<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/Kconfig, branch v5.1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc</title>
<updated>2019-03-06T22:18:59+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-06T22:18:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=45763bf4bc1ebdf8eb95697607e1fd042a3e1221'/>
<id>45763bf4bc1ebdf8eb95697607e1fd042a3e1221</id>
<content type='text'>
Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver patch pull request for 5.1-rc1.

  The largest thing by far is the new habanalabs driver for their AI
  accelerator chip. For now it is in the drivers/misc directory but will
  probably move to a new directory soon along with other drivers of this
  type.

  Other than that, just the usual set of individual driver updates and
  fixes. There's an "odd" merge in here from the DRM tree that they
  asked me to do as the MEI driver is starting to interact with the i915
  driver, and it needed some coordination. All of those patches have
  been properly acked by the relevant subsystem maintainers.

  All of these have been in linux-next with no reported issues, most for
  quite some time"

* tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (219 commits)
  habanalabs: adjust Kconfig to fix build errors
  habanalabs: use %px instead of %p in error print
  habanalabs: use do_div for 64-bit divisions
  intel_th: gth: Fix an off-by-one in output unassigning
  habanalabs: fix little-endian&lt;-&gt;cpu conversion warnings
  habanalabs: use NULL to initialize array of pointers
  habanalabs: fix little-endian&lt;-&gt;cpu conversion warnings
  habanalabs: soft-reset device if context-switch fails
  habanalabs: print pointer using %p
  habanalabs: fix memory leak with CBs with unaligned size
  habanalabs: return correct error code on MMU mapping failure
  habanalabs: add comments in uapi/misc/habanalabs.h
  habanalabs: extend QMAN0 job timeout
  habanalabs: set DMA0 completion to SOB 1007
  habanalabs: fix validation of WREG32 to DMA completion
  habanalabs: fix mmu cache registers init
  habanalabs: disable CPU access on timeouts
  habanalabs: add MMU DRAM default page mapping
  habanalabs: Dissociate RAZWI info from event types
  misc/habanalabs: adjust Kconfig to fix build errors
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver patch pull request for 5.1-rc1.

  The largest thing by far is the new habanalabs driver for their AI
  accelerator chip. For now it is in the drivers/misc directory but will
  probably move to a new directory soon along with other drivers of this
  type.

  Other than that, just the usual set of individual driver updates and
  fixes. There's an "odd" merge in here from the DRM tree that they
  asked me to do as the MEI driver is starting to interact with the i915
  driver, and it needed some coordination. All of those patches have
  been properly acked by the relevant subsystem maintainers.

  All of these have been in linux-next with no reported issues, most for
  quite some time"

* tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (219 commits)
  habanalabs: adjust Kconfig to fix build errors
  habanalabs: use %px instead of %p in error print
  habanalabs: use do_div for 64-bit divisions
  intel_th: gth: Fix an off-by-one in output unassigning
  habanalabs: fix little-endian&lt;-&gt;cpu conversion warnings
  habanalabs: use NULL to initialize array of pointers
  habanalabs: fix little-endian&lt;-&gt;cpu conversion warnings
  habanalabs: soft-reset device if context-switch fails
  habanalabs: print pointer using %p
  habanalabs: fix memory leak with CBs with unaligned size
  habanalabs: return correct error code on MMU mapping failure
  habanalabs: add comments in uapi/misc/habanalabs.h
  habanalabs: extend QMAN0 job timeout
  habanalabs: set DMA0 completion to SOB 1007
  habanalabs: fix validation of WREG32 to DMA completion
  habanalabs: fix mmu cache registers init
  habanalabs: disable CPU access on timeouts
  habanalabs: add MMU DRAM default page mapping
  habanalabs: Dissociate RAZWI info from event types
  misc/habanalabs: adjust Kconfig to fix build errors
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-03-06T15:13:56+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-06T15:13:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c8f5ed6ef972ed4fd10b0c2e2baec3b6803d3c73'/>
<id>c8f5ed6ef972ed4fd10b0c2e2baec3b6803d3c73</id>
<content type='text'>
Pull EFI updates from Ingo Molnar:
 "The main EFI changes in this cycle were:

