Now that the arch_{spin,read,write}_relax macros default to cpu_relax(),
remove the redundant definitions for parisc.
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
We seem to be nearly the only platform which does not provide the
sys_utimes syscall. Adding it now makes our life much easier with
userspace applications (like dietlibc and e2fsprogs) since we then
behave like all other platforms too and don't need extra patches which
are hard to get upstream anyway because we are not a mainstream
architecture.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13
The attached change removes the unused and experimental
CONFIG_PARISC_TMPALIAS code. It doesn't work and I don't believe it will
ever be used.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
STI console is used on parisc and m68k HP machines. This patch partly reverts
my previous commit and as such restores the fonts for the m68k machines.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13
Pull ARM SoC fixes from Olof Johansson:
"Only two patches this time, one to fix ethernet probe order on at91
(better fix with proper device aliasing will be done for 3.15, this is
stop-gap), and one update to MAINTAINERS due to Freescale moving their
repo to kernel.org"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: at91: fix network interface ordering for sama5d36
MAINTAINERS: update IMX kernel git tree
Pull drm fixes from Dave Airlie:
"Some final few intel fixes, all regressions, all stable cc, and one
exynos oops fixer.
The biggest is probably the intel display error irqs one, but it seems
to fix a few crashes on startup, and one use after free in drm core"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/exynos: Fix (more) freeing issues in exynos_drm_drv.c
drm/i915: Disable stolen memory when DMAR is active
Revert "drm/i915: don't touch the VDD when disabling the panel"
drm: Fix use-after-free in the shadow-attache exit code
drm/i915: Don't enable display error interrupts from the start
drm/i915: Fix scanline counter fixup on BDW
drm/i915: Add a workaround for HSW scanline counter weirdness
drm/i915: Fix PSR programming
Commit 7982e90c3a ("block: fix q->flush_rq NULL pointer crash on
dm-mpath flush") moved an allocation to blk_init_allocated_queue(), but
neglected to free that allocation on the error paths that follow.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Srikar Dronamraju reports that commit b0c29f79ec ("futexes: Avoid
taking the hb->lock if there's nothing to wake up") causes java threads
getting stuck on futexes when runing specjbb on a power7 numa box.
The cause appears to be that the powerpc spinlocks aren't using the same
ticket lock model that we use on x86 (and other) architectures, which in
turn result in the "spin_is_locked()" test in hb_waiters_pending()
occasionally reporting an unlocked spinlock even when there are pending
waiters.
So this reinstates Davidlohr Bueso's original explicit waiter counting
code, which I had convinced Davidlohr to drop in favor of figuring out
the pending waiters by just using the existing state of the spinlock and
the wait queue.
Reported-and-tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Original-code-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull trace fix from Steven Rostedt:
"Vaibhav Nagarnaik discovered that since 3.10 a clean-up patch made the
array index in the trace event format bogus.
He supplied an elegant solution that uses __stringify() and also
removes the need for the event_storage and event_storage_mutex and
also cuts off a few K of overhead from the trace events"
* tag 'trace-fixes-v3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix array size mismatch in format string
Add remove_linear_migration_ptes_from_nonlinear(), to fix an interesting
little include/linux/swapops.h:131 BUG_ON(!PageLocked) found by trinity:
indicating that remove_migration_ptes() failed to find one of the
migration entries that was temporarily inserted.
The problem comes from remap_file_pages()'s switch from vma_interval_tree
(good for inserting the migration entry) to i_mmap_nonlinear list (no good
for locating it again); but can only be a problem if the remap_file_pages()
range does not cover the whole of the vma (zap_pte() clears the range).
remove_migration_ptes() needs a file_nonlinear method to go down the
i_mmap_nonlinear list, applying linear location to look for migration
entries in those vmas too, just in case there was this race.
The file_nonlinear method does need rmap_walk_control.arg to do this;
but it never needed vma passed in - vma comes from its own iteration.
