Commit Graph

345 Commits

Author SHA1 Message Date
Steven Rostedt 89c837351d kmemleak: No need for scanning specific module sections
As kmemleak now scans all module sections that are allocated, writable
and non executable, there's no need to scan individual sections that
might reference data.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2013-05-17 09:53:36 +01:00
Steven Rostedt 06c9494c0e kmemleak: Scan all allocated, writeable and not executable module sections
Instead of just picking data sections by name (names that start
with .data, .bss or .ref.data), use the section flags and scan all
sections that are allocated, writable and not executable. Which should
cover all sections of a module that might reference data.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[catalin.marinas@arm.com: removed unused 'name' variable]
[catalin.marinas@arm.com: collapsed 'if' blocks]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2013-05-17 09:53:07 +01:00
Rusty Russell 944a1fa012 module: don't unlink the module until we've removed all exposure.
Otherwise we get a race between unload and reload of the same module:
the new module doesn't see the old one in the list, but then fails because
it can't register over the still-extant entries in sysfs:

 [  103.981925] ------------[ cut here ]------------
 [  103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0()
 [  103.993606] Hardware name: CrownBay Platform
 [  103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe'
 [  104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe]
 [  104.011362] Pid: 3021, comm: modprobe Tainted: G        W    3.9.0-rc5+ #5
 [  104.018662] Call Trace:
 [  104.021286]  [<c103599d>] warn_slowpath_common+0x6d/0xa0
 [  104.026933]  [<c1168c8b>] ? sysfs_add_one+0xab/0xd0
 [  104.031986]  [<c1168c8b>] ? sysfs_add_one+0xab/0xd0
 [  104.037000]  [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30
 [  104.042188]  [<c1168c8b>] sysfs_add_one+0xab/0xd0
 [  104.046982]  [<c1168dbe>] create_dir+0x5e/0xa0
 [  104.051633]  [<c1168e78>] sysfs_create_dir+0x78/0xd0
 [  104.056774]  [<c1262bc3>] kobject_add_internal+0x83/0x1f0
 [  104.062351]  [<c126daf6>] ? kvasprintf+0x46/0x60
 [  104.067231]  [<c1262ebd>] kobject_add_varg+0x2d/0x50
 [  104.072450]  [<c1262f07>] kobject_init_and_add+0x27/0x30
 [  104.078075]  [<c1089240>] mod_sysfs_setup+0x80/0x540
 [  104.083207]  [<c1260851>] ? module_bug_finalize+0x51/0xc0
 [  104.088720]  [<c108ab29>] load_module+0x1429/0x18b0

We can teardown sysfs first, then to be sure, put the state in
MODULE_STATE_UNFORMED so it's ignored while we deconstruct it.

Reported-by: Veaceslav Falico <vfalico@redhat.com>
Tested-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-17 13:23:02 +09:30
James Hogan a4b6a77b77 module: fix symbol versioning with symbol prefixes
Fix symbol versioning on architectures with symbol prefixes. Although
the build was free from warnings the actual modules still wouldn't load
as the ____versions table contained unprefixed symbol names, which were
being compared against the prefixed symbol names when checking the
symbol versions.

This is fixed by modifying modpost to add the symbol prefix to the
____versions table it outputs (Modules.symvers still contains unprefixed
symbol names). The check_modstruct_version() function is also fixed as
it checks the version of the unprefixed "module_layout" symbol which
would no longer work.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Kliegman <kliegs@chromium.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (use VMLINUX_SYMBOL_STR)
2013-03-20 11:27:26 +10:30
Rusty Russell b92021b09d CONFIG_SYMBOL_PREFIX: cleanup.
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_".  But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to
do so.

Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something.  So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:

1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
   CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
   for pasting.

(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).

