linux.git/kernel/module.c, branch v2.6.27-rc4

modules: extend initcall_debug functionality to the module loader

2008-08-12T07:52:54+00:00

The kernel has this really nice facility where if you put "initcall_debug"
on the kernel commandline, it'll print which function it's going to
execute just before calling an initcall, and then after the call completes
it will

1) print if it had an error code

2) checks for a few simple bugs (like leaving irqs off)
and

3) print how long the init call took in milliseconds.

While trying to optimize the boot speed of my laptop, I have been loving
number 3 to figure out what to optimize...  ...  and then I wished that
the same thing was done for module loading.

This patch makes the module loader use this exact same functionality; it's
a logical extension in my view (since modules are just sort of late
binding initcalls anyway) and so far I've found it quite useful in finding
where things are too slow in my boot.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Rusty Russell

stop_machine: Wean existing callers off stop_machine_run()

2008-07-28T02:16:31+00:00

Signed-off-by: Rusty Russell

module: fix build warning with !CONFIG_KALLSYMS

2008-07-28T02:16:28+00:00

This patch fixed the warning:

  CC      kernel/module.o
  /home/wangcong/Projects/linux-2.6/kernel/module.c:332: warning:
‘lookup_symbol’ defined but not used

Signed-off-by: WANG Cong 
Signed-off-by: Rusty Russell

modules: Take a shortcut for checking if an address is in a module

2008-07-22T09:24:28+00:00

This patch keeps track of the boundaries of module allocation, in
order to speed up module_text_address().

Inspired by Arjan's version, which required arch-specific defines:

	Various pieces of the kernel (lockdep, latencytop, etc) tend
	to store backtraces, sometimes at a relatively high
	frequency. In itself this isn't a big performance deal (after
	all you're using diagnostics features), but there have been
	some complaints from people who have over 100 modules loaded
	that this is a tad too slow.

	This is due to the new backtracer code which looks at every
	slot on the stack to see if it's a kernel/module text address,
	so that's 1024 slots.  1024 times 100 modules... that's a lot
	of list walking.

Signed-off-by: Rusty Russell

module: turn longs into ints for module sizes

2008-07-22T09:24:27+00:00

This shrinks module.o and each *.ko file.

And finally, structure members which hold length of module
code (four such members there) and count of symbols
are converted from longs to ints.

We cannot possibly have a module where 32 bits won't
be enough to hold such counts.

For one, module loading checks module size for sanity
before loading, so such insanely big module will fail
that test first.

Signed-off-by: Denys Vlasenko 
Signed-off-by: Rusty Russell

Shrink struct module: CONFIG_UNUSED_SYMBOLS ifdefs

2008-07-22T09:24:27+00:00

module.c and module.h conatains code for finding
exported symbols which are declared with EXPORT_UNUSED_SYMBOL,
and this code is compiled in even if CONFIG_UNUSED_SYMBOLS is not set
and thus there can be no EXPORT_UNUSED_SYMBOLs in modules anyway
(because EXPORT_UNUSED_SYMBOL(x) are compiled out to nothing then).

This patch adds required #ifdefs.

Signed-off-by: Denys Vlasenko 
Signed-off-by: Rusty Russell

module: generic each_symbol iterator function

2008-07-22T09:24:26+00:00

Introduce an each_symbol() iterator to avoid duplicating the knowledge
about the 5 different sections containing symbols.  Currently only
used by find_symbol(), but will be used by symbol_put_addr() too.

(Includes NULL ptr deref fix by Jiri Kosina )

Signed-off-by: Rusty Russell 
Cc: Jiri Kosina

module: don't use stop_machine for waiting rmmod

2008-07-22T09:24:25+00:00

rmmod has a little-used "-w" option, meaning that instead of failing if the
module is in use, it should block until the module becomes unused.

In this case, we don't need to use stop_machine: Max Krasnyansky
indicated that would be useful for SystemTap which loads/unloads new
modules frequently.

Cc: Max Krasnyansky 
Signed-off-by: Rusty Russell

modules: proper cleanup of kobject without CONFIG_SYSFS

2008-05-23T03:09:33+00:00

kobject: '' (ffffffffa0104050): is not initialized, yet kobject_put() is being called.
------------[ cut here ]------------
WARNING: at /home/den/src/linux-netns26/lib/kobject.c:583 kobject_put+0x53/0x55()
Modules linked in: ipv6 nfsd lockd nfs_acl auth_rpcgss sunrpc exportfs ide_cd_mod cdrom button [last unloaded: pktgen]
comm: rmmod Tainted: G        W 2.6.26-rc3 #585
Call Trace:
  [] warn_on_slowpath+0x58/0x7a
  [] ? printk+0x67/0x69
  [] ? printk+0x67/0x69
  [] kobject_put+0x53/0x55
  [] free_module+0x87/0xfa
  [] sys_delete_module+0x178/0x1e1
  [] ? lockdep_sys_exit_thunk+0x35/0x67
  [] ? trace_hardirqs_on_thunk+0x35/0x3a
  [] system_call_after_swapgs+0x7b/0x80
---[ end trace 8f5aafa7f6406cf8 ]---

mod->mkobj.kobj is not initialized without CONFIG_SYSFS. Do not call
kobject_put in this case.

Signed-off-by: Denis V. Lunev 
Cc: Rusty Russell 
Cc: Kay Sievers 
Signed-off-by: Rusty Russell

module loading ELF handling: use SELFMAG instead of numeric constant

2008-05-23T03:09:32+00:00

Signed-off-by: Cyrill Gorcunov 
Signed-off-by: Andrew Morton 
Signed-off-by: Rusty Russell