Linus Torvalds
4e02370f64
During testing Sedat Dilek hit a "suspicious RCU usage" splat that pointed ...
out a real bug. During suspend and resume the tlb_flush tracepoint is
called when the CPU is going offline. As the CPU has been noted as offline,
RCU is ignoring that CPU, which means that it can not use RCU protected
locks. When tracepoints are activated, they require RCU locking, and
if RCU is ignoring a CPU that runs a tracepoint, there is a chance that
the tracepoint could cause corruption.
The solution was to change the tracepoint into a TRACE_EVENT_CONDITION()
which allows us to check a condition to determine if the tracepoint
should be called or not. If the condition is not met, the rcu protected
code will not be executed. By adding the condition
"cpu_online(smp_processor_id())", this will prevent the RCU protected
code from being executed if the CPU is marked offline.
After adding this, another bug was discovered. As RCU checks rcu callers,
if a rcu call is not done, there is no check (obviously). We found that
tracepoints could be added in RCU ignored locations and not have lockdep
complain until the tracepoint is activated. This missed places where
tracepoints were added in places they should not have been. To fix this,
code was added in 3.18 that if lockdep is enabled, any tracepoint will
still call the rcu checks even if the tracepoint is not enabled. The bug
here, is that the check does not take the CONDITION into account. As the
condition may prevent tracepoints from being activated in RCU ignored
areas (as the one patch does), we get false positives when we enable
lockdep and hit a tracepoint that the condition prevents it from being
called in a RCU ignored location. The fix for this is to add the
CONDITION to the rcu checks, even if the tracepoint is not enabled.
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Merge tag 'trace-fixes-v3.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace fixes from Steven Rostedt:
"During testing Sedat Dilek hit a "suspicious RCU usage" splat that
pointed out a real bug. During suspend and resume the tlb_flush
tracepoint is called when the CPU is going offline. As the CPU has
been noted as offline, RCU is ignoring that CPU, which means that it
can not use RCU protected locks. When tracepoints are activated, they
require RCU locking, and if RCU is ignoring a CPU that runs a
tracepoint, there is a chance that the tracepoint could cause
corruption.
The solution was to change the tracepoint into a
TRACE_EVENT_CONDITION() which allows us to check a condition to
determine if the tracepoint should be called or not. If the condition
is not met, the rcu protected code will not be executed. By adding
the condition "cpu_online(smp_processor_id())", this will prevent the
RCU protected code from being executed if the CPU is marked offline.
After adding this, another bug was discovered. As RCU checks rcu
callers, if a rcu call is not done, there is no check (obviously). We
found that tracepoints could be added in RCU ignored locations and not
have lockdep complain until the tracepoint is activated. This missed
places where tracepoints were added in places they should not have
been. To fix this, code was added in 3.18 that if lockdep is enabled,
any tracepoint will still call the rcu checks even if the tracepoint
is not enabled. The bug here, is that the check does not take the
CONDITION into account. As the condition may prevent tracepoints from
being activated in RCU ignored areas (as the one patch does), we get
false positives when we enable lockdep and hit a tracepoint that the
condition prevents it from being called in a RCU ignored location.
The fix for this is to add the CONDITION to the rcu checks, even if
the tracepoint is not enabled"
* tag 'trace-fixes-v3.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
x86/tlb/trace: Do not trace on CPU that is offline
tracing: Add condition check to RCU lockdep checks
2015-02-08 18:08:14 -08:00
Char/Misc driver patches for 3.19-rc1
2014-12-14 16:43:47 -08:00
can: dev: Consolidate and unify state change handling
2014-12-07 21:22:09 +01:00
libceph: fix sparse endianness warnings
2015-01-08 20:36:57 +03:00
ARM: OMAP2+: clock: fix DPLL code to use new determine rate APIs
2014-12-15 17:05:08 -08:00
fsl /bestcomm
This is the bulk of GPIO changes for the v3.19 series:
2014-12-14 14:05:05 -08:00
USB patches for 3.19-rc1
2014-12-14 14:57:16 -08:00
Merge 3.18-rc7 into staging-work.
