Pull scheduler fixes from Ingo Molnar: "Three small fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/clock: Prevent tracing recursion in sched_clock_cpu() stop_machine: Fix^2 race between stop_two_cpus() and stop_cpus() sched/deadline: Deny unprivileged users to set/change SCHED_DEADLINE policy
Pull perf fixes from Ingo Molnar: "Misc smaller fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Fix leak in uncore_type_init failure paths perf machine: Use map as success in ip__resolve_ams perf symbols: Fix crash in elf_section_by_name perf trace: Decode architecture-specific signal numbers
While testing and documenting the msgrcv() MSG_COPY flag that Stanislav
Kinsbursky added in commit 4a674f34ba04 ("ipc: introduce message queue
copy feature" => kernel 3.8), I discovered a couple of bugs in the
implementation. The two bugs concern MSG_COPY interactions with other
msgrcv() flags, namely:
(A) MSG_COPY + MSG_EXCEPT
(B) MSG_COPY + !IPC_NOWAIT
The bugs are distinct (and the fix for the first one is obvious),
however my fix for both is a single-line patch, which is why I'm
combining them in a single mail, rather than writing two mails+patches.
===== (A) MSG_COPY + MSG_EXCEPT =====
With the addition of the MSG_COPY flag, there are now two msgrcv()
flags--MSG_COPY and MSG_EXCEPT--that modify the meaning of the 'msgtyp'
argument in unrelated ways. Specifying both in the same call is a
logical error that is currently permitted, with the effect that MSG_COPY
has priority and MSG_EXCEPT is ignored. The call should give an error
if both flags are specified. The patch below implements that behavior.
===== (B) (B) MSG_COPY + !IPC_NOWAIT =====
The test code that was submitted in commit 3a665531a3b7 ("selftests: IPC
message queue copy feature test") shows MSG_COPY being used in
conjunction with IPC_NOWAIT. In other words, if there is no message at
the position 'msgtyp'. return immediately with the error in ENOMSG.
What was not (fully) tested is the behavior if MSG_COPY is specified
*without* IPC_NOWAIT, and there is an odd behavior. If the queue
contains less than 'msgtyp' messages, then the call blocks until the
next message is written to the queue. At that point, the msgrcv() call
returns a copy of the newly added message, regardless of whether that
message is at the ordinal position 'msgtyp'. This is clearly bogus, and
problematic for applications that might want to make use of the MSG_COPY
flag.
I considered the following possible solutions to this problem:
(1) Force the call to block until a message *does* appear at the
position 'msgtyp'.
(2) If the MSG_COPY flag is specified, the kernel should implicitly add
IPC_NOWAIT, so that the call fails with ENOMSG for this case.
(3) If the MSG_COPY flag is specified, but IPC_NOWAIT is not, generate
an error (probably, EINVAL is the right one).
I do not know if any application would really want to have the
functionality of solution (1), especially since an application can
determine in advance the number of messages in the queue using msgctl()
IPC_STAT. Obviously, this solution would be the most work to implement.
Solution (2) would have the effect of silently fixing any applications
that tried to employ broken behavior. However, it would mean that if we
later decided to implement solution (1), then user-space could not
easily detect what the kernel supports (but, since I'm somewhat doubtful
that solution (1) is needed, I'm not sure that this is much of a
problem).
Solution (3) would have the effect of informing broken applications that
they are doing something broken. The downside is that this would cause
a ABI breakage for any applications that are currently employing the
broken behavior. However:
a) Those applications are almost certainly not getting the results they
expect.
b) Possibly, those applications don't even exist, because MSG_COPY is
currently hidden behind CONFIG_CHECKPOINT_RESTORE.
The upside of solution (3) is that if we later decided to implement
solution (1), user-space could determine what the kernel supports, via
the error return.
In my view, solution (3) is mildly preferable to solution (2), and
solution (1) could still be done later if anyone really cares. The
patch below implements solution (3).