   - Use 32-bit alignment for efi_guid_t

   - Allow the SetVirtualAddressMap() call to be omitted

   - Implement earlycon=efifb based on existing earlyprintk code

   - Various minor fixes and code cleanups from Sai, Ard and me"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Fix build error due to enum collision between efi.h and ima.h
  efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation
  x86: Make ARCH_USE_MEMREMAP_PROT a generic Kconfig symbol
  efi/arm/arm64: Allow SetVirtualAddressMap() to be omitted
  efi: Replace GPL license boilerplate with SPDX headers
  efi/fdt: Apply more cleanups
  efi: Use 32-bit alignment for efi_guid_t
  efi/memattr: Don't bail on zero VA if it equals the region's PA
  x86/efi: Mark can_free_region() as an __init function
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull EFI updates from Ingo Molnar:
 "The main EFI changes in this cycle were:

   - Use 32-bit alignment for efi_guid_t

   - Allow the SetVirtualAddressMap() call to be omitted

   - Implement earlycon=efifb based on existing earlyprintk code

   - Various minor fixes and code cleanups from Sai, Ard and me"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Fix build error due to enum collision between efi.h and ima.h
  efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation
  x86: Make ARCH_USE_MEMREMAP_PROT a generic Kconfig symbol
  efi/arm/arm64: Allow SetVirtualAddressMap() to be omitted
  efi: Replace GPL license boilerplate with SPDX headers
  efi/fdt: Apply more cleanups
  efi: Use 32-bit alignment for efi_guid_t
  efi/memattr: Don't bail on zero VA if it equals the region's PA
  x86/efi: Mark can_free_region() as an __init function
</pre>
</div>
</content>
</entry>
<entry>
<title>32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option</title>
<updated>2019-02-19T09:10:05+00:00</updated>
<author>
<name>Yury Norov</name>
<email>ynorov@caviumnetworks.com</email>
</author>
<published>2018-05-16T08:18:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=942fa985e9f161ac018ce2230d3e6f7668cca6ac'/>
<id>942fa985e9f161ac018ce2230d3e6f7668cca6ac</id>
<content type='text'>
All new 32-bit architectures should have 64-bit userspace off_t type, but
existing architectures has 32-bit ones.

To enforce the rule, new config option is added to arch/Kconfig that defaults
ARCH_32BIT_OFF_T to be disabled for new 32-bit architectures. All existing
32-bit architectures enable it explicitly.

New option affects force_o_largefile() behaviour. Namely, if userspace
off_t is 64-bits long, we have no reason to reject user to open big files.

Note that even if architectures has only 64-bit off_t in the kernel
(arc, c6x, h8300, hexagon, nios2, openrisc, and unicore32),
a libc may use 32-bit off_t, and therefore want to limit the file size
to 4GB unless specified differently in the open flags.

Signed-off-by: Yury Norov &lt;ynorov@caviumnetworks.com&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Yury Norov &lt;ynorov@marvell.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All new 32-bit architectures should have 64-bit userspace off_t type, but
existing architectures has 32-bit ones.

To enforce the rule, new config option is added to arch/Kconfig that defaults
ARCH_32BIT_OFF_T to be disabled for new 32-bit architectures. All existing
32-bit architectures enable it explicitly.

New option affects force_o_largefile() behaviour. Namely, if userspace
off_t is 64-bits long, we have no reason to reject user to open big files.

Note that even if architectures has only 64-bit off_t in the kernel
(arc, c6x, h8300, hexagon, nios2, openrisc, and unicore32),
a libc may use 32-bit off_t, and therefore want to limit the file size
to 4GB unless specified differently in the open flags.

Signed-off-by: Yury Norov &lt;ynorov@caviumnetworks.com&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Yury Norov &lt;ynorov@marvell.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>y2038: use time32 syscall names on 32-bit</title>
<updated>2019-02-06T23:13:28+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2019-01-01T00:13:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=00bf25d693e7f69497cb7f61d46ef99fe295a8a5'/>
<id>00bf25d693e7f69497cb7f61d46ef99fe295a8a5</id>
<content type='text'>
This is the big flip, where all 32-bit architectures set COMPAT_32BIT_TIME
and use the _time32 system calls from the former compat layer instead
of the system calls that take __kernel_timespec and similar arguments.

The temporary redirects for __kernel_timespec, __kernel_itimerspec
and __kernel_timex can get removed with this.

It would be easy to split this commit by architecture, but with the new
generated system call tables, it's easy enough to do it all at once,
which makes it a little easier to check that the changes are the same
in each table.

Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the big flip, where all 32-bit architectures set COMPAT_32BIT_TIME
and use the _time32 system calls from the former compat layer instead
of the system calls that take __kernel_timespec and similar arguments.

The temporary redirects for __kernel_timespec, __kernel_itimerspec
and __kernel_timex can get removed with this.

It would be easy to split this commit by architecture, but with the new
generated system call tables, it's easy enough to do it all at once,
which makes it a little easier to check that the changes are the same
in each table.

Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Make ARCH_USE_MEMREMAP_PROT a generic Kconfig symbol</title>
<updated>2019-02-04T07:27:29+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2019-02-02T09:41:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ce9084ba0d1d8030adee7038ace32f8d9d423d0f'/>
<id>ce9084ba0d1d8030adee7038ace32f8d9d423d0f</id>
<content type='text'>
Turn ARCH_USE_MEMREMAP_PROT into a generic Kconfig symbol, and fix the
dependency expression to reflect that AMD_MEM_ENCRYPT depends on it,
instead of the other way around. This will permit ARCH_USE_MEMREMAP_PROT
to be selected by other architectures.

Note that the encryption related early memremap routines in
arch/x86/mm/ioremap.c cannot be built for 32-bit x86 without triggering
the following warning:

     arch/x86//mm/ioremap.c: In function 'early_memremap_encrypted':
  &gt;&gt; arch/x86/include/asm/pgtable_types.h:193:27: warning: conversion from
                     'long long unsigned int' to 'long unsigned int' changes
                     value from '9223372036854776163' to '355' [-Woverflow]
      #define __PAGE_KERNEL_ENC (__PAGE_KERNEL | _PAGE_ENC)
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
     arch/x86//mm/ioremap.c:713:46: note: in expansion of macro '__PAGE_KERNEL_ENC'
       return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC);

which essentially means they are 64-bit only anyway. However, we cannot
make them dependent on CONFIG_ARCH_HAS_MEM_ENCRYPT, since that is always
defined, even for i386 (and changing that results in a slew of build errors)

So instead, build those routines only if CONFIG_AMD_MEM_ENCRYPT is
defined.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: AKASHI Takahiro &lt;takahiro.akashi@linaro.org&gt;
Cc: Alexander Graf &lt;agraf@suse.de&gt;
Cc: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Heinrich Schuchardt &lt;xypron.glpk@gmx.de&gt;
Cc: Jeffrey Hugo &lt;jhugo@codeaurora.org&gt;
Cc: Lee Jones &lt;lee.jones@linaro.org&gt;
Cc: Leif Lindholm &lt;leif.lindholm@linaro.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Peter Jones &lt;pjones@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sai Praneeth Prakhya &lt;sai.praneeth.prakhya@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190202094119.13230-9-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Turn ARCH_USE_MEMREMAP_PROT into a generic Kconfig symbol, and fix the
dependency expression to reflect that AMD_MEM_ENCRYPT depends on it,
instead of the other way around. This will permit ARCH_USE_MEMREMAP_PROT
to be selected by other architectures.

Note that the encryption related early memremap routines in
arch/x86/mm/ioremap.c cannot be built for 32-bit x86 without triggering
the following warning:

     arch/x86//mm/ioremap.c: In function 'early_memremap_encrypted':
  &gt;&gt; arch/x86/include/asm/pgtable_types.h:193:27: warning: conversion from
                     'long long unsigned int' to 'long unsigned int' changes
                     value from '9223372036854776163' to '355' [-Woverflow]
      #define __PAGE_KERNEL_ENC (__PAGE_KERNEL | _PAGE_ENC)
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
     arch/x86//mm/ioremap.c:713:46: note: in expansion of macro '__PAGE_KERNEL_ENC'
       return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC);

which essentially means they are 64-bit only anyway. However, we cannot
make them dependent on CONFIG_ARCH_HAS_MEM_ENCRYPT, since that is always
defined, even for i386 (and changing that results in a slew of build errors)