2014-12-02 16:20:59 -08:00
Merge branch 'irq-irqdomain-arm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-12-15 17:30:09 -08:00
lockd: eliminate LOCKD_DEBUG
2014-11-24 17:24:08 -05:00
Merge remote-tracking branch 'regulator/fix/s2mps11' into regulator-linus
2015-01-16 12:05:35 +00:00
net/mlx4_core: Fix kernel Oops (mem corruption) when working with more than 80 VFs
2015-02-02 19:38:04 -08:00
IB/mlx5: Handle page faults
2014-12-15 18:19:03 -08:00
mmc: sdhci: Disable re-tuning for HS400
2015-01-12 10:14:56 +01:00
mtd: nand: add ATO manufacturer info
2014-11-25 20:11:12 -08:00
phy: phy-ti-pipe3: fix inconsistent enumeration of PCIe gen2 cards
2014-12-23 15:44:32 +05:30
Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
2014-12-15 15:52:01 -08:00
Merge remote-tracking branches 'regulator/topic/sky81452' and 'regulator/topic/stub' into regulator-next
2014-12-05 11:14:43 +00:00
soc /ti
spi: core: Add spi_transfer_is_last() helper
2014-11-24 18:53:42 +00:00
sunrpc: convert to lockless lookup of queued server threads
2014-12-09 11:22:22 -05:00
USB patches for 3.19-rc1
2014-12-14 14:57:16 -08:00
ACPI / processor: Rename acpi_(un)map_lsapic() to acpi_(un)map_cpu()
2015-01-05 23:34:26 +01:00
Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
2014-12-23 18:13:16 -08:00
syscalls: implement execveat() system call
2014-12-13 12:42:51 -08:00
blk: introduce generic io stat accounting help function
2014-11-24 08:04:44 -07:00
Driver core patches for 3.19-rc1
2014-12-14 16:10:09 -08:00
blk-mq: Add helper to abort requeued requests
2015-01-08 08:55:53 -07:00
blk-mq: Allow requests to never expire
2015-01-08 08:59:01 -07:00
Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
2014-12-13 14:14:23 -08:00
net: sock: allow eBPF programs to be attached to sockets
2014-12-05 21:47:32 -08:00
Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2014-12-11 18:57:19 -08:00
clk: Change clk_ops->determine_rate to return a clk_hw as the best parent
2014-12-03 16:21:37 -08:00
mm: cma: split cma-reserved in dmesg log
2014-12-18 19:08:10 -08:00
mm, compaction: simplify deferred compaction
2014-12-10 17:41:06 -08:00
syscalls: implement execveat() system call
2014-12-13 12:42:51 -08:00
kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)
2015-01-13 20:39:09 +01:00
coresight: fixed comments in coresight.h
2014-11-26 19:28:11 -08:00
thermal: cpu_cooling: return ERR_PTR() for !CPU_THERMAL or !THERMAL_OF
2014-12-17 09:00:04 -04:00
cpufreq: Introduce ->ready() callback for cpufreq drivers
2014-11-29 23:38:38 +01:00
cpuidle / ACPI: remove unused CPUIDLE_FLAG_TIME_INVALID
2014-12-17 02:26:28 +01:00
groups: Consolidate the setgroups permission checks
2014-12-05 17:19:27 -06:00
Driver core patches for 3.19-rc1
2014-12-14 16:10:09 -08:00
PM: Eliminate CONFIG_PM_RUNTIME
2014-12-19 22:55:06 +01:00
Driver core patches for 3.19-rc1
2014-12-14 16:10:09 -08:00
dma-mapping: detect and configure IOMMU in of_dma_configure
2014-12-01 16:50:45 +00:00
dmaengine: clarify the issue_pending expectations
2014-12-05 20:55:27 +05:30
eeprom-93cx6: Add (read-only) support for 8-bit mode
2014-11-25 15:42:53 +01:00
net: Add functions for handling padding frame and adding to length
2014-12-08 20:47:41 -05:00
ethtool: Support for configurable RSS hash function
2014-12-08 21:07:10 -05:00
fault-inject: add ratelimit option
2014-12-13 12:42:52 -08:00
include/linux/file.h: remove get_unused_fd() macro
2014-12-10 17:41:10 -08:00
net: sock: allow eBPF programs to be attached to sockets
2014-12-05 21:47:32 -08:00
vfs: renumber FMODE_NONOTIFY and add to uniqueness check
2015-01-08 15:10:52 -08:00
fsnotify: remove destroy_list from fsnotify_mark
2014-12-13 12:42:53 -08:00
tracing: Add tp_printk cmdline to have tracepoints go to printk()
2014-12-15 10:17:38 -05:00
genetlink: synchronize socket closing and family removal
2015-01-16 17:04:25 -05:00
mm, gfp: escalatedly define GFP_HIGHUSER and GFP_HIGHUSER_MOVABLE
2014-12-13 12:42:48 -08:00
net, lib: kill arch_fast_hash library bits
2014-12-10 15:17:46 -05:00
Merge branches 'for-3.19/hid-report-len', 'for-3.19/i2c-hid', 'for-3.19/lenovo', 'for-3.19/logitech', 'for-3.19/microsoft', 'for-3.19/plantronics', 'for-3.19/rmi', 'for-3.19/sony' and 'for-3.19/wacom' into for-linus
2014-12-12 11:15:33 +01:00
