by Sam Ravnborg

[permalink] [raw]

Subject: Re: 2.6.16-rc1-mm5

On Fri, Feb 03, 2006 at 12:07:04AM -0800, Andrew Morton wrote:
>
> Known problems:
>
> - Sam has added a new check in the kbuild tree. It detects multiple
> instances of EXPORT_SYMBOL(foo) across separate .o files.
>
> It catches a _lot_ of problems. You'll see something like this:

Sigh. I did a 'make allmodconfig' on x86_64 and found to my suprise only
a sinlge symbol being exported more than one time.

This is purely a consistency check introduced by commit:
http://www.kernel.org/git/?p=linux/kernel/git/sam/kbuild.git;a=commit;h=cd1f125e5808203d3bf58f1d04a9cbd33f60fdb6

I can rip it out again if the noise/value ratio is too high.

> Patches would be nice, but be warned that fixing these is not as trivial
> as one might think:
>
> - If one export is in generic code and the other is in arch code then
>
> - If you remove the export in generic code, you need to check all
> architectures for breakage.
We should IMO try to keep the exports in generic code.
The exports should go with the function definition - right after closing
'{'.
All other ways of exporting function is a call for inconsistency.
A gret deal of effort has been put into getting rid of ksym files
- good. But exports should not be scattered far away form the function
definition.

> - If you remove the export in arch code then you need to be sure
> that the generic .o file a) always compiles in the offending function
> and b) is always linked into vmlinux.
Placing the export just below the function definition should cover this
in 90% of the cases. The rest is macros..

>
> If possible, the best approach is to put the EXPORT_SYMBOL
> immediately after the symbol which is being exported. And if it's
> a function, pleeeze don't put a blank line between the end of the
> function and the export - I've no idea why people do that...
Agreed.

Sam

2006-02-04 09:31:27

On 3/02/2006 9:07 p.m., Andrew Morton wrote:
> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.16-rc1/2.6.16-rc1-mm5/
>
>
> - The ntp/time rework patches from John Stultz have been resurrected and fixed.
>
> - There's now a `hot-fixes' directory at the above URL. Please look in
> there for any updates which should be applied.
>
>
> Known problems:

[Andrew just released another -mm while I was typing this one up]

I've been hunting down some hard-to-catch reboots in the last two -mm releases
that leave no traces in the log other than an abrupt halt of all logging, at
first I thought I was chasing a Netfilter problem but after a few days of full
Netfilter debugging on, I came to the conclusion that the problem wasn't
necessarily Netfilter specific as I was still seeing reboots with no Netfilter
errors logged immediately before the crash. With most of the debugging options
turned on in "Kernel Hacking" and the machine running like a dog for a few days,
it seemed stable (unfortunately).

Anyway, I might have finally hit the jackpot this time, as it only ever seemed
to crash when I was at work. But I'm here, and it just did it...