So instead, build those routines only if CONFIG_AMD_MEM_ENCRYPT is
defined.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: AKASHI Takahiro &lt;takahiro.akashi@linaro.org&gt;
Cc: Alexander Graf &lt;agraf@suse.de&gt;
Cc: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Heinrich Schuchardt &lt;xypron.glpk@gmx.de&gt;
Cc: Jeffrey Hugo &lt;jhugo@codeaurora.org&gt;
Cc: Lee Jones &lt;lee.jones@linaro.org&gt;
Cc: Leif Lindholm &lt;leif.lindholm@linaro.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Peter Jones &lt;pjones@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sai Praneeth Prakhya &lt;sai.praneeth.prakhya@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190202094119.13230-9-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>m68k/atari: Implement arch_nvram_ops methods and enable CONFIG_HAVE_ARCH_NVRAM_OPS</title>
<updated>2019-01-22T09:21:44+00:00</updated>
<author>
<name>Finn Thain</name>
<email>fthain@telegraphics.com.au</email>
</author>
<published>2019-01-15T04:18:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=666047fe2a4c9e1bc255ca0549d825b40832886c'/>
<id>666047fe2a4c9e1bc255ca0549d825b40832886c</id>
<content type='text'>
Atari RTC NVRAM uses a checksum so implement the remaining arch_nvram_ops
methods for the set_checksum and initialize ioctls. Enable
CONFIG_HAVE_ARCH_NVRAM_OPS.

Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Finn Thain &lt;fthain@telegraphics.com.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Atari RTC NVRAM uses a checksum so implement the remaining arch_nvram_ops
methods for the set_checksum and initialize ioctls. Enable
CONFIG_HAVE_ARCH_NVRAM_OPS.

Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Finn Thain &lt;fthain@telegraphics.com.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jump_label: move 'asm goto' support test to Kconfig</title>
<updated>2019-01-06T00:46:51+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2018-12-30T15:14:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e9666d10a5677a494260d60d1fa0b73cc7646eb3'/>
<id>e9666d10a5677a494260d60d1fa0b73cc7646eb3</id>
<content type='text'>
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) &amp;&amp; defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) &amp;&amp; defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: speed up mremap by 20x on large regions</title>
<updated>2019-01-04T21:13:48+00:00</updated>
<author>
<name>Joel Fernandes (Google)</name>
<email>joel@joelfernandes.org</email>
</author>
<published>2019-01-03T23:28:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2c91bd4a4e2e530582d6fd643ea7b86b27907151'/>
<id>2c91bd4a4e2e530582d6fd643ea7b86b27907151</id>
<content type='text'>
Android needs to mremap large regions of memory during memory management
related operations.  The mremap system call can be really slow if THP is
not enabled.  The bottleneck is move_page_tables, which is copying each
pte at a time, and can be really slow across a large map.  Turning on
THP may not be a viable option, and is not for us.  This patch speeds up
the performance for non-THP system by copying at the PMD level when
possible.

The speedup is an order of magnitude on x86 (~20x).  On a 1GB mremap,
the mremap completion times drops from 3.4-3.6 milliseconds to 144-160
microseconds.

Before:
Total mremap time for 1GB data: 3521942 nanoseconds.
Total mremap time for 1GB data: 3449229 nanoseconds.
Total mremap time for 1GB data: 3488230 nanoseconds.

After:
Total mremap time for 1GB data: 150279 nanoseconds.
Total mremap time for 1GB data: 144665 nanoseconds.
Total mremap time for 1GB data: 158708 nanoseconds.

If THP is enabled the optimization is mostly skipped except in certain
situations.

[joel@joelfernandes.org: fix 'move_normal_pmd' unused function warning]
  Link: http://lkml.kernel.org/r/20181108224457.GB209347@google.com
Link: http://lkml.kernel.org/r/20181108181201.88826-3-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) &lt;joel@joelfernandes.org&gt;
Acked-by: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Reviewed-by: William Kucharski &lt;william.kucharski@oracle.com&gt;
Cc: Julia Lawall &lt;Julia.Lawall@lip6.fr&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Android needs to mremap large regions of memory during memory management
related operations.  The mremap system call can be really slow if THP is
not enabled.  The bottleneck is move_page_tables, which is copying each
pte at a time, and can be really slow across a large map.  Turning on
THP may not be a viable option, and is not for us.  This patch speeds up
the performance for non-THP system by copying at the PMD level when
possible.

The speedup is an order of magnitude on x86 (~20x).  On a 1GB mremap,
the mremap completion times drops from 3.4-3.6 milliseconds to 144-160
microseconds.

Before:
Total mremap time for 1GB data: 3521942 nanoseconds.
Total mremap time for 1GB data: 3449229 nanoseconds.
Total mremap time for 1GB data: 3488230 nanoseconds.