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull MIPS fixes from Ralf Baechle:
"Another set of five fixes. The most interesting one is a fix for race
condition in the local_irq_disable() implementation used by .S code
for pre-MIPS R2 processors only. It leaves a race that's hard but not
impossible to hit; the others fairly obvious"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Make local_irq_disable macro safe for non-Mipsr2
MIPS: Octeon: Fix warning in of_device_alloc on cn3xxx
MIPS: ftrace: Tweak safe_load()/safe_store() macros
MIPS: BCM47XX: Check all (32) GPIOs when looking for a pin
MIPS: Fix possible build error with transparent hugepages enabled
Pull sound fixes from Takashi Iwai:
"Just two minor bug fixes: a fix for a regression in oxygen driver that
was introduced in 3.14-rc1, and a stable fix for the return value of
compress offload open callback"
* tag 'sound-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: compress: Pass through return value of open ops callback
ALSA: oxygen: Xonar DG(X): fix Stereo Upmixing regression
In event format strings, the array size is reported in two locations.
One in array subscript and then via the "size:" attribute. The values
reported there have a mismatch.
For e.g., in sched:sched_switch the prev_comm and next_comm character
arrays have subscript values as [32] where as the actual field size is
16.
name: sched_switch
ID: 301
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1;signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:char prev_comm[32]; offset:8; size:16; signed:1;
field:pid_t prev_pid; offset:24; size:4; signed:1;
field:int prev_prio; offset:28; size:4; signed:1;
field:long prev_state; offset:32; size:8; signed:1;
field:char next_comm[32]; offset:40; size:16; signed:1;
field:pid_t next_pid; offset:56; size:4; signed:1;
field:int next_prio; offset:60; size:4; signed:1;
After bisection, the following commit was blamed:
92edca0 tracing: Use direct field, type and system names
This commit removes the duplication of strings for field->name and
field->type assuming that all the strings passed in
__trace_define_field() are immutable. This is not true for arrays, where
the type string is created in event_storage variable and field->type for
all array fields points to event_storage.
Use __stringify() to create a string constant for the type string.
Also, get rid of event_storage and event_storage_mutex that are not
needed anymore.
also, an added benefit is that this reduces the overhead of events a bit more:
text data bss dec hex filename
8424787 2036472 1302528 11763787 b3804b vmlinux
8420814 2036408 1302528 11759750 b37086 vmlinux.patched
Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com
Cc: Laurent Chavey <chavey@google.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
For non-mipsr2 processors, the local_irq_disable contains an mfc0-mtc0
pair with instructions inbetween. With preemption enabled, this sequence
may get preempted and effect a stale value of CP0_STATUS when executing
the mtc0 instruction. This commit avoids this scenario by incrementing
the preempt count before the mfc0 and decrementing it after the mtc9.
[ralf@linux-mips.org: This patch is sorting out the part that were missed
by e97c5b6098 [MIPS: Make irqflags.h functions preempt-safe for non-mipsr2
cpus.] I also re-enabled the inclusion of <asm/asm-offsets.h> at the top
of <asm/asmmacro.h>].
Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: cernekee@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/6164/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Just fixed resource release issue at open fail.
* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
drm/exynos: Fix (more) freeing issues in exynos_drm_drv.c
The following commit [0] fixed a use-after-free, but left the subdrv open
in the error path.
[0] commit 6ca605f7c7
drm/exynos: Fix freeing issues in exynos_drm_drv.c
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Fix some "Bad rss-counter state" reports on exit, arising from the
interaction between page migration and remap_file_pages(): zap_pte()
must count a migration entry when zapping it.
And yes, it is possible (though very unusual) to find an anon page or
swap entry in a VM_SHARED nonlinear mapping: coming from that horrid
get_user_pages(write, force) case which COWs even in a shared mapping.
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: Sasha Levin sasha.levin@oracle.com>
Tested-by: Dave Jones davej@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull PCI resource management fix from Bjorn Helgaas:
"This is a fix for an AGP regression exposed by e501b3d87f ("agp:
Support 64-bit APBASE"), which we merged in v3.14-rc1.
We've warned about the conflict between the GART and PCI resources and
cleared out the PCI resource for a long time, but after e501b3d87f,
we still *use* that cleared-out PCI resource. I think the GART
resource is incorrect, so this patch removes it"
* tag 'pci-v3.14-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
Revert "[PATCH] Insert GART region into resource map"
Pull cgroup fix from Tejun Heo:
"One really late cgroup patch to fix error path in create_css().
Hitting this bug would be pretty rare but still possible and it gets
delayed we'd need to backport it through -stable anyway. It only
updates error path in create_css() and has low chance of new
breakages"
* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix a failure path in create_css()
Due to name collision in ftrace safe_load and safe_store macros,
these macros cannot take expressions as operands.
