This patch implements the new 'rcu_pending' interface under each rsp
directory, by using the 'CPU units sequence reading', thus avoiding loss
of tracing data.
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This patch implements the new 'rcudata.csv' interface under each rsp
directory, by using the 'CPU units sequence reading', thus avoiding loss
of tracing data.
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This patch implements the new 'rcudata' interface under each rsp
directory, by using the 'CPU units sequence reading', thus avoiding loss
of tracing data.
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This patch add the fundamental facility used by the following patches, so we
can implement the 'CPU units sequence reading' later.
This helps us avoid losing data when there are too many CPUs and too
small of a buffer, since this new approach allows userspace to read out
the data one CPU at a time. Thus, if the buffer is not large enough,
userspace will get whatever CPUs fit, and can then issue another read
for the remainder of the data.
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This patch will create subdirectory according to each flavor of rcu, the new
structure will be:
/debugfs/rcu/ -> rsp_0
-> rsp_1
-> ...
So we can go to '/debugfs/rcu/rsp_0' and get the cpu info of rsp_0 there.
The flavors of RCU are currently rcu_bh, rcu_preempt, and rcu_sched.
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds the counters to rcu_state and updates them in
synchronize_rcu_expedited() to provide the data needed for debugfs
tracing.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tracing (debugfs) of expedited RCU primitives is required, which in turn
requires that the relevant data be located where the tracing code can find
it, not in its current static global variables in kernel/rcutree.c.
This commit therefore moves sync_sched_expedited_started and
sync_sched_expedited_done to the rcu_state structure, as fields
->expedited_start and ->expedited_done, respectively.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
There is a counter scheme similar to ticket locking that
synchronize_sched_expedited() uses to service multiple concurrent
callers with the same expedited grace period. Upon entry, a
sync_sched_expedited_started variable is atomically incremented,
and upon completion of a expedited grace period a separate
sync_sched_expedited_done variable is atomically incremented.
However, if a synchronize_sched_expedited() is delayed while
in try_stop_cpus(), concurrent invocations will increment the
sync_sched_expedited_started counter, which will eventually overflow.
If the original synchronize_sched_expedited() resumes execution just
as the counter overflows, a concurrent invocation could incorrectly
conclude that an expedited grace period elapsed in zero time, which
would be bad. One could rely on counter size to prevent this from
happening in practice, but the goal is to formally validate this
code, so it needs to be fixed anyway.
This commit therefore checks the gap between the two counters before
incrementing sync_sched_expedited_started, and if the gap is too
large, does a normal grace period instead. Overflow is thus only
possible if there are more than about 3.5 billion threads on 32-bit
systems, which can be excluded until such time as task_struct fits
into a single byte and 4G/4G patches are accepted into mainline.
It is also easy to encode this limitation into mechanical theorem
provers.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The ->onofflock field in the rcu_state structure at one time synchronized
CPU-hotplug operations for RCU. However, its scope has decreased over time
so that it now only protects the lists of orphaned RCU callbacks. This
commit therefore renames it to ->orphan_lock to reflect its current use.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit causes rcutorture to print the errno if cpu_down() fails
when the rcutorture "verbose" module parameter is specified.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
In the old days, _rcu_barrier() acquired ->onofflock to exclude
rcu_send_cbs_to_orphanage(), which allowed the latter to avoid memory
barriers in callback handling. However, _rcu_barrier() recently started
doing get_online_cpus() to lock out CPU-hotplug operations entirely, which
means that the comment in rcu_send_cbs_to_orphanage() that talks about
->onofflock is now obsolete. This commit therefore fixes the comment.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pull arm64 fixes from Catalin Marinas:
"Main changes:
- AArch64 Linux compilation fixes following 3.7-rc1 changes
(MODULES_USE_ELF_RELA, update_vsyscall() prototype)
- Unnecessary register setting in start_thread() (thanks to Al Viro)
- ptrace fixes"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
arm64: fix alignment padding in assembly code
arm64: ptrace: use HW_BREAKPOINT_EMPTY type for disabled breakpoints
arm64: ptrace: make structure padding explicit for debug registers
arm64: No need to set the x0-x2 registers in start_thread()
arm64: Ignore memory blocks below PHYS_OFFSET
arm64: Fix the update_vsyscall() prototype
arm64: Select MODULES_USE_ELF_RELA
arm64: Remove duplicate inclusion of mmu_context.h in smp.c
An interesting effect of using the generic version of linkage.h
is that the padding is defined in terms of x86 NOPs, which can have
even more interesting effects when the assembly code looks like this:
ENTRY(func1)
mov x0, xzr
ENDPROC(func1)
// fall through
ENTRY(func2)
mov x0, #1
ret
ENDPROC(func2)
Admittedly, the code is not very nice. But having code from another
architecture doesn't look completely sane either.
The fix is to add arm64's version of linkage.h, which causes the insertion
of proper AArch64 NOPs.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The min/max call needed to have explicit types on some architectures
(e.g. mn10300). Use clamp_t instead to avoid the warning:
kernel/sys.c: In function 'override_release':
kernel/sys.c:1287:10: warning: comparison of distinct pointer types lacks a cast [enabled by default]
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf fixes from Ingo Molnar:
"Assorted small fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf python: Properly link with libtraceevent
perf hists browser: Add back callchain folding symbol
perf tools: Fix build on sparc.
perf python: Link with libtraceevent
perf python: Initialize 'page_size' variable
tools lib traceevent: Fix missed freeing of subargs in free_arg() in filter
lib tools traceevent: Add back pevent assignment in __pevent_parse_format()
perf hists browser: Fix off-by-two bug on the first column
perf tools: Remove warnings on JIT samples for srcline sort key
perf tools: Fix segfault when using srcline sort key
perf: Require exclude_guest to use PEBS - kernel side enforcement
perf tool: Precise mode requires exclude_guest
Namhyung Kim reported that the build fails with:
GEN python/perf.so
gcc: error: python_ext_build/tmp//../../libtraceevent.a: No such file or directory
error: command 'gcc' failed with exit status 1
cp: cannot stat `python_ext_build/lib/perf.so': No such file or directory
make: *** [python/perf.so] Error 1
We need to propagate the TE_PATH variable to the setup.py file.
