Booting without SYSFS fills dmesg like this
------------[ cut here ]------------
WARNING: at lib/kref.c:43 kref_get+0x20/0x30()
Modules linked in: loop(+)
Pid: 994, comm: modprobe Tainted: G M 2.6.25-rc1 #6
Call Trace:
[<ffffffff802317f4>] warn_on_slowpath+0x64/0x90
[<ffffffff8028db08>] init_object+0x88/0xa0
[<ffffffff8028f55e>] __slab_alloc+0xbe/0x550
[<ffffffff8031aa28>] kvasprintf+0x58/0x90
[<ffffffff8031874c>] vsnprintf+0x33c/0x6e0
[<ffffffff8031aa41>] kvasprintf+0x71/0x90
[<ffffffff8022c597>] hrtick_set+0x77/0x140
[<ffffffff80314860>] kref_get+0x20/0x30
[<ffffffff80313932>] kobject_get+0x12/0x20
[<ffffffff803139f9>] kobject_add_internal+0x49/0xf0
[<ffffffff80313bb3>] kobject_add_varg+0x73/0x80
[<ffffffff80313fa4>] kobject_add+0x54/0x80
[<ffffffff8028ec53>] check_object+0x103/0x230
[<ffffffff8028db08>] init_object+0x88/0xa0
[<ffffffff80313744>] kobject_create+0x14/0x40
[<ffffffff8028fbd3>] kmem_cache_alloc+0xd3/0xe0
[<ffffffff803136b4>] kobject_init+0x34/0xb0
[<ffffffff8031375b>] kobject_create+0x2b/0x40
[<ffffffff8031400c>] kobject_create_and_add+0x3c/0x80
[<ffffffff8025e137>] load_module+0x1847/0x1970
[<ffffffff80288800>] alloc_pages_current+0x0/0x90
[<ffffffff8025e2c2>] sys_init_module+0x62/0x1a0
On Fri, 15 Feb 2008 14:08:53 +0300 Alexey Dobriyan <[email protected]> wrote:
> Booting without SYSFS fills dmesg like this
Does the system normally boot without sysfs? Surprised.
> ------------[ cut here ]------------
> WARNING: at lib/kref.c:43 kref_get+0x20/0x30()
> Modules linked in: loop(+)
> Pid: 994, comm: modprobe Tainted: G M 2.6.25-rc1 #6
>
> Call Trace:
> [<ffffffff802317f4>] warn_on_slowpath+0x64/0x90
> [<ffffffff8028db08>] init_object+0x88/0xa0
> [<ffffffff8028f55e>] __slab_alloc+0xbe/0x550
> [<ffffffff8031aa28>] kvasprintf+0x58/0x90
> [<ffffffff8031874c>] vsnprintf+0x33c/0x6e0
> [<ffffffff8031aa41>] kvasprintf+0x71/0x90
> [<ffffffff8022c597>] hrtick_set+0x77/0x140
> [<ffffffff80314860>] kref_get+0x20/0x30
> [<ffffffff80313932>] kobject_get+0x12/0x20
> [<ffffffff803139f9>] kobject_add_internal+0x49/0xf0
> [<ffffffff80313bb3>] kobject_add_varg+0x73/0x80
> [<ffffffff80313fa4>] kobject_add+0x54/0x80
> [<ffffffff8028ec53>] check_object+0x103/0x230
> [<ffffffff8028db08>] init_object+0x88/0xa0
> [<ffffffff80313744>] kobject_create+0x14/0x40
> [<ffffffff8028fbd3>] kmem_cache_alloc+0xd3/0xe0
> [<ffffffff803136b4>] kobject_init+0x34/0xb0
> [<ffffffff8031375b>] kobject_create+0x2b/0x40
> [<ffffffff8031400c>] kobject_create_and_add+0x3c/0x80
> [<ffffffff8025e137>] load_module+0x1847/0x1970
> [<ffffffff80288800>] alloc_pages_current+0x0/0x90
> [<ffffffff8025e2c2>] sys_init_module+0x62/0x1a0
>
Is this a regression?
