Konstantin Khlebnikov [Mon, 8 Jun 2020 04:42:55 +0000 (21:42 -0700)]
doc: cgroup: update note about conditions when oom killer is invoked
Starting from v4.19 commit 29ef680ae7c2 ("memcg, oom: move out_of_memory
back to the charge path") cgroup oom killer is no longer invoked only
from page faults. Now it implements the same semantics as global OOM
killer: allocation context invokes OOM killer and keeps retrying until
success.
[akpm@linux-foundation.org: fixes per Randy]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <guro@fb.com> Cc: Randy Dunlap <rdunlap@infradead.org> Link: http://lkml.kernel.org/r/158894738928.208854.5244393925922074518.stgit@buzz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Mon, 8 Jun 2020 04:42:52 +0000 (21:42 -0700)]
module: move the set_fs hack for flush_icache_range to m68k
flush_icache_range generally operates on kernel addresses, but for some
reason m68k needed a set_fs override. Move that into the m68k code
insted of keeping it in the module loader.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Jessica Yu <jeyu@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Link: http://lkml.kernel.org/r/20200515143646.3857579-30-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Mon, 8 Jun 2020 04:42:37 +0000 (21:42 -0700)]
m68k: implement flush_icache_user_range
Rename the current flush_icache_range to flush_icache_user_range as per
commit ae92ef8a4424 ("PATCH] flush icache in correct context") there
seems to be an assumption that it operates on user addresses. Add a
flush_icache_range around it that for now is a no-op.
Christoph Hellwig [Mon, 8 Jun 2020 04:42:34 +0000 (21:42 -0700)]
arm: rename flush_cache_user_range to flush_icache_user_range
flush_icache_user_range will be the name for a generic primitive. Move
the arm name so that arm already has an implementation.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Russell King <linux@armlinux.org.uk> Link: http://lkml.kernel.org/r/20200515143646.3857579-24-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Mon, 8 Jun 2020 04:42:32 +0000 (21:42 -0700)]
xtensa: implement flush_icache_user_range
The Xtensa implementation of flush_icache_range seems to be able to cope
with user addresses. Just define flush_icache_user_range to
flush_icache_range.
Christoph Hellwig [Mon, 8 Jun 2020 04:42:28 +0000 (21:42 -0700)]
sh: implement flush_icache_user_range
The SuperH implementation of flush_icache_range seems to be able to cope
with user addresses. Just define flush_icache_user_range to
flush_icache_range.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Link: http://lkml.kernel.org/r/20200515143646.3857579-22-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Mon, 8 Jun 2020 04:42:22 +0000 (21:42 -0700)]
mm: rename flush_icache_user_range to flush_icache_user_page
The function currently known as flush_icache_user_range only operates on
a single page. Rename it to flush_icache_user_page as we'll need the
name flush_icache_user_range for something else soon.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20200515143646.3857579-20-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
flush_icache_user_range is only used by <asm-generic/cacheflush.h>, so
remove it from the architectures that implement it, but don't use
<asm-generic/cacheflush.h>.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Russell King <linux@armlinux.org.uk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@pku.edu.cn> Link: http://lkml.kernel.org/r/20200515143646.3857579-19-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Mon, 8 Jun 2020 04:41:45 +0000 (21:41 -0700)]
asm-generic: improve the flush_dcache_page stub
There is a magic ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE cpp symbol that
guards non-stub availability of flush_dcache_pagge. Use that to check
if flush_dcache_pagg is implemented.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/20200515143646.3857579-8-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Mon, 8 Jun 2020 04:41:25 +0000 (21:41 -0700)]
arm: fix the flush_icache_range arguments in set_fiq_handler
Patch series "sort out the flush_icache_range mess", v2.
flush_icache_range is mostly used for kernel address, except for the
following cases:
- the nommu brk and mmap implementations
- the read_code helper that is only used for binfmt_flat,
binfmt_elf_fdpic, and binfmt_aout including the broken
ia32 compat version
- binfmt_flat itself
none of which really are used by a typical MMU enabled kernel, as a.out
can only be build for alpha and m68k to start with.
But strangely enough commit ae92ef8a4424 ("PATCH] flush icache in
correct context") added a "set_fs(KERNEL_DS)" around the
flush_icache_range call in the module loader, because apparently m68k
assumed user pointers.
This series first cleans up the cacheflush implementations, largely by
switching as much as possible to the asm-generic version after a few
preparations, then moves the misnamed current flush_icache_user_range to
a new name, to finally introduce a real flush_icache_user_range to be
used for the above use cases to flush the instruction cache for a
userspace address range. The last patch then drops the set_fs in the
module code and moves it into the m68k implementation.