PS. For anyone out there still listening, it's the usual story:
documenting an API (and the thinking about, and the testing of the API,
that documentation entails) is the one of the single best ways of
finding bugs in the API, as I've learned from a lot of experience. Best
to do that documentation before releasing the API.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull SCSI fixes from James Bottomley: "This is a set of six fixes. Two are instant crash/null deref types (storvsc and isci). The two qla2xxx are initialisation problems that cause MSI-X failures and card misdetection, the isci erroneous macro is actually illegal C that's causing a miscompile with certain gcc versions and the be2iscsi bad if expression is a static checker fix" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: [SCSI] storvsc: NULL pointer dereference fix [SCSI] qla2xxx: Poll during initialization for ISP25xx and ISP83xx [SCSI] isci: correct erroneous for_each_isci_host macro [SCSI] isci: fix reset timeout handling [SCSI] be2iscsi: fix bad if expression [SCSI] qla2xxx: Fix multiqueue MSI-X registration.
Pull x86 fixes from Peter Anvin: "Two x86 fixes: Suresh's eager FPU fix, and a fix to the NUMA quirk for AMD northbridges. This only includes Suresh's fix patch, not the "mostly a cleanup" patch which had __init issues" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/amd/numa: Fix northbridge quirk to assign correct NUMA node x86, fpu: Check tsk_used_math() in kernel_fpu_end() for eager FPU
Pull ACPI and power management fixes from Rafael Wysocki:
"Three of these are regression fixes, for two recent regressions and
one introduced during the 3.13 cycle, and the fourth one is a working
version of the fix that had to be reverted last time.
Specifics:
- A recent ACPI resources handling fix overlooked the fact that it
had to update the ACPI PNP subsystem's resources parsing too and
caused confusing warning messages to be printed during system
intialization on some systems (with arguably buggy ACPI tables).
Fix from Zhang Rui.
- Moving the early ACPI initialization before timekeeping_init()
earlier in this cycle broke fast TSC calibration on at least one
system, so it needs to be done later, but still before
efi_enter_virtual_mode() to allow the EFI initialization to refer
to ACPI.
- A change related to code duplication reduction in the cpufreq core
inadvertently caused cpufreq intialization to fail for some CPUs
handled by intel_pstate by adding checks that may fail for that
driver, but aren't even necessary when it is used. The issue is
addressed by preventing those checks from run in the configurations
in which they aren't needed.
- If the Hardware Reduced ACPI flag is set in the ACPI tables, system
suspend, hibernation and ACPI power off will only work when special
sleep control and sleep status registeres are provided (their
addresses in the ACPI tables are not zero). If those registers are
not available, the features in question have no chances to work, so
they shouldn't even be regarded as supported. That helps with
power off in particular, because alternative power off methods may
be used then and they may actually work"
* tag 'pm+acpi-3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / sleep: Add extra checks for HW Reduced ACPI mode sleep states
ACPI / init: Invoke early ACPI initialization later
cpufreq: Skip current frequency initialization for ->setpolicy drivers
PNP / ACPI: proper handling of ACPI IO/Memory resource parsing failures
Pull device-mapper fixes form Mike Snitzer: "Two small fixes for the DM cache target: - fix corruption with >2TB fast device due to truncation bug - fix access beyond end of origin device due to a partial block" * tag 'dm-3.14-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache: fix access beyond end of origin device dm cache: fix truncation bug when copying a block to/from >2TB fast device
For systems with multiple servers and routed fabric, all northbridges get assigned to the first server. Fix this by also using the node reported from the PCI bus. For single-fabric systems, the northbriges are on PCI bus 0 by definition, which are on NUMA node 0 by definition, so this is invarient on most systems. Tested on fam10h and fam15h single and multi-fabric systems and candidate for stable. Signed-off-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Steffen Persvold <sp@numascale.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1394710981-3596-1-git-send-email-daniel@numascale.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull drm fixes from Dave Airlie: "Pretty minor set of fixes for radeon, ttm and vmwgfx. The ttm ones are a regression and an oops seen on server chipsets" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm/vmwgfx: Fix a surface reference corner-case in legacy emulation mode drm/radeon/cik: properly set compute ring status on disable drm/radeon/cik: stop the sdma engines in the enable() function drm/radeon/cik: properly set sdma ring status on disable drm/radeon: fix runpm disabling on non-PX harder drm/ttm: don't oops if no invalidate_caches() drm/ttm: Work around performance regression with VM_PFNMAP