On Feb 18, 2008 1:59 PM, Andrew Morton <[email protected]> wrote:
> On Fri, 15 Feb 2008 14:08:53 +0300 Alexey Dobriyan <[email protected]> wrote:
>
> > Booting without SYSFS fills dmesg like this
>
> Does the system normally boot without sysfs? Surprised.
>
>
> > ------------[ cut here ]------------
> > WARNING: at lib/kref.c:43 kref_get+0x20/0x30()
> > Modules linked in: loop(+)
> > Pid: 994, comm: modprobe Tainted: G M 2.6.25-rc1 #6
> >
> > Call Trace:
> > [<ffffffff802317f4>] warn_on_slowpath+0x64/0x90
> > [<ffffffff8028db08>] init_object+0x88/0xa0
> > [<ffffffff8028f55e>] __slab_alloc+0xbe/0x550
> > [<ffffffff8031aa28>] kvasprintf+0x58/0x90
> > [<ffffffff8031874c>] vsnprintf+0x33c/0x6e0
> > [<ffffffff8031aa41>] kvasprintf+0x71/0x90
> > [<ffffffff8022c597>] hrtick_set+0x77/0x140
> > [<ffffffff80314860>] kref_get+0x20/0x30
> > [<ffffffff80313932>] kobject_get+0x12/0x20
> > [<ffffffff803139f9>] kobject_add_internal+0x49/0xf0
> > [<ffffffff80313bb3>] kobject_add_varg+0x73/0x80
> > [<ffffffff80313fa4>] kobject_add+0x54/0x80
> > [<ffffffff8028ec53>] check_object+0x103/0x230
> > [<ffffffff8028db08>] init_object+0x88/0xa0
> > [<ffffffff80313744>] kobject_create+0x14/0x40
> > [<ffffffff8028fbd3>] kmem_cache_alloc+0xd3/0xe0
> > [<ffffffff803136b4>] kobject_init+0x34/0xb0
> > [<ffffffff8031375b>] kobject_create+0x2b/0x40
> > [<ffffffff8031400c>] kobject_create_and_add+0x3c/0x80
> > [<ffffffff8025e137>] load_module+0x1847/0x1970
> > [<ffffffff80288800>] alloc_pages_current+0x0/0x90
> > [<ffffffff8025e2c2>] sys_init_module+0x62/0x1a0
> >
>
> Is this a regression?
Alexey,
do you always see these messages with every modprobe of a module?
Can you enable CONFIG_DEBUG_KOBJECT=y? It might give a hint where we
miss to initialization of a kobject when sysfs is not compiled in.
Thanks,
Kay
On Tue, Feb 19, 2008 at 09:19:25AM +0100, Kay Sievers wrote:
> On Feb 18, 2008 1:59 PM, Andrew Morton <[email protected]> wrote:
> > On Fri, 15 Feb 2008 14:08:53 +0300 Alexey Dobriyan <[email protected]> wrote:
> >
> > > Booting without SYSFS fills dmesg like this
> >
> > Does the system normally boot without sysfs? Surprised.