This patch (of 29):
The arguments passed look bogus, try to fix them to something that seems
to make sense.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Keith Busch <keith.busch@intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nick Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Song Liu <songliubraving@fb.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200515143646.3857579-1-hch@lst.de Link: http://lkml.kernel.org/r/20200515143646.3857579-2-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This code was using get_user_pages*(), in approximately a "Case 5"
scenario (accessing the data within a page), using the categorization
from [1]. That means that it's time to convert the get_user_pages*() +
put_page() calls to pin_user_pages*() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small part
of fixing a long-standing disconnect between pinning pages, and file
systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/
Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Link: http://lkml.kernel.org/r/20200529234309.484480-3-jhubbard@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Hubbard [Mon, 8 Jun 2020 04:41:11 +0000 (21:41 -0700)]
docs: mm/gup: pin_user_pages.rst: add a "case 5"
Patch series "vhost, docs: convert to pin_user_pages(), new "case 5""
It recently became clear to me that there are some get_user_pages*()
callers that don't fit neatly into any of the four cases that are so far
listed in pin_user_pages.rst. vhost.c is one of those.
Add a Case 5 to the documentation, and refer to that when converting
vhost.c.
Thanks to Jan Kara for helping me (again) in understanding the
interaction between get_user_pages() and page writeback [1].
This is based on today's mmotm, which has a nearby patch to
pin_user_pages.rst that rewords cases 3 and 4.
Note that I have only compile-tested the vhost.c patch, although that
does also include cross-compiling for a few other arches. Any run-time
testing would be greatly appreciated.
There are four cases listed in pin_user_pages.rst. These are intended
to help developers figure out whether to use get_user_pages*(), or
pin_user_pages*(). However, the four cases do not cover all the
situations. For example, drivers/vhost/vhost.c has a "pin, write to
page, set page dirty, unpin" case.
Add a fifth case, to help explain that there is a general pattern that
requires pin_user_pages*() API calls.
John Hubbard [Mon, 8 Jun 2020 04:41:08 +0000 (21:41 -0700)]
mm/gup: documentation fix for pin_user_pages*() APIs
All of the pin_user_pages*() API calls will cause pages to be
dma-pinned. As such, they are all suitable for either DMA, RDMA, and/or
Direct IO.
The documentation should say so, but it was instead saying that three of
the API calls were only suitable for Direct IO. This was discovered
when a reviewer wondered why an API call that specifically recommended
against Case 2 (DMA/RDMA) was being used in a DMA situation [1].
Fix this by simply deleting those claims. The gup.c comments already
refer to the more extensive Documentation/core-api/pin_user_pages.rst,
which does have the correct guidance. So let's just write it once,
there.
This code was using get_user_pages*(), and all of the callers so far
were in a "Case 2" scenario (DMA/RDMA), using the categorization from [1].
That means that it's time to convert the get_user_pages*() + put_page()
calls to pin_user_pages*() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small part
of fixing a long-standing disconnect between pinning pages, and file
systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/
Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Link: http://lkml.kernel.org/r/20200527223243.884385-3-jhubbard@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Hubbard [Mon, 8 Jun 2020 04:41:02 +0000 (21:41 -0700)]
mm/gup: introduce pin_user_pages_locked()
Patch series "mm/gup: introduce pin_user_pages_locked(), use it in frame_vector.c", v2.
This adds yet one more pin_user_pages*() variant, and uses that to
convert mm/frame_vector.c.
With this, along with maybe 20 or 30 other recent patches in various
trees, we are close to having the relevant gup call sites
converted--with the notable exception of the bio/block layer.
This patch (of 2):
Introduce pin_user_pages_locked(), which is nearly identical to
get_user_pages_locked() except that it sets FOLL_PIN and rejects
FOLL_GET.
As with other pairs of get_user_pages*() and pin_user_pages() API calls,
it's prudent to assert that FOLL_PIN is *not* set in the
get_user_pages*() call, so add that as part of this.
Souptick Joarder [Mon, 8 Jun 2020 04:40:55 +0000 (21:40 -0700)]
mm/gup.c: convert to use get_user_{page|pages}_fast_only()
API __get_user_pages_fast() renamed to get_user_pages_fast_only() to
align with pin_user_pages_fast_only().
As part of this we will get rid of write parameter. Instead caller will
pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any
existing functionality of the API.
All the callers are changed to pass FOLL_WRITE.
Also introduce get_user_page_fast_only(), and use it in a few places
that hard-code nr_pages to 1.
Updated the documentation of the API.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm] Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Suchanek <msuchanek@suse.de> Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rafael Aquini [Mon, 8 Jun 2020 04:40:51 +0000 (21:40 -0700)]
kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted
Users with SYS_ADMIN capability can add arbitrary taint flags to the
running kernel by writing to /proc/sys/kernel/tainted or issuing the
command 'sysctl -w kernel.tainted=...'. This interface, however, is
open for any integer value and this might cause an invalid set of flags
being committed to the tainted_mask bitset.
This patch introduces a simple way for proc_taint() to ignore any
eventual invalid bit coming from the user input before committing those
bits to the kernel tainted_mask.
Signed-off-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Link: http://lkml.kernel.org/r/20200512223946.888020-1-aquini@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guilherme G. Piccoli [Mon, 8 Jun 2020 04:40:48 +0000 (21:40 -0700)]
panic: add sysctl to dump all CPUs backtraces on oops event
Usually when the kernel reaches an oops condition, it's a point of no
return; in case not enough debug information is available in the kernel
splat, one of the last resorts would be to collect a kernel crash dump
and analyze it. The problem with this approach is that in order to
collect the dump, a panic is required (to kexec-load the crash kernel).
