1. 10 10月, 2012 5 次提交
    • D
      MODSIGN: Implement module signature checking · 48ba2462
      David Howells 提交于
      Check the signature on the module against the keys compiled into the kernel or
      available in a hardware key store.
      
      Currently, only RSA keys are supported - though that's easy enough to change,
      and the signature is expected to contain raw components (so not a PGP or
      PKCS#7 formatted blob).
      
      The signature blob is expected to consist of the following pieces in order:
      
       (1) The binary identifier for the key.  This is expected to match the
           SubjectKeyIdentifier from an X.509 certificate.  Only X.509 type
           identifiers are currently supported.
      
       (2) The signature data, consisting of a series of MPIs in which each is in
           the format of a 2-byte BE word sizes followed by the content data.
      
       (3) A 12 byte information block of the form:
      
      	struct module_signature {
      		enum pkey_algo		algo : 8;
      		enum pkey_hash_algo	hash : 8;
      		enum pkey_id_type	id_type : 8;
      		u8			__pad;
      		__be32			id_length;
      		__be32			sig_length;
      	};
      
           The three enums are defined in crypto/public_key.h.
      
           'algo' contains the public-key algorithm identifier (0->DSA, 1->RSA).
      
           'hash' contains the digest algorithm identifier (0->MD4, 1->MD5, 2->SHA1,
            etc.).
      
           'id_type' contains the public-key identifier type (0->PGP, 1->X.509).
      
           '__pad' should be 0.
      
           'id_length' should contain in the binary identifier length in BE form.
      
           'sig_length' should contain in the signature data length in BE form.
      
           The lengths are in BE order rather than CPU order to make dealing with
           cross-compilation easier.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor Kconfig fix)
      48ba2462
    • D
      MODSIGN: Provide module signing public keys to the kernel · 631cc66e
      David Howells 提交于
      Include a PGP keyring containing the public keys required to perform module
      verification in the kernel image during build and create a special keyring
      during boot which is then populated with keys of crypto type holding the public
      keys found in the PGP keyring.
      
      These can be seen by root:
      
      [root@andromeda ~]# cat /proc/keys
      07ad4ee0 I-----     1 perm 3f010000     0     0 crypto    modsign.0: RSA 87b9b3bd []
      15c7f8c3 I-----     1 perm 1f030000     0     0 keyring   .module_sign: 1/4
      ...
      
      It is probably worth permitting root to invalidate these keys, resulting in
      their removal and preventing further modules from being loaded with that key.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      631cc66e
    • D
      MODSIGN: Automatically generate module signing keys if missing · d441108c
      David Howells 提交于
      Automatically generate keys for module signing if they're absent so that
      allyesconfig doesn't break.  The builder should consider generating their own
      key and certificate, however, so that the keys are appropriately named.
      
      The private key for the module signer should be placed in signing_key.priv
      (unencrypted!) and the public key in an X.509 certificate as signing_key.x509.
      
      If a transient key is desired for signing the modules, a config file for
      'openssl req' can be placed in x509.genkey, looking something like the
      following:
      
      	[ req ]
      	default_bits = 4096
      	distinguished_name = req_distinguished_name
      	prompt = no
      	x509_extensions = myexts
      
      	[ req_distinguished_name ]
      	O = Magarathea
      	CN = Glacier signing key
      	emailAddress = slartibartfast@magrathea.h2g2
      
      	[ myexts ]
      	basicConstraints=critical,CA:FALSE
      	keyUsage=digitalSignature
      	subjectKeyIdentifier=hash
      	authorityKeyIdentifier=hash
      
      The build process will use this to configure:
      
      	openssl req -new -nodes -utf8 -sha1 -days 36500 -batch \
      		-x509 -config x509.genkey \
      		-outform DER -out signing_key.x509 \
      		-keyout signing_key.priv
      
      to generate the key.
      
      Note that it is required that the X.509 certificate have a subjectKeyIdentifier
      and an authorityKeyIdentifier.  Without those, the certificate will be
      rejected.  These can be used to check the validity of a certificate.
      