powerpc updates for 3.19
2014-12-11 17:48:14 -08:00
mm: hugetlb_cgroup: convert to lockless page counters
2014-12-10 17:41:04 -08:00
hyperv: Add support for vNIC hot removal
2014-12-08 20:24:11 -05:00
i2c: Only include slave support if selected
2015-01-26 22:05:20 +01:00
bridge: add new brport flag LEARNING_SYNC
2014-12-02 20:01:23 -08:00
net: Fix vlan_get_protocol for stacked vlan
2015-01-30 18:03:47 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-12-09 21:21:34 -08:00
linux/interrupt.h: remove the definition of unused tasklet_hi_enable
2014-12-12 15:15:41 -05:00
ARM: SoC/iommu configuration for 3.19
2014-12-16 14:53:01 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2014-12-16 15:53:03 -08:00
ipmi: Use the proper type for acpi_handle
2014-12-11 15:04:06 -06:00
ipmi: Remove the now unused priority from SMI sender
2014-12-11 15:04:11 -06:00
Merge branch 'irq-irqdomain-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-12-10 09:01:01 -08:00
printk: add and use LOGLEVEL_<level> defines for KERN_<LEVEL> equivalents
2014-12-10 17:41:11 -08:00
sched: don't cause task state changes in nested sleep debugging
2015-02-01 12:23:32 -08:00
genirq: Prevent proc race against freeing of irq descriptors
2014-12-13 13:33:07 +01:00
include/linux/kmemleak.h: needs slab.h
2014-12-13 12:42:47 -08:00
Second round of changes for KVM for arm/arm64 for v3.19; fixes reboot
2014-12-15 13:06:40 +01:00
KVM: move APIC types to arch/x86/
2014-12-18 09:39:51 +01:00
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds
2014-12-15 18:28:25 -08:00
libata: allow sata_sil24 to opt-out of tag ordered submission
2015-01-19 09:10:07 -05:00
mailbox: add tx_prepare client callback
2014-11-27 12:50:59 +05:30
bus: mvebu-mbus: provide a mechanism to save SDRAM window configuration
2014-11-30 16:40:11 +00:00
memcg: fix possible use-after-free in memcg_kmem_get_cache()
2014-12-13 12:42:49 -08:00
vm_area_operations: kill ->migrate()
2014-12-17 08:26:51 -05:00
vm: add VM_FAULT_SIGSEGV handling support
2015-01-29 10:51:32 -08:00
mm/debug-pagealloc: prepare boottime configurable on/off
2014-12-13 12:42:48 -08:00
Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
2014-12-15 15:52:01 -08:00
mm/page_ext: resurrect struct page extending code for debugging
2014-12-13 12:42:48 -08:00
module: make module_refcount() a signed integer.
2015-01-22 11:15:54 +10:30
module: remove mod arg from module_free, rename module_memfree().
2015-01-20 11:38:33 +10:30
make nameidata completely opaque outside of fs/namei.c
2014-12-10 21:32:13 -05:00
netdevice: Add missing parentheses in macro
2015-01-14 16:34:41 -05:00
netlink/genetlink: pass network namespace to bind/unbind
2014-12-27 03:07:50 -05:00
nfs: Add DEALLOCATE support
2014-11-25 16:38:32 -05:00
NFS: fix subtle change in COMMIT behavior
2014-11-24 17:00:42 -05:00
NFSv4: Cache the NFSv4/v4.1 client owner_id in the struct nfs_client
2015-01-05 19:40:53 -08:00
nfs: Add ALLOCATE support
2014-11-25 16:38:32 -05:00
take the targets of /proc/*/ns/* symlinks to separate fs
2014-12-10 21:30:20 -05:00
Devicetree changes for v3.19
2014-12-11 13:06:58 -08:00
iommu: store DT-probed IOMMU data privately
2014-12-05 14:35:52 +00:00
of/reconfig: Add OF_DYNAMIC notifier for platform_bus_type
2014-11-24 22:25:06 +00:00
mailbox/omap: adapt to the new mailbox framework
2014-11-27 12:51:04 +05:30
mm: page_alloc: embed OOM killing naturally into allocation slowpath
2015-01-26 13:37:18 -08:00
mm: memcontrol: remove obsolete kmemcg pinning tricks
2014-12-10 17:41:05 -08:00
mm/page_owner: keep track of page owners
2014-12-13 12:42:48 -08:00
mm/page_owner: keep track of page owners
2014-12-13 12:42:48 -08:00
mm: get rid of radix tree gfp mask for pagecache_get_page
2014-12-29 12:45:45 -08:00
PCI: Add pci_claim_bridge_resource() to clip window if necessary
2015-01-16 10:04:42 -06:00
USB patches for 3.19-rc1
2014-12-14 14:57:16 -08:00
percpu: remove __get_cpu_var and __raw_get_cpu_var macros
2014-12-13 12:42:53 -08:00
Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
2014-12-11 18:36:26 -08:00
perf: Tighten (and fix) the grouping condition
2015-01-28 13:17:35 +01:00
perf: Move task_pt_regs sampling into arch code
2015-01-09 11:12:28 +01:00
net: Allow FIXED_PHY to be modular.