When in an environment of multiple virtual machines, users may prefer to
try living with the oops, at least until being able to properly shutdown
their VMs / finish their important tasks.
This patch implements a way to collect a bit more debug details when an
oops event is reached, by printing all the CPUs backtraces through the
usage of NMIs (on architectures that support that). The sysctl added
(and documented) here was called "oops_all_cpu_backtrace", and when set
will (as the name suggests) dump all CPUs backtraces.
Far from ideal, this may be the last option though for users that for
some reason cannot panic on oops. Most of times oopses are clear enough
to indicate the kernel portion that must be investigated, but in virtual
environments it's possible to observe hypervisor/KVM issues that could
lead to oopses shown in other guests CPUs (like virtual APIC crashes).
This patch hence aims to help debug such complex issues without
resorting to kdump.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200327224116.21030-1-gpiccoli@canonical.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guilherme G. Piccoli [Mon, 8 Jun 2020 04:40:45 +0000 (21:40 -0700)]
kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected
Commit 401c636a0eeb ("kernel/hung_task.c: show all hung tasks before
panic") introduced a change in that we started to show all CPUs
backtraces when a hung task is detected _and_ the sysctl/kernel
parameter "hung_task_panic" is set. The idea is good, because usually
when observing deadlocks (that may lead to hung tasks), the culprit is
another task holding a lock and not necessarily the task detected as
hung.
The problem with this approach is that dumping backtraces is a slightly
expensive task, specially printing that on console (and specially in
many CPU machines, as servers commonly found nowadays). So, users that
plan to collect a kdump to investigate the hung tasks and narrow down
the deadlock definitely don't need the CPUs backtrace on dmesg/console,
which will delay the panic and pollute the log (crash tool would easily
grab all CPUs traces with 'bt -a' command).
Also, there's the reciprocal scenario: some users may be interested in
seeing the CPUs backtraces but not have the system panic when a hung
task is detected. The current approach hence is almost as embedding a
policy in the kernel, by forcing the CPUs backtraces' dump (only) on
hung_task_panic.
This patch decouples the panic event on hung task from the CPUs
backtraces dump, by creating (and documenting) a new sysctl called
"hung_task_all_cpu_backtrace", analog to the approach taken on soft/hard
lockups, that have both a panic and an "all_cpu_backtrace" sysctl to
allow individual control. The new mechanism for dumping the CPUs
backtraces on hung task detection respects "hung_task_warnings" by not
dumping the traces in case there's no warnings left.
Guilherme G. Piccoli [Mon, 8 Jun 2020 04:40:42 +0000 (21:40 -0700)]
kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases
After a recent change introduced by Vlastimil's series [0], kernel is
able now to handle sysctl parameters on kernel command line; also, the
series introduced a simple infrastructure to convert legacy boot
parameters (that duplicate sysctls) into sysctl aliases.
This patch converts the watchdog parameters softlockup_panic and
{hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure.
It fixes the documentation too, since the alias only accepts values 0 or
1, not the full range of integers.
We also took the opportunity here to improve the documentation of the
previously converted hung_task_panic (see the patch series [0]) and put
the alias table in alphabetical order.
Vlastimil Babka [Mon, 8 Jun 2020 04:40:38 +0000 (21:40 -0700)]
lib/test_sysctl: support testing of sysctl. boot parameter
Testing is done by a new parameter debug.test_sysctl.boot_int which
defaults to 0 and it's expected that the tester passes a boot parameter
that sets it to 1. The test checks if it's set to 1.
To distinguish true failure from parameter not being set, the test
checks /proc/cmdline for the expected parameter, and whether test_sysctl
is built-in and not a module.
[vbabka@suse.cz: skip the new test if boot_int sysctl is not present] Link: http://lkml.kernel.org/r/305af605-1e60-cf84-fada-6ce1ca37c102@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: David Rientjes <rientjes@google.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com> Cc: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200427180433.7029-6-vbabka@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Mon, 8 Jun 2020 04:40:35 +0000 (21:40 -0700)]
tools/testing/selftests/sysctl/sysctl.sh: support CONFIG_TEST_SYSCTL=y
The testing script recommends CONFIG_TEST_SYSCTL=y, but actually only
works with CONFIG_TEST_SYSCTL=m. Testing of sysctl setting via boot
param however requires the test to be built-in, so make sure the test
script supports it.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: David Rientjes <rientjes@google.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com> Cc: Kees Cook <keescook@chromium.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200427180433.7029-5-vbabka@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Mon, 8 Jun 2020 04:40:31 +0000 (21:40 -0700)]
kernel/hung_task convert hung_task_panic boot parameter to sysctl
We can now handle sysctl parameters on kernel command line and have
infrastructure to convert legacy command line options that duplicate
sysctl to become a sysctl alias.
This patch converts the hung_task_panic parameter. Note that the sysctl
handler is more strict and allows only 0 and 1, while the legacy
parameter allowed any non-zero value. But there is little reason anyone
would not be using 1.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: David Rientjes <rientjes@google.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200427180433.7029-4-vbabka@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Mon, 8 Jun 2020 04:40:27 +0000 (21:40 -0700)]
kernel/sysctl: support handling command line aliases
We can now handle sysctl parameters on kernel command line, but
historically some parameters introduced their own command line
equivalent, which we don't want to remove for compatibility reasons.
