Jonathan Corbet [Thu, 10 May 2018 15:59:02 +0000 (09:59 -0600)]
Revert "Documentation/features/vm: Remove arch support status file for 'pte_special'"
The removal of this file appears to have been premature; it's not a feature
enabled by Kconfig, but it's a arch-level feature regardless. Put it back
for now until some happy future time when we decide how we really want to
document such features.
The document describes NUMA memory policy and as it is a part of the Linux
documentation it's obvious that this is Linux memory policy. Besides,
"Linux memory policy" may refer to other policies, e.g. memory hotplug
policy, and using term NUMA makes the documentation less ambiguous.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Jonathan Corbet [Tue, 8 May 2018 15:29:02 +0000 (09:29 -0600)]
Merge branch 'features' into docs-next
Andrea Parri dice:
This series provides the script 'features-refresh.sh', which operates on
the arch support status files, and it applies this script to refresh the
status files in place; previous discussions about this series are at [1].
Andrea Parri [Mon, 7 May 2018 10:43:41 +0000 (12:43 +0200)]
Documentation/features/locking: Use '!RWSEM_GENERIC_SPINLOCK' as Kconfig for 'rwsem-optimized'
Uses '!RWSEM_GENERIC_SPINLOCK' in place of 'Optimized asm/rwsem.h' as
Kconfig for 'rwsem-optimized': the new Kconfig expresses this feature
equivalently, while also enabling the script 'features-refresh.sh' to
operate on the corresponding arch support status file. Also refreshes
the status matrix by using the script 'features-refresh.sh'.
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Andrea Parri [Mon, 7 May 2018 10:43:40 +0000 (12:43 +0200)]
Documentation/features/core: Add arch support status files for 'cBPF-JIT' and 'eBPF-JIT'
Commit 6077776b5908e split 'HAVE_BPF_JIT' into cBPF and eBPF variant.
Adds arch support status files for the new variants, and removes the
status file corresponding to 'HAVE_BPT_JIT'. The new status matrices
were auto-generated using the script 'features-refresh.sh'.
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Andrea Parri [Mon, 7 May 2018 10:43:39 +0000 (12:43 +0200)]
Documentation/features: Refresh the arch support status files in place
Now that the script 'features-refresh.sh' is available, uses this script
to refresh all the arch-support.txt files in place.
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
which operates on the arch-support.txt files and refreshes them in place.
This way [1],
"[...] we soft- decouple the refreshing of the entries from the
introduction of the features, while still making it all easy to
keep sync and to extend."
Mike Rapoport [Tue, 24 Apr 2018 06:40:27 +0000 (09:40 +0300)]
docs/vm: ksm: udpate description of stable_node_{dups,chains}
Remove implementation details from sysfs parameter descriptions.
Also move the paragraph discussing fragmentation issues and their possible
solution to the "Design" section.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Make the description of stable_node_chains_prune_millisecs sysfs parameter
less implementation aware and add a few words about this parameter in the
"Design" section.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Mike Rapoport [Tue, 24 Apr 2018 06:40:24 +0000 (09:40 +0300)]
docs/vm: ksm: add "Design" section
Include the KSM description from the source code comment, add a subsection
about reverse mapping and include kernel-doc references for KSM data
structures.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Mike Rapoport [Tue, 24 Apr 2018 06:40:22 +0000 (09:40 +0300)]
mm/ksm: docs: extend overview comment and make it "DOC:"
The existing comment provides a good overview of KSM implementation. Let's
update it to reflect recent additions of "chain" and "dup" variants of the
stable tree nodes and mark it as "DOC:" for inclusion into the KSM
documentation.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Using incorrect :functions: syntax (extra space) causes an odd kernel-doc
warning, so fix that.
Documentation/driver-api/device_connection.rst:42: ERROR: Error in "kernel-doc" directive:
Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Randy Dunlap [Fri, 27 Apr 2018 01:11:02 +0000 (18:11 -0700)]
documentation: core-api: rearrange a few kernel-api chapters and sections
Rearrange some kernel-api chapters and sections to group them
together better.
- move Bit Operations from Basic C Library Functions to Basic
Kernel Library Functions (now adjacent to Bitmap Operations since
they are not typical C library functions)
- move Sorting from Math Functions to Basic Kernel Library Functions
since sort functions are more Basic than Math Functions
- move Text Searching from Math Functions to Basic Kernel Library
Functions (keep Sorting and Searching close to each other)
- combine CRC and Math functions together into the (newly named)
CRC and Math Functions chapter
Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Jonathan Corbet [Fri, 27 Apr 2018 23:13:20 +0000 (17:13 -0600)]
Merge tag 'v4.17-rc2' into docs-next
Merge -rc2 to pick up the changes to
Documentation/core-api/kernel-api.rst that hit mainline via the
networking tree. In their absence, subsequent patches cannot be
applied.