> >
> >
> > > ------------[ cut here ]------------
> > > WARNING: at lib/kref.c:43 kref_get+0x20/0x30()
> > > Modules linked in: loop(+)
> > > Pid: 994, comm: modprobe Tainted: G M 2.6.25-rc1 #6
> > >
> > > Call Trace:
> > > [<ffffffff802317f4>] warn_on_slowpath+0x64/0x90
> > > [<ffffffff8028db08>] init_object+0x88/0xa0
> > > [<ffffffff8028f55e>] __slab_alloc+0xbe/0x550
> > > [<ffffffff8031aa28>] kvasprintf+0x58/0x90
> > > [<ffffffff8031874c>] vsnprintf+0x33c/0x6e0
> > > [<ffffffff8031aa41>] kvasprintf+0x71/0x90
> > > [<ffffffff8022c597>] hrtick_set+0x77/0x140
> > > [<ffffffff80314860>] kref_get+0x20/0x30
> > > [<ffffffff80313932>] kobject_get+0x12/0x20
> > > [<ffffffff803139f9>] kobject_add_internal+0x49/0xf0
> > > [<ffffffff80313bb3>] kobject_add_varg+0x73/0x80
> > > [<ffffffff80313fa4>] kobject_add+0x54/0x80
> > > [<ffffffff8028ec53>] check_object+0x103/0x230
> > > [<ffffffff8028db08>] init_object+0x88/0xa0
> > > [<ffffffff80313744>] kobject_create+0x14/0x40
> > > [<ffffffff8028fbd3>] kmem_cache_alloc+0xd3/0xe0
> > > [<ffffffff803136b4>] kobject_init+0x34/0xb0
> > > [<ffffffff8031375b>] kobject_create+0x2b/0x40
> > > [<ffffffff8031400c>] kobject_create_and_add+0x3c/0x80
> > > [<ffffffff8025e137>] load_module+0x1847/0x1970
> > > [<ffffffff80288800>] alloc_pages_current+0x0/0x90
> > > [<ffffffff8025e2c2>] sys_init_module+0x62/0x1a0
> > >
> >
> > Is this a regression?
>
> Alexey,
> do you always see these messages with every modprobe of a module?
Yep.
> Can you enable CONFIG_DEBUG_KOBJECT=y? It might give a hint where we
> miss to initialization of a kobject when sysfs is not compiled in.
It looks like this:
kobject: 'button' (ffff81017f307248): kobject_uevent_env
kobject: 'button' (ffff81017f307248): fill_kobj_path: path = '/bus/acpi/drivers/button'
------------[ cut here ]------------
WARNING: at lib/kref.c:43 kref_get+0x2d/0x30()
Modules linked in: battery(+) button dock thermal processor sbs ac sbshc af_packet loop
Pid: 1642, comm: modprobe Not tainted 2.6.25-rc2 #2
Call Trace:
[<ffffffff8022a8cf>] warn_on_slowpath+0x5f/0x80
[<ffffffff8024cb06>] ? mark_held_locks+0x56/0xa0
[<ffffffff80282c00>] ? __slab_alloc+0xc0/0x4b0
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f7f87>] ? kvasprintf+0x57/0x90
[<ffffffff802f5c18>] ? vsnprintf+0x328/0x6e0
[<ffffffff802f7fa0>] ? kvasprintf+0x70/0x90
[<ffffffff802f1ced>] kref_get+0x2d/0x30
[<ffffffff802f0c4a>] kobject_get+0x1a/0x30
[<ffffffff802f0d39>] kobject_add_internal+0x59/0x160
[<ffffffff802f0f6e>] kobject_add_varg+0x6e/0x80
[<ffffffff802f1399>] kobject_add+0x69/0x90
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f1c4e>] ? kref_init+0xe/0x10
[<ffffffff802f0927>] ? kobject_init+0x37/0xa0
[<ffffffff802f09c3>] ? kobject_create+0x33/0x40
[<ffffffff802f13fe>] kobject_create_and_add+0x3e/0x80
[<ffffffff80255adf>] sys_init_module+0x19df/0x1b30
[<ffffffff8024d928>] ? __lock_acquire+0x748/0x10b0
[<ffffffff803249a0>] ? acpi_bus_register_driver+0x0/0x40