Let's solve this properly:
1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR().
4) Make everyone use them.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Tested-by: James Hogan <james.hogan@imgtec.com> (metag)
2013-03-15 15:09:43 +10:30
Linus Torvalds d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro 3dadecce20 switch vfs_getattr() to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:08 -05:00
Rusty Russell a3535c7e4f module: clean up load_module a little more.
1fb9341ac3 made our locking in
load_module more complicated: we grab the mutex once to insert the
module in the list, then again to upgrade it once it's formed.

Since the locking is self-contained, it's neater to do this in
separate functions.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-21 17:20:09 +10:30
Rusty Russell 373d4d0997 taint: add explicit flag to show whether lock dep is still OK.
Fix up all callers as they were before, with make one change: an
unsigned module taints the kernel, but doesn't turn off lockdep.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-21 17:17:57 +10:30
Rusty Russell 64748a2c90 module: printk message when module signature fail taints kernel.
Reported-by: Chris Samuel <chris@csamuel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-21 17:17:05 +10:30
Linus Torvalds ee61abb322 module: fix missing module_mutex unlock
Commit 1fb9341ac3 ("module: put modules in list much earlier") moved
some of the module initialization code around, and in the process
changed the exit paths too.  But for the duplicate export symbol error
case the change made the ddebug_cleanup path jump to after the module
mutex unlock, even though it happens with the mutex held.

Rusty has some patches to split this function up into some helper
functions, hopefully the mess of complex goto targets will go away
eventually.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-20 20:22:58 -08:00
Linus Torvalds 226364766f Various minor fixes, but a slightly more complex one to fix the per-cpu overload
problem introduced recently by kvm id changes.
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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module fixes and a virtio block fix from Rusty Russell:
 "Various minor fixes, but a slightly more complex one to fix the
  per-cpu overload problem introduced recently by kvm id changes."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: put modules in list much earlier.
  module: add new state MODULE_STATE_UNFORMED.
  module: prevent warning when finit_module a 0 sized file
  virtio-blk: Don't free ida when disk is in use
2013-01-20 16:44:28 -08:00
Tejun Heo 774a1221e8 module, async: async_synchronize_full() on module init iff async is used
If the default iosched is built as module, the kernel may deadlock
while trying to load the iosched module on device probe if the probing
was running off async.  This is because async_synchronize_full() at
the end of module init ends up waiting for the async job which
initiated the module loading.

 async A				modprobe

 1. finds a device
 2. registers the block device
 3. request_module(default iosched)
					4. modprobe in userland
					5. load and init module
					6. async_synchronize_full()

Async A waits for modprobe to finish in request_module() and modprobe
waits for async A to finish in async_synchronize_full().

Because there's no easy to track dependency once control goes out to
userland, implementing properly nested flushing is difficult.  For
now, make module init perform async_synchronize_full() iff module init
has queued async jobs as suggested by Linus.

This avoids the described deadlock because iosched module doesn't use
async and thus wouldn't invoke async_synchronize_full().  This is
hacky and incomplete.  It will deadlock if async module loading nests;
however, this works around the known problem case and seems to be the
best of bad options.

For more details, please refer to the following thread.

  http://thread.gmane.org/gmane.linux.kernel/1420814

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Alex Riesen <raa.lkml@gmail.com>
Tested-by: Ming Lei <ming.lei@canonical.com>
Tested-by: Alex Riesen <raa.lkml@gmail.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-16 09:05:33 -08:00
Rusty Russell 1fb9341ac3 module: put modules in list much earlier.
Prarit's excellent bug report:
> In recent Fedora releases (F17 & F18) some users have reported seeing
> messages similar to
>
> [   15.478160] kvm: Could not allocate 304 bytes percpu data
> [   15.478174] PERCPU: allocation failed, size=304 align=32, alloc from
> reserved chunk failed
>
> during system boot.  In some cases, users have also reported seeing this
> message along with a failed load of other modules.
>
> What is happening is systemd is loading an instance of the kvm module for
> each cpu found (see commit e9bda3b).  When the module load occurs the kernel
> currently allocates the modules percpu data area prior to checking to see
> if the module is already loaded or is in the process of being loaded.  If
> the module is already loaded, or finishes load, the module loading code
> releases the current instance's module's percpu data.

