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Give up on the notion that we can remove page-flags.h from mm.h. There
are currently 14 inline functions which use a PageFoo function. Also, two
of the files directly included by mm.h include page-flags.h themselves,
and there are probably more indirect inclusions. So just include it at
the top like any other header file.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-3-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Patch series "THP prep patches".
These are some generic cleanups and improvements, which I would like
merged into mmotm soon. The first one should be a performance improvement
for all users of compound pages, and the others are aimed at getting code
to compile away when CONFIG_TRANSPARENT_HUGEPAGE is disabled (ie small
systems). Also better documented / less confusing than the current prefix
mixture of compound, hpage and thp.
This patch (of 7):
This removes a few instructions from functions which need to know how many
pages are in a compound page. The storage used is either page->mapping on
64-bit or page->index on 32-bit. Both of these are fine to overlay on
tail pages.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-1-willy@infradead.org
Link: http://lkml.kernel.org/r/20200629151959.15779-2-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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I had stopped using gkurz@linux.vnet.ibm.com a while back already but this
email address was shutdown last June when I quit IBM. It's about time to
map it to groug@kaod.org.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/159724692879.76040.4938578139173154028.stgit@bahia.lan
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Make sure execve() returns the expected errno values for non-regular
files.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Marc Zyngier <maz@kernel.org>
Link: http://lkml.kernel.org/r/20200813231723.2725102-3-keescook@chromium.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Patch series "Fix S_ISDIR execve() errno".
Fix an errno change for execve() of directories, noticed by Marc Zyngier.
Along with the fix, include a regression test to avoid seeing this return
in the future.
This patch (of 2):
The return code for attempting to execute a directory has always been
EACCES. Adjust the S_ISDIR exec test to reflect the old errno instead of
the general EISDIR for other kinds of "open" attempts on directories.
Fixes: 633fb6ac3980 ("exec: move S_ISREG() check earlier")
Reported-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Greg Kroah-Hartman <gregkh@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@google.com>
Link: http://lkml.kernel.org/r/20200813231723.2725102-2-keescook@chromium.org
Link: https://lore.kernel.org/lkml/20200813151305.6191993b@why
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch replaces all memcpy() calls with LZ4_memcpy() which calls
__builtin_memcpy() so the compiler can inline it.
LZ4 relies heavily on memcpy() with a constant size being inlined. In x86
and i386 pre-boot environments memcpy() cannot be inlined because memcpy()
doesn't get defined as __builtin_memcpy().
An equivalent patch has been applied upstream so that the next import
won't lose this change [1].
I've measured the kernel decompression speed using QEMU before and after
this patch for the x86_64 and i386 architectures. The speed-up is about
10x as shown below.
Code Arch Kernel Size Time Speed
v5.8 x86_64 11504832 B 148 ms 79 MB/s
patch x86_64 11503872 B 13 ms 885 MB/s
v5.8 i386 9621216 B 91 ms 106 MB/s
patch i386 9620224 B 10 ms 962 MB/s
I also measured the time to decompress the initramfs on x86_64, i386, and
arm. All three show the same decompression speed before and after, as
expected.
[1] https://github.com/lz4/lz4/pull/890
Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Link: http://lkml.kernel.org/r/20200803194022.2966806-1-nickrterrell@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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empty zone"
This reverts commit 26e7deadaae175.
Sonny reported that one of their tests started failing on the latest
kernel on their Chrome OS platform. The root cause is that the above
commit removed the protection line of empty zone, while the parser used in
the test relies on the protection line to mark the end of each zone.
Let's revert it to avoid breaking userspace testing or applications.
Fixes: 26e7deadaae175 ("mm/vmstat.c: do not show lowmem reserve protection information of empty zone)"
Reported-by: Sonny Rao <sonnyrao@chromium.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [5.8.x]
Link: http://lkml.kernel.org/r/20200811075412.12872-1-bhe@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The #ifdef statement that guards the generic version of pud_alloc_one() by
mistake used __HAVE_ARCH_PUD_FREE instead of __HAVE_ARCH_PUD_ALLOC_ONE.
Fix it.
Fixes: d9e8b929670b ("asm-generic: pgalloc: provide generic pud_alloc_one() and pud_free_one()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200812191415.GE163101@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The Landisk setup code maps the CF IDE area using ioremap_prot(), and
passes the resulting virtual addresses to the pata_platform driver,
disguising them as I/O port addresses. Hence the pata_platform driver
translates them again using ioport_map().
As CONFIG_GENERIC_IOMAP=n, and CONFIG_HAS_IOPORT_MAP=y, the
SuperH-specific mapping code in arch/sh/kernel/ioport.c translates
I/O port addresses to virtual addresses by adding sh_io_port_base, which
defaults to -1, thus breaking the assumption of an identity mapping.
