So the /proc/PID/stat 'wchan' field (the 30th field, which contains
the absolute kernel address of the kernel function a task is blocked in)
leaks absolute kernel addresses to unprivileged user-space:
seq_put_decimal_ull(m, ' ', wchan);
The absolute address might also leak via /proc/PID/wchan as well, if
KALLSYMS is turned off or if the symbol lookup fails for some reason:
static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
unsigned long wchan;
char symname[KSYM_NAME_LEN];
wchan = get_wchan(task);
if (lookup_symbol_name(wchan, symname) < 0) {
if (!ptrace_may_access(task, PTRACE_MODE_READ))
return 0;
seq_printf(m, "%lu", wchan);
} else {
seq_printf(m, "%s", symname);
}
return 0;
}
This isn't ideal, because for example it trivially leaks the KASLR offset
to any local attacker:
fomalhaut:~> printf "%016lx\n" $(cat /proc/$$/stat | cut -d' ' -f35)
ffffffff8123b380
Most real-life uses of wchan are symbolic:
ps -eo pid:10,tid:10,wchan:30,comm
and procps uses /proc/PID/wchan, not the absolute address in /proc/PID/stat:
triton:~/tip> strace -f ps -eo pid:10,tid:10,wchan:30,comm 2>&1 | grep wchan | tail -1
open("/proc/30833/wchan", O_RDONLY) = 6
There's one compatibility quirk here: procps relies on whether the
absolute value is non-zero - and we can provide that functionality
by outputing "0" or "1" depending on whether the task is blocked
(whether there's a wchan address).
These days there appears to be very little legitimate reason
user-space would be interested in the absolute address. The
absolute address is mostly historic: from the days when we
didn't have kallsyms and user-space procps had to do the
decoding itself via the System.map.
So this patch sets all numeric output to "0" or "1" and keeps only
symbolic output, in /proc/PID/wchan.
( The absolute sleep address can generally still be profiled via
perf, by tasks with sufficient privileges. )
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150930135917.GA3285@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The next patches on the series need this modifications to pass clean
checkpath.pl.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The new Properties Table feature introduced in UEFIv2.5 may
split memory regions that cover PE/COFF memory images into
separate code and data regions. Since these regions only differ
in the type (runtime code vs runtime data) and the permission
bits, but not in the memory type attributes (UC/WC/WT/WB), the
spec does not require them to be aligned to 64 KB.
Since the relative offset of PE/COFF .text and .data segments
cannot be changed on the fly, this means that we can no longer
pad out those regions to be mappable using 64 KB pages.
Unfortunately, there is no annotation in the UEFI memory map
that identifies data regions that were split off from a code
region, so we must apply this logic to all adjacent runtime
regions whose attributes only differ in the permission bits.
So instead of rounding each memory region to 64 KB alignment at
both ends, only round down regions that are not directly
preceded by another runtime region with the same type
attributes. Since the UEFI spec does not mandate that the memory
map be sorted, this means we also need to sort it first.
Note that this change will result in all EFI_MEMORY_RUNTIME
regions whose start addresses are not aligned to the OS page
size to be mapped with executable permissions (i.e., on kernels
compiled with 64 KB pages). However, since these mappings are
only active during the time that UEFI Runtime Services are being
invoked, the window for abuse is rather small.
Tested-by: Mark Salter <msalter@redhat.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [UEFI 2.4 only]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org> # v4.0+
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443218539-7610-3-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Beginning with UEFI v2.5 EFI_PROPERTIES_TABLE was introduced
that signals that the firmware PE/COFF loader supports splitting
code and data sections of PE/COFF images into separate EFI
memory map entries. This allows the kernel to map those regions
with strict memory protections, e.g. EFI_MEMORY_RO for code,
EFI_MEMORY_XP for data, etc.
Unfortunately, an unwritten requirement of this new feature is
that the regions need to be mapped with the same offsets
relative to each other as observed in the EFI memory map. If
this is not done crashes like this may occur,
BUG: unable to handle kernel paging request at fffffffefe6086dd
IP: [<fffffffefe6086dd>] 0xfffffffefe6086dd
Call Trace:
[<ffffffff8104c90e>] efi_call+0x7e/0x100
[<ffffffff81602091>] ? virt_efi_set_variable+0x61/0x90
[<ffffffff8104c583>] efi_delete_dummy_variable+0x63/0x70
[<ffffffff81f4e4aa>] efi_enter_virtual_mode+0x383/0x392
[<ffffffff81f37e1b>] start_kernel+0x38a/0x417
[<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef
Here 0xfffffffefe6086dd refers to an address the firmware
expects to be mapped but which the OS never claimed was mapped.
