summaryrefslogtreecommitdiff
path: root/kernel
AgeCommit message (Collapse)Author
2012-10-10MODSIGN: Make mrproper should remove generated files.Rusty Russell
It doesn't, because the clean targets don't include kernel/Makefile, and because two files were missing from the list. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certsDavid Howells
Place an indication that the certificate should use utf8 strings into the x509.genkey template generated by kernel/Makefile. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10MODSIGN: Use the same digest for the autogen key sig as for the module sigDavid Howells
Use the same digest type for the autogenerated key signature as for the module signature so that the hash algorithm is guaranteed to be present in the kernel. Without this, the X.509 certificate loader may reject the X.509 certificate so generated because it was self-signed and the signature will be checked against itself - but this won't work if the digest algorithm must be loaded as a module. The symptom is that the key fails to load with the following message emitted into the kernel log: MODSIGN: Problem loading in-kernel X.509 certificate (-65) the error in brackets being -ENOPKG. What you should see is something like: MODSIGN: Loaded cert 'Magarathea: Glacier signing key: 9588321144239a119d3406d4c4cf1fbae1836fa0' Note that this doesn't apply to certificates that are not self-signed as we don't check those currently as they require the parent CA certificate to be available. Reported-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10MODSIGN: Implement module signature checkingDavid Howells
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: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor Kconfig fix)
2012-10-10MODSIGN: Provide module signing public keys to the kernelDavid Howells
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: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10MODSIGN: Automatically generate module signing keys if missingDavid Howells
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: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10MODSIGN: Add FIPS policyDavid Howells
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>
2012-10-10module: signature checking hookRusty Russell
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>
2012-09-28module: wait when loading a module which is currently initializing.Rusty Russell
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>
2012-09-28module: fix symbol waiting when module fails before initRusty Russell
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>
2012-09-28Make most arch asm/module.h files use asm-generic/module.hDavid Howells
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>
2012-09-28module: taint kernel when lve module is loadedMatthew Garrett
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
2012-09-17Merge branch 'for-3.6-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull another workqueue fix from Tejun Heo: "Unfortunately, yet another late fix. This too is discovered and fixed by Lai. This bug was introduced during this merge window by commit 25511a477657 ("workqueue: reimplement CPU online rebinding to handle idle workers") which started using WORKER_REBIND flag for idle rebind too. The bug is relatively easy to trigger if the CPU rapidly goes through off, on and then off (and stay off). The fix is on the safer side. This hasn't been on linux-next yet but I'm pushing early so that it can get more exposure before v3.6 release." * 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn()
2012-09-17workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn()Lai Jiangshan
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 25511a477 "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: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2012-09-17pid-namespace: limit value of ns_last_pid to (0, max_pid)Andrew Vagin
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: Andrew Vagin <avagin@openvz.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-16Revert "sched: Improve scalability via 'CPU buddies', which withstand random ↵Linus Torvalds
perturbations" This reverts commit 970e178985cadbca660feb02f4d2ee3a09f7fdda. Nikolay Ulyanitsky reported thatthe 3.6-rc5 kernel has a 15-20% performance drop on PostgreSQL 9.2 on his machine (running "pgbench"). Borislav Petkov was able to reproduce this, and bisected it to this commit 970e178985ca ("sched: Improve scalability via 'CPU buddies' ...") apparently because the new single-idle-buddy model simply doesn't find idle CPU's to reschedule on aggressively enough. Mike Galbraith suspects that it is likely due to the user-mode spinlocks in PostgreSQL not reacting well to preemption, but we don't really know the details - I'll just revert the commit for now. There are hopefully other approaches to improve scheduler scalability without it causing these kinds of downsides. Reported-by: Nikolay Ulyanitsky <lystor@gmail.com> Bisected-by: Borislav Petkov <bp@alien8.de> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-14Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Smaller fixlets" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix kernel-doc warnings in kernel/sched/fair.c sched: Unthrottle rt runqueues in __disable_runtime() sched: Add missing call to calc_load_exit_idle() sched: Fix load avg vs cpu-hotplug