Fix this by setting sh_io_port_base to zero.
Fixes: 37b7a97884ba64bf ("sh: machvec IO death.")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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Other architectures expect that syscall_set_return_value gets an already
negative value as error. That's also what kernel/seccomp.c provides.
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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Port sh to use the new SECCOMP_FILTER code.
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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This avoids out-of-range jumps that get auto-replaced by the assembler
and prepares for the changes needed to implement SECCOMP_FILTER cleanly.
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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Use the copy_thread_tls() calling convention which passes tls through a
register. This is required so we can remove the copy_thread{_tls}() split
and remove the HAVE_COPY_THREAD_TLS macro.
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Rich Felker <dalias@libc.org>
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This switches to using common code for the DMA allocations, including
potential use of the CMA allocator if configured.
Switching to the generic code enables DMA allocations from atomic
context, which is required by the DMA API documentation, and also
adds various other minor features drivers start relying upon. It
also makes sure we have on tested code base for all architectures
that require uncached pte bits for coherent DMA allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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The code handling non-coherent DMA depends on being able to remap code
as non-cached. But that can't be done without an MMU, so using this
option on NOMMU builds is broken.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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Have a single definition that architetures can select.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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Both functions are only used by compiled in core code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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No need to expose the details of trapped I/O to drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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Move the internal implementation details of ioremap out of line, no need
to expose any of this to drivers for a slow path API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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ioremap_fixed is an internal implementation detail and should not be
exposed to drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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There is no point in having __KERNEL__ ifdefs in headers not exported to
userspace.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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Ensure there is an order for the selects. Also remove a duplicate
one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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The sh build is full of warnings when building with gcc 9.2.1. While
fixing those would be great, at least avoid failing the build.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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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:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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Drop all configs with the CONFIG_SOC_CAMERA prefix since those
have been removed.
SOC_CAMERA support for the sh architecture was removed a long time ago.
Drop it from the configs.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Rich Felker <dalias@libc.org>
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The SH implementation never called stacktrace_ops.stack().
Presumably this was copied from the x86 implementation.
Hence remove the method, and all implementations (most of them are
dummies).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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- Convert from printk() to pr_*(),
- Add missing continuations.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rich Felker <dalias@libc.org>
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- Convert from printk() to pr_*(),
- Add missing continuations,
- Join broken messages.
Note that printk(KERN_DEBUG ...) is retained, to preserve behavior
(pr_debug() is a dummy if DEBUG is not defined).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rich Felker <dalias@libc.org>
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- Convert from printk() to pr_*(),
- Add missing continuation.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rich Felker <dalias@libc.org>
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Rejoin the broken lines by using pr_cont().
Convert the remaining printk() calls to pr_*() while at it.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rich Felker <dalias@libc.org>
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Rejoin the broken lines by dropping the log level parameters and using
pr_cont().
Use "%px" to print sensible addresses in call traces.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rich Felker <dalias@libc.org>
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Rejoin the broken lines by using pr_cont().
Convert the remaining printk() calls to pr_*() while at it.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rich Felker <dalias@libc.org>
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This reverts commit 8b92f34877225c8eb85e3ab7f1177fc248ba26d0.
"data" became the log level in commit 539e786cc37ee5cb ("sh: add loglvl
to show_trace()"), so we do need to keep the printk() before the
continuation in print_trace_address().
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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This reverts commit 2deebe4d56d638269a4a728086d64de5734b460a.
printk_address() is always used as a continuation of the previous
logging, hence it should not include a log level.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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Somewhere along the patch handling path, both the old "printk(KERN_ALERT
....)" and the new "pr_alert(...)" were retained, leading to the
duplicate printing of "PC:".
Drop the old one.
Fixes: eaabf98b0932a540 ("sh: fault: modernize printing of kernel messages")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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As of commit 37744feebc086908 ("sh: remove sh5 support"), support for
the SH5-based Cayman platform can no longer be selected.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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Since the removal of core support for SH5, Cayman support can no longer
be selected.
Fixes: 37744feebc086908 ("sh: remove sh5 support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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Fix typo: "triger" --> "trigger"
Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Signed-off-by: Rich Felker <dalias@libc.org>
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This reverts commit d1f56f318d234fc5db230af2f3e0088f689ab3c0.
__delay() is an internal implementation detail on several architectures.
Drivers should not call __delay() directly, as it has non-standardized
semantics, or may not even exist.
Hence there is no need to export __delay() to modules.
See also include/asm-generic/delay.h:
/* Undefined functions to get compile-time errors */
...
extern void __delay(unsigned long loops);
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
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Trying to build the kernel with CONFIG_INFINIBAND_USER_ACCESS enabled fails
ERROR: "__get_user_unknown" [drivers/infiniband/core/ib_uverbs.ko] undefined!
with on SH since the kernel misses a 64-bit implementation of get_user().