Now we have a new state MODULE_STATE_UNFORMED, we can insert the
module into the list (and thus guarantee its uniqueness) before we
allocate the per-cpu region.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Prarit Bhargava <prarit@redhat.com>
2013-01-12 13:27:46 +10:30
Rusty Russell 0d21b0e347 module: add new state MODULE_STATE_UNFORMED.
You should never look at such a module, so it's excised from all paths
which traverse the modules list.

We add the state at the end, to avoid gratuitous ABI break (ksplice).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-12 13:27:05 +10:30
Sasha Levin 52441fa8f2 module: prevent warning when finit_module a 0 sized file
If we try to finit_module on a file sized 0 bytes vmalloc will
scream and spit out a warning.

Since modules have to be bigger than 0 bytes anyways we can just
check that beforehand and avoid the warning.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-03 11:10:32 +10:30
Linus Torvalds 7a684c452e Nothing all that exciting; a new module-from-fd syscall for those who want
to verify the source of the module (ChromeOS) and/or use standard IMA on it
 or other security hooks.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module update from Rusty Russell:
 "Nothing all that exciting; a new module-from-fd syscall for those who
  want to verify the source of the module (ChromeOS) and/or use standard
  IMA on it or other security hooks."

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  MODSIGN: Fix kbuild output when using default extra_certificates
  MODSIGN: Avoid using .incbin in C source
  modules: don't hand 0 to vmalloc.
  module: Remove a extra null character at the top of module->strtab.
  ASN.1: Use the ASN1_LONG_TAG and ASN1_INDEFINITE_LENGTH constants
  ASN.1: Define indefinite length marker constant
  moduleparam: use __UNIQUE_ID()
  __UNIQUE_ID()
  MODSIGN: Add modules_sign make target
  powerpc: add finit_module syscall.
  ima: support new kernel module syscall
  add finit_module syscall to asm-generic
  ARM: add finit_module syscall to ARM
  security: introduce kernel_module_from_file hook
  module: add flags arg to sys_finit_module()
  module: add syscall to load module from fd
2012-12-19 07:55:08 -08:00
Tao Ma 8ec7d50f1e kernel: remove reference to feature-removal-schedule.txt
In commit 9c0ece069b ("Get rid of Documentation/feature-removal.txt"),
Linus removed feature-removal-schedule.txt from Documentation, but there
is still some reference to this file.  So remove them.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:12 -08:00
Rusty Russell 82fab442f5 modules: don't hand 0 to vmalloc.
In commit d0a21265df David Rientjes unified various archs'
module_alloc implementation (including x86) and removed the graduitous
shortcut for size == 0.

Then, in commit de7d2b567d, Joe Perches added a warning for
zero-length vmallocs, which can happen without kallsyms on modules
with no init sections (eg. zlib_deflate).

Fix this once and for all; the module code has to handle zero length
anyway, so get it right at the caller and remove the now-gratuitous
checks within the arch-specific module_alloc implementations.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42608
Reported-by: Conrad Kostecki <ConiKost@gmx.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-14 13:06:43 +10:30
Satoru Takeuchi 54523ec71f module: Remove a extra null character at the top of module->strtab.
There is a extra null character('\0') at the top of module->strtab for
each module. Commit 59ef28b introduced this bug and this patch fixes it.