Mike Rapoport [Wed, 18 Apr 2018 08:07:49 +0000 (11:07 +0300)]
docs/admin-guide/mm: start moving here files from Documentation/vm
Several documents in Documentation/vm fit quite well into the "admin/user
guide" category. The documents that don't overload the reader with lots of
implementation details and provide coherent description of certain feature
can be moved to Documentation/admin-guide/mm.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Mike Rapoport [Wed, 18 Apr 2018 08:07:47 +0000 (11:07 +0300)]
docs/vm: pagemap: change document title
"pagemap from the Userspace Perspective" is not very descriptive for
unaware readers. Since the document describes how to examine a process page
tables, let's title it "Examining Process Page Tables"
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Mike Rapoport [Wed, 18 Apr 2018 08:07:45 +0000 (11:07 +0300)]
docs/vm: hugetlbpage: move section about kernel development to hugetlbfs_reserv
The hugetlbpage describes hugetlbfs from the user perspective and newer
hugetlbfs_reserv document targets kernel developers. Hence the section
about hugetlbfs kernel development naturally belongs there.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Some lines used spaces instead of tabs at line start.
This can cause mangled lines in editors due to inconsistency.
Replace spaces for tabs where appropriate.
Signed-off-by: Thymo van Beers <thymovanbeers@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Jonathan Corbet [Fri, 27 Apr 2018 22:48:42 +0000 (16:48 -0600)]
Merge branch 'tglx-license' into docs-next
Thomas said:
There are a few bogus SPDX identifiers in various files and SPDX
Identifiers used in tree or about to be used which have no corresponding
License Text file in the LICENSES directory or use the new variant of the
GPL-2.0[+] license identifiers which are not mentioned in the GPL-2.0
Valid-License-Identifiers: tags.
There is no tool which can be used to scan the tree and also nothing which
helps people who submit patches to check their stuff before submission.
The following series cleans that up:
- Add GPL-2.0-only and GPL-2.0-or-later identifiers to the GPL2.0 license
and the Linux-syscall-note exception
- Add X11, Apache-2.0, CC-BY-SA-4.0, CCDL-1.0, Linux-OpenIB license texts
to the LICENSES directory along with the required documentation texts
- Add a checker script which can read a single file or even a patch from
the command line or does a full git tree scan
[Thomas also wins some sort of special prize for including an SPDX-checking
patch that complains about itself!]
Thomas Gleixner [Thu, 26 Apr 2018 13:54:27 +0000 (15:54 +0200)]
scripts: Add SPDX checker script
The SPDX-License-Identifiers are growing in the kernel and so grow
expression failures and license IDs are used which have no corresponding
license text file in the LICENSES directory.
Add a script which gathers information from the LICENSES directory,
i.e. the various tags in the licenses and exception files and then scans
either input from stdin, which it treats as a single file or if started
without arguments it scans the full kernel tree.
It checks whether the license expression syntax is correct and also
validates whether the license identifiers used in the expressions are
available in the LICENSES files.
positional arguments:
path Check path or file. If not given full git tree scan.
For stdin use "-"
optional arguments:
-h, --help show this help message and exit
-m MAXLINES, --maxlines MAXLINES
Maximum number of lines to scan in a file. Default 15
-v, --verbose Verbose statistics output
Files checked: 61332
Lines checked: 669181
Files with SPDX: 16169
Files with errors: 5
real 0m2.642s
user 0m2.231s
sys 0m0.467s
That's a full tree sweep on my laptop. Note, this runs single threaded.
It scans by default the first 15 lines for a SPDX identifier where the
current max inside a top comment is at line 10. But that's going to be
faster once the identifiers are all in the first two lines as documented.
The python wizards will surely know how to do that smarter and faster, but
its at least better than no tool at all.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[jc: Fixed ironically erroneous SPDX tag and did chmod +x ] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Thomas Gleixner [Wed, 25 Apr 2018 20:30:26 +0000 (22:30 +0200)]
LICENSES: Add Linux-OpenIB license text
The infiniband code uses a variant of the OpenIB license. This license is
BSD-2-Clause with the MIT disclaimer. The linux kernel uses this license
extensively throughout the driver subsystem since 2005. Note that the
OpenIB.org license is a true match to BSD-2-Clause.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Thomas Gleixner [Wed, 25 Apr 2018 20:30:21 +0000 (22:30 +0200)]
LICENSES/GPL2.0: Add GPL-2.0-only/or-later as valid identifiers
Quite some files have been flagged with the new GPL-2.0-only and
GPL-2.0-or-later identifiers which replace the original GPL-2.0 and
GPL-2.0+ identifiers in the SPDX license identifier specification, but the
identifiers are not mentioned as valid in the GPL-2.0 license file.