2012-09-14Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This tree includes various fixes" Ingo really needs to improve on the whole "explain git pull" part. "Various fixes" indeed. * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/hwpb: Invoke __perf_event_disable() if interrupts are already disabled perf/x86: Enable Intel Cedarview Atom suppport perf_event: Switch to internal refcount, fix race with close() oprofile, s390: Fix uninitialized memory access when writing to oprofilefs perf/x86: Fix microcode revision check for SNB-PEBS
2012-09-12Merge branch 'for-3.6-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fixes from Tejun Heo: "It's later than I'd like but well the timing just didn't work out this time. There are three bug fixes. One from before 3.6-rc1 and two from the new CPU hotplug code. Kudos to Lai for discovering all of them and providing fixes. * Atomicity bug when clearing a flag and setting another. The two operation should have been atomic but wasn't. This bug has existed for a long time but is unlikely to have actually happened. Fix is safe. Marked for -stable. * If CPU hotplug cycles happen back-to-back before workers finish the previous cycle, the states could get out of sync and it could get stuck. Fixed by waiting for workers to complete before finishing hotplug cycle. * While CPU hotplug is in progress, idle workers could be depleted which can then lead to deadlock. I think both happening together is highly unlikely but still better to fix it and the fix isn't too scary. There's another workqueue related regression which reported a few days ago: https://bugzilla.kernel.org/show_bug.cgi?id=47301 It's a bit of head scratcher but there is a semi-reliable reproduce case, so I'm hoping to resolve it soonish." * 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: fix possible idle worker depletion across CPU hotplug workqueue: restore POOL_MANAGING_WORKERS workqueue: fix possible deadlock in idle worker rebinding workqueue: move WORKER_REBIND clearing in rebind_workers() to the end of the function workqueue: UNBOUND -> REBIND morphing in rebind_workers() should be atomic
2012-09-10workqueue: fix possible idle worker depletion across CPU hotplugLai Jiangshan
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: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2012-09-10workqueue: restore POOL_MANAGING_WORKERSLai Jiangshan
This patch restores POOL_MANAGING_WORKERS which was replaced by pool->manager_mutex by 6037315269 "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: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2012-09-05workqueue: fix possible deadlock in idle worker rebindingTejun Heo
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: Tejun Heo <tj@kernel.org> Original-patch-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <1346516916-1991-3-git-send-email-laijs@cn.fujitsu.com>
2012-09-05workqueue: move WORKER_REBIND clearing in rebind_workers() to the end of the ↵Tejun Heo
function This doesn't make any functional difference and is purely to help the next patch to be simpler. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
2012-09-04workqueue: UNBOUND -> REBIND morphing in rebind_workers() should be atomicLai Jiangshan
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: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org
2012-09-04perf/hwpb: Invoke __perf_event_disable() if interrupts are already disabledK.Prasad
While debugging a warning message on PowerPC while using hardware breakpoints, it was discovered that when perf_event_disable is invoked through hw_breakpoint_handler function with interrupts disabled, a subsequent IPI in the code path would trigger a WARN_ON_ONCE message in smp_call_function_single function. This patch calls __perf_event_disable() when interrupts are already disabled, instead of perf_event_disable(). Reported-by: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com> Signed-off-by: K.Prasad <Prasad.Krishnan@gmail.com> [naveen.n.rao@linux.vnet.ibm.com: v3: Check to make sure we target current task] Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120802081635.5811.17737.stgit@localhost.localdomain [ Fixed build error on MIPS. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-04perf_event: Switch to internal refcount, fix race with close()Al Viro
Don't mess with file refcounts (or keep a reference to file, for that matter) in perf_event. Use explicit refcount of its own instead. Deal with the race between the final reference to event going away and new children getting created for it by use of atomic_long_inc_not_zero() in inherit_event(); just have the latter free what it had allocated and return NULL, that works out just fine (children of siblings of something doomed are created as singletons, same as if the child of leader had been created and immediately killed). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120820135925.GG23464@ZenIV.linux.org.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-04sched: Fix kernel-doc warnings in kernel/sched/fair.cRandy Dunlap