Live dump log of the current linus git kernel(HEAD is 2844a4870):
============================================================================
crash> mod | grep loop
ffffffffa01db0a0  loop             16689  (not loaded)  [CONFIG_KALLSYMS]
crash> module.core_symtab ffffffffa01db0a0
  core_symtab = 0xffffffffa01db320crash> rd 0xffffffffa01db320 12
ffffffffa01db320:  0000005500000001 0000000000000000   ....U...........
ffffffffa01db330:  0000000000000000 0002007400000002   ............t...
ffffffffa01db340:  ffffffffa01d8000 0000000000000038   ........8.......
ffffffffa01db350:  001a00640000000e ffffffffa01daeb0   ....d...........
ffffffffa01db360:  00000000000000a0 0002007400000019   ............t...
ffffffffa01db370:  ffffffffa01d8068 000000000000001b   h...............
crash> module.core_strtab ffffffffa01db0a0
  core_strtab = 0xffffffffa01dbb30 ""
crash> rd 0xffffffffa01dbb30 4
ffffffffa01dbb30:  615f70616d6b0000 66780063696d6f74   ..kmap_atomic.xf
ffffffffa01dbb40:  73636e75665f7265 72665f646e696600   er_funcs.find_fr
============================================================================

We expect Just first one byte of '\0', but actually first two bytes
are '\0'. Here is The relationship between symtab and strtab.

	symtab_idx	strtab_idx	symbol
	-----------------------------------------------
	0		0x1		"\0" # startab_idx should be 0
	1		0x2		"kmap_atomic"
	2		0xe		"xfer_funcs"
	3		0x19		"find_fr..."

By applying this patch, it becomes as follows.

	symtab_idx	strtab_idx	symbol
	-----------------------------------------------
	0		0x0		"\0"	# extra byte is removed
	1		0x1		"kmap_atomic"
	2		0xd		"xfer_funcs"
	3		0x18		"find_fr..."

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: Masaki Kimura <masaki.kimura.kz@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-14 13:06:43 +10:30
Kees Cook 2e72d51b4a security: introduce kernel_module_from_file hook
Now that kernel module origins can be reasoned about, provide a hook to
the LSMs to make policy decisions about the module file. This will let
Chrome OS enforce that loadable kernel modules can only come from its
read-only hash-verified root filesystem. Other LSMs can, for example,
read extended attributes for signatures, etc.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-14 13:05:24 +10:30
Rusty Russell 2f3238aebe module: add flags arg to sys_finit_module()
Thanks to Michael Kerrisk for keeping us honest.  These flags are actually
useful for eliminating the only case where kmod has to mangle a module's
internals: for overriding module versioning.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Acked-by: Kees Cook <keescook@chromium.org>
2012-12-14 13:05:23 +10:30
Kees Cook 34e1169d99 module: add syscall to load module from fd
As part of the effort to create a stronger boundary between root and
kernel, Chrome OS wants to be able to enforce that kernel modules are
being loaded only from our read-only crypto-hash verified (dm_verity)
root filesystem. Since the init_module syscall hands the kernel a module
as a memory blob, no reasoning about the origin of the blob can be made.

Earlier proposals for appending signatures to kernel modules would not be
useful in Chrome OS, since it would involve adding an additional set of
keys to our kernel and builds for no good reason: we already trust the
contents of our root filesystem. We don't need to verify those kernel
modules a second time. Having to do signature checking on module loading
would slow us down and be redundant. All we need to know is where a
module is coming from so we can say yes/no to loading it.

If a file descriptor is used as the source of a kernel module, many more
things can be reasoned about. In Chrome OS's case, we could enforce that
the module lives on the filesystem we expect it to live on.  In the case
of IMA (or other LSMs), it would be possible, for example, to examine
extended attributes that may contain signatures over the contents of
the module.

This introduces a new syscall (on x86), similar to init_module, that has
only two arguments. The first argument is used as a file descriptor to
the module and the second argument is a pointer to the NULL terminated
string of module arguments.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-12-14 13:05:22 +10:30
Rusty Russell 59ef28b1f1 module: fix out-by-one error in kallsyms
Masaki found and patched a kallsyms issue: the last symbol in a
module's symtab wasn't transferred.  This is because we manually copy
the zero'th entry (which is always empty) then copy the rest in a loop
starting at 1, though from src[0].  His fix was minimal, I prefer to
rewrite the loops in more standard form.

