<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/uapi/asm-generic, branch v4.14.219</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.219</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.219'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2017-11-02T10:19:54Z</updated>
<entry>
<title>License cleanup: add SPDX license identifier to uapi header files with no license</title>
<updated>2017-11-02T10:19:54Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:08:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=6f52b16c5b29b89d92c0e7236f4655dc8491ad70'/>
<id>urn:sha1:6f52b16c5b29b89d92c0e7236f4655dc8491ad70</id>
<content type='text'>
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace</title>
<updated>2017-09-12T01:34:47Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-09-12T01:34:47Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=dd198ce7141aa8dd9ffcc9549de422fb055508de'/>
<id>urn:sha1:dd198ce7141aa8dd9ffcc9549de422fb055508de</id>
<content type='text'>
Pull namespace updates from Eric Biederman:
 "Life has been busy and I have not gotten half as much done this round
  as I would have liked. I delayed it so that a minor conflict
  resolution with the mips tree could spend a little time in linux-next
  before I sent this pull request.

  This includes two long delayed user namespace changes from Kirill
  Tkhai. It also includes a very useful change from Serge Hallyn that
  allows the security capability attribute to be used inside of user
  namespaces. The practical effect of this is people can now untar
  tarballs and install rpms in user namespaces. It had been suggested to
  generalize this and encode some of the namespace information
  information in the xattr name. Upon close inspection that makes the
  things that should be hard easy and the things that should be easy
  more expensive.

  Then there is my bugfix/cleanup for signal injection that removes the
  magic encoding of the siginfo union member from the kernel internal
  si_code. The mips folks reported the case where I had used FPE_FIXME
  me is impossible so I have remove FPE_FIXME from mips, while at the
  same time including a return statement in that case to keep gcc from
  complaining about unitialized variables.

  I almost finished the work to get make copy_siginfo_to_user a trivial
  copy to user. The code is available at:

     git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git neuter-copy_siginfo_to_user-v3

  But I did not have time/energy to get the code posted and reviewed
  before the merge window opened.

  I was able to see that the security excuse for just copying fields
  that we know are initialized doesn't work in practice there are buggy
  initializations that don't initialize the proper fields in siginfo. So
  we still sometimes copy unitialized data to userspace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  Introduce v3 namespaced file capabilities
  mips/signal: In force_fcr31_sig return in the impossible case
  signal: Remove kernel interal si_code magic
  fcntl: Don't use ambiguous SIG_POLL si_codes
  prctl: Allow local CAP_SYS_ADMIN changing exe_file
  security: Use user_namespace::level to avoid redundant iterations in cap_capable()
  userns,pidns: Verify the userns for new pid namespaces
  signal/testing: Don't look for __SI_FAULT in userspace
  signal/mips: Document a conflict with SI_USER with SIGFPE
  signal/sparc: Document a conflict with SI_USER with SIGFPE
  signal/ia64: Document a conflict with SI_USER with SIGFPE
  signal/alpha: Document a conflict with SI_USER for SIGTRAP
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2017-09-07T03:49:49Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-09-07T03:49:49Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=d34fc1adf01ff87026da85fb972dc259dc347540'/>
<id>urn:sha1:d34fc1adf01ff87026da85fb972dc259dc347540</id>
<content type='text'>
Merge updates from Andrew Morton:

 - various misc bits

 - DAX updates

 - OCFS2

 - most of MM

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (119 commits)
  mm,fork: introduce MADV_WIPEONFORK
  x86,mpx: make mpx depend on x86-64 to free up VMA flag
  mm: add /proc/pid/smaps_rollup
  mm: hugetlb: clear target sub-page last when clearing huge page
  mm: oom: let oom_reap_task and exit_mmap run concurrently
  swap: choose swap device according to numa node
  mm: replace TIF_MEMDIE checks by tsk_is_oom_victim
  mm, oom: do not rely on TIF_MEMDIE for memory reserves access
  z3fold: use per-cpu unbuddied lists
  mm, swap: don't use VMA based swap readahead if HDD is used as swap
  mm, swap: add sysfs interface for VMA based swap readahead
  mm, swap: VMA based swap readahead
  mm, swap: fix swap readahead marking
  mm, swap: add swap readahead hit statistics
  mm/vmalloc.c: don't reinvent the wheel but use existing llist API
  mm/vmstat.c: fix wrong comment
  selftests/memfd: add memfd_create hugetlbfs selftest
  mm/shmem: add hugetlbfs support to memfd_create()
  mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups
  mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas()
  ...
</content>
</entry>
<entry>
<title>mm,fork: introduce MADV_WIPEONFORK</title>
<updated>2017-09-07T00:27:30Z</updated>
<author>
<name>Rik van Riel</name>
<email>riel@redhat.com</email>
</author>
<published>2017-09-06T23:25:15Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=d2cd9ede6e193dd7d88b6d27399e96229a551b19'/>
<id>urn:sha1:d2cd9ede6e193dd7d88b6d27399e96229a551b19</id>
<content type='text'>
Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty
in the child process after fork.  This differs from MADV_DONTFORK in one
important way.