We can, however, convert them to the generic infrastructure with a table
translating the legacy command line parameters to their sysctl names,
and removing the one-off param handlers.
This patch adds the support and makes the first conversion to
demonstrate it, on the (deprecated) numa_zonelist_order parameter.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: David Rientjes <rientjes@google.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200427180433.7029-3-vbabka@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Mon, 8 Jun 2020 04:40:24 +0000 (21:40 -0700)]
kernel/sysctl: support setting sysctl parameters from kernel command line
Patch series "support setting sysctl parameters from kernel command line", v3.
This series adds support for something that seems like many people
always wanted but nobody added it yet, so here's the ability to set
sysctl parameters via kernel command line options in the form of
sysctl.vm.something=1
The important part is Patch 1. The second, not so important part is an
attempt to clean up legacy one-off parameters that do the same thing as
a sysctl. I don't want to remove them completely for compatibility
reasons, but with generic sysctl support the idea is to remove the
one-off param handlers and treat the parameters as aliases for the
sysctl variants.
I have identified several parameters that mention sysctl counterparts in
Documentation/admin-guide/kernel-parameters.txt but there might be more.
The conversion also has varying level of success:
- numa_zonelist_order is converted in Patch 2 together with adding the
necessary infrastructure. It's easy as it doesn't really do anything
but warn on deprecated value these days.
- hung_task_panic is converted in Patch 3, but there's a downside that
now it only accepts 0 and 1, while previously it was any integer
value
- nmi_watchdog maps to two sysctls nmi_watchdog and hardlockup_panic,
so there's no straighforward conversion possible
- traceoff_on_warning is a flag without value and it would be required
to handle that somehow in the conversion infractructure, which seems
pointless for a single flag
This patch (of 5):
A recently proposed patch to add vm_swappiness command line parameter in
addition to existing sysctl [1] made me wonder why we don't have a
general support for passing sysctl parameters via command line.
Googling found only somebody else wondering the same [2], but I haven't
found any prior discussion with reasons why not to do this.
Settings the vm_swappiness issue aside (the underlying issue might be
solved in a different way), quick search of kernel-parameters.txt shows
there are already some that exist as both sysctl and kernel parameter -
hung_task_panic, nmi_watchdog, numa_zonelist_order, traceoff_on_warning.
A general mechanism would remove the need to add more of those one-offs
and might be handy in situations where configuration by e.g.
/etc/sysctl.d/ is impractical.
Hence, this patch adds a new parse_args() pass that looks for parameters
prefixed by 'sysctl.' and tries to interpret them as writes to the
corresponding sys/ files using an temporary in-kernel procfs mount.
This mechanism was suggested by Eric W. Biederman [3], as it handles
all dynamically registered sysctl tables, even though we don't handle
modular sysctls. Errors due to e.g. invalid parameter name or value
are reported in the kernel log.
The processing is hooked right before the init process is loaded, as
some handlers might be more complicated than simple setters and might
need some subsystems to be initialized. At the moment the init process
can be started and eventually execute a process writing to /proc/sys/
then it should be also fine to do that from the kernel.
Sysctls registered later on module load time are not set by this
mechanism - it's expected that in such scenarios, setting sysctl values
from userspace is practical enough.
Rafael Aquini [Mon, 8 Jun 2020 04:40:17 +0000 (21:40 -0700)]
kernel: add panic_on_taint
Analogously to the introduction of panic_on_warn, this patch introduces
a kernel option named panic_on_taint in order to provide a simple and
generic way to stop execution and catch a coredump when the kernel gets
tainted by any given flag.
This is useful for debugging sessions as it avoids having to rebuild the
kernel to explicitly add calls to panic() into the code sites that
introduce the taint flags of interest.
For instance, if one is interested in proceeding with a post-mortem
analysis at the point a given code path is hitting a bad page (i.e.
unaccount_page_cache_page(), or slab_bug()), a coredump can be collected
by rebooting the kernel with 'panic_on_taint=0x20' amended to the
command line.
Another, perhaps less frequent, use for this option would be as a means
for assuring a security policy case where only a subset of taints, or no
single taint (in paranoid mode), is allowed for the running system. The
optional switch 'nousertaint' is handy in this particular scenario, as
it will avoid userspace induced crashes by writes to sysctl interface
/proc/sys/kernel/tainted causing false positive hits for such policies.
Orson Zhai [Mon, 8 Jun 2020 04:40:14 +0000 (21:40 -0700)]
dynamic_debug: add an option to enable dynamic debug for modules only
Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG,
CONFIG_DYNAMIC_DEBUG_CORE will only enable core function of dynamic
debug. With the DYNAMIC_DEBUG_MODULE defined for any modules, dynamic
debug will be tied to them.
This is useful for people who only want to enable dynamic debug for
kernel modules without worrying about kernel image size and memory
consumption is increasing too much.