There are two loops: one to get the size, and one to copy.  Make these
identical: always count entry 0 and any defined symbol in an allocated
non-init section.

This bug exists since the following commit was introduced.
   module: reduce symbol table for loaded modules (v2)
   commit: 4a4962263f

LKML: http://lkml.org/lkml/2012/10/24/27
Reported-by: Masaki Kimura <masaki.kimura.kz@hitachi.com>
Cc: stable@kernel.org
2012-10-31 13:56:37 +10:30
David Howells caabe24057 MODSIGN: Move the magic string to the end of a module and eliminate the search
Emit the magic string that indicates a module has a signature after the
signature data instead of before it.  This allows module_sig_check() to
be made simpler and faster by the elimination of the search for the
magic string.  Instead we just need to do a single memcmp().

This works because at the end of the signature data there is the
fixed-length signature information block.  This block then falls
immediately prior to the magic number.

From the contents of the information block, it is trivial to calculate
the size of the signature data and thus the size of the actual module
data.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-19 17:30:40 -07:00
David Howells 1d0059f3a4 MODSIGN: Add FIPS policy
If we're in FIPS mode, we should panic if we fail to verify the signature on a
module or we're asked to load an unsigned module in signature enforcing mode.
Possibly FIPS mode should automatically enable enforcing mode.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10 20:01:19 +10:30
Rusty Russell 106a4ee258 module: signature checking hook
We do a very simple search for a particular string appended to the module
(which is cache-hot and about to be SHA'd anyway).  There's both a config
option and a boot parameter which control whether we accept or fail with
unsigned modules and modules that are signed with an unknown key.

If module signing is enabled, the kernel will be tainted if a module is
loaded that is unsigned or has a signature for which we don't have the
key.

(Useful feedback and tweaks by David Howells <dhowells@redhat.com>)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10 20:00:55 +10:30
Rusty Russell 9bb9c3be56 module: wait when loading a module which is currently initializing.
The original module-init-tools module loader used a fnctl lock on the
.ko file to avoid attempts to simultaneously load a module.
Unfortunately, you can't get an exclusive fcntl lock on a read-only
fd, making this not work for read-only mounted filesystems.
module-init-tools has a hacky sleep-and-loop for this now.

It's not that hard to wait in the kernel, and only return -EEXIST once
the first module has finished loading (or continue loading the module
if the first one failed to initialize for some reason).  It's also
consistent with what we do for dependent modules which are still loading.

Suggested-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 14:31:03 +09:30
Rusty Russell 6f13909f4f module: fix symbol waiting when module fails before init
We use resolve_symbol_wait(), which blocks if the module containing
the symbol is still loading.  However:

1) The module_wq we use is only woken after calling the modules' init
   function, but there are other failure paths after the module is
   placed in the linked list where we need to do the same thing.

2) wake_up() only wakes one waiter, and our waitqueue is shared by all
   modules, so we need to wake them all.

3) wake_up_all() doesn't imply a memory barrier: I feel happier calling
   it after we've grabbed and dropped the module_mutex, not just after
   the state assignment.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 14:31:03 +09:30
David Howells 786d35d45c Make most arch asm/module.h files use asm-generic/module.h
Use the mapping of Elf_[SPE]hdr, Elf_Addr, Elf_Sym, Elf_Dyn, Elf_Rel/Rela,
ELF_R_TYPE() and ELF_R_SYM() to either the 32-bit version or the 64-bit version
into asm-generic/module.h for all arches bar MIPS.

Also, use the generic definition mod_arch_specific where possible.

To this end, I've defined three new config bools:

 (*) HAVE_MOD_ARCH_SPECIFIC

     Arches define this if they don't want to use the empty generic
     mod_arch_specific struct.

 (*) MODULES_USE_ELF_RELA

     Arches define this if their modules can contain RELA records.  This causes
     the Elf_Rela mapping to be emitted and allows apply_relocate_add() to be
     defined by the arch rather than have the core emit an error message.