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff80406122>] ? trace_hardirqs_on_thunk+0x35/0x3a
[<ffffffff8020b57b>] system_call_after_swapgs+0x7b/0x80
---[ end trace 033c2b23880cf02a ]---
kobject: 'notes' (ffff81017ec370a8): kobject_add_internal: parent: '<NULL>', set: '<NULL>'
kobject: 'battery' (ffff81017f382db0): kobject_add_internal: parent: 'drivers', set: 'drivers'
kobject: 'battery' (ffff81017f382db0): kobject_uevent_env
kobject: 'battery' (ffff81017f382db0): fill_kobj_path: path = '/bus/acpi/drivers/battery'
------------[ cut here ]------------
WARNING: at lib/kref.c:43 kref_get+0x2d/0x30()
Modules linked in: bay(+) battery button dock thermal processor sbs ac sbshc af_packet loop
Pid: 1650, comm: modprobe Not tainted 2.6.25-rc2 #2
Call Trace:
[<ffffffff8022a8cf>] warn_on_slowpath+0x5f/0x80
[<ffffffff8024cb06>] ? mark_held_locks+0x56/0xa0
[<ffffffff80282c00>] ? __slab_alloc+0xc0/0x4b0
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f7f87>] ? kvasprintf+0x57/0x90
[<ffffffff802f5c18>] ? vsnprintf+0x328/0x6e0
[<ffffffff802f7fa0>] ? kvasprintf+0x70/0x90
[<ffffffff802f1ced>] kref_get+0x2d/0x30
[<ffffffff802f0c4a>] kobject_get+0x1a/0x30
[<ffffffff802f0d39>] kobject_add_internal+0x59/0x160
[<ffffffff802f0f6e>] kobject_add_varg+0x6e/0x80
[<ffffffff802f1399>] kobject_add+0x69/0x90
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f1c4e>] ? kref_init+0xe/0x10
[<ffffffff802f0927>] ? kobject_init+0x37/0xa0
[<ffffffff802f09c3>] ? kobject_create+0x33/0x40
[<ffffffff802f13fe>] kobject_create_and_add+0x3e/0x80
[<ffffffff80255adf>] sys_init_module+0x19df/0x1b30
[<ffffffff8024d928>] ? __lock_acquire+0x748/0x10b0
[<ffffffff80353510>] ? device_remove_file+0x0/0x10
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff80406122>] ? trace_hardirqs_on_thunk+0x35/0x3a
[<ffffffff8020b57b>] system_call_after_swapgs+0x7b/0x80
---[ end trace 033c2b23880cf02a ]---
kobject: 'notes' (ffff81017ec371f8): kobject_add_internal: parent: '<NULL>', set: '<NULL>'
kobject: '<NULL>' (ffffffff88031350): kobject_cleanup
------------[ cut here ]------------
WARNING: at lib/kref.c:43 kref_get+0x2d/0x30()
Modules linked in: fan(+) battery button dock thermal processor sbs ac sbshc af_packet loop
Pid: 1659, comm: modprobe Not tainted 2.6.25-rc2 #2
Call Trace:
[<ffffffff8022a8cf>] warn_on_slowpath+0x5f/0x80
[<ffffffff8024cb06>] ? mark_held_locks+0x56/0xa0
[<ffffffff80282c00>] ? __slab_alloc+0xc0/0x4b0
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f7f87>] ? kvasprintf+0x57/0x90
[<ffffffff802f5c18>] ? vsnprintf+0x328/0x6e0
[<ffffffff802f7fa0>] ? kvasprintf+0x70/0x90
[<ffffffff802f1ced>] kref_get+0x2d/0x30
[<ffffffff802f0c4a>] kobject_get+0x1a/0x30
[<ffffffff802f0d39>] kobject_add_internal+0x59/0x160
[<ffffffff802f0f6e>] kobject_add_varg+0x6e/0x80
[<ffffffff802f1399>] kobject_add+0x69/0x90
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f1c4e>] ? kref_init+0xe/0x10
[<ffffffff802f0927>] ? kobject_init+0x37/0xa0
[<ffffffff802f09c3>] ? kobject_create+0x33/0x40