Fedora Core release 4 (Rawhide)
Kernel 2.6.16-rc1-mm5 on an i686

tornado.reub.net login: BUG: unable to handle kernel paging request at virtual
address b0446000
printing eip:
b013fe7a
*pde = 018e9163
*pte = 00446000
Oops: 0002 [#1]
SMP
last sysfs file: /devices/pci0000:00/0000:00:1f.3/i2c-0/0-002e/vrm
Modules linked in: nfsd exportfs lockd sunrpc lm85 hwmon_vid eeprom ipv6 ip_gre
iptable_filter iptable_nat ip_nat ip_conntrack nfnetlink iptable_mangle
ip_tables binfmt_misc ide_cd cdrom serio_raw piix hw_random i2c_i801
CPU: 1
EIP: 0060:[<b013fe7a>] Not tainted VLI
EFLAGS: 00010282 (2.6.16-rc1-mm5 #1)
EIP is at get_page_from_freelist+0x325/0x386
eax: 00000000 ebx: b10088c0 ecx: 00000400 edx: b03c2780
esi: 00000000 edi: b0446000 ebp: b2bddeb8 esp: b2bdde5c
ds: 007b es: 007b ss: 0068
Process check_ifopersta (pid: 21337, threadinfo=b2bdd000 task=b4974ab0)
Stack: <0>00000002 00000044 b0446000 b03c2900 00000001 00000001 00000000 b03c2780
00000000 00000002 00000000 000280d2 b03c35ac b10088c0 00000000 b2bddfa0
00000282 00000001 00000000 00000001 b03c35a8 b4974ab0 000280d2 b2bddef8
Call Trace:
[<b0103bf5>] show_stack_log_lvl+0xc5/0xea
[<b0103db8>] show_registers+0x19e/0x22b
[<b0103f61>] die+0x11c/0x22c
[<b01137c4>] do_page_fault+0x27a/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b013ff30>] __alloc_pages+0x55/0x2bf
[<b0147a53>] __handle_mm_fault+0x6e5/0x7fb
[<b0113917>] do_page_fault+0x3cd/0x5de
[<b0103737>] error_code+0x4f/0x54
Code: db 0f 8e 2e ff ff ff 8b 5d d8 c7 45 dc 00 00 00 00 31 f6 ba 03 00 00 00 89
d8 e8 4f 46 fd ff 89 45 <1>BUG: unable to handle kernel paging request at
virtual address b0444000
printing eip:
b013fe7a
*pde = 018e9163
*pte = 00444000
ac b9 00 04 00 00 89 c7 89 f0 <f3> ab ba 03 00 00 00 8b 45 ac e8 b2 46 fd ff 83
45 dc 01 83 c3
<0>Oops: 0002 [#2]
note: check_ifopersta[21337] exited with preempt_count 1
SMP
last sysfs file: /devices/pci0000:00/0000:00:1f.3/i2c-0/0-002e/vrm
Modules linked in: nfsd exportfs lockd sunrpc lm85 hwmon_vid eeprom ipv6 ip_gre
iptable_filter iptable_nat ip_nat ip_conntrack nfnetlink iptable_mangle
ip_tables binfmt_misc ide_cd cdrom serio_raw piix hw_random i2c_i801
CPU: 0
EIP: 0060:[<b013fe7a>] Not tainted VLI
EFLAGS: 00010282 (2.6.16-rc1-mm5 #1)
EIP is at get_page_from_freelist+0x325/0x386
eax: 00000000 ebx: b1008880 ecx: 00000400 edx: b03c2780
esi: 00000000 edi: b0444000 ebp: e2857eb8 esp: e2857e5c
ds: 007b es: 007b ss: 0068
Process python (pid: 2532, threadinfo=e2857000 task=de395570)
Stack: <0>00000002 00000044 b0444000 b03c2900 00000001 00000001 00000000 b03c2780
00000000 00000002 00000000 000280d2 b03c35ac b1008880 00000000 b016629f
00000286 00000001 00000000 00000001 b03c35a8 de395570 000280d2 e2857ef8
Call Trace:
[<b0103bf5>] show_stack_log_lvl+0xc5/0xea
[<b0103db8>] show_registers+0x19e/0x22b