Reported-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/n/tip-8umiPbm4sxpknKivbjgykhut@git.kernel.org
[ Fixed superfluous variable build error. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
* The python binding needs to link with libtraceevent and to initialize
the 'page_size' variable so that mmaping works again.
* The callchain folding character that appears on the TUI just before
the overhead had disappeared due to recent changes, add it back.
* Intel PEBS in VT-x context uses the DS address as a guest linear address,
even though its programmed by the host as a host linear address. This either
results in guest memory corruption and or the hardware faulting and 'crashing'
the virtual machine. Therefore we have to disable PEBS on VT-x enter and
re-enable on VT-x exit, enforcing a strict exclude_guest.
Kernel side enforcement fix by Peter Zijlstra, tooling side fix by David Ahern.
* Fix build on sparc due to UAPI, fix from David Miller.
* Fixes for the srclike sort key for unresolved symbols and when processing
samples in JITted code, where we don't have an ELF file, just an special
symbol table, fixes from Namhyung Kim.
* Fix some leaks in libtraceevent, from Steven Rostedt.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull ARM soc fixes from Olof Johansson:
"A set of fixes and some minor cleanups for -rc2:
- A series from Arnd that fixes warnings in drivers and other code
included by ARM defconfigs. Most have been acked by corresponding
maintainers (and seem quite hard to argue not picking up anyway in
the few exception cases).
- A few misc patches from the list for integrator/vt8500/i.MX
- A batch of fixes to OMAP platforms, fixing:
- boot problems on beaglebone,
- regression fixes for local timers
- clockdomain locking fixes
- a few boot/sparse warnings
- For Tegra:
- Clock rate calculation overflow fix
- Revert a change that removed timer clocks and a fix for symbol
name clashes
- For Renesas:
- IO accessor / annotation cleanups to remove warnings
- For Kirkwood/Dove/mvebu:
- Fixes for device trees for Dove (some minor cleanups, some fixes)
- Fixes for the mvebu gpio driver
- Fix build problem for Feroceon due to missing ifdefs
- Fix lsxl DTS files"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
ARM: kirkwood: fix buttons on lsxl boards
ARM: kirkwood: fix LEDs names for lsxl boards
ARM: Kirkwood: fix disabling CACHE_FEROCEON_L2
gpio: mvebu: Add missing breaks in mvebu_gpio_irq_set_type
ARM: dove: Add crypto engine to DT
ARM: dove: Remove watchdog from DT
ARM: dove: Restructure SoC device tree descriptor
ARM: dove: Fix clock names of sata and gbe
ARM: dove: Fix tauros2 device tree init
ARM: dove: Add pcie clock support
ARM: OMAP2+: Allow kernel to boot even if GPMC fails to reserve memory
ARM: OMAP: clockdomain: Fix locking on _clkdm_clk_hwmod_enable / disable
ARM: s3c: mark s3c2440_clk_add as __init_refok
spi/s3c64xx: use correct dma_transfer_direction type
ARM: OMAP4: devices: fixup OMAP4 DMIC platform device error message
ARM: OMAP2+: clock data: Add dev-id for the omap-gpmc dummy fck
ARM: OMAP: resolve sparse warning concerning debug_card_init()
ARM: OMAP4: Fix twd_local_timer_register regression
ARM: tegra: add tegra_timer clock
ARM: tegra: rename tegra system timer
...
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>
The module build process no longer creates intermediate files for module
signing, so remove them from .gitignore.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Turn sign-file into perl and merge in x509keyid. The latter doesn't
need to be a separate script as it doesn't actually need to work out the
SHA1 sum of the X.509 certificate itself, since it can get that from the
X.509 certificate.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A collection of warning fixes on non-ARM code from Arnd Bergmann:
* 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: s3c: mark s3c2440_clk_add as __init_refok
spi/s3c64xx: use correct dma_transfer_direction type
pcmcia: sharpsl: don't discard sharpsl_pcmcia_ops
USB: EHCI: mark ehci_orion_conf_mbus_windows __devinit
mm/slob: use min_t() to compare ARCH_SLAB_MINALIGN
SCSI: ARM: make fas216_dumpinfo function conditional
SCSI: ARM: ncr5380/oak uses no interrupts
/proc/<pid>/numa_maps scans vma and show mempolicy under
mmap_sem. It sometimes accesses task->mempolicy which can
be freed without mmap_sem and numa_maps can show some
garbage while scanning.
This patch tries to take reference count of task->mempolicy at reading
numa_maps before calling get_vma_policy(). By this, task->mempolicy
will not be freed until numa_maps reaches its end.
V2->v3
- updated comments to be more verbose.
- removed task_lock() in numa_maps code.
V1->V2
- access task->mempolicy only once and remember it. Becase kernel/exit.c
can overwrite it.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Wang
Paul E. McKenney
Linus Torvalds
Marc Zyngier
Kees Cook
Arnaldo Carvalho de Melo
Ingo Molnar
David Howells
Olof Johansson
KAMEZAWA Hiroyuki