      Note that 'make distclean' will remove signing_key.{priv,x509} and x509.genkey,
      whether or not they were generated automatically.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      d441108c
    • D
      MODSIGN: Add FIPS policy · 1d0059f3
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      1d0059f3
    • R
      module: signature checking hook · 106a4ee2
      Rusty Russell 提交于
      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: NRusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      106a4ee2
  2. 28 9月, 2012 4 次提交
    • R
      module: wait when loading a module which is currently initializing. · 9bb9c3be
      Rusty Russell 提交于
      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: NLucas De Marchi <lucas.demarchi@profusion.mobi>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      9bb9c3be
    • R
      module: fix symbol waiting when module fails before init · 6f13909f
      Rusty Russell 提交于
      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: NRusty Russell <rusty@rustcorp.com.au>
      6f13909f
    • D
      Make most arch asm/module.h files use asm-generic/module.h · 786d35d4
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      Acked-by: NSam Ravnborg <sam@ravnborg.org>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      786d35d4
    • M
      module: taint kernel when lve module is loaded · c99af375
      Matthew Garrett 提交于
      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: NMatthew Garrett <mjg59@srcf.ucam.org>
      Cc: Alex Lyashkov <umka@cloudlinux.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Cc: stable@kernel.org
      c99af375
  3. 18 9月, 2012 2 次提交
    • L
      workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn() · 960bd11b
      Lai Jiangshan 提交于
      busy_worker_rebind_fn() didn't clear WORKER_REBIND if rebinding failed
      (CPU is down again).  This used to be okay because the flag wasn't
      used for anything else.
      
      However, after 25511a47 "workqueue: reimplement CPU online rebinding
      to handle idle workers", WORKER_REBIND is also used to command idle
      workers to rebind.  If not cleared, the worker may confuse the next
      CPU_UP cycle by having REBIND spuriously set or oops / get stuck by
      prematurely calling idle_worker_rebind().
      
        WARNING: at /work/os/wq/kernel/workqueue.c:1323 worker_thread+0x4cd/0x5
       00()
        Hardware name: Bochs
        Modules linked in: test_wq(O-)
        Pid: 33, comm: kworker/1:1 Tainted: G           O 3.6.0-rc1-work+ #3
        Call Trace:
         [<ffffffff8109039f>] warn_slowpath_common+0x7f/0xc0
         [<ffffffff810903fa>] warn_slowpath_null+0x1a/0x20
         [<ffffffff810b3f1d>] worker_thread+0x4cd/0x500
         [<ffffffff810bc16e>] kthread+0xbe/0xd0
         [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
        ---[ end trace e977cf20f4661968 ]---
        BUG: unable to handle kernel NULL pointer dereference at           (null)
        IP: [<ffffffff810b3db0>] worker_thread+0x360/0x500
        PGD 0
        Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
        Modules linked in: test_wq(O-)
        CPU 0
        Pid: 33, comm: kworker/1:1 Tainted: G        W  O 3.6.0-rc1-work+ #3 Bochs Bochs
        RIP: 0010:[<ffffffff810b3db0>]  [<ffffffff810b3db0>] worker_thread+0x360/0x500
        RSP: 0018:ffff88001e1c9de0  EFLAGS: 00010086
        RAX: 0000000000000000 RBX: ffff88001e633e00 RCX: 0000000000004140
        RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
        RBP: ffff88001e1c9ea0 R08: 0000000000000000 R09: 0000000000000001
        R10: 0000000000000002 R11: 0000000000000000 R12: ffff88001fc8d580
        R13: ffff88001fc8d590 R14: ffff88001e633e20 R15: ffff88001e1c6900
        FS:  0000000000000000(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
        CR2: 0000000000000000 CR3: 00000000130e8000 CR4: 00000000000006f0
        DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
        DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
        Process kworker/1:1 (pid: 33, threadinfo ffff88001e1c8000, task ffff88001e1c6900)
        Stack:
         ffff880000000000 ffff88001e1c9e40 0000000000000001 ffff88001e1c8010
         ffff88001e519c78 ffff88001e1c9e58 ffff88001e1c6900 ffff88001e1c6900
         ffff88001e1c6900 ffff88001e1c6900 ffff88001fc8d340 ffff88001fc8d340
        Call Trace:
         [<ffffffff810bc16e>] kthread+0xbe/0xd0
         [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
        Code: b1 00 f6 43 48 02 0f 85 91 01 00 00 48 8b 43 38 48 89 df 48 8b 00 48 89 45 90 e8 ac f0 ff ff 3c 01 0f 85 60 01 00 00 48 8b 53 50 <8b> 02 83 e8 01 85 c0 89 02 0f 84 3b 01 00 00 48 8b 43 38 48 8b
        RIP  [<ffffffff810b3db0>] worker_thread+0x360/0x500
         RSP <ffff88001e1c9de0>
        CR2: 0000000000000000
      