Add them to the license file and to the Linux-syscall-note exception to
make everything consistent again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Cc: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* tag 'drm-fixes-for-v4.17-rc2' of git://people.freedesktop.org/~airlied/linux: (23 commits)
drm/amd/powerplay: header file interface to SMU update
drm/amd/pp: Fix bug voltage can't be OD separately on VI
drm/amd/display: Don't program bypass on linear regamma LUT
drm/i915: Fix LSPCON TMDS output buffer enabling from low-power state
drm/i915/audio: Fix audio detection issue on GLK
drm/i915: Call i915_perf_fini() on init_hw error unwind
drm/i915/bios: filter out invalid DDC pins from VBT child devices
drm/i915/pmu: Inspect runtime PM state more carefully while estimating RC6
drm/i915: Do no use kfree() to free a kmem_cache_alloc() return value
drm/exynos: exynos_drm_fb -> drm_framebuffer
drm/exynos: Move dma_addr out of exynos_drm_fb
drm/exynos: Move GEM BOs to drm_framebuffer
drm: Fix HDCP downstream dev count read
drm/vc4: Fix memory leak during BO teardown
drm/i915/execlists: Clear user-active flag on preemption completion
drm/i915/gvt: Add drm_format_mod update
drm/i915/gvt: Disable primary/sprite/cursor plane at virtual display initialization
drm/i915/gvt: Delete redundant error message in fb_decode.c
drm/i915/gvt: Cancel dma map when resetting ggtt entries
drm/i915/gvt: Missed to cancel dma map for ggtt entries
...
Dave Airlie [Sun, 22 Apr 2018 22:54:06 +0000 (08:54 +1000)]
Merge branch 'drm-next-4.17' of git://people.freedesktop.org/~agd5f/linux into drm-next
- Fix a dark screen issue in DC
- Fix clk/voltage dependency tracking for wattman
- Update SMU interface for vega12
* 'drm-next-4.17' of git://people.freedesktop.org/~agd5f/linux:
drm/amd/powerplay: header file interface to SMU update
drm/amd/pp: Fix bug voltage can't be OD separately on VI
drm/amd/display: Don't program bypass on linear regamma LUT
Dave Airlie [Sun, 22 Apr 2018 22:53:41 +0000 (08:53 +1000)]
Merge tag 'exynos-drm-fixes-for-v4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-next
Remove Exynos specific framebuffer structure and
relevant functions.
- it removes exynos_drm_fb structure which is a wrapper of
drm_framebuffer and unnecessary two exynos specific callback
functions, exynos_drm_destory() and exynos_drm_fb_create_handle()
because we can reuse existing drm common callback ones instead.
* tag 'exynos-drm-fixes-for-v4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
drm/exynos: exynos_drm_fb -> drm_framebuffer
drm/exynos: Move dma_addr out of exynos_drm_fb
drm/exynos: Move GEM BOs to drm_framebuffer
drm/amdkfd: Deallocate SDMA queues correctly
drm/amdkfd: Fix scratch memory with HWS enabled
Dave Airlie [Sun, 22 Apr 2018 22:53:27 +0000 (08:53 +1000)]
Merge tag 'drm-intel-next-fixes-2018-04-19' of git://anongit.freedesktop.org/drm/drm-intel into drm-next
- Fix for FDO #105549: Avoid OOPS on bad VBT (Jani)
- Fix rare pre-emption race (Chris)
- Fix RC6 race against PM transitions (Tvrtko)
* tag 'drm-intel-next-fixes-2018-04-19' of git://anongit.freedesktop.org/drm/drm-intel:
drm/i915/audio: Fix audio detection issue on GLK
drm/i915: Call i915_perf_fini() on init_hw error unwind
drm/i915/bios: filter out invalid DDC pins from VBT child devices
drm/i915/pmu: Inspect runtime PM state more carefully while estimating RC6
drm/i915: Do no use kfree() to free a kmem_cache_alloc() return value
drm/i915/execlists: Clear user-active flag on preemption completion
drm/i915/gvt: Add drm_format_mod update
drm/i915/gvt: Disable primary/sprite/cursor plane at virtual display initialization
drm/i915/gvt: Delete redundant error message in fb_decode.c
drm/i915/gvt: Cancel dma map when resetting ggtt entries
drm/i915/gvt: Missed to cancel dma map for ggtt entries
drm/i915/gvt: Make MI_USER_INTERRUPT nop in cmd parser
drm/i915/gvt: Mark expected switch fall-through in handle_g2v_notification
drm/i915/gvt: throw error on unhandled vfio ioctls
Dave Airlie [Sun, 22 Apr 2018 22:52:54 +0000 (08:52 +1000)]
Merge tag 'drm-misc-fixes-2018-04-18-1' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-fixes:
stable: vc4: Fix memory leak during BO teardown (Daniel)
dp: Add i2c retry for LSPCON adapters (Imre)
hdcp: Fix device count mask (Ramalingam)
Cc: Daniel J Blueman <daniel@quora.org Cc: Imre Deak <imre.deak@intel.com> Cc: Ramalingam C <ramalingam.c@intel.com>
* tag 'drm-misc-fixes-2018-04-18-1' of git://anongit.freedesktop.org/drm/drm-misc:
drm/i915: Fix LSPCON TMDS output buffer enabling from low-power state
drm: Fix HDCP downstream dev count read
drm/vc4: Fix memory leak during BO teardown
Merge tag '4.17-rc1-SMB3-CIFS' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
"Various SMB3/CIFS fixes.