After:
Total mremap time for 1GB data: 150279 nanoseconds.
Total mremap time for 1GB data: 144665 nanoseconds.
Total mremap time for 1GB data: 158708 nanoseconds.

If THP is enabled the optimization is mostly skipped except in certain
situations.

[joel@joelfernandes.org: fix 'move_normal_pmd' unused function warning]
  Link: http://lkml.kernel.org/r/20181108224457.GB209347@google.com
Link: http://lkml.kernel.org/r/20181108181201.88826-3-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) &lt;joel@joelfernandes.org&gt;
Acked-by: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Reviewed-by: William Kucharski &lt;william.kucharski@oracle.com&gt;
Cc: Julia Lawall &lt;Julia.Lawall@lip6.fr&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux</title>
<updated>2018-11-01T18:46:27+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-11-01T18:46:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2d6bb6adb714b133db92ccd4bfc9c20f75f71f3f'/>
<id>2d6bb6adb714b133db92ccd4bfc9c20f75f71f3f</id>
<content type='text'>
Pull stackleak gcc plugin from Kees Cook:
 "Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin
  was ported from grsecurity by Alexander Popov. It provides efficient
  stack content poisoning at syscall exit. This creates a defense
  against at least two classes of flaws:

   - Uninitialized stack usage. (We continue to work on improving the
     compiler to do this in other ways: e.g. unconditional zero init was
     proposed to GCC and Clang, and more plugin work has started too).

   - Stack content exposure. By greatly reducing the lifetime of valid
     stack contents, exposures via either direct read bugs or unknown
     cache side-channels become much more difficult to exploit. This
     complements the existing buddy and heap poisoning options, but
     provides the coverage for stacks.

  The x86 hooks are included in this series (which have been reviewed by
  Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already
  been merged through the arm64 tree (written by Laura Abbott and
  reviewed by Mark Rutland and Will Deacon).

  With VLAs having been removed this release, there is no need for
  alloca() protection, so it has been removed from the plugin"

* tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  arm64: Drop unneeded stackleak_check_alloca()
  stackleak: Allow runtime disabling of kernel stack erasing
  doc: self-protection: Add information about STACKLEAK feature
  fs/proc: Show STACKLEAK metrics in the /proc file system
  lkdtm: Add a test for STACKLEAK
  gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack
  x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull stackleak gcc plugin from Kees Cook:
 "Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin
  was ported from grsecurity by Alexander Popov. It provides efficient
  stack content poisoning at syscall exit. This creates a defense
  against at least two classes of flaws:

   - Uninitialized stack usage. (We continue to work on improving the
     compiler to do this in other ways: e.g. unconditional zero init was
     proposed to GCC and Clang, and more plugin work has started too).

   - Stack content exposure. By greatly reducing the lifetime of valid
     stack contents, exposures via either direct read bugs or unknown
     cache side-channels become much more difficult to exploit. This
     complements the existing buddy and heap poisoning options, but
     provides the coverage for stacks.

  The x86 hooks are included in this series (which have been reviewed by
  Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already
  been merged through the arm64 tree (written by Laura Abbott and
  reviewed by Mark Rutland and Will Deacon).

  With VLAs having been removed this release, there is no need for
  alloca() protection, so it has been removed from the plugin"

* tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  arm64: Drop unneeded stackleak_check_alloca()
  stackleak: Allow runtime disabling of kernel stack erasing
  doc: self-protection: Add information about STACKLEAK feature
  fs/proc: Show STACKLEAK metrics in the /proc file system
  lkdtm: Add a test for STACKLEAK
  gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack
  x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace</title>
<updated>2018-10-30T16:49:56+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-10-30T16:49:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=343a9f35409b68b6de66ecd0db90a277aee90ec2'/>
<id>343a9f35409b68b6de66ecd0db90a277aee90ec2</id>
<content type='text'>
Pull tracing updates from Steven Rostedt:
 "The biggest change here is the updates to kprobes

  Back in January I posted patches to create function based events.
  These were the events that you suggested I make to allow developers to
  easily create events in code where no trace event exists. After
  posting those changes for review, it was suggested that we implement
  this instead with kprobes.

  The problem with kprobes is that the interface is too complex and
  needs to be simplified. Masami Hiramatsu posted patches in March and
  I've been playing with them a bit. There's been a bit of clean up in
  the kprobe code that was inspired by the function based event patches,
  and a couple of enhancements to the kprobe event interface.