 (*) MODULES_USE_ELF_REL

     Arches define this if their modules can contain REL records.  This causes
     the Elf_Rel mapping to be emitted and allows apply_relocate() to be
     defined by the arch rather than have the core emit an error message.

Note that it is possible to allow both REL and RELA records: m68k and mips are
two arches that do this.

With this, some arch asm/module.h files can be deleted entirely and replaced
with a generic-y marker in the arch Kbuild file.

Additionally, I have removed the bits from m32r and score that handle the
unsupported type of relocation record as that's now handled centrally.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 14:31:03 +09:30
Matthew Garrett c99af3752b module: taint kernel when lve module is loaded
Cloudlinux have a product called lve that includes a kernel module. This
was previously GPLed but is now under a proprietary license, but the
module continues to declare MODULE_LICENSE("GPL") and makes use of some
EXPORT_SYMBOL_GPL symbols. Forcibly taint it in order to avoid this.

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Alex Lyashkov <umka@cloudlinux.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
2012-09-28 14:31:02 +09:30
David Howells ef26a5a6ea Guard check in module loader against integer overflow
The check:

	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))

may not work if there's an overflow in the right-hand side of the condition.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-05-23 22:28:53 +09:30
Jim Cromie b48420c1d3 dynamic_debug: make dynamic-debug work for module initialization
This introduces a fake module param $module.dyndbg.  Its based upon
Thomas Renninger's $module.ddebug boot-time debugging patch from
https://lkml.org/lkml/2010/9/15/397

The 'fake' module parameter is provided for all modules, whether or
not they need it.  It is not explicitly added to each module, but is
implemented in callbacks invoked from parse_args.

For builtin modules, dynamic_debug_init() now directly calls
parse_args(..., &ddebug_dyndbg_boot_params_cb), to process the params
undeclared in the modules, just after the ddebug tables are processed.

While its slightly weird to reprocess the boot params, parse_args() is
already called repeatedly by do_initcall_levels().  More importantly,
the dyndbg queries (given in ddebug_query or dyndbg params) cannot be
activated until after the ddebug tables are ready, and reusing
parse_args is cleaner than doing an ad-hoc parse.  This reparse would
break options like inc_verbosity, but they probably should be params,
like verbosity=3.

ddebug_dyndbg_boot_params_cb() handles both bare dyndbg (aka:
ddebug_query) and module-prefixed dyndbg params, and ignores all other
parameters.  For example, the following will enable pr_debug()s in 4
builtin modules, in the order given:

  dyndbg="module params +p; module aio +p" module.dyndbg=+p pci.dyndbg

For loadable modules, parse_args() in load_module() calls
ddebug_dyndbg_module_params_cb().  This handles bare dyndbg params as
passed from modprobe, and errors on other unknown params.

Note that modprobe reads /proc/cmdline, so "modprobe foo" grabs all
foo.params, strips the "foo.", and passes these to the kernel.
ddebug_dyndbg_module_params_cb() is again called for the unknown
params; it handles dyndbg, and errors on others.  The "doing" arg
added previously contains the module name.

For non CONFIG_DYNAMIC_DEBUG builds, the stub function accepts
and ignores $module.dyndbg params, other unknowns get -ENOENT.

If no param value is given (as in pci.dyndbg example above), "+p" is
assumed, which enables all pr_debug callsites in the module.

The dyndbg fake parameter is not shown in /sys/module/*/parameters,
thus it does not use any resources.  Changes to it are made via the
control file.

Also change pr_info in ddebug_exec_queries to vpr_info,
no need to see it all the time.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
CC: Thomas Renninger <trenn@suse.de>
CC: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30 14:31:46 -04:00
Sasha Levin f946eeb931 module: Remove module size limit
Module size was limited to 64MB, this was legacy limitation due to vmalloc()
which was removed a while ago.

Limiting module size to 64MB is both pointless and affects real world use
cases.