      There was no reason to keep WORKER_REBIND on failure in the first
      place - WORKER_UNBOUND is guaranteed to be set in such cases
      preventing incorrectly activating concurrency management.  Always
      clear WORKER_REBIND.
      
      tj: Updated comment and description.
      Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      960bd11b
    • A
      pid-namespace: limit value of ns_last_pid to (0, max_pid) · 579035dc
      Andrew Vagin 提交于
      The kernel doesn't check the pid for negative values, so if you try to
      write -2 to /proc/sys/kernel/ns_last_pid, you will get a kernel panic.
      
      The crash happens because the next pid is -1, and alloc_pidmap() will
      try to access to a nonexistent pidmap.
      
        map = &pid_ns->pidmap[pid/BITS_PER_PAGE];
      Signed-off-by: NAndrew Vagin <avagin@openvz.org>
      Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
      Acked-by: NOleg Nesterov <oleg@redhat.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      579035dc
  4. 17 9月, 2012 1 次提交
  5. 11 9月, 2012 2 次提交
    • L
      workqueue: fix possible idle worker depletion across CPU hotplug · ee378aa4
      Lai Jiangshan 提交于
      To simplify both normal and CPU hotplug paths, worker management is
      prevented while CPU hoplug is in progress.  This is achieved by CPU
      hotplug holding the same exclusion mechanism used by workers to ensure
      there's only one manager per pool.
      
      If someone else seems to be performing the manager role, workers
      proceed to execute work items.  CPU hotplug using the same mechanism
      can lead to idle worker depletion because all workers could proceed to
      execute work items while CPU hotplug is in progress and CPU hotplug
      itself wouldn't actually perform the worker management duty - it
      doesn't guarantee that there's an idle worker left when it releases
      management.
      
      This idle worker depletion, under extreme circumstances, can break
      forward-progress guarantee and thus lead to deadlock.
      
      This patch fixes the bug by using separate mechanisms for manager
      exclusion among workers and hotplug exclusion.  For manager exclusion,
      POOL_MANAGING_WORKERS which was restored by the previous patch is
      used.  pool->manager_mutex is now only used for exclusion between the
      elected manager and CPU hotplug.  The elected manager won't proceed
      without holding pool->manager_mutex.
      
      This ensures that the worker which won the manager position can't skip
      managing while CPU hotplug is in progress.  It will block on
      manager_mutex and perform management after CPU hotplug is complete.
      
      Note that hotplug may happen while waiting for manager_mutex.  A
      manager isn't either on idle or busy list and thus the hoplug code
      can't unbind/rebind it.  Make the manager handle its own un/rebinding.
      
      tj: Updated comment and description.
      Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      ee378aa4
    • L
      workqueue: restore POOL_MANAGING_WORKERS · 552a37e9
      Lai Jiangshan 提交于
      This patch restores POOL_MANAGING_WORKERS which was replaced by
      pool->manager_mutex by 60373152 "workqueue: use mutex for global_cwq
      manager exclusion".
      
      There's a subtle idle worker depletion bug across CPU hotplug events
      and we need to distinguish an actual manager and CPU hotplug
      preventing management.  POOL_MANAGING_WORKERS will be used for the
      former and manager_mutex the later.
      
      This patch just lays POOL_MANAGING_WORKERS on top of the existing
      manager_mutex and doesn't introduce any synchronization changes.  The
      next patch will update it.
      