Fix two kernel-doc warnings in kernel/sched/fair.c: Warning(kernel/sched/fair.c:3660): Excess function parameter 'cpus' description in 'update_sg_lb_stats' Warning(kernel/sched/fair.c:3806): Excess function parameter 'cpus' description in 'update_sd_lb_stats' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/50303714.3090204@xenotime.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-04sched: Unthrottle rt runqueues in __disable_runtime()Peter Boonstoppel
migrate_tasks() uses _pick_next_task_rt() to get tasks from the real-time runqueues to be migrated. When rt_rq is throttled _pick_next_task_rt() won't return anything, in which case migrate_tasks() can't move all threads over and gets stuck in an infinite loop. Instead unthrottle rt runqueues before migrating tasks. Additionally: move unthrottle_offline_cfs_rqs() to rq_offline_fair() Signed-off-by: Peter Boonstoppel <pboonstoppel@nvidia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/r/5FBF8E85CA34454794F0F7ECBA79798F379D3648B7@HQMAIL04.nvidia.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-04sched: Add missing call to calc_load_exit_idle()Charles Wang
Azat Khuzhin reported high loadavg in Linux v3.6 After checking the upstream scheduler code, I found Peter's commit: 5167e8d5417b sched/nohz: Rewrite and fix load-avg computation -- again not fully applied, missing the call to calc_load_exit_idle(). After that idle exit in sampling window will always be calculated to non-idle, and the load will be higher than normal. This patch adds the missing call to calc_load_exit_idle(). Signed-off-by: Charles Wang <muming.wq@taobao.com> Cc: stable@kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1345449754-27130-1-git-send-email-muming.wq@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-04sched: Fix load avg vs cpu-hotplugPeter Zijlstra
Rabik and Paul reported two different issues related to the same few lines of code. Rabik's issue is that the nr_uninterruptible migration code is wrong in that he sees artifacts due to this (Rabik please do expand in more detail). Paul's issue is that this code as it stands relies on us using stop_machine() for unplug, we all would like to remove this assumption so that eventually we can remove this stop_machine() usage altogether. The only reason we'd have to migrate nr_uninterruptible is so that we could use for_each_online_cpu() loops in favour of for_each_possible_cpu() loops, however since nr_uninterruptible() is the only such loop and its using possible lets not bother at all. The problem Rabik sees is (probably) caused by the fact that by migrating nr_uninterruptible we screw rq->calc_load_active for both rqs involved. So don't bother with fancy migration schemes (meaning we now have to keep using for_each_possible_cpu()) and instead fold any nr_active delta after we migrate all tasks away to make sure we don't have any skewed nr_active accounting. Reported-by: Rakib Mullick <rakib.mullick@gmail.com> Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1345454817.23018.27.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-01time: Move ktime_t overflow checking into timespec_valid_strictJohn Stultz
Andreas Bombe reported that the added ktime_t overflow checking added to timespec_valid in commit 4e8b14526ca7 ("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: Andreas 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: John Stultz <john.stultz@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-23Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This tree contains misc fixlets: a perf script python binding fix, a uprobes fix and a syscall tracing fix." * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf tools: Add missing files to build the python binding uprobes: Fix mmap_region()'s mm->mm_rb corruption if uprobe_mmap() fails tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1
2012-08-23Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "Mostly small fixes for the fallout of the timekeeping overhaul in 3.6 along with stable fixes to address an accumulation problem and missing sanity checks for RTC readouts and user space provided values." * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Avoid making adjustments if we haven't accumulated anything time: Avoid potential shift overflow with large shift values time: Fix casting issue in timekeeping_forward_now time: Ensure we normalize the timekeeper in tk_xtime_add time: Improve sanity checking of timekeeping inputs
2012-08-22time: Avoid making adjustments if we haven't accumulated anythingJohn Stultz
If update_wall_time() is called and the current offset isn't large enough to accumulate, avoid re-calling timekeeping_adjust which may change the clock freq and can cause 1ns inconsistencies with CLOCK_REALTIME_COARSE/CLOCK_MONOTONIC_COARSE. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1345595449-34965-5-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-22time: Avoid potential shift overflow with large shift valuesJohn Stultz