The issue is that included in these regions are relative
addresses to other regions which were emitted by the firmware
toolchain before the "splitting" of sections occurred at
runtime.
Needless to say, we don't satisfy this unwritten requirement on
x86_64 and instead map the EFI memory map entries in reverse
order. The above crash is almost certainly triggerable with any
kernel newer than v3.13 because that's when we rewrote the EFI
runtime region mapping code, in commit d2f7cbe7b2 ("x86/efi:
Runtime services virtual mapping"). For kernel versions before
v3.13 things may work by pure luck depending on the
fragmentation of the kernel virtual address space at the time we
map the EFI regions.
Instead of mapping the EFI memory map entries in reverse order,
where entry N has a higher virtual address than entry N+1, map
them in the same order as they appear in the EFI memory map to
preserve this relative offset between regions.
This patch has been kept as small as possible with the intention
that it should be applied aggressively to stable and
distribution kernels. It is very much a bugfix rather than
support for a new feature, since when EFI_PROPERTIES_TABLE is
enabled we must map things as outlined above to even boot - we
have no way of asking the firmware not to split the code/data
regions.
In fact, this patch doesn't even make use of the more strict
memory protections available in UEFI v2.5. That will come later.
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Chun-Yi <jlee@suse.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: James Bottomley <JBottomley@Odin.com>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443218539-7610-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add support for 10 and 12 bit Bayer formats to the test pattern generator
and the vivid driver.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Add the missing support for v4l2_sdr_format (V4L2_BUF_TYPE_SDR_CAPTURE).
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Fix the following 'make htmldocs' warnings:
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'frame_height'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'hfreq'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'vsync'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'active_width'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'polarities'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'interlaced'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'fmt'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'frame_height'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'hfreq'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'vsync'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'polarities'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'interlaced'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'aspect'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'fmt'
.//include/media/v4l2-dv-timings.h:184: warning: No description found for parameter 'hor_landscape'
.//include/media/v4l2-dv-timings.h:184: warning: No description found for parameter 'vert_portrait'
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Use a type-safe assignment instead of memcpy. And it is easier to read as well.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Document this new transfer function used by High Dynamic Range content.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created. In the case of
a shared IRQ, multiple tasks can race to create a directory. This
race condition seems to have been present forever, but is easier to
hit with async probing.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
The current code writes a set of registers that are reserved on the
tlc320aic3104. The change skips those registers for that IC.
Signed-off-by: Rick Mann <rmann@latencyzero.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
When resolving regulator-regulator supplies we ignore probe deferral
returns from regulator_dev_lookup() (such as are generated for DT when
we can see a supply is registered) and just fall back to the dummy
regulator if there are full constraints (as is the case for DT). This
means that probe deferral is broken for DT systems, fix that by paying
attention to -EPROBE_DEFER return codes like we do -ENODEV.
A further patch will simplify this further, this is a minimal fix for
the specific issue.
Fixes: 9f7e25edb1 (regulator: core: Handle full constraints systems when resolving supplies)
Reported-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonnie@kernel.org>
Cc: stable@vger.kernel.org
The DEFINE_PCI_DEVICE_TABLE() macro is deprecated. Use
'struct pci_device_id' instead of DEFINE_PCI_DEVICE_TABLE(),
with the goal of getting rid of this macro completely.
This Coccinelle semantic patch performs this transformation:
@@
identifier a;
declarer name DEFINE_PCI_DEVICE_TABLE;
initializer i;
@@
- DEFINE_PCI_DEVICE_TABLE(a)
+ const struct pci_device_id a[] = i;
Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20151001085201.GA16939@localhost
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix this warning:
arch/s390/configs/performance_defconfig:380:warning: symbol value 'm' invalid for SCSI_DH
Introduced via 086b91d052
(scsi_dh: integrate into the core SCSI code)
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
And replace the blk_mq_tag_busy_iter with it - the driver use has been
replaced with a new helper a while ago, and internal to the block we
only need the new version.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk_mq_complete_request may be a no-op if the request has already
been completed by others means (e.g. a timeout or cancellation), but
currently drivers have to set rq->errors before calling
blk_mq_complete_request, which might leave us with the wrong error value.
Add an error parameter to blk_mq_complete_request so that we can
defer setting rq->errors until we known we won the race to complete the
request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This device has always ACPI companion because driver supports only ACPI
enumeration. Therefore there is no need to test it in bcm_acpi_probe() and
we can pass it directly to acpi_dev_get_resources() (which will return
-EINVAL in case of NULL argument is passed).