      Note that this patch fixes a non-critical anomaly where
      too_many_workers() may return %true spuriously while CPU hotplug is in
      progress.  While the issue could schedule idle timer spuriously, it
      didn't trigger any actual misbehavior.
      
      tj: Rewrote patch description.
      Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      552a37e9
  6. 06 9月, 2012 2 次提交
    • T
      workqueue: fix possible deadlock in idle worker rebinding · ec58815a
      Tejun Heo 提交于
      Currently, rebind_workers() and idle_worker_rebind() are two-way
      interlocked.  rebind_workers() waits for idle workers to finish
      rebinding and rebound idle workers wait for rebind_workers() to finish
      rebinding busy workers before proceeding.
      
      Unfortunately, this isn't enough.  The second wait from idle workers
      is implemented as follows.
      
      	wait_event(gcwq->rebind_hold, !(worker->flags & WORKER_REBIND));
      
      rebind_workers() clears WORKER_REBIND, wakes up the idle workers and
      then returns.  If CPU hotplug cycle happens again before one of the
      idle workers finishes the above wait_event(), rebind_workers() will
      repeat the first part of the handshake - set WORKER_REBIND again and
      wait for the idle worker to finish rebinding - and this leads to
      deadlock because the idle worker would be waiting for WORKER_REBIND to
      clear.
      
      This is fixed by adding another interlocking step at the end -
      rebind_workers() now waits for all the idle workers to finish the
      above WORKER_REBIND wait before returning.  This ensures that all
      rebinding steps are complete on all idle workers before the next
      hotplug cycle can happen.
      
      This problem was diagnosed by Lai Jiangshan who also posted a patch to
      fix the issue, upon which this patch is based.
      
      This is the minimal fix and further patches are scheduled for the next
      merge window to simplify the CPU hotplug path.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Original-patch-by: NLai Jiangshan <laijs@cn.fujitsu.com>
      LKML-Reference: <1346516916-1991-3-git-send-email-laijs@cn.fujitsu.com>
      ec58815a
    • T
      workqueue: move WORKER_REBIND clearing in rebind_workers() to the end of the function · 90beca5d
      Tejun Heo 提交于
      This doesn't make any functional difference and is purely to help the
      next patch to be simpler.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      90beca5d
  7. 05 9月, 2012 1 次提交
    • L
      workqueue: UNBOUND -> REBIND morphing in rebind_workers() should be atomic · 96e65306
      Lai Jiangshan 提交于
      The compiler may compile the following code into TWO write/modify
      instructions.
      
      	worker->flags &= ~WORKER_UNBOUND;
      	worker->flags |= WORKER_REBIND;
      
      so the other CPU may temporarily see worker->flags which doesn't have
      either WORKER_UNBOUND or WORKER_REBIND set and perform local wakeup
      prematurely.
      
      Fix it by using single explicit assignment via ACCESS_ONCE().
      
      Because idle workers have another WORKER_NOT_RUNNING flag, this bug
      doesn't exist for them; however, update it to use the same pattern for
      consistency.
      
      tj: Applied the change to idle workers too and updated comments and
          patch description a bit.
      Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: stable@vger.kernel.org
      96e65306
  8. 04 9月, 2012 6 次提交
  9. 02 9月, 2012 1 次提交
    • J
      time: Move ktime_t overflow checking into timespec_valid_strict · cee58483
      John Stultz 提交于
      Andreas Bombe reported that the added ktime_t overflow checking added to
      timespec_valid in commit 4e8b1452 ("time: Improve sanity checking of
      timekeeping inputs") was causing problems with X.org because it caused
      timeouts larger then KTIME_T to be invalid.
      
      Previously, these large timeouts would be clamped to KTIME_MAX and would
      never expire, which is valid.
      
      This patch splits the ktime_t overflow checking into a new
      timespec_valid_strict function, and converts the timekeeping codes
      internal checking to use this more strict function.
      Reported-and-tested-by: NAndreas Bombe <aeb@debian.org>
      Cc: Zhouping Liu <zliu@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: stable@vger.kernel.org
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cee58483
  10. 22 8月, 2012 6 次提交
  11. 21 8月, 2012 1 次提交
  12. 19 8月, 2012 1 次提交
  13. 18 8月, 2012 1 次提交
  14. 15 8月, 2012 4 次提交
  15. 14 8月, 2012 3 次提交