[<ffffffff802f13fe>] kobject_create_and_add+0x3e/0x80
[<ffffffff80255adf>] sys_init_module+0x19df/0x1b30
[<ffffffff8024d928>] ? __lock_acquire+0x748/0x10b0
[<ffffffff803249a0>] ? acpi_bus_register_driver+0x0/0x40
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff80406122>] ? trace_hardirqs_on_thunk+0x35/0x3a
[<ffffffff8020b57b>] system_call_after_swapgs+0x7b/0x80
---[ end trace 033c2b23880cf02a ]---
kobject: 'notes' (ffff81017ec372a0): kobject_add_internal: parent: '<NULL>', set: '<NULL>'
kobject: 'fan' (ffff81017f307db0): kobject_add_internal: parent: 'drivers', set: 'drivers'
kobject: 'fan' (ffff81017f307db0): kobject_uevent_env
kobject: 'fan' (ffff81017f307db0): fill_kobj_path: path = '/bus/acpi/drivers/fan'
------------[ cut here ]------------
WARNING: at lib/kref.c:43 kref_get+0x2d/0x30()
Modules linked in: container(+) fan battery button dock thermal processor sbs ac sbshc af_packet loop
Pid: 1667, comm: modprobe Not tainted 2.6.25-rc2 #2
Call Trace:
[<ffffffff8022a8cf>] warn_on_slowpath+0x5f/0x80
[<ffffffff8024cb06>] ? mark_held_locks+0x56/0xa0
[<ffffffff80282c00>] ? __slab_alloc+0xc0/0x4b0
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f7f87>] ? kvasprintf+0x57/0x90
[<ffffffff802f5c18>] ? vsnprintf+0x328/0x6e0
[<ffffffff802f7fa0>] ? kvasprintf+0x70/0x90
[<ffffffff802f1ced>] kref_get+0x2d/0x30
[<ffffffff802f0c4a>] kobject_get+0x1a/0x30
[<ffffffff802f0d39>] kobject_add_internal+0x59/0x160
[<ffffffff802f0f6e>] kobject_add_varg+0x6e/0x80
[<ffffffff802f1399>] kobject_add+0x69/0x90
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff802f1c4e>] ? kref_init+0xe/0x10
[<ffffffff802f0927>] ? kobject_init+0x37/0xa0
[<ffffffff802f09c3>] ? kobject_create+0x33/0x40
[<ffffffff802f13fe>] kobject_create_and_add+0x3e/0x80
[<ffffffff80255adf>] sys_init_module+0x19df/0x1b30
[<ffffffff8024d928>] ? __lock_acquire+0x748/0x10b0
[<ffffffff803249a0>] ? acpi_bus_register_driver+0x0/0x40
[<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
[<ffffffff80406122>] ? trace_hardirqs_on_thunk+0x35/0x3a
[<ffffffff8020b57b>] system_call_after_swapgs+0x7b/0x80
---[ end trace 033c2b23880cf02a ]---
kobject: 'notes' (ffff81017ec37498): kobject_add_internal: parent: '<NULL>', set: '<NULL>'
kobject: 'container' (ffff81017f307000): kobject_add_internal: parent: 'drivers', set: 'drivers'
kobject: 'container' (ffff81017f307000): kobject_uevent_env
kobject: 'container' (ffff81017f307000): fill_kobj_path: path = '/bus/acpi/drivers/container'
On Tue, 2008-02-19 at 15:03 +0300, Alexey Dobriyan wrote:
> On Tue, Feb 19, 2008 at 09:19:25AM +0100, Kay Sievers wrote:
> > On Feb 18, 2008 1:59 PM, Andrew Morton <[email protected]> wrote:
> > > On Fri, 15 Feb 2008 14:08:53 +0300 Alexey Dobriyan <[email protected]> wrote:
> > >
> > > > Booting without SYSFS fills dmesg like this
> > Can you enable CONFIG_DEBUG_KOBJECT=y? It might give a hint where we
> > miss to initialization of a kobject when sysfs is not compiled in.