Cc: Tim Abbott <tim.abbott@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-26 12:50:53 +10:30
Steven Rostedt d53799be67 module: move __module_get and try_module_get() out of line.
With the preempt, tracepoint and everything, it's getting a bit
chubby.  For an Ubuntu-based config:

Before:
	$ size -t `find * -name '*.ko'` | grep TOTAL
	56199906        3870760	1606616	61677282	3ad1ee2	(TOTALS)
	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	8509342	 850368	3358720	12718430	 c2115e	vmlinux

After:
	$ size -t `find * -name '*.ko'` | grep TOTAL
	56183760	3867892	1606616	61658268	3acd49c	(TOTALS)
	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	8501842	 849088	3358720	12709650	 c1ef12	vmlinux

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (made all out-of-line)
2012-03-26 12:50:52 +10:30
Pawel Moll 026cee0086 params: <level>_initcall-like kernel parameters
This patch adds a set of macros that can be used to declare
kernel parameters to be parsed _before_ initcalls at a chosen
level are executed.  We rename the now-unused "flags" field of
struct kernel_param as the level.  It's signed, for when we
use this for early params as well, in future.

Linker macro collating init calls had to be modified in order
to add additional symbols between levels that are later used
by the init code to split the calls into blocks.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-26 12:50:51 +10:30
Dave Young 02608bef8f module: add kernel param to force disable module load
Sometimes we need to test a kernel of same version with code or config
option changes.

We already have sysctl to disable module load, but add a kernel
parameter will be more convenient.

Since modules_disabled is int, so here use bint type in core_param.
TODO: make sysctl accept bool and change modules_disabled to bool

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-26 12:50:50 +10:30
Kevin Winchester 53999bf34d error: implicit declaration of function 'module_flags_taint'
Recent changes to kernel/module.c caused the following compile
error:

  kernel/module.c: In function ‘show_taint’:
  kernel/module.c:1024:2: error: implicit declaration of function ‘module_flags_taint’ [-Werror=implicit-function-declaration]
  cc1: some warnings being treated as errors

Correct this error by moving the definition of module_flags_taint
outside of the #ifdef CONFIG_MODULE_UNLOAD section.

Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-15 16:21:07 -08:00
Kay Sievers cca3e70730 modules: sysfs - export: taint, coresize, initsize
Recent tools do not want to use /proc to retrieve module information. A few
values are currently missing from sysfs to replace the information available
in /proc/modules.

This adds /sys/module/*/{coresize,initsize,taint} attributes.

TAINT_PROPRIETARY_MODULE (P) and TAINT_OOT_MODULE (O) flags are both always
shown now, and do no longer exclude each other, also in /proc/modules.

Replace the open-coded sysfs attribute initializers with the __ATTR() macro.

Add the new attributes to Documentation/ABI.

Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:15 +10:30
Jim Cromie 5e12416927 module: replace DEBUGP with pr_debug
Use more flexible pr_debug.  This allows:

  echo "module module +p" > /dbg/dynamic_debug/control

to turn on debug messages when needed.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:15 +10:30
Eric Dumazet bd77c04772 module: struct module_ref should contains long fields
module_ref contains two "unsigned int" fields.

Thats now too small, since some machines can open more than 2^32 files.

Check commit 518de9b39e (fs: allow for more than 2^31 files) for
reference.

We can add an aligned(2 * sizeof(unsigned long)) attribute to force
alloc_percpu() allocating module_ref areas in single cache lines.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Tejun Heo <tj@kernel.org>
CC: Robin Holt <holt@sgi.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:14 +10:30
Kevin Cernekee 48fd11880b module: Fix performance regression on modules with large symbol tables
Looking at /proc/kallsyms, one starts to ponder whether all of the extra
strtab-related complexity in module.c is worth the memory savings.

Instead of making the add_kallsyms() loop even more complex, I tried the
other route of deleting the strmap logic and naively copying each string
into core_strtab with no consideration for consolidating duplicates.