Implement the missing 64-bit get_user() as __get_user_u64(), matching the
already existing __put_user_u64() which implements the 64-bit put_user().
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Rich Felker <dalias@libc.org>
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Function dma_alloc_coherent use in buf already zeroes out memory,
so memset is not needed.
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Rich Felker <dalias@libc.org>
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The pgd kmem_cache allocation both specified __GFP_ZERO and had a
constructor which makes no sense. Remove __GFP_ZERO and zero the user
parts of the pgd explicitly.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Rich Felker <dalias@libc.org>
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Exception vector is missing on nommu platform and that is an issue.
This patch is tested in Sipeed Maix Bit Dev Board.
Fixes: 79b1feba5455 ("RISC-V: Setup exception vector early")
Suggested-by: Anup Patel <anup@brainfault.org>
Suggested-by: Atish Patra <atishp@atishpatra.org>
Signed-off-by: Qiu Wenbo <qiuwenbo@phytium.com.cn>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Pull more SCSI updates from James Bottomley:
"This is the set of patches which arrived too late to stabilise in
-next for the first pull.
It's really just an lpfc driver update and an assortment of minor
fixes, all in drivers. The only core update is to the zone block
device driver, which isn't the one most people use"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: lpfc: Update lpfc version to 12.8.0.3
scsi: lpfc: Fix LUN loss after cable pull
scsi: lpfc: Fix validation of bsg reply lengths
scsi: lpfc: Fix retry of PRLI when status indicates its unsupported
scsi: lpfc: Fix oops when unloading driver while running mds diags
scsi: lpfc: Fix RSCN timeout due to incorrect gidft counter
scsi: lpfc: Fix no message shown for lpfc_hdw_queue out of range value
scsi: lpfc: Fix FCoE speed reporting
scsi: lpfc: Add missing misc_deregister() for lpfc_init()
scsi: lpfc: nvmet: Avoid hang / use-after-free again when destroying targetport
scsi: scsi_transport_sas: Add spaces around binary operator "|"
scsi: sd_zbc: Improve zone revalidation
scsi: libfc: Free skb in fc_disc_gpn_id_resp() for valid cases
scsi: fcoe: Memory leak fix in fcoe_sysfs_fcf_del()
scsi: target: Make iscsit_register_transport() return void
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git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding:
"The majority of this batch is conversion of the PWM period and duty
cycle to 64-bit unsigned integers, which is required so that some
types of hardware can generate the full range of signals that they're
capable of.
The remainder is mostly minor fixes and cleanups"
* tag 'pwm/for-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
pwm: bcm-iproc: handle clk_get_rate() return
pwm: Replace HTTP links with HTTPS ones
pwm: omap-dmtimer: Repair pwm_omap_dmtimer_chip's broken kerneldoc header
pwm: mediatek: Provide missing kerneldoc description for 'soc' arg
pwm: bcm-kona: Remove impossible comparison when validating duty cycle
pwm: bcm-iproc: Remove impossible comparison when validating duty cycle
pwm: iqs620a: Use lowercase hexadecimal literals for consistency
pwm: Convert period and duty cycle to u64
clk: pwm: Use 64-bit division function
backlight: pwm_bl: Use 64-bit division function
pwm: sun4i: Use nsecs_to_jiffies to avoid a division
pwm: sifive: Use 64-bit division macro
pwm: iqs620a: Use 64-bit division
pwm: imx27: Use 64-bit division macro
pwm: imx-tpm: Use 64-bit division macro
pwm: clps711x: Use 64-bit division macro
hwmon: pwm-fan: Use 64-bit division macro
drm/i915: Use 64-bit division macro
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"All device-specific small fixes and quirks mostly for usual suspects,
USB-audio and HD-audio"
* tag 'sound-fix-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: echoaudio: Fix potential Oops in snd_echo_resume()
ALSA: hda/hdmi: Use force connectivity quirk on another HP desktop
ALSA: hda/realtek - Fix unused variable warning
ALSA: hda - reverse the setting value in the micmute_led_set
ALSA: echoaduio: Drop superfluous volatile modifier
ALSA: usb-audio: Disable Lenovo P620 Rear line-in volume control
ALSA: usb-audio: add quirk for Pioneer DDJ-RB
ALSA: usb-audio: work around streaming quirk for MacroSilicon MS2109
ALSA: hda - fix the micmute led status for Lenovo ThinkCentre AIO
ALSA: usb-audio: fix overeager device match for MacroSilicon MS2109
ALSA: hda/realtek: Fix pin default on Intel NUC 8 Rugged
ALSA: usb-audio: Creative USB X-Fi Pro SB1095 volume knob support
ALSA: usb-audio: fix spelling mistake "buss" -> "bus"
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This remoes the code from the COW path to call debug_dma_assert_idle(),
which was added many years ago.