>
> It looks like this:
> ------------[ cut here ]------------
> WARNING: at lib/kref.c:43 kref_get+0x2d/0x30()
> Modules linked in: battery(+) button dock thermal processor sbs ac sbshc af_packet loop
> Pid: 1642, comm: modprobe Not tainted 2.6.25-rc2 #2
>
> Call Trace:
> [<ffffffff8022a8cf>] warn_on_slowpath+0x5f/0x80
> [<ffffffff8024cb06>] ? mark_held_locks+0x56/0xa0
> [<ffffffff80282c00>] ? __slab_alloc+0xc0/0x4b0
> [<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
> [<ffffffff802f7f87>] ? kvasprintf+0x57/0x90
> [<ffffffff802f5c18>] ? vsnprintf+0x328/0x6e0
> [<ffffffff802f7fa0>] ? kvasprintf+0x70/0x90
> [<ffffffff802f1ced>] kref_get+0x2d/0x30
> [<ffffffff802f0c4a>] kobject_get+0x1a/0x30
> [<ffffffff802f0d39>] kobject_add_internal+0x59/0x160
> [<ffffffff802f0f6e>] kobject_add_varg+0x6e/0x80
> [<ffffffff802f1399>] kobject_add+0x69/0x90
> [<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
> [<ffffffff802f1c4e>] ? kref_init+0xe/0x10
> [<ffffffff802f0927>] ? kobject_init+0x37/0xa0
> [<ffffffff802f09c3>] ? kobject_create+0x33/0x40
> [<ffffffff802f13fe>] kobject_create_and_add+0x3e/0x80
> [<ffffffff80255adf>] sys_init_module+0x19df/0x1b30
> [<ffffffff8024d928>] ? __lock_acquire+0x748/0x10b0
> [<ffffffff803249a0>] ? acpi_bus_register_driver+0x0/0x40
> [<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
> [<ffffffff80406122>] ? trace_hardirqs_on_thunk+0x35/0x3a
> [<ffffffff8020b57b>] system_call_after_swapgs+0x7b/0x80
>
> ---[ end trace 033c2b23880cf02a ]---
> kobject: 'notes' (ffff81017ec370a8): kobject_add_internal: parent: '<NULL>', set: '<NULL>'
Ok, seems the "notes" directory should not be created if SYSFS is not
configured. The "notes" kobject tries to reference the module kobject as
a parent, which isn't initialized in that case.
Does that fix it?
Thanks,
Kay
From: Kay Sievers <[email protected]>
Subject: modules: do not try to add sysfs attributes if !CONFIG_SYSFS
Signed-off-by: Kay Sievers <[email protected]>
---
module.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index 92595ba..2dd60c8 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -987,6 +987,7 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
return ret;
}
+#ifdef CONFIG_SYSFS
/*
* /sys/module/foo/sections stuff
@@ -1169,7 +1170,7 @@ static void remove_notes_attrs(struct module *mod)
free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
}
-#else
+#else /* CONFIG_KALLSYMS */
static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
char *sectstrings, Elf_Shdr *sechdrs)
@@ -1190,7 +1191,6 @@ static inline void remove_notes_attrs(struct module *mod)
}
#endif /* CONFIG_KALLSYMS */
-#ifdef CONFIG_SYSFS
int module_add_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
@@ -1231,9 +1231,7 @@ void module_remove_modinfo_attrs(struct module *mod)
}
kfree(mod->modinfo_attrs);
}
-#endif
-#ifdef CONFIG_SYSFS
int mod_sysfs_init(struct module *mod)
{
int err;
@@ -1299,7 +1297,7 @@ out_unreg:
kobject_put(&mod->mkobj.kobj);
return err;
}
-#endif
+#endif /* CONFIG_SYSFS */
static void mod_kobject_remove(struct module *mod)
{
On Tue, Feb 19, 2008 at 02:10:02PM +0100, Kay Sievers wrote:
> On Tue, 2008-02-19 at 15:03 +0300, Alexey Dobriyan wrote:
> > On Tue, Feb 19, 2008 at 09:19:25AM +0100, Kay Sievers wrote:
> > > On Feb 18, 2008 1:59 PM, Andrew Morton <[email protected]> wrote:
> > > > On Fri, 15 Feb 2008 14:08:53 +0300 Alexey Dobriyan <[email protected]> wrote:
> > > >
> > > > > Booting without SYSFS fills dmesg like this
>
> > > Can you enable CONFIG_DEBUG_KOBJECT=y? It might give a hint where we
> > > miss to initialization of a kobject when sysfs is not compiled in.