For example, compiler will complain for a macro call like the following:
safe_store_code(new_code2, ip + 4, faulted);
arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
: [dst] "r" (dst), [src] "r" (src)\
^
arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
safe_store_code(new_code2, ip + 4, faulted);
^
arch/mips/kernel/ftrace.c:118:32: error: undefined named operand 'ip + 4'
safe_store_code(new_code2, ip + 4, faulted);
^
arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
: [dst] "r" (dst), [src] "r" (src)\
^
arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
safe_store_code(new_code2, ip + 4, faulted);
^
This build error is triggered by a4671094 [MIPS: ftrace: Fix icache flush
range error]. Tweak variable naming in those macros to allow flexible
operands.
Signed-off-by: Viller Hsiao <villerhsiao@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
Cc: mingo@redhat.com
Cc: Qais.Yousef@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/6622/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
two more fixes, both regressions.
* tag 'drm-intel-fixes-2014-03-19' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Disable stolen memory when DMAR is active
Revert "drm/i915: don't touch the VDD when disabling the panel"
Pull timer fix from Thomas Gleixner:
"A single bugfix: make the scheduler clock on Vybrid SoCs count
forward"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource: vf_pit_timer: use complement for sched_clock reading
The snd_compr_open function would always return 0 even if the compressed
ops open function failed, obviously this is incorrect. Looks like this
was introduced by a small typo in:
commit a0830dbd4e
ALSA: Add a reference counter to card instance
This patch returns the value from the compressed op as it should.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
We have reports of heavy screen corruption if we try to use the stolen
memory reserved by the BIOS whilst the DMA-Remapper is active. This
quirk may be only specific to a few machines or BIOSes, but first lets
apply the big hammer and always disable use of stolen memory when DMAR
is active.
v2 by Jani: Rebase on -fixes, only look at intel_iommu_gfx_mapped.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68535
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
If online_css() fails, we should remove cgroup files belonging
to css->ss.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This reverts commit 56dd669a13, which makes the GART visible in
/proc/iomem. This fixes a regression: e501b3d87f ("agp: Support 64-bit
APBASE") exposed an existing problem with a conflict between the GART
region and a PCI BAR region.
The GART addresses are bus addresses, not CPU addresses, and therefore
should not be inserted in iomem_resource.
On many machines, the GART region is addressable by the CPU as well as by
an AGP master, but CPU addressability is not required by the spec. On some
of these machines, the GART is mapped by a PCI BAR, and in that case, the
PCI core automatically inserts it into iomem_resource, just as it does for
all BARs.
Inserting it here means we'll have a conflict if the PCI core later tries
to claim the GART region, so let's drop the insertion here.
The conflict indirectly causes X failures, as reported by Jouni in the
bugzilla below. We detected the conflict even before e501b3d87f, but
after it the AGP code (fix_northbridge()) uses the PCI resource (which is
zeroed because of the conflict) instead of reading the BAR again.
Conflicts:
arch/x86_64/kernel/aperture.c
Fixes: e501b3d87f agp: Support 64-bit APBASE
Link: https://bugzilla.kernel.org/show_bug.cgi?id=72201
Reported-and-tested-by: Jouni Mettälä <jtmettala@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Pull another kvm fix from Paolo Bonzini:
"A fix for a PowerPC bug that was introduced during the 3.14 merge
window"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: PPC: Book3S HV: Fix register usage when loading/saving VRSAVE
KVM: PPC: Book3S HV: Remove bogus duplicate code
The code introduced in commit 1f91ecc14d ("ALSA: oxygen: modify
adjust_dg_dac_routing function") accidentally disregarded the old value
of the playback routing register, so it broke the "Stereo Upmixing"
mixer control.
The unmuted parts of the channel routing are the same for all settings
of the output destination, so it suffices to revert that part of the
patch.