Google shows that it hasn't caught anything in the 6+ years we've had it
apart from a false positive, and Hugh just noticed how it had a very
unfortunate spinlock serialization in the COW path.
He fixed that issue the previous commit (a85ffd59bd36: "dma-debug: fix
debug_dma_assert_idle(), use rcu_read_lock()"), but let's see if anybody
even notices when we remove this function entirely.
NOTE! We keep the dma tracking infrastructure that was added by the
commit that introduced it. Partly to make it easier to resurrect this
debug code if we ever deside to, and partly because that tracking by pfn
and offset looks quite reasonable.
The problem with this debug code was simply that it was expensive and
didn't seem worth it, not that it was wrong per se.
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Since commit 2a9127fcf229 ("mm: rewrite wait_on_page_bit_common()
logic") improved unlock_page(), it has become more noticeable how
cow_user_page() in a kernel with CONFIG_DMA_API_DEBUG=y can create and
suffer from heavy contention on DMA debug's radix_lock in
debug_dma_assert_idle().
It is only doing a lookup: use rcu_read_lock() and rcu_read_unlock()
instead; though that does require the static ents[] to be moved
onstack...
...but, hold on, isn't that radix_tree_gang_lookup() and loop doing
quite the wrong thing: searching CACHELINES_PER_PAGE entries for an
exact match with the first cacheline of the page in question?
radix_tree_gang_lookup() is the right tool for the job, but we need
nothing more than to check the first entry it can find, reporting if
that falls anywhere within the page.
(Is RCU safe here? As safe as using the spinlock was. The entries are
never freed, so don't need to be freed by RCU. They may be reused, and
there is a faint chance of a race, with an offending entry reused while
printing its error info; but the spinlock did not prevent that either,
and I agree that it's not worth worrying about. ]
[ Side noe: this patch is a clear improvement to the status quo, but the
next patch will be removing this debug function entirely.
But just in case we decide we want to resurrect the debugging code
some day, I'm first applying this improvement patch so that it doesn't
get lost - Linus ]
Fixes: 3b7a6418c749 ("dma debug: account for cachelines and read-only mappings in overlap tracking")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timekeeping updates from Thomas Gleixner:
"A set of timekeeping/VDSO updates:
- Preparatory work to allow S390 to switch over to the generic VDSO
implementation.
S390 requires that the VDSO data pointer is handed in to the
counter read function when time namespace support is enabled.
Adding the pointer is a NOOP for all other architectures because
the compiler is supposed to optimize that out when it is unused in
the architecture specific inline. The change also solved a similar
problem for MIPS which fortunately has time namespaces not yet
enabled.
S390 needs to update clock related VDSO data independent of the
timekeeping updates. This was solved so far with yet another
sequence counter in the S390 implementation. A better solution is
to utilize the already existing VDSO sequence count for this. The
core code now exposes helper functions which allow to serialize
against the timekeeper code and against concurrent readers.
S390 needs extra data for their clock readout function. The initial
common VDSO data structure did not provide a way to add that. It
now has an embedded architecture specific struct embedded which
defaults to an empty struct.
Doing this now avoids tree dependencies and conflicts post rc1 and
allows all other architectures which work on generic VDSO support
to work from a common upstream base.
- A trivial comment fix"
* tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Delete repeated words in comments
lib/vdso: Allow to add architecture-specific vdso data
timekeeping/vsyscall: Provide vdso_update_begin/end()
vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more timer updates from Thomas Gleixner:
"A set of posix CPU timer changes which allows to defer the heavy work
of posix CPU timers into task work context. The tick interrupt is
reduced to a quick check which queues the work which is doing the
heavy lifting before returning to user space or going back to guest
mode. Moving this out is deferring the signal delivery slightly but
posix CPU timers are inaccurate by nature as they depend on the tick
so there is no real damage. The relevant test cases all passed.
This lifts the last offender for RT out of the hard interrupt context
tick handler, but it also has the general benefit that the actual
heavy work is accounted to the task/process and not to the tick
interrupt itself.
Further optimizations are possible to break long sighand lock hold and
interrupt disabled (on !RT kernels) times when a massive amount of
posix CPU timers (which are unpriviledged) is armed for a
task/process.
This is currently only enabled for x86 because the architecture has to
ensure that task work is handled in KVM before entering a guest, which
was just established for x86 with the new common entry/exit code which
got merged post 5.8 and is not the case for other KVM architectures"
* tag 'timers-core-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Select POSIX_CPU_TIMERS_TASK_WORK
posix-cpu-timers: Provide mechanisms to defer timer handling to task_work
posix-cpu-timers: Split run_posix_cpu_timers()
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