   - If the arch supports it (we added support for x86), you can place a
     kprobe event at the start of a function and use $arg1, $arg2, etc
     to reference the arguments of a function. (Before you needed to
     know what register or where on the stack the argument was).

   - The second is a way to see array of events. For example, if you
     reference a mac address, you can add:

	echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' &gt; kprobe_events

     And this will produce:

	mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}

  Other changes include

   - Exporting trace_dump_stack to modules

   - Have the stack tracer trace the entire stack (stop trying to remove
     tracing itself, as we keep removing too much).

   - Added support for SDT in uprobes"

[ SDT - "Statically Defined Tracing" are userspace markers for tracing.
  Let's not use random TLA's in explanations unless they are fairly
  well-established as generic (at least for kernel people) - Linus ]

* tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  tracing: Have stack tracer trace full stack
  tracing: Export trace_dump_stack to modules
  tracing: probeevent: Fix uninitialized used of offset in parse args
  tracing/kprobes: Allow kprobe-events to record module symbol
  tracing/kprobes: Check the probe on unloaded module correctly
  tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
  tracing: probeevent: Add $argN for accessing function args
  x86: ptrace: Add function argument access API
  tracing: probeevent: Add array type support
  tracing: probeevent: Add symbol type
  tracing: probeevent: Unify fetch_insn processing common part
  tracing: probeevent: Append traceprobe_ for exported function
  tracing: probeevent: Return consumed bytes of dynamic area
  tracing: probeevent: Unify fetch type tables
  tracing: probeevent: Introduce new argument fetching code
  tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions
  tracing: probeevent: Cleanup argument field definition
  tracing: probeevent: Cleanup print argument functions
  trace_uprobe: support reference counter in fd-based uprobe
  perf probe: Support SDT markers having reference counter (semaphore)
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tracing updates from Steven Rostedt:
 "The biggest change here is the updates to kprobes

  Back in January I posted patches to create function based events.
  These were the events that you suggested I make to allow developers to
  easily create events in code where no trace event exists. After
  posting those changes for review, it was suggested that we implement
  this instead with kprobes.

  The problem with kprobes is that the interface is too complex and
  needs to be simplified. Masami Hiramatsu posted patches in March and
  I've been playing with them a bit. There's been a bit of clean up in
  the kprobe code that was inspired by the function based event patches,
  and a couple of enhancements to the kprobe event interface.

   - If the arch supports it (we added support for x86), you can place a
     kprobe event at the start of a function and use $arg1, $arg2, etc
     to reference the arguments of a function. (Before you needed to
     know what register or where on the stack the argument was).

   - The second is a way to see array of events. For example, if you
     reference a mac address, you can add:

	echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' &gt; kprobe_events

     And this will produce:

	mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}

  Other changes include

   - Exporting trace_dump_stack to modules

   - Have the stack tracer trace the entire stack (stop trying to remove
     tracing itself, as we keep removing too much).

   - Added support for SDT in uprobes"

[ SDT - "Statically Defined Tracing" are userspace markers for tracing.
  Let's not use random TLA's in explanations unless they are fairly
  well-established as generic (at least for kernel people) - Linus ]

* tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  tracing: Have stack tracer trace full stack
  tracing: Export trace_dump_stack to modules
  tracing: probeevent: Fix uninitialized used of offset in parse args
  tracing/kprobes: Allow kprobe-events to record module symbol
  tracing/kprobes: Check the probe on unloaded module correctly
  tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
  tracing: probeevent: Add $argN for accessing function args
  x86: ptrace: Add function argument access API
  tracing: probeevent: Add array type support
  tracing: probeevent: Add symbol type
  tracing: probeevent: Unify fetch_insn processing common part
  tracing: probeevent: Append traceprobe_ for exported function
  tracing: probeevent: Return consumed bytes of dynamic area
  tracing: probeevent: Unify fetch type tables
  tracing: probeevent: Introduce new argument fetching code
  tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions
  tracing: probeevent: Cleanup argument field definition
  tracing: probeevent: Cleanup print argument functions
  trace_uprobe: support reference counter in fd-based uprobe
  perf probe: Support SDT markers having reference counter (semaphore)
  ...
</pre>
</div>
</content>
</entry>
</feed>