Fixes: 1f91ecc14d ('ALSA: oxygen: modify adjust_dg_dac_routing function')
Tested-by: Roman Volkov <v1ron@mail.ru>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Pull two 'perf bench' fixes from Arnaldo:
* Make 'perf bench mem' (i.e. no args) mean 'run all tests' so that we can run
all tests, not stopping at the numa ones. (Arnaldo Carvalho de Melo)
* Fix NULL pointer dereference after last test in in "perf bench all" (Patrick Palka)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If CONFIG_TRANSPARENT_HUGEPAGE is enabled, but CONFIG_HUGETLB_PAGE is not,
it is possible to end up with a configuration that fails to build with the
following error:
include/linux/huge_mm.h:125:2: error: #error "hugepages can't be allocated by the buddy allocator"
This is due to CONFIG_FORCE_MAX_ZONEORDER defaulting to 11. It already has
ranges that change the valid values when HUGETLB_PAGE is enabled, but this
is not done for TRANSPARENT_HUGEPAGE. Fix by changing the HUGETLB_PAGE
dependencies to MIPS_HUGE_TLB_SUPPORT, which includes both
TRANSPARENT_HUGEPAGE and HUGETLB_PAGE.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6391/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Two 3.14 specific fixes, two cc: stable.
* tag 'drm-intel-fixes-2014-03-17' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Don't enable display error interrupts from the start
drm/i915: Fix scanline counter fixup on BDW
drm/i915: Add a workaround for HSW scanline counter weirdness
drm/i915: Fix PSR programming
Pull final final block IO fixes from Jens Axboe:
"Yes, the last round was final. This one is final final.
The mtip32xx fix could have waited, but it's so simple and gets rid of
two warning spewages on load. The two block flush fixes are critical
for blk-mq, and are the primary reason for this late pull request"
* 'for-linus' of git://git.kernel.dk/linux-block:
mtip32xx: fix bad use of smp_processor_id()
block: change flush sequence list addition back to front add
block: fix q->flush_rq NULL pointer crash on dm-mpath flush
Pull MIPS updates from Ralf Baechle:
"A fair number of fixes all across arch/mips. Nothing really stands
out though APRP, the FPU code and syscall tracing code received
multiple patches those all were small"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: mark O32+FP64 experimental for now
MIPS: ftrace: Fix icache flush range error
MIPS: Fix syscall tracing interface
MIPS: asm: syscall: Fix copying system call arguments
MIPS: Octeon: Fix fall through on bar type OCTEON_DMA_BAR_TYPE_SMALL
MIPS: FPU: Fix conflict of register usage
MIPS: Replace CONFIG_MIPS64 and CONFIG_MIPS32_R2
MIPS: math-emu: Fix prefx detection and COP1X function field definition
MIPS: APRP: Choose the correct VPE loader by fixing the linking
MIPS: APRP: Unregister rtlx interrupt hook at module exit
MIPS: APRP: Fix the linking of rtlx interrupt hook
MIPS: bcm47xx: Include missing errno.h for ENXIO
MIPS: Alchemy: Fix unchecked kstrtoul return value
MIPS: Fix randconfig build error.
Commit 597ce1723e "MIPS: Support for 64-bit FP with O32 binaries"
introduced support for setting Status.FR=1 for O32 binaries with the
EF_MIPS_FP64 ELF header flag set. Whilst this flag is currently
supported by binutils it does introduce an ABI break within userland.
Objects built with EF_MIPS_FP64 cannot be safely linked with those built
without it since code in either object may assume behaviour specific to
a value of FR.
More recently there has been discussion around avoiding further
fragmentation of the O32 ABI whilst still allowing the use of FR=1 and
features such as MSA which depend upon it. Details of the plan to allow
this are still being worked on, and whilst the kernel will need the
ability to handle FR=1 with O32 tasks it is unclear what else it may
need to provide to a userland which seeks to avoid another ABI break. In
order to prevent the proliferation of userland which may rely upon the
current EF_MIPS_FP64 behaviour this patch marks the kernel support for
it experimental & disables it by default. Under current proposals it is
likely that this support can simply be enabled again later, but possibly
after the introduction of further interfaces with userland and support
for the MIPS R5 UFR feature.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/6549/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull HID fixes from Jiri Kosina:
- fix for ordering of device removal actions in hidraw, by Fernando
Luis Vázquez Cao
- fix for uninitialized workqueue usage in hid-sony, by Frank Praznik
- device ID addition for new variant of Logitech G27, from Simon Wood
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: hid-lg4ff: Support new version of G27
HID: hidraw: fix warning destroying hidraw device files after parent
HID: sony: Fix work queue issues.
The syscall_get_arguments function expects the arguments to be copied
to the '*args' argument but instead a local variable was used to hold
the system call argument. As a result of which, this variable was
never passed to the filter and any filter testing the system call
arguments would fail. This is fixed by passing the '*args' variable
as the destination memory for the system call arguments.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6402/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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 4a674f34ba ("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 3a665531a3 ("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