Performance on an "already exists" insmod of nvidia.ko (runs
add_kallsyms() but does not actually initialize the module):

	Original scheme: 1.230s
	With naive copying: 0.058s

Extra space used: 35k (of a 408k module).

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <73defb5e4bca04a6431392cc341112b1@localhost>
2012-01-13 09:32:14 +10:30
Kevin Cernekee 70b1e9161e module: Add comments describing how the "strmap" logic works
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:13 +10:30
Linus Torvalds 32aaeffbd4 Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
2011-11-06 19:44:47 -08:00
Ben Hutchings 2449b8ba07 module,bug: Add TAINT_OOT_MODULE flag for modules not built in-tree
Use of the GPL or a compatible licence doesn't necessarily make the code
any good.  We already consider staging modules to be suspect, and this
should also be true for out-of-tree modules which may receive very
little review.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reviewed-by: Dave Jones <davej@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (patched oops-tracing.txt)
2011-11-07 07:54:42 +10:30
Ben Hutchings 1cd0d6c302 module: Enable dynamic debugging regardless of taint
Dynamic debugging is currently disabled for tainted modules, except
for TAINT_CRAP.  This prevents use of dynamic debugging for
out-of-tree modules once the next patch is applied.

This condition was apparently intended to avoid a crash if a force-
loaded module has an incompatible definition of dynamic debug
structures.  However, a administrator that forces us to load a module
is claiming that it *is* compatible even though it fails our version
checks.  If they are mistaken, there are any number of ways the module
could crash the system.

As a side-effect, proprietary and other tainted modules can now use
dynamic_debug.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-11-07 07:54:40 +10:30
Paul Gortmaker 9984de1a5a kernel: Map most files to use export.h instead of module.h
The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else.  Revector them
onto the isolated export header for faster compile times.

Nothing to see here but a whole lot of instances of:

  -#include <linux/module.h>
  +#include <linux/export.h>

This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 09:20:12 -04:00
Mathieu Desnoyers b75ef8b44b Tracepoint: Dissociate from module mutex
Copy the information needed from struct module into a local module list
held within tracepoint.c from within the module coming/going notifier.

This vastly simplifies locking of tracepoint registration /
unregistration, because we don't have to take the module mutex to
register and unregister tracepoints anymore. Steven Rostedt ran into
dependency problems related to modules mutex vs kprobes mutex vs ftrace
mutex vs tracepoint mutex that seems to be hard to fix without removing
this dependency between tracepoint and module mutex. (note: it should be
investigated whether kprobes could benefit of being dissociated from the
modules mutex too.)

This also fixes module handling of tracepoint list iterators, because it
was expecting the list to be sorted by pointer address. Given we have
control on our own list now, it's OK to sort this list which has
tracepoints as its only purpose. The reason why this sorting is required
is to handle the fact that seq files (and any read() operation from
user-space) cannot hold the tracepoint mutex across multiple calls, so
list entries may vanish between calls. With sorting, the tracepoint
iterator becomes usable even if the list don't contain the exact item
pointed to by the iterator anymore.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Jason Baron <jbaron@redhat.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20110810191839.GC8525@Krystal
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-08-10 20:38:14 -04:00
Kay Sievers 88bfa32479 module: add /sys/module/<name>/uevent files
Userspace wants to manage module parameters with udev rules.
This currently only works for loaded modules, but not for
built-in ones.

To allow access to the built-in modules we need to
re-trigger all module load events that happened before any
userspace was running. We already do the same thing for all
devices, subsystems(buses) and drivers.

This adds the currently missing /sys/module/<name>/uevent files
to all module entries.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split & trivial fix)
2011-07-24 22:06:04 +09:30
Kay Sievers 4befb026cf module: change attr callbacks to take struct module_kobject
This simplifies the next patch, where we have an attribute on a
builtin module (ie. module == NULL).

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split into 2)
2011-07-24 22:06:04 +09:30