not reproduce this issue. anyone?
--
Hideaki YOSHIFUJI @ USAGI Project <[email protected]>
GPG FP: 9022 65EB 1ECF 3AD1 0BDF 80D8 4807 F894 E062 0EEA
On Tue, 2003-08-26 at 01:03, YOSHIFUJI Hideaki / 吉藤英明 wrote:
> Hello.
>
> In article <[email protected]> (at Mon, 25 Aug 2003 18:32:06 +0200), Marcel Sebek <[email protected]> says:
>
> > This Oops appears on 2.5.74+ kernels (including 2.6.0-test4) when
> > I'm trying to read /proc/net/igmp with 'less', 'cat' displays
> > the file content without oops:
> :
> > [snip]
> > ...
> > bash# mount /proc
> > bash# cat /proc/net/igmp
> > Idx Device : Count Querier Group Users Timer Reporter
> > bash# less /proc/net/igmp
> > Idx Device : Count Querier Group Users Timer Reporter
> > bash# ifup -a
> > bash# cat /proc/net/igmp
> > Idx Device : Count Querier Group Users Timer Reporter
> > 1 lo : 0 V2
> > 010000E0 1 0:FFFA22F0 0
> > bash# less /proc/net/igmp
> > Unable to handle kernel paging request at virtual address 08051be0
> > printing eip:
> > 08051be0
> > *pde = 0fb66067
> > *pfe = 00000000
> > Oops: 0004 [#1]
> > CPU: 0
> > EIP: 0073:[<08051be0>] Not tainted
> > EFLAGS: 00010246
> > EIP is at 0x8051be0
> > eax: 0805fb68 ebx: 00000001 ecx: 00000000 edx: 00000019
> > esi: 08060649 edi: 08057543 ebp: bffffd8c esp: bfffda50
> > ds: 007b es: 007b ss: 007b
> > Process less (pid 20, threadinfo = cfab6000 task = c13560cd)
> > <0>Kernel panic: Fatal exception in interrupt
> > In interrupt handler - not syncing
>
> I could not reproduce this issue. anyone?
I can confirm. I have it with 2.6.0-test4.
Let me know what useful info I can provide. The oops is the same.
--
Owen Ford <[email protected]>
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
I can verify this on 2.6.0-test4-mm1 and 2.6.0-test3-mm4
- --
Christan Axelsson
[email protected]
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Version: GnuPG v1.2.2 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org
iD8DBQE/SwEbyqbmAWw8VdkRAg6SAJ98RVCbWmsVTH/vtg0McK7vSshn4QCffiI9
q7B10AWRBqYC64JD0UHG6LQ=
=lpLs
-----END PGP SIGNATURE-----
On Tue, 2003-08-26 at 01:41, Christian Axelsson wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> I can verify this on 2.6.0-test4-mm1 and 2.6.0-test3-mm4
>
> - --
> Christan Axelsson
> [email protected]
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.2.2 (GNU/Linux)
> Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org
>
> iD8DBQE/SwEbyqbmAWw8VdkRAg6SAJ98RVCbWmsVTH/vtg0McK7vSshn4QCffiI9
> q7B10AWRBqYC64JD0UHG6LQ=
> =lpLs
> -----END PGP SIGNATURE-----
>
>
> -
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It goes back even farther. I have it with all of the 2.6 series.
--
Owen Ford <[email protected]>
Please CC: netdev.
In article <[email protected]> (at 26 Aug 2003 01:23:06 -0500), Owen Ford <[email protected]> says:
> > I could not reproduce this issue. anyone?
>
> I can confirm. I have it with 2.6.0-test4.
>
> Let me know what useful info I can provide. The oops is the same.
Okay, everyone. I'll try to fix this.
--
Hideaki YOSHIFUJI @ USAGI Project <[email protected]>
GPG FP: 9022 65EB 1ECF 3AD1 0BDF 80D8 4807 F894 E062 0EEA
On Tue, 26 Aug 2003, YOSHIFUJI Hideaki / [iso-2022-jp] $B5HF#1QL@(B wrote:
> I could not reproduce this issue. anyone?
'less /proc/net/igmp' does it for me.
- James
--
James Morris
<[email protected]>
Hello.
In article <[email protected]> (at Tue, 26 Aug 2003 17:32:26 +0900 (JST)), YOSHIFUJI Hideaki / $B5HF#1QL@(B <[email protected]> says:
> > I can confirm. I have it with 2.6.0-test4.