There are three more security related fixes in progress that are not
included in this set but they are still being tested and reviewed, so
sending this unrelated set of smaller fixes now"
* tag '4.17-rc1-SMB3-CIFS' of git://git.samba.org/sfrench/cifs-2.6:
CIFS: fix typo in cifs_dbg
cifs: do not allow creating sockets except with SMB1 posix exensions
cifs: smbd: Dump SMB packet when configured
cifs: smbd: Check for iov length on sending the last iov
fs: cifs: Adding new return type vm_fault_t
cifs: smb2ops: Fix NULL check in smb2_query_symlink
Merge tag 'for-4.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"This contains a few fixups to the qgroup patches that were merged this
dev cycle, unaligned access fix, blockgroup removal corner case fix
and a small debugging output tweak"
* tag 'for-4.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: print-tree: debugging output enhancement
btrfs: Fix race condition between delayed refs and blockgroup removal
btrfs: fix unaligned access in readdir
btrfs: Fix wrong btrfs_delalloc_release_extents parameter
btrfs: delayed-inode: Remove wrong qgroup meta reservation calls
btrfs: qgroup: Use independent and accurate per inode qgroup rsv
btrfs: qgroup: Commit transaction in advance to reduce early EDQUOT
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A small set of fixes for x86:
- Prevent X2APIC ID 0xFFFFFFFF from being treated as valid, which
causes the possible CPU count to be wrong.
- Prevent 32bit truncation in calc_hpet_ref() which causes the TSC
calibration to fail
- Fix the page table setup for temporary text mappings in the resume
code which causes resume failures
- Make the page table dump code handle HIGHPTE correctly instead of
oopsing
- Support for topologies where NUMA nodes share an LLC to prevent a
invalid topology warning and further malfunction on such systems.
- Remove the now unused pci-nommu code
- Remove stale function declarations"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/power/64: Fix page-table setup for temporary text mapping
x86/mm: Prevent kernel Oops in PTDUMP code with HIGHPTE=y
x86,sched: Allow topologies where NUMA nodes share an LLC
x86/processor: Remove two unused function declarations
x86/acpi: Prevent X2APIC id 0xffffffff from being accounted
x86/tsc: Prevent 32bit truncation in calc_hpet_ref()
x86: Remove pci-nommu.c
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"A larger set of updates for perf.
Kernel:
- Handle the SBOX uncore monitoring correctly on Broadwell CPUs which
do not have SBOX.
- Store context switch out type in PERF_RECORD_SWITCH[_CPU_WIDE]. The
percentage of preempting and non-preempting context switches help
understanding the nature of workloads (CPU or IO bound) that are
running on a machine. This adds the kernel facility and userspace
changes needed to show this information in 'perf script' and 'perf
report -D' (Alexey Budankov)
- Remove a WARN_ON() in the trace/kprobes code which is pointless
because the return error code is already telling the caller what's
wrong.
- Revert a fugly workaround for clang BPF targets.
- Fix sample_max_stack maximum check and do not proceed when an error
has been detect, return them to avoid misidentifying errors (Jiri
Olsa)
- Add SPDX idenitifiers and get rid of GPL boilderplate.