[orson.zhai@unisoc.com: v2] Link: http://lkml.kernel.org/r/1587408228-10861-1-git-send-email-orson.unisoc@gmail.com Signed-off-by: Orson Zhai <orson.zhai@unisoc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Petr Mladek <pmladek@suse.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Randy Dunlap <rdunlap@infradead.org> Link: http://lkml.kernel.org/r/1586521984-5890-1-git-send-email-orson.unisoc@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
for (i = 0; i < 1000; i++)
if (unshare(CLONE_NEWIPC) < 0)
error(EXIT_FAILURE, errno, "unshare");
}
goes from
Command being timed: "./ipc-namespace"
User time (seconds): 0.00
System time (seconds): 0.06
Percent of CPU this job got: 0%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:08.05
to
Command being timed: "./ipc-namespace"
User time (seconds): 0.00
System time (seconds): 0.02
Percent of CPU this job got: 96%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.03
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Manfred Spraul <manfred@colorfullife.com> Link: http://lkml.kernel.org/r/20200225145419.527994-1-gscrivan@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SeongJae Park [Mon, 8 Jun 2020 04:40:04 +0000 (21:40 -0700)]
mm/page_idle.c: skip offline pages
'Idle page tracking' users can pass random pfn that might be mapped to an
offline page. To avoid accessing such pages, this commit modifies the
'page_idle_get_page()' to use 'pfn_to_online_page()' instead of
'pfn_valid()' and 'pfn_to_page()' combination, so that the pfn mapped to
an offline page can be skipped.
Reported-by: David Hildenbrand <david@redhat.com> Signed-off-by: SeongJae Park <sjpark@amazon.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Link: http://lkml.kernel.org/r/20200605092502.18018-2-sjpark@amazon.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 7 Jun 2020 19:19:06 +0000 (12:19 -0700)]
vfs: clean up posix_acl_permission() logic aroudn MAY_NOT_BLOCK
posix_acl_permission() does not care about MAY_NOT_BLOCK, and in fact
the permission logic internally must not check that bit (it's only for
upper layers to decide whether they can block to do IO to look up the
acl information or not).
But the way the code was written, it _looked_ like it cared, since the
function explicitly did not mask that bit off.
But it has exactly two callers: one for when that bit is set, which
first clears the bit before calling posix_acl_permission(), and the
other call site when that bit was clear.
So stop the silly games "saving" the MAY_NOT_BLOCK bit that must not be
used for the actual permission test, and that currently is pointlessly
cleared by the callers when the function itself should just not care.
Linus Torvalds [Fri, 5 Jun 2020 20:40:45 +0000 (13:40 -0700)]
vfs: do not do group lookup when not necessary
Rasmus Villemoes points out that the 'in_group_p()' tests can be a
noticeable expense, and often completely unnecessary. A common
situation is that the 'group' bits are the same as the 'other' bits
wrt the permissions we want to test.
So rewrite 'acl_permission_check()' to not bother checking for group
ownership when the permission check doesn't care.
For example, if we're asking for read permissions, and both 'group' and
'other' allow reading, there's really no reason to check if we're part
of the group or not: either way, we'll allow it.
Rasmus says:
"On a bog-standard Ubuntu 20.04 install, a workload consisting of
compiling lots of userspace programs (i.e., calling lots of
short-lived programs that all need to get their shared libs mapped in,
and the compilers poking around looking for system headers - lots of
/usr/lib, /usr/bin, /usr/include/ accesses) puts in_group_p around
0.1% according to perf top.
System-installed files are almost always 0755 (directories and
binaries) or 0644, so in most cases, we can avoid the binary search
and the cost of pulling the cred->groups array and in_group_p() .text
into the cpu cache"
Michał Mirosław [Mon, 8 Jun 2020 16:50:39 +0000 (18:50 +0200)]
ALSA: pcm: disallow linking stream to itself
Prevent SNDRV_PCM_IOCTL_LINK linking stream to itself - the code
can't handle it. Fixed commit is not where bug was introduced, but
changes the context significantly.
Takashi Iwai [Fri, 5 Jun 2020 06:41:17 +0000 (08:41 +0200)]
ALSA: usb-audio: Manage auto-pm of all bundled interfaces
Currently USB-audio driver manages the auto-pm of the primary
interface although a card may consist of multiple interfaces.
This may leave the secondary and other interfaces left running
unnecessarily after the auto-suspend.
This patch allows the driver managing the auto-pm of all bundled
interfaces per card. The chip->pm_intf field is extended as
chip->intf[] to contain the array of assigned interfaces, and the
runtime-PM is performed to all those interfaces.
Alexander A. Klimov [Tue, 26 May 2020 06:05:44 +0000 (08:05 +0200)]
Replace HTTP links with HTTPS ones: documentation
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Jonathan Corbet [Wed, 3 Jun 2020 22:10:20 +0000 (16:10 -0600)]
docs: Update the location of the LF NDA program
The link to the Linux Foundation NDA program got broken in one of their
web-site thrashups; now that the information is back online, point to its
current location. This should last until the next thrashup...
Shaokun Zhang [Fri, 5 Jun 2020 09:43:41 +0000 (17:43 +0800)]
drivers/perf: hisi: Fix wrong value for all counters enable
In L3C uncore PMU drivers, bit16 is used to control all counters enable &
disable. Wrong value is given in the driver and its default value is 1'b1,
it can work because each PMU counter has its own control bits too.