[<b0103f61>] die+0x11c/0x22c
[<b01137c4>] do_page_fault+0x27a/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b013ff30>] __alloc_pages+0x55/0x2bf
[<b0147a53>] __handle_mm_fault+0x6e5/0x7fb
[<b0113917>] do_page_fault+0x3cd/0x5de
[<b0103737>] error_code+0x4f/0x54
Code: db 0f 8e 2e ff ff ff 8b 5d d8 c7 45 dc 00 00 00 00 31 f6 ba 03 00 00 00 89
d8 e8 4f 46 fd ff 89 45 ac b9 00 04 00 00 89 c7 89 f0 <f3> ab ba 03 00 00 00 8b
45 ac e8 b2 46 fd ff 83 45 dc 01 83 c3
<6>note: python[2532] exited with preempt_count 1
BUG: sleeping function called from invalid context at include/linux/rwsem.h:43
in_atomic():1, irqs_disabled():0
[<b010412b>] show_trace+0xd/0xf
[<b0104251>] dump_stack+0x17/0x19
[<b0114eb1>] __might_sleep+0xa0/0xa7
[<b011d386>] exit_mm+0x32/0x164
[<b011e9ba>] do_exit+0x108/0x845
[<b0104071>] do_trap+0x0/0x9e
[<b01137c4>] do_page_fault+0x27a/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b013ff30>] __alloc_pages+0x55/0x2bf
[<b0147a53>] __handle_mm_fault+0x6e5/0x7fb
[<b0113917>] do_page_fault+0x3cd/0x5de
[<b0103737>] error_code+0x4f/0x54
BUG: unable to handle kernel paging request at virtual address b0445000
BUG: unable to handle kernel paging request at virtual address b0412004
printing eip:
b016986e
*pde = 018e9163
*pte = 00412000
Oops: 0002 [#3]
SMP
last sysfs file: /devices/pci0000:00/0000:00:1f.3/i2c-0/0-002e/vrm
Modules linked in: nfsd exportfs lockd sunrpc lm85 hwmon_vid eeprom ipv6 ip_gre
iptable_filter iptable_nat ip_nat ip_conntrack nfnetlink iptable_mangle
ip_tables binfmt_misc ide_cd cdrom serio_raw piix hw_random i2c_i801
CPU: 0
EIP: 0060:[<b016986e>] Not tainted VLI
EFLAGS: 00010286 (2.6.16-rc1-mm5 #1)
EIP is at __pollwait+0x9f/0xd2
eax: b0412008 ebx: 00000014 ecx: 00000000 edx: b0412000
esi: 00000000 edi: e9b5ec50 ebp: e9b5ebf8 esp: e9b5ebe4
ds: 007b es: 007b ss: 0068
Process dovecot (pid: 2235, threadinfo=e9b5e000 task=efc3e570)
Stack: <0>c290b000 d25b82c0 c290b000 e9b5ec50 d25b82c0 e9b5ec14 b0162a80 cf8b4254
00000000 00000020 d25b82c0 00000014 e9b5efa0 b0168a80 e9b5ec50 e9b5efa8
08073ed0 000000d0 08073fa0 e9b5ee90 e9b5ee90 0000001a e9b5ec50 00000000
Call Trace:
[<b0103bf5>] show_stack_log_lvl+0xc5/0xea
[<b0103db8>] show_registers+0x19e/0x22b
[<b0103f61>] die+0x11c/0x22c
[<b01137c4>] do_page_fault+0x27a/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b0162a80>] pipe_poll+0x2c/0xae
[<b0168a80>] do_sys_poll+0x25f/0x47d
[<b0168cda>] sys_poll+0x3c/0x4e
[<b0102b3f>] sysenter_past_esp+0x54/0x75
Code: 5d c3 85 f6 74 10 8b 56 04 83 c2 1c 8d 86 00 10 00 00 39 c2 76 1f 31 d2 b8
d0 00 00 00 e8 35 69 fd ff 89 c2 85 c0 74 18 8d 40 08 <89> 42 04 89 32 89 57 04
89 d6 8b 4e 04 8d 41 1c 89 46 04 eb 82
<1> printing eip:
b013fe7a
*pde = 018e9163
*pte = 00445000
Oops: 0002 [#4]
SMP
last sysfs file: /devices/pci0000:00/0000:00:1f.3/i2c-0/0-002e/vrm
