modules: Fix build error in moduleloader.h

Fengguang Wu's build bot detected that if moduleloader.h is included in
a C file (used by ftrace and kprobes to access module_alloc() when
available), that it can fail to build if CONFIG_MODULES and
CONFIG_MODULES_USE_ELF_REL is not defined.

This is because there's a printk() that dereferences struct module to
print the name of the module. But as struct module does not exist when
CONFIG_MODULES is not defined we get this error:

   include/linux/moduleloader.h: In function 'apply_relocate':
>> include/linux/moduleloader.h:48:63: error: dereferencing pointer to
>> incomplete type
     printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name);
								  ^
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Based-on-the-true-story-by: Steven Rostedt <rostedt@goodmis.org>
Confirms-rustys-story-ends-the-same-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
module: add within_module() function

It is just a small optimization that allows to replace few
occurrences of within_module_init() || within_module_core()
with a single call.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
module: return bool from within_module*()

The within_module*() functions return only true or false. Let's use bool as
the return type.

Note that it should not change kABI because these are inline functions.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
sysfs: disallow world-writable files.

This check was introduced in 2006 by Alexey Dobriyan (9774a1f54f173)
for module parameters; we removed it when we unified the check into
VERIFY_OCTAL_PERMISSIONS() as sysfs didn't have the same requirement.
Now all those users are fixed, reintroduce it.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
scripts: modpost: fix compilation warning

The scripts/mod/modpost.c triggers the following warning:

scripts/mod/modpost.c: In function ‘remove_dot’:
scripts/mod/modpost.c:1710:10: warning: ignoring return value of ‘strtoul’, declared with attribute warn_unused_result [-Wunused-result]

The remove_dot function that calls strtoul does not care about the
numeric value of the string that is parsed but only looks for the
end of the numeric sequence.  As such, it's equivalent to just skip
over all digits.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
scripts: modpost: Remove numeric suffix pattern matching

For several years, the pattern "foo$" has effectively been treated as
equivalent to "foo" due to a bug in the (misnamed) helper
number_prefix(). This hasn't been observed to cause any problems, so
remove the broken $ functionality and change all foo$ patterns to foo.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
ARM: avoid ARM binutils leaking ELF local symbols

Symbols starting with .L are ELF local symbols and should not appear
in ELF symbol tables.  However, unfortunately ARM binutils leaks the
.LANCHOR symbols into the symbol table, which leads kallsyms to report
these symbols rather than the real name.  It is not very useful when
%pf reports symbols against these leaked .LANCHOR symbols.

Arrange for kallsyms to ignore these symbols using the same mechanism
that is used for the ARM mapping symbols.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio: console: remove unnecessary null test before debugfs_remove_recursive

Fix checkpatch warning:
WARNING: debugfs_remove_recursive(NULL) is safe this check is probably not required

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: virtualization@lists.linux-foundation.org
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio: Replace DEFINE_PCI_DEVICE_TABLE macro use

We should prefer `struct pci_device_id` over `DEFINE_PCI_DEVICE_TABLE` to meet
kernel coding style guidelines. This issue was reported by checkpatch.

Signed-off-by: Benoit Taine <benoit.taine@lip6.fr>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio: rng: remove unused struct element

vdev is unused in struct virtrng_info, remove it.

CC: Amos Kong <akong@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio: rng: re-arrange struct elements for better packing

Re-arrange the elements of the virtrng_info struct to pack it better.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio: rng: delay hwrng_register() till driver is ready

Instead of calling hwrng_register() in the probe routing, call it in the
scan routine.  This ensures that when hwrng_register() is successful,
and it requests a few random bytes to seed the kernel's pool at init,
we're ready to service that request.

This will also enable us to remove the workaround added previously to
check whether probe was completed, and only then ask for data from the
host.  The revert follows in the next commit.

There's a slight behaviour change here on unsuccessful hwrng_register().
Previously, when hwrng_register() failed, the probe() routine would
fail, and the vqs would be torn down, and driver would be marked not
initialized.  Now, the vqs will remain initialized, driver would be
marked initialized as well, but won't be available in the list of RNGs
available to hwrng core.  To fix the failures, the procedure remains the
same, i.e. unload and re-load the module, and hope things succeed the
next time around.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Revert "hwrng: virtio - ensure reads happen after successful probe"

This reverts commit e052dbf554610e2104c5a7518c4d8374bed701bb.

Now that we use the virtio ->scan() function to register with the hwrng
core, we will not get read requests till probe is successfully finished.

So revert the workaround we had in place to refuse read requests while
we were not yet setup completely.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
drivers/video/fbdev/s3c2410fb.c: don't make debug world-writable.

We don't want random users to be able to spam the logs, and commit
37549e94c77a94a9c32b5ae3313a3801cb66adf9 (sysfs: disallow
world-writable files.) finally makes this a build error.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
arch/powerpc/platforms/powernv/opal-elog.c: fix world-writable sysfs files

If you don't have a store function, you're not writable anyway!

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs files

If you don't have a store function, you're not writable anyway!

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Revert "proc: Point /proc/{mounts,net} at /proc/thread-self/{mounts,net} instead of /proc/self/{mounts,net}"

This reverts commits 344470cac42e and e81324407269.

It turns out that the exact path in the symlink matters, if for somewhat
unfortunate reasons: some apparmor configurations don't allow dhclient
access to the per-thread /proc files.  As reported by Jörg Otte:

  audit: type=1400 audit(1407684227.003:28): apparmor="DENIED"
    operation="open" profile="/sbin/dhclient"
    name="/proc/1540/task/1540/net/dev" pid=1540 comm="dhclient"
    requested_mask="r" denied_mask="r" fsuid=0 ouid=0

so we had better revert this for now.  We might be able to work around
this in practice by only using the per-thread symlinks if the thread
isn't the thread group leader, and if the namespaces differ between
threads (which basically never happens).

We'll see. In the meantime, the revert was made to be intentionally easy.

Reported-by: Jörg Otte <jrg.otte@gmail.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio updates from Rusty Russell.

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  Revert "hwrng: virtio - ensure reads happen after successful probe"
  virtio: rng: delay hwrng_register() till driver is ready
  virtio: rng: re-arrange struct elements for better packing
  virtio: rng: remove unused struct element
  virtio: Replace DEFINE_PCI_DEVICE_TABLE macro use
  virtio: console: remove unnecessary null test before debugfs_remove_recursive
Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "This finally applies the stricter sysfs perms checking we pulled out
  before last merge window.  A few stragglers are fixed (thanks
  linux-next!)"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs files
  arch/powerpc/platforms/powernv/opal-elog.c: fix world-writable sysfs files
  drivers/video/fbdev/s3c2410fb.c: don't make debug world-writable.
  ARM: avoid ARM binutils leaking ELF local symbols
  scripts: modpost: Remove numeric suffix pattern matching
  scripts: modpost: fix compilation warning
  sysfs: disallow world-writable files.
  module: return bool from within_module*()
  module: add within_module() function
  modules: Fix build error in moduleloader.h