Tools:
- Synchronize kernel ABI headers, v4.17-rc1 (Ingo Molnar)
- Support MAP_FIXED_NOREPLACE, noticed when updating the
tools/include/ copies (Arnaldo Carvalho de Melo)
- Add '\n' at the end of parse-options error messages (Ravi Bangoria)
- Add s390 support for detailed/verbose PMU event description (Thomas
Richter)
- perf annotate fixes and improvements:
* Allow showing offsets in more than just jump targets, use the
new 'O' hotkey in the TUI, config ~/.perfconfig
annotate.offset_level for it and for --stdio2 (Arnaldo Carvalho
de Melo)
* Use the resolved variable names from objdump disassembled lines
to make them more compact, just like was already done for some
instructions, like "mov", this eventually will be done more
generally, but lets now add some more to the existing mechanism
(Arnaldo Carvalho de Melo)
- perf record fixes:
* Change warning for missing topology sysfs entry to debug, as not
all architectures have those files, s390 being one of those
(Thomas Richter)
* Remove old error messages about things that unlikely to be the
root cause in modern systems (Andi Kleen)
* Enable 1ms interval for printing event counters values in
(Alexey Budankov)
- perf test fixes:
* Run dwarf unwind on arm32 (Kim Phillips)
* Remove unused ptrace.h include from LLVM test, sidesteping older
clang's lack of support for some asm constructs (Arnaldo
Carvalho de Melo)
* Fixup BPF test using epoll_pwait syscall function probe, to cope
with the syscall routines renames performed in this development
cycle (Arnaldo Carvalho de Melo)
- perf version fixes:
* Do not print info about HAVE_LIBAUDIT_SUPPORT in 'perf version
--build-options' when HAVE_SYSCALL_TABLE_SUPPORT is true, as
libaudit won't be used in that case, print info about
syscall_table support instead (Jin Yao)
- Build system fixes:
* Use HAVE_..._SUPPORT used consistently (Jin Yao)
* Restore READ_ONCE() C++ compatibility in tools/include (Mark
Rutland)
* Give hints about package names needed to build jvmti (Arnaldo
Carvalho de Melo)"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
perf/x86/intel/uncore: Fix SBOX support for Broadwell CPUs
perf/x86/intel/uncore: Revert "Remove SBOX support for Broadwell server"
coresight: Move to SPDX identifier
perf test BPF: Fixup BPF test using epoll_pwait syscall function probe
perf tests mmap: Show which tracepoint is failing
perf tools: Add '\n' at the end of parse-options error messages
perf record: Remove suggestion to enable APIC
perf record: Remove misleading error suggestion
perf hists browser: Clarify top/report browser help
perf mem: Allow all record/report options
perf trace: Support MAP_FIXED_NOREPLACE
perf: Remove superfluous allocation error check
perf: Fix sample_max_stack maximum check
perf: Return proper values for user stack errors
perf list: Add s390 support for detailed/verbose PMU event description
perf script: Extend misc field decoding with switch out event type
perf report: Extend raw dump (-D) out with switch out event type
perf/core: Store context switch out type in PERF_RECORD_SWITCH[_CPU_WIDE]
tools/headers: Synchronize kernel ABI headers, v4.17-rc1
trace_kprobe: Remove warning message "Could not insert probe at..."
...
Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull /dev/random fixes from Ted Ts'o:
"Fix some bugs in the /dev/random driver which causes getrandom(2) to
unblock earlier than designed.
Thanks to Jann Horn from Google's Project Zero for pointing this out
to me"
* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: add new ioctl RNDRESEEDCRNG
random: crng_reseed() should lock the crng instance that it is modifying
random: set up the NUMA crng instances after the CRNG is fully initialized
random: use a different mixing algorithm for add_device_randomness()
random: fix crng_ready() test
Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
"A regression fix, new unit test infrastructure and a build fix:
- Regression fix addressing support for the new NVDIMM label storage
area access commands (_LSI, _LSR, and _LSW).
The Intel specific version of these commands communicated the
"Device Locked" status on the label-storage-information command.
However, these new commands (standardized in ACPI 6.2) communicate
the "Device Locked" status on the label-storage-read command, and
the driver was missing the indication.
Reading from locked persistent memory is similar to reading
unmapped PCI memory space, returns all 1's.
- Unit test infrastructure is added to regression test the "Device
Locked" detection failure.
- A build fix is included to allow the "of_pmem" driver to be built
as a module and translate an Open Firmware described device to its
local numa node"
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
MAINTAINERS: Add backup maintainers for libnvdimm and DAX
device-dax: allow MAP_SYNC to succeed
Revert "libnvdimm, of_pmem: workaround OF_NUMA=n build error"
libnvdimm, of_pmem: use dev_to_node() instead of of_node_to_nid()
tools/testing/nvdimm: enable labels for nfit_test.1 dimms
tools/testing/nvdimm: fix missing newline in nfit_test_dimm 'handle' attribute
tools/testing/nvdimm: support nfit_test_dimm attributes under nfit_test.1
tools/testing/nvdimm: allow custom error code injection
libnvdimm, dimm: handle EACCES failures from label reads
Merge tag 'sound-4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"A few small fixes:
- a fix for the NULL-dereference in rawmidi compat ioctls, triggered
by fuzzer
- HD-audio Realtek codec quirks, a VIA controller fixup
- a long-standing bug fix in LINE6 MIDI"
* tag 'sound-4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: rawmidi: Fix missing input substream checks in compat ioctls
ALSA: hda/realtek - adjust the location of one mic
ALSA: hda/realtek - set PINCFG_HEADSET_MIC to parse_flags
ALSA: hda - New VIA controller suppor no-snoop path
ALSA: line6: Use correct endpoint type for midi output
Merge tag 'linux-watchdog-4.17-rc2' of git://www.linux-watchdog.org/linux-watchdog
Pull watchdog fixes from Wim Van Sebroeck:
- fall-through fixes
- MAINTAINER change for hpwdt
- renesas-wdt: Add support for WDIOF_CARDRESET
- aspeed: set bootstatus during probe
* tag 'linux-watchdog-4.17-rc2' of git://www.linux-watchdog.org/linux-watchdog:
aspeed: watchdog: Set bootstatus during probe
watchdog: renesas-wdt: Add support for WDIOF_CARDRESET
watchdog: wafer5823wdt: Mark expected switch fall-through
watchdog: w83977f_wdt: Mark expected switch fall-through
watchdog: sch311x_wdt: Mark expected switch fall-through
watchdog: hpwdt: change maintainer.