2014-12-16 15:02:23 -05:00
common object embedded into various struct ....ns
2014-12-04 14:31:00 -05:00
PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
2014-12-13 00:45:24 +01:00
Merge branches 'pm-domains', 'powercap' and 'pm-tools'
2014-12-29 21:24:00 +01:00
PM / OPP Introduce APIs to remove OPPs
2014-11-29 23:53:20 +01:00
PM: Drop CONFIG_PM_RUNTIME from the driver core
2014-12-04 00:46:58 +01:00
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
2014-12-12 15:26:48 -08:00
printk: add dummy routine for when CONFIG_PRINTK=n
2015-01-26 13:37:18 -08:00
take the targets of /proc/*/ns/* symlinks to separate fs
2014-12-10 21:30:20 -05:00
pstore-ram: Allow optional mapping with pgprot_noncached
2014-12-11 13:38:31 -08:00
exit: ptrace: shift "reap dead" code from exit_ptrace() to forget_original_parent()
2014-12-10 17:41:10 -08:00
spi: spi-pxa2xx: SPI support for Intel Quark X1000
2014-11-26 18:07:45 +00:00
quota: Switch ->get_dqblk() and ->set_dqblk() to use bytes as space units
2015-01-28 09:01:40 +01:00
quota: Switch ->get_dqblk() and ->set_dqblk() to use bytes as space units
2015-01-28 09:01:40 +01:00
ratelimit: add initialization macro
2014-12-13 12:42:52 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
2014-12-12 10:08:06 -08:00
mm: prevent endless growth of anon_vma hierarchy
2015-01-08 15:10:51 -08:00
rtnetlink: delay RTM_DELLINK notification until after ndo_uninit()
2014-12-09 13:36:57 -05:00
syscalls: implement execveat() system call
2014-12-13 12:42:51 -08:00
serial: core: Add big-endian iotype
2014-11-25 17:06:40 -08:00
mm: vmscan: invoke slab shrinkers from shrink_zone()
2014-12-13 12:42:48 -08:00
net: Pull out core bits of __netdev_alloc_skb and add __napi_alloc_skb
2014-12-10 13:31:57 -05:00
memcg: fix possible use-after-free in memcg_kmem_get_cache()
2014-12-13 12:42:49 -08:00
net: introduce helper macro for_each_cmsghdr
2014-12-10 22:41:55 -05:00
spmi: Remove shutdown/suspend/resume kernel-doc
2014-11-26 19:33:57 -08:00
stacktrace: introduce snprint_stack_trace for buffer output
2014-12-13 12:42:48 -08:00
mm: move swp_entry_t definition to include/linux/mm_types.h
2014-12-13 12:42:47 -08:00
mm: page_cgroup: rename file to mm/swap_cgroup.c
2014-12-10 17:41:09 -08:00
syscalls: implement execveat() system call
2014-12-13 12:42:51 -08:00
Merge branch 'for-davem-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2014-12-10 13:17:23 -05:00
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal into thermal-soc
2014-12-21 22:49:12 +08:00
Merge branch 'fortglx/3.19-stable/time' of https://git.linaro.org/people/john.stultz/linux into timers/urgent
2015-01-22 12:28:02 +01:00
Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-12-10 10:13:28 -08:00
tracing: Add condition check to RCU lockdep checks
2015-02-07 19:34:25 -05:00
new helper: iter_is_iovec()
2014-12-17 06:43:56 -05:00
USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
2014-12-04 00:51:54 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2014-12-17 12:31:40 -08:00
common object embedded into various struct ....ns
2014-12-04 14:31:00 -05:00
ARM: vexpress: Remove non-DT code
2014-11-28 16:08:16 +01:00
A balloon enhancement, and a minor race-on-module-unload theoretical
2014-12-17 10:37:56 -08:00
virtio: memory access APIs
2014-12-09 12:05:24 +02:00
virtio: core support for config generation
2014-12-14 18:21:31 +02:00
mm,vmacache: count number of system-wide flushes
2014-12-13 12:42:48 -08:00
vmci: propagate msghdr all way down to __qp_memcpy_from_queue()
2014-12-09 16:28:23 -05:00
vringh: update for virtio 1.0 APIs
2014-12-15 23:49:28 +02:00
sched/wait: Remove might_sleep() from wait_event_cmd()
2015-02-03 12:14:25 +01:00
mm: protect set_page_dirty() from ongoing truncation
2015-01-08 15:10:51 -08:00