Let's fix the wrong value.
Fixes: 2940bc433370 ("perf: hisi: Add support for HiSilicon SoC L3C PMU driver") Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/1591350221-32275-1-git-send-email-zhangshaokun@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>
Christoph Hellwig [Wed, 3 Jun 2020 05:52:35 +0000 (07:52 +0200)]
net/sysctl: remove leftover __user annotations on neigh_proc_dointvec*
Remove the leftover __user annotation on the prototypes for
neigh_proc_dointvec*. The implementations already got this right, but
the headers kept the __user tags around.
Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Reported-by: build test robot <lkp@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix test race, in which background poll can get either 5 or 6 samples,
depending on timing of notification. Prevent this by open-coding sample
triggering and forcing notification for the very last sample only.
Also switch to using atomic increments and exchanges for more obviously
reliable counting and checking. Additionally, check expected processed sample
counters for single-threaded use cases as well.
Eiichi Tsukata [Sat, 6 Jun 2020 04:26:27 +0000 (13:26 +0900)]
KVM: x86: Fix APIC page invalidation race
Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried
to fix inappropriate APIC page invalidation by re-introducing arch
specific kvm_arch_mmu_notifier_invalidate_range() and calling it from
kvm_mmu_notifier_invalidate_range_start. However, the patch left a
possible race where the VMCS APIC address cache is updated *before*
it is unmapped:
Because of the above race, there can be a mismatch between the
host physical address stored in the APIC_ACCESS_PAGE VMCS field and
the host physical address stored in the EPT entry for the APIC GPA
(0xfee0000). When this happens, the processor will not trap APIC
accesses, and will instead show the raw contents of the APIC-access page.
Because Windows OS periodically checks for unexpected modifications to
the LAPIC register, this will show up as a BSOD crash with BugCheck
CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in
https://bugzilla.redhat.com/show_bug.cgi?id=1751017.
The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range()
cannot guarantee that no additional references are taken to the pages in
the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately,
this case is supported by the MMU notifier API, as documented in
include/linux/mmu_notifier.h:
* If the subsystem
* can't guarantee that no additional references are taken to
* the pages in the range, it has to implement the
* invalidate_range() notifier to remove any references taken
* after invalidate_range_start().
The fix therefore is to reload the APIC-access page field in the VMCS
from kvm_mmu_notifier_invalidate_range() instead of ..._range_start().
Hui Wang [Mon, 8 Jun 2020 11:55:41 +0000 (19:55 +0800)]
ALSA: hda/realtek - add a pintbl quirk for several Lenovo machines
A couple of Lenovo ThinkCentre machines all have 2 front mics and they
use the same codec alc623 and have the same pin config, so add a
pintbl entry for those machines to apply the fixup
ALC283_FIXUP_HEADSET_MIC.
Michał Mirosław [Mon, 8 Jun 2020 10:06:32 +0000 (12:06 +0200)]
ALSA: pcm: fix snd_pcm_link() lockdep splat
Add and use snd_pcm_stream_lock_nested() in snd_pcm_link/unlink
implementation. The code is fine, but generates a lockdep complaint:
============================================
WARNING: possible recursive locking detected
5.7.1mq+ #381 Tainted: G O
--------------------------------------------
pulseaudio/4180 is trying to acquire lock: ffff888402d6f508 (&group->lock){-...}-{2:2}, at: snd_pcm_common_ioctl+0xda8/0xee0 [snd_pcm]
but task is already holding lock: ffff8883f7a8cf18 (&group->lock){-...}-{2:2}, at: snd_pcm_common_ioctl+0xe4e/0xee0 [snd_pcm]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&group->lock);
lock(&group->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by pulseaudio/4180:
#0: ffffffffa1a05190 (snd_pcm_link_rwsem){++++}-{3:3}, at: snd_pcm_common_ioctl+0xca0/0xee0 [snd_pcm]
#1: ffff8883f7a8cf18 (&group->lock){-...}-{2:2}, at: snd_pcm_common_ioctl+0xe4e/0xee0 [snd_pcm]
[...]
Geert Uytterhoeven [Mon, 8 Jun 2020 10:00:49 +0000 (12:00 +0200)]
spi: spidev_test: Use %u to format unsigned numbers
Consistently use %u to format unsigned numbers.
For "bits" this doesn't matter that much, as it is "uint8_t".
However, "speed" is "uint32_t", so in case people use "-s -1" to force
the maximum, they would see:
Bartosz Golaszewski [Sun, 7 Jun 2020 09:34:21 +0000 (11:34 +0200)]
regmap: fix the kerneldoc for regmap_test_bits()
The kerneldoc comment for regmap_test_bits() says that it returns -1 on
regmap_read() failure. This is not true - it will propagate the error
code returned by regmap_read(). Fix it.
Fixes: aa2ff9dbaedd ("regmap: provide helpers for simple bit operations") Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Link: https://lore.kernel.org/r/20200607093421.22209-1-brgl@bgdev.pl Signed-off-by: Mark Brown <broonie@kernel.org>
Paolo Bonzini [Mon, 8 Jun 2020 11:11:47 +0000 (07:11 -0400)]
KVM: SVM: fix calls to is_intercept
is_intercept takes an INTERCEPT_* constant, not SVM_EXIT_*; because
of this, the compiler was removing the body of the conditionals,
as if is_intercept returned 0.
