linux-toradex.git/include/linux/module.h, branch v2.6.32.51

Revert "module: fix __module_ref_addr()"

2010-05-12T22:11:42+00:00

This reverts commit d150a2b96558a7349cbf3a72a279c37bc67d50fb.

Thanks to Jiri Benc for finding the problem that this patch is
not correct for the 2.6.32-stable series.

Cc: Jiri Kosina 
Signed-off-by: Greg Kroah-Hartman

module: fix __module_ref_addr()

2010-04-26T14:41:35+00:00

The __module_ref_addr() problem disappears in 2.6.34-rc kernels because these
percpu accesses were re-factored.

__module_ref_addr() should use per_cpu_ptr() to obfuscate the pointer
(RELOC_HIDE is needed for per cpu pointers).

This non-standard per-cpu pointer use has been introduced by commit
720eba31f47aeade8ec130ca7f4353223c49170f

It causes a NULL pointer exception on some configurations when CONFIG_TRACING is
enabled on 2.6.33. This patch fixes the problem (acknowledged by Randy who
reported the bug).

It did not appear to hurt previously because most of the accesses were done
through local_inc, which probably obfuscated the access enough that no compiler
optimizations were done. But with local_read() done when CONFIG_TRACING is
active, this becomes a problem. Non-CONFIG_TRACING is probably affected as well
(module.c contains local_set and local_read that use __module_ref_addr()), but I
guess nobody noticed because we've been lucky enough that the compiler did not
generate the inappropriate optimization pattern there.

This patch should be queued for the 2.6.29.x through 2.6.33.x stable branches.
(tested on 2.6.33.1 x86_64)

Signed-off-by: Mathieu Desnoyers 
Tested-by: Randy Dunlap 
CC: Eric Dumazet 
CC: Rusty Russell 
CC: Peter Zijlstra 
CC: Tejun Heo 
CC: Ingo Molnar 
CC: Andrew Morton 
CC: Linus Torvalds 
CC: Greg Kroah-Hartman 
CC: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

module: preferred way to use MODULE_AUTHOR

2009-09-24T15:02:58+00:00

For the longest time now we've been using multiple MODULE_AUTHOR()
statements when a module has more than one author, but the comment here
disagrees.

Signed-off-by: Johannes Berg 
Cc: Jiri Kosina 
Cc: Luciano Coelho 
Signed-off-by: Andrew Morton 
Signed-off-by: Rusty Russell

module: reduce string table for loaded modules (v2)

2009-09-24T15:02:57+00:00

Also remove all parts of the string table (referenced by the symbol
table) that are not needed for kallsyms use (i.e. which were only
referenced by symbols discarded by the previous patch, or not
referenced at all for whatever reason).

Signed-off-by: Jan Beulich 
Signed-off-by: Rusty Russell

module: reduce symbol table for loaded modules (v2)

2009-09-24T15:02:57+00:00

Discard all symbols not interesting for kallsyms use: absolute,
section, and in the common case (!KALLSYMS_ALL) data ones.

Signed-off-by: Jan Beulich 
Signed-off-by: Rusty Russell

tracing: Remove markers

2009-09-18T19:22:08+00:00

Now that the last users of markers have migrated to the event
tracer we can kill off the (now orphan) support code.

Signed-off-by: Christoph Hellwig 
Acked-by: Mathieu Desnoyers 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
LKML-Reference: <20090917173527.GA1699@lst.de>
Signed-off-by: Ingo Molnar

tracing/events: Add module tracepoints

2009-08-17T09:25:08+00:00

Add trace points to trace module_load, module_free, module_get,
module_put and module_request, and use trace_event facility to
get the trace output.

Here's the sample output:

     TASK-PID    CPU#    TIMESTAMP  FUNCTION
        | |       |          |         |
    <...>-42    [000]     1.758380: module_request: fb0 wait=1 call_site=fb_open
    ...
    <...>-60    [000]     3.269403: module_load: scsi_wait_scan
    <...>-60    [000]     3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0
    <...>-61    [001]     3.273168: module_free: scsi_wait_scan
    ...
    <...>-1021  [000]    13.836081: module_load: sunrpc
    <...>-1021  [000]    13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1
    <...>-1027  [000]    13.848098: module_get: sunrpc call_site=try_module_get refcnt=0
    <...>-1027  [000]    13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1
    <...>-1027  [000]    13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0
    ...
 modprobe-2587  [001]  1088.437213: module_load: trace_events_sample F
 modprobe-2587  [001]  1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0

Note:

- the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0

- the module refcnt is percpu, so it can be negative in a
  specific cpu

Signed-off-by: Li Zefan 
Acked-by: Rusty Russell 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Rusty Russell 
LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com>
Signed-off-by: Ingo Molnar

kernel: constructor support

2009-06-18T20:03:57+00:00

Call constructors (gcc-generated initcall-like functions) during kernel
start and module load.  Constructors are e.g.  used for gcov data
initialization.

Disable constructor support for usermode Linux to prevent conflicts with
host glibc.

Signed-off-by: Peter Oberparleiter 
Acked-by: Rusty Russell 
Acked-by: WANG Cong 
Cc: Sam Ravnborg 
Cc: Jeff Dike 
Cc: Andi Kleen 
Cc: Huang Ying 
Cc: Li Wei 
Cc: Michael Ellerman 
Cc: Ingo Molnar 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

headers: move module_bug_finalize()/module_bug_cleanup() definitions into module.h

2009-06-17T02:47:48+00:00

They're in linux/bug.h at present, which causes include order tangles.  In
particular, linux/bug.h cannot be used by linux/atomic.h because,
according to Nikanth:

linux/bug.h pulls in linux/module.h => linux/spinlock.h => asm/spinlock.h
(which uses atomic_inc) => asm/atomic.h.

bug.h is a pretty low-level thing and module.h is a higher-level thing,
IMO.

Cc: Nikanth Karthikesan 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

module: trim exception table on init free.

2009-06-12T12:17:04+00:00

It's theoretically possible that there are exception table entries
which point into the (freed) init text of modules.  These could cause
future problems if other modules get loaded into that memory and cause
an exception as we'd see the wrong fixup.  The only case I know of is
kvm-intel.ko (when CONFIG_CC_OPTIMIZE_FOR_SIZE=n).

Amerigo fixed this long-standing FIXME in the x86 version, but this
patch is more general.

This implements trim_init_extable(); most archs are simple since they
use the standard lib/extable.c sort code.  Alpha and IA64 use relative
addresses in their fixups, so thier trimming is a slight variation.

Sparc32 is unique; it doesn't seem to define ARCH_HAS_SORT_EXTABLE,
yet it defines its own sort_extable() which overrides the one in lib.
It doesn't sort, so we have to mark deleted entries instead of
actually trimming them.

Inspired-by: Amerigo Wang 
Signed-off-by: Rusty Russell 
Cc: linux-alpha@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-ia64@vger.kernel.org