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Tree wide grep for "hci_bcm" doesn't reveal there is any code registering
this platform device and "struct acpi_device_id" use for passing the
platform data looks a debug/test code leftover to me.
I'm assuming this driver effectively supports only ACPI enumeration and
thus test for ACPI_HANDLE() and platform data can be removed.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There is no need to call acpi_match_device() in driver's probe path and
verify does it find a match to given ACPI _HIDs in .acpi_match_table as
driver/platform/acpi core code has found the match prior calling the probe.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Driver doesn't handle possible error from acpi_dev_get_resources(). Test it
and return the error code in case of error.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Caller of acpi_dev_get_resources() should free the constructed resource
list by calling the acpi_dev_free_resource_list() in order to avoid memory
leak.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If we couldn't get a high precisions vblank timestamp, we currently
store a zeroed timestamp instead and assume the next vblank irq to
get us something better. This makes sense when trying to update the
timestamp from eg. vblank enable. But if we do this from the vblank
irq we will never get a vblank timestamp unless we high precision
timestamps are available and succeeded. This break weston for instance
on drivers lacking high precision timestamps.
To fix this, zero the timestamp only when not called from vbl irq.
When called from the irq, we still want the timestamp, even if not
perfect.
This fixes a regression from
4dfd64862f drm: Use vblank timestamps to guesstimate how many vblanks were missed
Cc: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Reported-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Somehow the wrong version of the patch to remove the use of custom
gpio.h on mips has been merged. This patch add the missing fixes for a
build error on jz4740 because linux/gpio.h doesn't provide any machine
specfics definitions anymore.
Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11089/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
User visible:
- By default use the most precise "cycles" hw counter available, i.e.
when the user doesn't specify any event, it will try using cycles:ppp,
cycles:pp, etc (Arnaldo Carvalho de Melo)
- Remove blank lines, headers when piping output in 'perf list', so that it can
be sanely used with 'wc -l', etc (Arnaldo Carvalho de Melo)
- Amend documentation about max_stack and synthesized callchains (Adrian Hunter)
- Fix 'perf probe -l' for probes added to kernel module functions (Masami Hiramatsu)
Build fixes:
- Fix shadowed declarations that break the build on older distros (Jiri Olsa)
- Fix build break on powerpc due to sample_reg_masks (Sukadev Bhattiprolu)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=VWu8
-----END PGP SIGNATURE-----
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes:
User visible changes:
- By default use the most precise "cycles" hw counter available, i.e.
when the user doesn't specify any event, it will try using cycles:ppp,
cycles:pp, etc. (Arnaldo Carvalho de Melo)
- Remove blank lines, headers when piping output in 'perf list', so that it can
be sanely used with 'wc -l', etc. (Arnaldo Carvalho de Melo)
- Amend documentation about max_stack and synthesized callchains. (Adrian Hunter)
- Fix 'perf probe -l' for probes added to kernel module functions. (Masami Hiramatsu)
Build fixes:
- Fix shadowed declarations that break the build on older distros. (Jiri Olsa)
- Fix build break on powerpc due to sample_reg_masks. (Sukadev Bhattiprolu)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There is some unneeded code in "hci_intel" probing. First
acpi_match_device() call is needless as driver/platform/acpi core code has
already done the matching before calling the probe and the driver does not
use the returned pointer to matching _HID other than checking is it NULL.
Then tree wide grep for "hci_intel" doesn't reveal that there is any code
registering this platform device so it looks this device is always backed
with ACPI companion so also ACPI_HANDLE() test can be removed.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Arch Makefiles can set KBUILD_DEFCONFIG to tell kbuild the name of the
defconfig that should be built by default.
However currently there is an assumption that KBUILD_DEFCONFIG points to
a file at arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG).
We would like to use a target, using merge_config, as our defconfig, so
adapt the logic in scripts/kconfig/Makefile to allow that.
To minimise the chance of breaking anything, we first check if
KBUILD_DEFCONFIG is a file, and if so we do the old logic. If it's not a
file, then we call the top-level Makefile with KBUILD_DEFCONFIG as the
target.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Marek <mmarek@suse.com>
This add helper virt_to_pfn and remove the opencoded usage of the
same.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc has a link register (lr) used for calling functions. We "bl
<func>" to call a function, and "blr" to return back to the call site.