This unveils a latent bug: when clearing the VINTR intercept,
int_ctl must also be changed in the L1 VMCB (svm->nested.hsave),
just like the intercept itself is also changed in the L1 VMCB.
Otherwise V_IRQ remains set and, due to the VINTR intercept being clear,
we get a spurious injection of a vector 0 interrupt on the next
L2->L1 vmexit.
Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Fri, 5 Jun 2020 11:59:06 +0000 (13:59 +0200)]
Revert "KVM: x86: work around leak of uninitialized stack contents"
handle_vmptrst()/handle_vmread() stopped injecting #PF unconditionally
and switched to nested_vmx_handle_memory_failure() which just kills the
guest with KVM_EXIT_INTERNAL_ERROR in case of MMIO access, zeroing
'exception' in kvm_write_guest_virt_system() is not needed anymore.
but it is only set when GVA to GPA conversion fails. In case it doesn't but
we still fail kvm_vcpu_read_guest_page(), X86EMUL_IO_NEEDED is returned and
nested_vmx_get_vmptr() calls kvm_inject_emulated_page_fault() with zeroed
'exception'. This happen when the argument is MMIO.
Paolo also noticed that nested_vmx_get_vmptr() is not the only place in
KVM code where kvm_read/write_guest_virt*() return result is mishandled.
VMX instructions along with INVPCID have the same issue. This was already
noticed before, e.g. see commit 541ab2aeb282 ("KVM: x86: work around
leak of uninitialized stack contents") but was never fully fixed.
KVM could've handled the request correctly by going to userspace and
performing I/O but there doesn't seem to be a good need for such requests
in the first place.
Introduce vmx_handle_memory_failure() as an interim solution.
Note, nested_vmx_get_vmptr() now has three possible outcomes: OK, PF,
KVM_EXIT_INTERNAL_ERROR and callers need to know if userspace exit is
needed (for KVM_EXIT_INTERNAL_ERROR) in case of failure. We don't seem
to have a good enum describing this tristate, just add "int *ret" to
nested_vmx_get_vmptr() interface to pass the information.
Reported-by: syzbot+2a7156e11dc199bdbd8a@syzkaller.appspotmail.com Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200605115906.532682-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rafael J. Wysocki [Thu, 4 Jun 2020 17:22:26 +0000 (19:22 +0200)]
ACPI: PM: Avoid using power resources if there are none for D0
As recently reported, some platforms provide a list of power
resources for device power state D3hot, through the _PR3 object,
but they do not provide a list of power resources for device power
state D0.
Among other things, this causes acpi_device_get_power() to return
D3hot as the current state of the device in question if all of the
D3hot power resources are "on", because it sees the power_resources
flag set and calls acpi_power_get_inferred_state() which finds that
D3hot is the shallowest power state with all of the associated power
resources turned "on", so that's what it returns. Moreover, that
value takes precedence over the acpi_dev_pm_explicit_get() return
value, because it means a deeper power state. The device may very
well be in D0 physically at that point, however.
Moreover, the presence of _PR3 without _PR0 for a given device
means that only one D3-level power state can be supported by it.
Namely, because there are no power resources to turn "off" when
transitioning the device from D0 into D3cold (which should be
supported since _PR3 is present), the evaluation of _PS3 should
be sufficient to put it straight into D3cold, but this means that
the effect of turning "on" the _PR3 power resources is unclear,
so it is better to avoid doing that altogether. Consequently,
there is no practical way do distinguish D3cold from D3hot for
the device in question and the power states of it can be labeled
so that D3hot is the deepest supported one (and Linux assumes
that putting a device into D3hot via ACPI may cause power to be
removed from it anyway, for legacy reasons).
To work around the problem described above modify the ACPI
enumeration of devices so that power resources are only used
for device power management if the list of D0 power resources
is not empty and make it mart D3cold as supported only if that
is the case and the D3hot list of power resources is not empty
too.
Chris Wilson [Thu, 4 Jun 2020 10:37:30 +0000 (11:37 +0100)]
drm/i915/gem: Mark the buffer pool as active for the cmdparser
If the execbuf is interrupted after building the cmdparser pipeline, and
before we commit to submitting the request to HW, we would attempt to
clean up the cmdparser early. While we held active references to the vma
being parsed and constructed, we did not hold an active reference for
the buffer pool itself. The result was that an interrupted execbuf could
still have run the cmdparser pipeline, but since the buffer pool was
idle, its target vma could have been recycled.
Note this problem only occurs if the cmdparser is running async due to
pipelined waits on busy fences, and the execbuf is interrupted.
Michael S. Tsirkin [Mon, 8 Jun 2020 05:43:22 +0000 (01:43 -0400)]
virtio-mem: drop unnecessary initialization
rc is initialized to -ENIVAL but that's never used. Drop it.