Merge tag 'linux-kselftest-4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest fix from Shuah Khan:
"A fix from Michael Ellerman to not run dnotify_test by default to
prevent Kselftest running forever"
* tag 'linux-kselftest-4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests/filesystems: Don't run dnotify_test by default
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- kasan: avoid pfn_to_nid() before the page array is initialised
- Fix typo causing the "upgrade" of known signals to SIGKILL
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: signal: don't force known signals to SIGKILL
arm64: kasan: avoid pfn_to_nid() before page array is initialized
- "fork: unconditionally clear stack on fork" is a non-bugfix which got
lost during the merge window - performance concerns appear to have
been adequately addressed.
- and a bunch of fixes
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/filemap.c: fix NULL pointer in page_cache_tree_insert()
mm: memcg: add __GFP_NOWARN in __memcg_schedule_kmem_cache_create()
fs, elf: don't complain MAP_FIXED_NOREPLACE unless -EEXIST error
kexec_file: do not add extra alignment to efi memmap
proc: fix /proc/loadavg regression
proc: revalidate kernel thread inodes to root:root
autofs: mount point create should honour passed in mode
MAINTAINERS: add personal addresses for Sascha and Uwe
kasan: add no_sanitize attribute for clang builds
rapidio: fix rio_dma_transfer error handling
mm: enable thp migration for shmem thp
writeback: safer lock nesting
mm, pagemap: fix swap offset value for PMD migration entry
mm: fix do_pages_move status handling
fork: unconditionally clear stack on fork
Merge tag 'perf-urgent-for-mingo-4.17-20180420' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fixes and improvements from Arnaldo Carvalho de Melo:
- Store context switch out type in PERF_RECORD_SWITCH[_CPU_WIDE].
The percentage of preempting and non-preempting context switches help
understanding the nature of workloads (CPU or IO bound) that are running
on a machine. This adds the kernel facility and userspace changes needed
to show this information in 'perf script' and 'perf report -D' (Alexey Budankov)
- Remove old error messages about things that unlikely to be the root cause
in modern systems (Andi Kleen)
- Synchronize kernel ABI headers, v4.17-rc1 (Ingo Molnar)
- Support MAP_FIXED_NOREPLACE, noticed when updating the tools/include/
copies (Arnaldo Carvalho de Melo)
- Fixup BPF test using epoll_pwait syscall function probe, to cope with
the syscall routines renames performed in this development cycle (Arnaldo Carvalho de Melo)
- Fix sample_max_stack maximum check and do not proceed when an error
has been detect, return them to avoid misidentifying errors (Jiri Olsa)
- Add '\n' at the end of parse-options error messages (Ravi Bangoria)
- Add s390 support for detailed/verbose PMU event description (Thomas Richter)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Matthew Wilcox [Fri, 20 Apr 2018 21:56:20 +0000 (14:56 -0700)]
mm/filemap.c: fix NULL pointer in page_cache_tree_insert()
f2fs specifies the __GFP_ZERO flag for allocating some of its pages.
Unfortunately, the page cache also uses the mapping's GFP flags for
allocating radix tree nodes. It always masked off the __GFP_HIGHMEM
flag, and masks off __GFP_ZERO in some paths, but not all. That causes
radix tree nodes to be allocated with a NULL list_head, which causes
backtraces like:
The __GFP_DMA and __GFP_DMA32 flags would also be able to sneak through
if they are ever used. Fix them all by using GFP_RECLAIM_MASK at the
innermost location, and remove it from earlier in the callchain.
Link: http://lkml.kernel.org/r/20180411060320.14458-2-willy@infradead.org Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check") Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reported-by: Chris Fries <cfries@google.com> Debugged-by: Minchan Kim <minchan@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Fri, 20 Apr 2018 21:56:17 +0000 (14:56 -0700)]
mm: memcg: add __GFP_NOWARN in __memcg_schedule_kmem_cache_create()
If there is heavy memory pressure, page allocation with __GFP_NOWAIT
fails easily although it's order-0 request. I got below warning 9 times
for normal boot.
__memcg_schedule_kmem_cache_create() tries to create a shadow slab cache
and the worker allocation failure is not really critical because we will
retry on the next kmem charge. We might miss some charges but that
shouldn't be critical. The excessive allocation failure report is not
very helpful.
[mhocko@kernel.org: changelog update] Link: http://lkml.kernel.org/r/20180418022912.248417-1-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
And __efi_memmap_init maps with the size including the alignment bytes
but efi_memmap_unmap use nr_maps * desc_size which does not include the
extra bytes.
The alignment in kexec code is only needed for the kexec buffer internal
use Actually kexec should pass exact size of the efi memmap to 2nd
kernel.