The lr is only a single register, so if we call another function from
inside this function (ie. nested calls), software must save away the
lr on the software stack before calling the new function. Before
returning (ie. before the "blr"), the lr is restored by software from
the software stack.
This makes branch prediction quite difficult for the processor as it
will only know the branch target just before the "blr".
To help with this, modern powerpc processors keep a (non-architected)
hardware stack of lr called a "link stack". When a "bl <func>" is
run, the lr is pushed onto this stack. When a "blr" is called, the
branch predictor pops the lr value from the top of the link stack, and
uses it to predict the branch target. Hence the processor pipeline
knows a lot earlier the branch target.
This works great but there are some cases where you call "bl" but
without a matching "blr". Once such case is when trying to determine
the program counter (which can't be read directly). Here you "bl+4;
mflr" to get the program counter. If you do this, the link stack will
get out of sync with reality, causing the branch predictor to
mis-predict subsequent function returns.
To avoid this, modern micro-architectures have a special case of bl.
Using the form "bcl 20,31,+4", ensures the processor doesn't push to
the link stack.
The 32 and 64 bit variants of __get_datapage() use a "bl; mflr" to
determine the loaded address of the VDSO. The current versions of
these attempt to use this special bl variant.
Unfortunately they use +8 rather than the required +4. Hence the
current code results in the link stack getting out of sync with
reality and hence the resulting performance degradation.
This patch moves it to bcl+4 by moving __kernel_datapage_offset out of
__get_datapage().
With this patch, running a gettimeofday() (which uses
__get_datapage()) microbenchmark we get a decent bump in performance
on POWER7/8.
For the benchmark in tools/testing/selftests/powerpc/benchmarks/gettimeofday.c
POWER8:
64bit gets ~4% improvement
32bit gets ~9% improvement
POWER7:
64bit gets ~7% improvement
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reported-by: Aaron Sawdey <sawdey@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a benchmark directory to the powerpc selftests and adds a
gettimeofday() benchmark to it.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch defines macros for the three bolted SLB indexes we use.
Switch the functions that take the indexes as an argument to use the
enum.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Andy Lutomirski says:
Some dynamic loaders may be slightly faster if a GNU hash is
available.
This is unlikely to have any measurable effect on the time it takes
to resolve vdso symbols (since there are so few of them). In some
contexts, it can be a win for a different reason: if every DSO has a
GNU hash section, then libc can avoid calculating SysV hashes at
all. Both musl and glibc appear to have this optimization.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Surprisingly kbuild can't cope with tristates in the
<module>-$(CONFIG_FOO) pattern. This patch hacks up a solution.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
I arranged the code so that the compiler can remove the unecessary bits
in ip_vs_leave when CONFIG_SYSCTL is unset, and removed an explicit
CONFIG_SYSCTL.
Unfortunately when rebasing my work on top of that of Alex Gartrell I
missed the fact that the newly added function ip_vs_addr_is_unicast was
surrounded by CONFIG_SYSCTL.
So remove the now unnecessary CONFIG_SYSCTL guards around
ip_vs_addr_is_unicast. It is causing build failures today when
CONFIG_SYSCTL is not selected and any self respecting compiler will
notice that sysctl_cache_bypass is always false without CONFIG_SYSCTL
and not include the logic from the function ip_vs_addr_is_unicast in
the compiled code.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
The exynos_drm_gem_mmap_buffer() is not used outside so make it static.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
As of commit c99cd90d98 ("ARM: shmobile: r8a7779: Remove legacy
SoC code"), r8a7779_init_pm_domains() is no longer called.
Remove all related legacy PM Domain code.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
As of commit 4baadb9e05 ("ARM: shmobile: r8a7778: remove obsolete
setup code"), r8a7778_init_irq_dt() is no longer used outside
setup-r8a7778.c.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
shmobile_smp_apmu_cpu_shutdown() is used inside platsmp-apmu.c only.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
fimd_dp_clock_enable() was setting the always to enabled,
this patch fix this to actually use the value that is set to 'val'.
Reported-by: Emilio López <emilio.lopez@collabora.co.uk>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
This patch removes unnecessary pm suspend/resume functions.
All kms sub drivers will be controlled by top of Exynos drm driver
and connector dpms so these sub drivers shouldn't have their own
pm interfaces.
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Add REF2USB_TX clock support into MT8173 APMIXEDSYS. This clock
is needed by USB 3.0.
Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Most multimedia subsystem clocks will be accessed by multiple
drivers, so it's a better way to manage these clocks in CCF.
This patch adds clock support for MM, IMG, VDEC, VENC and VENC_LT
subsystems.
Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