Modules linked in: nfsd exportfs lockd sunrpc lm85 hwmon_vid eeprom ipv6 ip_gre
iptable_filter iptable_nat ip_nat ip_conntrack nfnetlink iptable_mangle
ip_tables binfmt_misc ide_cd cdrom serio_raw piix hw_random i2c_i801
CPU: 1
EIP: 0060:[<b013fe7a>] Not tainted VLI
EFLAGS: 00010282 (2.6.16-rc1-mm5 #1)
EIP is at get_page_from_freelist+0x325/0x386
eax: 00000000 ebx: b10088a0 ecx: 00000400 edx: b03c2780
esi: 00000000 edi: b0445000 ebp: b3253cb0 esp: b3253c54
ds: 007b es: 007b ss: 0068
Process gdb (pid: 21399, threadinfo=b3253000 task=bedc8570)
Stack: <0>00000002 00000044 b0445000 b03c2900 00000001 00000001 00000000 b03c2780
00000000 00000002 00000000 000280d2 b03c35ac b10088a0 00000000 00000000
00000282 00000001 00000000 00000001 b03c35a8 bedc8570 000280d2 b3253cf0
Call Trace:
[<b0103bf5>] show_stack_log_lvl+0xc5/0xea
[<b0103db8>] show_registers+0x19e/0x22b
[<b0103f61>] die+0x11c/0x22c
[<b01137c4>] do_page_fault+0x27a/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b013ff30>] __alloc_pages+0x55/0x2bf
[<b0147a53>] __handle_mm_fault+0x6e5/0x7fb
[<b0113917>] do_page_fault+0x3cd/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b013b9b9>] do_generic_mapping_read+0x2a4/0x4bf
[<b013c33b>] __generic_file_aio_read+0xe3/0x230
[<b013d808>] generic_file_read+0x8e/0xae
[<b0157dc1>] vfs_read+0x89/0x144
[<b015828b>] sys_read+0x3d/0x64
[<b0102b3f>] sysenter_past_esp+0x54/0x75
Code: db 0f 8e 2e ff ff ff 8b 5d d8 c7 45 dc 00 00 00 00 31 f6 ba 03 00 00 00 89
d8 e8 4f 46 fd ff 89 45 ac b9 00 04 00 00 89 c7 89 f0 <f3> ab ba 03 00 00 00 8b
45 ac e8 b2 46 fd ff 83 45 dc 01 83 c3
<6>note: gdb[21399] exited with preempt_count 1
BUG: sleeping function called from invalid context at include/linux/rwsem.h:43
in_atomic():1, irqs_disabled():0
[<b010412b>] show_trace+0xd/0xf
[<b0104251>] dump_stack+0x17/0x19
[<b0114eb1>] __might_sleep+0xa0/0xa7
[<b011d386>] exit_mm+0x32/0x164
[<b011e9ba>] do_exit+0x108/0x845
[<b0104071>] do_trap+0x0/0x9e
[<b01137c4>] do_page_fault+0x27a/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b013ff30>] __alloc_pages+0x55/0x2bf
[<b0147a53>] __handle_mm_fault+0x6e5/0x7fb
[<b0113917>] do_page_fault+0x3cd/0x5de
[<b0103737>] error_code+0x4f/0x54
[<b013b9b9>] do_generic_mapping_read+0x2a4/0x4bf
[<b013c33b>] __generic_file_aio_read+0xe3/0x230
[<b013d808>] generic_file_read+0x8e/0xae
[<b0157dc1>] vfs_read+0x89/0x144
[<b015828b>] sys_read+0x3d/0x64
[<b0102b3f>] sysenter_past_esp+0x54/0x75

The only patch applied to this release was this one in a thread started by
Ulrich Drepper:

--- devel/fs/namei.c~nameic-unlock-missing-in-error-case 2006-02-04 15:57
:22.000000000 -0800
+++ devel-akpm/fs/namei.c 2006-02-04 16:07:56.000000000 -0800

I'll build an rc2-mm1 now and see how we go, but I guess it'd still be good to
know if this one was ever fixed or not.

reuben