Andreas Schwab noticed that the 1 << tk->shift could overflow if the shift value was greater than 30, since 1 would be a 32bit long on 32bit architectures. This issue was introduced by 1e75fa8be (time: Condense timekeeper.xtime into xtime_sec) Use 1ULL instead to ensure we don't overflow on the shift. Reported-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/1345595449-34965-4-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-22time: Fix casting issue in timekeeping_forward_nowAndreas Schwab
arch_gettimeoffset returns a u32 value which when shifted by tk->shift can overflow. This issue was introduced with 1e75fa8be (time: Condense timekeeper.xtime into xtime_sec) Cast it to u64 first. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/1345595449-34965-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-22time: Ensure we normalize the timekeeper in tk_xtime_addJohn Stultz
Andreas noticed problems with resume on specific hardware after commit 1e75fa8b (time: Condense timekeeper.xtime into xtime_sec) combined with commit b44d50dca (time: Fix casting issue in tk_set_xtime and tk_xtime_add) After some digging I realized we aren't normalizing the timekeeper after the add. Add the missing normalize call. Reported-by: Andreas Schwab <schwab@linux-m68k.org> Tested-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/1345595449-34965-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-21Merge branch 'audit-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull audit-tree fixes from Miklos Szeredi: "The audit subsystem maintainers (Al and Eric) are not responding to repeated resends. Eric did ack them a while ago, but no response since then. So I'm sending these directly to you." * 'audit-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: audit: clean up refcounting in audit-tree audit: fix refcounting in audit-tree audit: don't free_chunk() after fsnotify_add_mark()
2012-08-21task_work: add a scheduling point in task_work_run()Eric Dumazet
It seems commit 4a9d4b024a31 ("switch fput to task_work_add") re- introduced the problem addressed in 944be0b22472 ("close_files(): add scheduling point") If a server process with a lot of files (say 2 million tcp sockets) is killed, we can spend a lot of time in task_work_run() and trigger a soft lockup. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-21Merge branch 'tip/perf/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull syscall tracing fix from Steve Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-08-21uprobes: Fix mmap_region()'s mm->mm_rb corruption if uprobe_mmap() failsOleg Nesterov
This patch fixes: https://bugzilla.redhat.com/show_bug.cgi?id=843640 If mmap_region()->uprobe_mmap() fails, unmap_and_free_vma path does unmap_region() but does not remove the soon-to-be-freed vma from rb tree. Actually there are more problems but this is how William noticed this bug. Perhaps we could do do_munmap() + return in this case, but in fact it is simply wrong to abort if uprobe_mmap() fails. Until at least we move the !UPROBE_COPY_INSN code from install_breakpoint() to uprobe_register(). For example, uprobe_mmap()->install_breakpoint() can fail if the probed insn is not supported (remember, uprobe_register() succeeds if nobody mmaps inode/offset), mmap() should not fail in this case. dup_mmap()->uprobe_mmap() is wrong too by the same reason, fork() can race with uprobe_register() and fail for no reason if it wins the race and does install_breakpoint() first. And, if nothing else, both mmap_region() and dup_mmap() return success if uprobe_mmap() fails. Change them to ignore the error code from uprobe_mmap(). Reported-and-tested-by: William Cohen <wcohen@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> # v3.5 Cc: Anton Arapov <anton@redhat.com> Cc: William Cohen <wcohen@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20120819171042.GB26957@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-08-20Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar. * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix migration thread runtime bogosity sched,rt: fix isolated CPUs leaving root_task_group indefinitely throttled sched,cgroup: Fix up task_groups list sched: fix divide by zero at {thread_group,task}_times sched, cgroup: Reduce rq->lock hold times for large cgroup hierarchies
2012-08-19Merge branch 'alpha' (alpha architecture patches)Linus Torvalds
Merge alpha architecture update from Michael Cree: "The Alpha Maintainer, Matt Turner, is currently unavailable, so I have collected up patches that have been posted to the linux-alpha mailing list over the last couple of months, and are forwarding them to you in the hope that you are prepared to accept them via me. The patches by Al Viro and myself I have been running against kernels for two months now so have had quite a bit of testing. All except one patch were intended for the 3.5 kernel but because of Matt's unavailability never got forwarded to you." * emailed patches from Michael Cree <mcree@orcon.net.nz>: (9 commits) alpha: Fix fall-out from disintegrating asm/system.h Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the casts alpha: fix fpu.h usage in userspace alpha/mm/fault.c: Port OOM changes to do_page_fault alpha: take kernel_execve() out of entry.S alpha: take a bunch of syscalls into osf_sys.c alpha: Use new generic strncpy_from_user() and strnlen_user() alpha: Wire up cross memory attach syscalls alpha: Don't export SOCK_NONBLOCK to user space.