If a child process accesses memory that was MADV_WIPEONFORK, it will get
zeroes.  The address ranges are still valid, they are just empty.

If a child process accesses memory that was MADV_DONTFORK, it will get a
segmentation fault, since those address ranges are no longer valid in
the child after fork.

Since MADV_DONTFORK also seems to be used to allow very large programs
to fork in systems with strict memory overcommit restrictions, changing
the semantics of MADV_DONTFORK might break existing programs.

MADV_WIPEONFORK only works on private, anonymous VMAs.

The use case is libraries that store or cache information, and want to
know that they need to regenerate it in the child process after fork.

Examples of this would be:
 - systemd/pulseaudio API checks (fail after fork) (replacing a getpid
   check, which is too slow without a PID cache)
 - PKCS#11 API reinitialization check (mandated by specification)
 - glibc's upcoming PRNG (reseed after fork)
 - OpenSSL PRNG (reseed after fork)

The security benefits of a forking server having a re-inialized PRNG in
every child process are pretty obvious.  However, due to libraries
having all kinds of internal state, and programs getting compiled with
many different versions of each library, it is unreasonable to expect
calling programs to re-initialize everything manually after fork.

A further complication is the proliferation of clone flags, programs
bypassing glibc's functions to call clone directly, and programs calling
unshare, causing the glibc pthread_atfork hook to not get called.

It would be better to have the kernel take care of this automatically.

The patch also adds MADV_KEEPONFORK, to undo the effects of a prior
MADV_WIPEONFORK.

This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO:

    https://man.openbsd.org/minherit.2

[akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines]
Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.com
Signed-off-by: Rik van Riel &lt;riel@redhat.com&gt;
Reported-by: Florian Weimer &lt;fweimer@redhat.com&gt;
Reported-by: Colm MacCártaigh &lt;colm@allcosts.net&gt;
Reviewed-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: "Kirill A. Shutemov" &lt;kirill@shutemov.name&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Drewry &lt;wad@chromium.org&gt;
Cc: &lt;linux-api@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: arch: consolidate mmap hugetlb size encodings</title>
<updated>2017-09-07T00:27:28Z</updated>
<author>
<name>Mike Kravetz</name>
<email>mike.kravetz@oracle.com</email>
</author>
<published>2017-09-06T23:23:29Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=aafd4562dfee81a40ba21b5ea3cf5e06664bc7f6'/>
<id>urn:sha1:aafd4562dfee81a40ba21b5ea3cf5e06664bc7f6</id>
<content type='text'>
A non-default huge page size can be encoded in the flags argument of the
mmap system call.  The definitions for these encodings are in arch
specific header files.  However, all architectures use the same values.

Consolidate all the definitions in the primary user header file
(uapi/linux/mman.h).  Include definitions for all known huge page sizes.
Use the generic encoding definitions in hugetlb_encode.h as the basis
for these definitions.

Link: http://lkml.kernel.org/r/1501527386-10736-3-git-send-email-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Anshuman Khandual &lt;khandual@linux.vnet.ibm.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Davidlohr Bueso &lt;dbueso@suse.de&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Michael Kerrisk &lt;mtk.manpages@gmail.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>
</entry>
<entry>
<title>mm: hugetlb: define system call hugetlb size encodings in single file</title>
<updated>2017-09-07T00:27:28Z</updated>
<author>
<name>Mike Kravetz</name>
<email>mike.kravetz@oracle.com</email>
</author>
<published>2017-09-06T23:23:25Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e652f694598273c5d749687032d1534a30e6a3a5'/>
<id>urn:sha1:e652f694598273c5d749687032d1534a30e6a3a5</id>
<content type='text'>
Patch series "Consolidate system call hugetlb page size encodings".