> >
> > It looks like this:
>
> > ------------[ cut here ]------------
> > WARNING: at lib/kref.c:43 kref_get+0x2d/0x30()
> > Modules linked in: battery(+) button dock thermal processor sbs ac sbshc af_packet loop
> > Pid: 1642, comm: modprobe Not tainted 2.6.25-rc2 #2
> >
> > Call Trace:
> > [<ffffffff8022a8cf>] warn_on_slowpath+0x5f/0x80
> > [<ffffffff8024cb06>] ? mark_held_locks+0x56/0xa0
> > [<ffffffff80282c00>] ? __slab_alloc+0xc0/0x4b0
> > [<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
> > [<ffffffff802f7f87>] ? kvasprintf+0x57/0x90
> > [<ffffffff802f5c18>] ? vsnprintf+0x328/0x6e0
> > [<ffffffff802f7fa0>] ? kvasprintf+0x70/0x90
> > [<ffffffff802f1ced>] kref_get+0x2d/0x30
> > [<ffffffff802f0c4a>] kobject_get+0x1a/0x30
> > [<ffffffff802f0d39>] kobject_add_internal+0x59/0x160
> > [<ffffffff802f0f6e>] kobject_add_varg+0x6e/0x80
> > [<ffffffff802f1399>] kobject_add+0x69/0x90
> > [<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
> > [<ffffffff802f1c4e>] ? kref_init+0xe/0x10
> > [<ffffffff802f0927>] ? kobject_init+0x37/0xa0
> > [<ffffffff802f09c3>] ? kobject_create+0x33/0x40
> > [<ffffffff802f13fe>] kobject_create_and_add+0x3e/0x80
> > [<ffffffff80255adf>] sys_init_module+0x19df/0x1b30
> > [<ffffffff8024d928>] ? __lock_acquire+0x748/0x10b0
> > [<ffffffff803249a0>] ? acpi_bus_register_driver+0x0/0x40
> > [<ffffffff8024cc9f>] ? trace_hardirqs_on+0xbf/0x150
> > [<ffffffff80406122>] ? trace_hardirqs_on_thunk+0x35/0x3a
> > [<ffffffff8020b57b>] system_call_after_swapgs+0x7b/0x80
> >
> > ---[ end trace 033c2b23880cf02a ]---
> > kobject: 'notes' (ffff81017ec370a8): kobject_add_internal: parent: '<NULL>', set: '<NULL>'
>
> Ok, seems the "notes" directory should not be created if SYSFS is not
> configured. The "notes" kobject tries to reference the module kobject as
> a parent, which isn't initialized in that case.
>
> Does that fix it?
Idea was good and below is patch which compiles and works. BTW, all noises
about improper ifdefs or more core than necessary should be ignored for
now -- sysfs stuff really wants to be separated into module-sysfs.c
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -992,7 +992,7 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
* /sys/module/foo/sections stuff
* J. Corbet <[email protected]>
*/
-#ifdef CONFIG_KALLSYMS
+#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
static ssize_t module_sect_show(struct module_attribute *mattr,
struct module *mod, char *buf)
{