2012-08-19alpha: take a bunch of syscalls into osf_sys.cAl Viro
New helper: current_thread_info(). Allows to do a bunch of odd syscalls in C. While we are at it, there had never been a reason to do osf_getpriority() in assembler. We also get "namespace"-aware (read: consistent with getuid(2), etc.) behaviour from getx?id() syscalls now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Michael Cree <mcree@orcon.net.nz> Acked-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-17tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1Will Deacon
syscall_get_nr can return -1 in the case that the task is not executing a system call. This patch fixes perf_syscall_{enter,exit} to check that the syscall number is valid before using it as an index into a bitmap. Link: http://lkml.kernel.org/r/1345137254-7377-1-git-send-email-will.deacon@arm.com Cc: Jason Baron <jbaron@redhat.com> Cc: Wade Farnsworth <wade_farnsworth@mentor.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-08-15time: Improve sanity checking of timekeeping inputsJohn Stultz
Unexpected behavior could occur if the time is set to a value large enough to overflow a 64bit ktime_t (which is something larger then the year 2262). Also unexpected behavior could occur if large negative offsets are injected via adjtimex. So this patch improves the sanity check timekeeping inputs by improving the timespec_valid() check, and then makes better use of timespec_valid() to make sure we don't set the time to an invalid negative value or one that overflows ktime_t. Note: This does not protect from setting the time close to overflowing ktime_t and then letting natural accumulation cause the overflow. Reported-by: CAI Qian <caiqian@redhat.com> Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Zhouping Liu <zliu@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1344454580-17031-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-15audit: clean up refcounting in audit-treeMiklos Szeredi
Drop the initial reference by fsnotify_init_mark early instead of audit_tree_freeing_mark() at destroy time. In the cases we destroy the mark before we drop the initial reference we need to get rid of the get_mark that balances the put_mark in audit_tree_freeing_mark(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2012-08-15audit: fix refcounting in audit-treeMiklos Szeredi
Refcounting of fsnotify_mark in audit tree is broken. E.g: refcount create_chunk alloc_chunk 1 fsnotify_add_mark 2 untag_chunk fsnotify_get_mark 3 fsnotify_destroy_mark audit_tree_freeing_mark 2 fsnotify_put_mark 1 fsnotify_put_mark 0 via destroy_list fsnotify_mark_destroy -1 This was reported by various people as triggering Oops when stopping auditd. We could just remove the put_mark from audit_tree_freeing_mark() but that would break freeing via inode destruction. So this patch simply omits a put_mark after calling destroy_mark or adds a get_mark before. The additional get_mark is necessary where there's no other put_mark after fsnotify_destroy_mark() since it assumes that the caller is holding a reference (or the inode is keeping the mark pinned, not the case here AFAICS). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reported-by: Valentin Avram <aval13@gmail.com> Reported-by: Peter Moody <pmoody@google.com> Acked-by: Eric Paris <eparis@redhat.com> CC: stable@vger.kernel.org
2012-08-15audit: don't free_chunk() after fsnotify_add_mark()Miklos Szeredi
Don't do free_chunk() after fsnotify_add_mark(). That one does a delayed unref via the destroy list and this results in use-after-free. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Acked-by: Eric Paris <eparis@redhat.com> CC: stable@vger.kernel.org
2012-08-13sched: Fix migration thread runtime bogosityMike Galbraith
Make stop scheduler class do the same accounting as other classes, Migration threads can be caught in the act while doing exec balancing, leading to the below due to use of unmaintained ->se.exec_start. The load that triggered this particular instance was an apparently out of control heavily threaded application that does system monitoring in what equated to an exec bomb, with one of the VERY frequently migrated tasks being ps. %CPU PID USER CMD 99.3 45 root [migration/10] 97.7 53 root [migration/12] 97.0 57 root [migration/13] 90.1 49 root [migration/11] 89.6 65 root [migration/15] 88.7 17 root [migration/3] 80.4 37 root [migration/8] 78.1 41 root [migration/9] 44.2 13 root [migration/2] Signed-off-by: Mike Galbraith <mgalbraith@suse.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1344051854.6739.19.camel@marge.simpson.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>