These patches are the result of discussions in
https://lkml.org/lkml/2017/3/8/548.  The following changes are made in the
patch set:

1) Put all the log2 encoded huge page size definitions in a common
   header file.  The idea is have a set of definitions that can be use as
   the basis for system call specific definitions such as MAP_HUGE_* and
   SHM_HUGE_*.

2) Remove MAP_HUGE_* definitions in arch specific files.  All these
   definitions are the same.  Consolidate all definitions in the primary
   user header file (uapi/linux/mman.h).

3) Remove SHM_HUGE_* definitions intended for user space from kernel
   header file, and add to user (uapi/linux/shm.h) header file.  Add
   definitions for all known huge page size encodings as in mmap.

This patch (of 3):

If hugetlb pages are requested in mmap or shmget system calls, a huge
page size other than default can be requested.  This is accomplished by
encoding the log2 of the huge page size in the upper bits of the flag
argument.  asm-generic and arch specific headers all define the same
values for these encodings.

Put common definitions in a single header file.  The primary uapi header
files for mmap and shm will use these definitions as a basis for
definitions specific to those system calls.

Link: http://lkml.kernel.org/r/1501527386-10736-2-git-send-email-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Michael Kerrisk &lt;mtk.manpages@gmail.com&gt;
Cc: Davidlohr Bueso &lt;dbueso@suse.de&gt;
Cc: Anshuman Khandual &lt;khandual@linux.vnet.ibm.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>sock: add SOCK_ZEROCOPY sockopt</title>
<updated>2017-08-04T04:37:29Z</updated>
<author>
<name>Willem de Bruijn</name>
<email>willemb@google.com</email>
</author>
<published>2017-08-03T20:29:40Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=76851d1212c11365362525e1e2c0a18c97478e6b'/>
<id>urn:sha1:76851d1212c11365362525e1e2c0a18c97478e6b</id>
<content type='text'>
The send call ignores unknown flags. Legacy applications may already
unwittingly pass MSG_ZEROCOPY. Continue to ignore this flag unless a
socket opts in to zerocopy.

Introduce socket option SO_ZEROCOPY to enable MSG_ZEROCOPY processing.
Processes can also query this socket option to detect kernel support
for the feature. Older kernels will return ENOPROTOOPT.

Signed-off-by: Willem de Bruijn &lt;willemb@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>signal: Remove kernel interal si_code magic</title>
<updated>2017-07-24T19:30:28Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2017-07-17T03:36:59Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=cc731525f26af85a1c3537da41e0abd1d35e0bdb'/>
<id>urn:sha1:cc731525f26af85a1c3537da41e0abd1d35e0bdb</id>
<content type='text'>
struct siginfo is a union and the kernel since 2.4 has been hiding a union
tag in the high 16bits of si_code using the values:
__SI_KILL
__SI_TIMER
__SI_POLL
__SI_FAULT
__SI_CHLD
__SI_RT
__SI_MESGQ
__SI_SYS

While this looks plausible on the surface, in practice this situation has
not worked well.

- Injected positive signals are not copied to user space properly
  unless they have these magic high bits set.

- Injected positive signals are not reported properly by signalfd
  unless they have these magic high bits set.

- These kernel internal values leaked to userspace via ptrace_peek_siginfo

- It was possible to inject these kernel internal values and cause the
  the kernel to misbehave.

- Kernel developers got confused and expected these kernel internal values
  in userspace in kernel self tests.

- Kernel developers got confused and set si_code to __SI_FAULT which
  is SI_USER in userspace which causes userspace to think an ordinary user
  sent the signal and that it was not kernel generated.

- The values make it impossible to reorganize the code to transform
  siginfo_copy_to_user into a plain copy_to_user.  As si_code must
  be massaged before being passed to userspace.

So remove these kernel internal si codes and make the kernel code simpler
and more maintainable.

To replace these kernel internal magic si_codes introduce the helper
function siginfo_layout, that takes a signal number and an si_code and
computes which union member of siginfo is being used.  Have
siginfo_layout return an enumeration so that gcc will have enough
information to warn if a switch statement does not handle all of union
members.