Link: http://lkml.kernel.org/r/20180417083600.GA1972@dhcp-128-65.nay.redhat.com Signed-off-by: Dave Young <dyoung@redhat.com> Reported-by: joeyli <jlee@suse.com> Tested-by: Randy Wright <rwright@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ian Kent [Fri, 20 Apr 2018 21:55:59 +0000 (14:55 -0700)]
autofs: mount point create should honour passed in mode
The autofs file system mkdir inode operation blindly sets the created
directory mode to S_IFDIR | 0555, ingoring the passed in mode, which can
cause selinux dac_override denials.
But the function also checks if the caller is the daemon (as no-one else
should be able to do anything here) so there's no point in not honouring
the passed in mode, allowing the daemon to set appropriate mode when
required.
MAINTAINERS: add personal addresses for Sascha and Uwe
The idea behind using kernel@pengutronix.de (i.e. the mail alias for the
kernel people at Pengutronix) as email address was to have a backup when
a given developer is on vacation or run over by a bus. Make this more
explicit by adding the alias as reviewer and use the personal address
for Sascha and me.
KASAN uses the __no_sanitize_address macro to disable instrumentation of
particular functions. Right now it's defined only for GCC build, which
causes false positives when clang is used.
This patch adds a definition for clang.
Note, that clang's revision 329612 or higher is required.
[andreyknvl@google.com: remove redundant #ifdef CONFIG_KASAN check] Link: http://lkml.kernel.org/r/c79aa31a2a2790f6131ed607c58b0dd45dd62a6c.1523967959.git.andreyknvl@google.com Link: http://lkml.kernel.org/r/4ad725cc903f8534f8c8a60f0daade5e3d674f8d.1523554166.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Paul Lawrence <paullawrence@google.com> Cc: Sandipan Das <sandipan@linux.vnet.ibm.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ioan Nicu [Fri, 20 Apr 2018 21:55:49 +0000 (14:55 -0700)]
rapidio: fix rio_dma_transfer error handling
Some of the mport_dma_req structure members were initialized late
inside the do_dma_request() function, just before submitting the
request to the dma engine. But we have some error branches before
that. In case of such an error, the code would return on the error
path and trigger the calling of dma_req_free() with a req structure
which is not completely initialized. This causes a NULL pointer
dereference in dma_req_free().
This patch fixes these error branches by making sure that all
necessary mport_dma_req structure members are initialized in
rio_dma_transfer() immediately after the request structure gets
allocated.
Link: http://lkml.kernel.org/r/20180412150605.GA31409@nokia.com Fixes: bbd876adb8c72 ("rapidio: use a reference count for struct mport_dma_req") Signed-off-by: Ioan Nicu <ioan.nicu.ext@nokia.com> Tested-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Acked-by: Alexandre Bounine <alex.bou9@gmail.com> Cc: Barry Wood <barry.wood@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Frank Kunz <frank.kunz@nokia.com> Cc: <stable@vger.kernel.org> [4.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
My testing for the latest kernel supporting thp migration showed an
infinite loop in offlining the memory block that is filled with shmem
thps. We can get out of the loop with a signal, but kernel should return
with failure in this case.
What happens in the loop is that scan_movable_pages() repeats returning
the same pfn without any progress. That's because page migration always
fails for shmem thps.
In memory offline code, memory blocks containing unmovable pages should be
prevented from being offline targets by has_unmovable_pages() inside
start_isolate_page_range(). So it's possible to change migratability for
non-anonymous thps to avoid the issue, but it introduces more complex and
thp-specific handling in migration code, so it might not good.
So this patch is suggesting to fix the issue by enabling thp migration for
shmem thp. Both of anon/shmem thp are migratable so we don't need
precheck about the type of thps.
Link: http://lkml.kernel.org/r/20180406030706.GA2434@hori1.linux.bs1.fc.nec.co.jp Fixes: commit 72b39cfc4d75 ("mm, memory_hotplug: do not fail offlining too early") Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Zi Yan <zi.yan@sent.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if
the page's memcg is undergoing move accounting, which occurs when a
process leaves its memcg for a new one that has
memory.move_charge_at_immigrate set.
unlocked_inode_to_wb_begin,end() use spin_lock_irq/spin_unlock_irq() if
the given inode is switching writeback domains. Switches occur when
enough writes are issued from a new domain.
This existing pattern is thus suspicious:
lock_page_memcg(page);
unlocked_inode_to_wb_begin(inode, &locked);
...
unlocked_inode_to_wb_end(inode, locked);
unlock_page_memcg(page);
If both inode switch and process memcg migration are both in-flight then
unlocked_inode_to_wb_end() will unconditionally enable interrupts while
still holding the lock_page_memcg() irq spinlock. This suggests the
possibility of deadlock if an interrupt occurs before unlock_page_memcg().