> >
> > Let me know what useful info I can provide. The oops is the same.
>
> Okay, everyone. I'll try to fix this.
Please try this patch.
Index: linux-2.6/net/ipv4/igmp.c
===================================================================
RCS file: /home/cvs/linux-2.5/net/ipv4/igmp.c,v
retrieving revision 1.33
diff -u -r1.33 igmp.c
--- linux-2.6/net/ipv4/igmp.c 21 Aug 2003 17:47:23 -0000 1.33
+++ linux-2.6/net/ipv4/igmp.c 26 Aug 2003 15:18:03 -0000
@@ -2122,6 +2122,7 @@
break;
}
read_unlock(&in_dev->lock);
+ in_dev_put(in_dev);
}
return im;
}
@@ -2181,7 +2182,9 @@
if (likely(state->in_dev != NULL)) {
read_unlock(&state->in_dev->lock);
in_dev_put(state->in_dev);
+ state->in_dev = NULL;
}
+ state->dev = NULL;
read_unlock(&dev_base_lock);
}
@@ -2284,6 +2287,7 @@
spin_unlock_bh(&im->lock);
}
read_unlock_bh(&idev->lock);
+ in_dev_put(idev);
}
return psf;
}
@@ -2350,12 +2354,16 @@
static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
{
struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
- if (likely(state->im != NULL))
+ if (likely(state->im != NULL)) {
spin_unlock_bh(&state->im->lock);
+ state->im = NULL;
+ }
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
in_dev_put(state->idev);
+ state->idev = NULL;
}
+ state->dev = NULL;
read_unlock(&dev_base_lock);
}
Index: linux-2.6/net/ipv6/mcast.c
===================================================================
RCS file: /home/cvs/linux-2.5/net/ipv6/mcast.c,v
retrieving revision 1.30
diff -u -r1.30 mcast.c
--- linux-2.6/net/ipv6/mcast.c 21 Aug 2003 23:44:54 -0000 1.30
+++ linux-2.6/net/ipv6/mcast.c 26 Aug 2003 15:18:03 -0000
@@ -2078,6 +2078,7 @@
break;
}
read_unlock_bh(&idev->lock);
+ in6_dev_put(idev);
}
return im;
}
@@ -2135,7 +2136,9 @@
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
in6_dev_put(state->idev);
+ state->idev = NULL;
}
+ state->dev = NULL;
read_unlock(&dev_base_lock);
}
@@ -2225,6 +2228,7 @@
spin_unlock_bh(&im->mca_lock);
}
read_unlock_bh(&idev->lock);
+ in6_dev_put(idev);
}
return psf;
}
@@ -2291,12 +2295,16 @@
static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
{
struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
- if (likely(state->im != NULL))
+ if (likely(state->im != NULL)) {
spin_unlock_bh(&state->im->mca_lock);
+ state->im = NULL;
+ }
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
in6_dev_put(state->idev);
+ state->idev = NULL;
}
+ state->dev = NULL;
read_unlock(&dev_base_lock);
}
--
Hideaki YOSHIFUJI @ USAGI Project <[email protected]>
GPG FP: 9022 65EB 1ECF 3AD1 0BDF 80D8 4807 F894 E062 0EEA
On Tue, 2003-08-26 at 11:54, YOSHIFUJI Hideaki / 吉藤英明 wrote:
> Hello.
>
> In article <[email protected]> (at Tue, 26 Aug 2003 17:32:26 +0900 (JST)), YOSHIFUJI Hideaki / 吉藤英明 <[email protected]> says:
>
> > > I can confirm. I have it with 2.6.0-test4.
> > >
> > > Let me know what useful info I can provide. The oops is the same.
> >
> > Okay, everyone. I'll try to fix this.
>
> Please try this patch.
That seems to have done the job nicely. Thanks.
--
Owen Ford <[email protected]>
On Tuesday 26 Aug 2003 17:54, YOSHIFUJI Hideaki / $B5HF#1QL@(B wrote:
> Hello.
>
> > Okay, everyone. I'll try to fix this.
>
> Please try this patch.
Works fine for me now, against an almost-vanilla 2.6.0-test4.
Thanks,
Matt
--
"It's the small gaps between the rain that count,
and learning how to live amongst them."
-- Jeff Noon