A couple of architectures have a messed up ABI that defines signal
specific duplications of SI_USER which causes more special cases in
siginfo_layout than I would like.  The good news is only problem
architectures pay the cost.

Update all of the code that used the previous magic __SI_ values to
use the new SIL_ values and to call siginfo_layout to get those
values.  Escept where not all of the cases are handled remove the
defaults in the switch statements so that if a new case is missed in
the future the lack will show up at compile time.

Modify the code that copies siginfo si_code to userspace to just copy
the value and not cast si_code to a short first.  The high bits are no
longer used to hold a magic union member.

Fixup the siginfo header files to stop including the __SI_ values in
their constants and for the headers that were missing it to properly
update the number of si_codes for each signal type.

The fixes to copy_siginfo_from_user32 implementations has the
interesting property that several of them perviously should never have
worked as the __SI_ values they depended up where kernel internal.
With that dependency gone those implementations should work much
better.

The idea of not passing the __SI_ values out to userspace and then
not reinserting them has been tested with criu and criu worked without
changes.

Ref: 2.4.0-test1
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</content>
</entry>
<entry>
<title>fcntl: Don't use ambiguous SIG_POLL si_codes</title>
<updated>2017-07-24T19:29:23Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2017-06-29T14:28:50Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=d08477aa975e97f1dc64c0ae59cebf98520456ce'/>
<id>urn:sha1:d08477aa975e97f1dc64c0ae59cebf98520456ce</id>
<content type='text'>
We have a weird and problematic intersection of features that when
they all come together result in ambiguous siginfo values, that
we can not support properly.

- Supporting fcntl(F_SETSIG,...) with arbitrary valid signals.

- Using positive values for POLL_IN, POLL_OUT, POLL_MSG, ..., etc
  that imply they are signal specific si_codes and using the
  aforementioned arbitrary signal to deliver them.

- Supporting injection of arbitrary siginfo values for debugging and
  checkpoint/restore.

The result is that just looking at siginfo si_codes of 1 to 6 are
ambigious.  It could either be a signal specific si_code or it could
be a generic si_code.

For most of the kernel this is a non-issue but for sending signals
with siginfo it is impossible to play back the kernel signals and
get the same result.

Strictly speaking when the si_code was changed from SI_SIGIO to
POLL_IN and friends between 2.2 and 2.4 this functionality was not
ambiguous, as only real time signals were supported.  Before 2.4 was
released the kernel began supporting siginfo with non realtime signals
so they could give details of why the signal was sent.

The result is that if F_SETSIG is set to one of the signals with signal
specific si_codes then user space can not know why the signal was sent.

I grepped through a bunch of userspace programs using debian code
search to get a feel for how often people choose a signal that results
in an ambiguous si_code.  I only found one program doing so and it was
using SIGCHLD to test the F_SETSIG functionality, and did not appear
to be a real world usage.

Therefore the ambiguity does not appears to be a real world problem in
practice.  Remove the ambiguity while introducing the smallest chance
of breakage by changing the si_code to SI_SIGIO when signals with
signal specific si_codes are targeted.

Fixes: v2.3.40 -- Added support for queueing non-rt signals
Fixes: v2.3.21 -- Changed the si_code from SI_SIGIO
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</content>
</entry>
<entry>
<title>tty: Fix TIOCGPTPEER ioctl definition</title>
<updated>2017-07-17T15:04:41Z</updated>
<author>
<name>Gleb Fotengauer-Malinovskiy</name>
<email>glebfm@altlinux.org</email>
</author>
<published>2017-07-17T13:29:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c6325179238f1d4683edbec53d8322575d76d7e2'/>
<id>urn:sha1:c6325179238f1d4683edbec53d8322575d76d7e2</id>
<content type='text'>
This ioctl does nothing to justify an _IOC_READ or _IOC_WRITE flag
because it doesn't copy anything from/to userspace to access the
argument.

Fixes: 54ebbfb16034 ("tty: add TIOCGPTPEER ioctl")
Signed-off-by: Gleb Fotengauer-Malinovskiy &lt;glebfm@altlinux.org&gt;
Acked-by: Aleksa Sarai &lt;asarai@suse.de&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