Due to configuration limitations this deadlock is not currently possible
because we don't mix cgroup writeback (a cgroupv2 feature) and
memory.move_charge_at_immigrate (a cgroupv1 feature).
If the kernel is hacked to always claim inode switching and memcg
moving_account, then this script triggers lockup in less than a minute:
cd /mnt/cgroup/memory
mkdir a b
echo 1 > a/memory.move_charge_at_immigrate
echo 1 > b/memory.move_charge_at_immigrate
(
echo $BASHPID > a/cgroup.procs
while true; do
dd if=/dev/zero of=/mnt/big bs=1M count=256
done
) &
while true; do
sync
done &
sleep 1h &
SLEEP=$!
while true; do
echo $SLEEP > a/cgroup.procs
echo $SLEEP > b/cgroup.procs
done
The deadlock does not seem possible, so it's debatable if there's any
reason to modify the kernel. I suggest we should to prevent future
surprises. And Wang Long said "this deadlock occurs three times in our
environment", so there's more reason to apply this, even to stable.
Stable 4.4 has minor conflicts applying this patch. For a clean 4.4 patch
see "[PATCH for-4.4] writeback: safer lock nesting"
https://lkml.org/lkml/2018/4/11/146
Wang Long said "this deadlock occurs three times in our environment"
[gthelen@google.com: v4] Link: http://lkml.kernel.org/r/20180411084653.254724-1-gthelen@google.com
[akpm@linux-foundation.org: comment tweaks, struct initialization simplification]
Change-Id: Ibb773e8045852978f6207074491d262f1b3fb613 Link: http://lkml.kernel.org/r/20180410005908.167976-1-gthelen@google.com Fixes: 682aa8e1a6a1 ("writeback: implement unlocked_inode_to_wb transaction and use it for stat updates") Signed-off-by: Greg Thelen <gthelen@google.com> Reported-by: Wang Long <wanglong19@meituan.com> Acked-by: Wang Long <wanglong19@meituan.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: <stable@vger.kernel.org> [v4.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm, pagemap: fix swap offset value for PMD migration entry
The swap offset reported by /proc/<pid>/pagemap may be not correct for
PMD migration entries. If addr passed into pagemap_pmd_range() isn't
aligned with PMD start address, the swap offset reported doesn't
reflect this. And in the loop to report information of each sub-page,
the swap offset isn't increased accordingly as that for PFN.
This may happen after opening /proc/<pid>/pagemap and seeking to a page
whose address doesn't align with a PMD start address. I have verified
this with a simple test program.
BTW: migration swap entries have PFN information, do we need to restrict
whether to show them?
[akpm@linux-foundation.org: fix typo, per Huang, Ying] Link: http://lkml.kernel.org/r/20180408033737.10897-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrei Vagin <avagin@openvz.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "Jerome Glisse" <jglisse@redhat.com> Cc: Daniel Colascione <dancol@google.com> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Fri, 20 Apr 2018 21:55:35 +0000 (14:55 -0700)]
mm: fix do_pages_move status handling
Li Wang has reported that LTP move_pages04 test fails with the current
tree:
LTP move_pages04:
TFAIL : move_pages04.c:143: status[1] is EPERM, expected EFAULT
The test allocates an array of two pages, one is present while the other
is not (resp. backed by zero page) and it expects EFAULT for the second
page as the man page suggests. We are reporting EPERM which doesn't make
any sense and this is a result of a bug from cf5f16b23ec9 ("mm: unclutter
THP migration").
do_pages_move tries to handle as many pages in one batch as possible so we
queue all pages with the same node target together and that corresponds to
[start, i] range which is then used to update status array.
add_page_for_migration will correctly notice the zero (resp. !present)
page and returns with EFAULT which gets written to the status. But if
this is the last page in the array we do not update start and so the last
store_status after the loop will overwrite the range of the last batch
with NUMA_NO_NODE (which corresponds to EPERM).
Fix this by simply bailing out from the last flush if the pagelist is
empty as there is clearly nothing more to do.
Link: http://lkml.kernel.org/r/20180418121255.334-1-mhocko@kernel.org Fixes: cf5f16b23ec9 ("mm: unclutter THP migration") Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Li Wang <liwang@redhat.com> Tested-by: Li Wang <liwang@redhat.com> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One of the classes of kernel stack content leaks[1] is exposing the
contents of prior heap or stack contents when a new process stack is
allocated. Normally, those stacks are not zeroed, and the old contents
remain in place. In the face of stack content exposure flaws, those
contents can leak to userspace.
Fixing this will make the kernel no longer vulnerable to these flaws, as
the stack will be wiped each time a stack is assigned to a new process.
There's not a meaningful change in runtime performance; it almost looks
like it provides a benefit.
It continues to look like it's faster, though the deviation is rather
wide, but I'm not sure what I could do that would be less noisy. I'm
open to ideas!
Link: http://lkml.kernel.org/r/20180221021659.GA37073@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / mirror_ubuntu-hirsute-kernel.git / log