Fixes: 5f1f79bbc9e2 ("virtio-mem: Paravirtualized memory hotplug") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
Kai-Heng Feng [Mon, 8 Jun 2020 06:26:28 +0000 (14:26 +0800)]
ALSA: usb-audio: Add vendor, product and profile name for HP Thunderbolt Dock
The HP Thunderbolt Dock has two separate USB devices, one is for speaker
and one is for headset. Add names for them so userspace can apply UCM
settings.
Dave Airlie [Mon, 8 Jun 2020 03:22:56 +0000 (13:22 +1000)]
Merge https://gitlab.freedesktop.org/drm/msm into drm-next-msm-5.8
* new gpu support: a405, a640, a650
* dpu: color processing support
* mdp5: support for msm8x36 (the thing with a405)
* some prep work for per-context pagetables (ie the part that
does not depend on in-flight iommu patches)
* last but not least, UABI update for submit ioctl to support
syncobj (from Bas)
Dave Airlie [Mon, 8 Jun 2020 01:59:56 +0000 (11:59 +1000)]
Merge tag 'drm-intel-next-fixes-2020-06-04' of git://anongit.freedesktop.org/drm/drm-intel into drm-next
- Includes gvt-next-fixes-2020-05-28
- Use after free fix for display global state.
- Whitelisting context-local timestamp on Gen9
and two scheduler fixes with deps (Cc: stable)
- Removal of write flag from sysfs files where
ineffective
Dave Airlie [Mon, 8 Jun 2020 01:55:33 +0000 (11:55 +1000)]
Merge tag 'amd-drm-fixes-5.8-2020-06-04' of git://people.freedesktop.org/~agd5f/linux into drm-next
amd-drm-fixes-5.8-2020-06-04
amdgpu:
- Prevent hwmon accesses while GPU is in reset
- CTF interrupt fix
- Backlight fix for renoir
- Fix for display sync groups
- Display bandwidth validation workaround
- Fix the build with certain Kconfig combinations for the Chelsio
inline TLS device, from Rohit Maheshwar and Vinay Kumar Yadavi.
- Fix leak in genetlink, from Cong Lang.
- Fix out of bounds packet header accesses in seg6, from Ahmed
Abdelsalam.
- Two XDP fixes in the ENA driver, from Sameeh Jubran
- Use rwsem in device rename instead of a seqcount because this code
can sleep, from Ahmed S. Darwish.
- Fix WoL regressions in r8169, from Heiner Kallweit.
- Fix qed crashes in kdump mode, from Alok Prasad.
- Fix the callbacks used for certain thermal zones in mlxsw, from Vadim
Pasternak.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (35 commits)
net: dsa: lantiq_gswip: fix and improve the unsupported interface error
mlxsw: core: Use different get_trend() callbacks for different thermal zones
net: dp83869: Reset return variable if PHY strap is read
rhashtable: Drop raw RCU deref in nested_table_free
cxgb4: Use kfree() instead kvfree() where appropriate
net: qed: fixes crash while running driver in kdump kernel
vsock/vmci: make vmci_vsock_transport_cb() static
net: ethtool: Fix comment mentioning typo in IS_ENABLED()
net: phy: mscc: fix Serdes configuration in vsc8584_config_init
net: mscc: Fix OF_MDIO config check
net: marvell: Fix OF_MDIO config check
net: dp83867: Fix OF_MDIO config check
net: dp83869: Fix OF_MDIO config check
net: ethernet: mvneta: fix MVNETA_SKB_HEADROOM alignment
ethtool: linkinfo: remove an unnecessary NULL check
net/xdp: use shift instead of 64 bit division
crypto/chtls:Fix compile error when CONFIG_IPV6 is disabled
inet_connection_sock: clear inet_num out of destroy helper
yam: fix possible memory leak in yam_init_driver
lan743x: Use correct MAC_CR configuration for 1 GBit speed
...
- Rework the sparc32 page tables so that READ_ONCE(*pmd), as done by
generic code, operates on a word sized element. From Will Deacon.
- Some scnprintf() conversions, from Chen Zhou.
- A pin_user_pages() conversion from John Hubbard.
- Several 32-bit ptrace register handling fixes and such from Al Viro.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next:
fix a braino in "sparc32: fix register window handling in genregs32_[gs]et()"
sparc32: mm: Only call ctor()/dtor() functions for first and last user
sparc32: mm: Disable SPLIT_PTLOCK_CPUS
sparc32: mm: Don't try to free page-table pages if ctor() fails
sparc32: register memory occupied by kernel as memblock.memory
sparc: remove unused header file nfs_fs.h
sparc32: fix register window handling in genregs32_[gs]et()
sparc64: fix misuses of access_process_vm() in genregs32_[sg]et()
oradax: convert get_user_pages() --> pin_user_pages()
sparc: use scnprintf() in show_pciobppath_attr() in vio.c
sparc: use scnprintf() in show_pciobppath_attr() in pci.c
tty: vcc: Fix error return code in vcc_probe()
sparc32: mm: Reduce allocation size for PMD and PTE tables
sparc32: mm: Change pgtable_t type to pte_t * instead of struct page *
sparc32: mm: Restructure sparc32 MMU page-table layout
sparc32: mm: Fix argument checking in __srmmu_get_nocache()
sparc64: Replace zero-length array with flexible-array
sparc: mm: return true,false in kern_addr_valid()
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