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<title>blackbird-obmc-linux/arch/xtensa/include/uapi, branch dev-5.0-raptor-04-16-2019</title>
<subtitle>Blackbird™ Linux sources for OpenBMC</subtitle>
<id>https://git.raptorcs.com/git/blackbird-obmc-linux/atom?h=dev-5.0-raptor-04-16-2019</id>
<link rel='self' href='https://git.raptorcs.com/git/blackbird-obmc-linux/atom?h=dev-5.0-raptor-04-16-2019'/>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/'/>
<updated>2019-01-06T01:22:15+00:00</updated>
<entry>
<title>arch: remove redundant UAPI generic-y defines</title>
<updated>2019-01-06T01:22:15+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-01-03T01:10:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=d6e4b3e326d8b44675b9e19534347d97073826aa'/>
<id>urn:sha1:d6e4b3e326d8b44675b9e19534347d97073826aa</id>
<content type='text'>
Now that Kbuild automatically creates asm-generic wrappers for missing
mandatory headers, it is redundant to list the same headers in
generic-y and mandatory-y.

Suggested-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
</content>
</entry>
<entry>
<title>arch: remove stale comments "UAPI Header export list"</title>
<updated>2019-01-06T00:46:51+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-01-03T01:10:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=d4ce5458ea1b7d8ca49c436d602095c4912777d3'/>
<id>urn:sha1:d4ce5458ea1b7d8ca49c436d602095c4912777d3</id>
<content type='text'>
These comments are leftovers of commit fcc8487d477a ("uapi: export all
headers under uapi directories").

Prior to that commit, exported headers must be explicitly added to
header-y. Now, all headers under the uapi/ directories are exported.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</content>
</entry>
<entry>
<title>xtensa: implement task_user_regset_view</title>
<updated>2018-12-17T21:48:21+00:00</updated>
<author>
<name>Max Filippov</name>
<email>jcmvbkbc@gmail.com</email>
</author>
<published>2018-11-10T03:32:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=06fbac8e8971f2fa526e189304dd95ee62f39dbe'/>
<id>urn:sha1:06fbac8e8971f2fa526e189304dd95ee62f39dbe</id>
<content type='text'>
- define struct user_pt_regs in the arch/xtensa/include/uapi/asm/ptrace.h
  with the same layout as xtensa_gregset_t; make xtensa_gregset_t a
  typedef;
- define REGSET_GPR regset, implement register get and set functions;
- define task_user_regset_view function and expose REGSET_GPR.

Signed-off-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
</content>
</entry>
<entry>
<title>xtensa: generate uapi header and syscall table header files</title>
<updated>2018-12-03T07:45:41+00:00</updated>
<author>
<name>Firoz Khan</name>
<email>firoz.khan@linaro.org</email>
</author>
<published>2018-11-13T10:19:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=5eacadb5e66b2b100695777ee7d68d8a2d9bd25c'/>
<id>urn:sha1:5eacadb5e66b2b100695777ee7d68d8a2d9bd25c</id>
<content type='text'>
System call table generation script must be run to gener-
ate unistd_32.h and syscall_table.h files. This patch will
have changes which will invokes the script.

This patch will generate unistd_32.h and syscall_table.h
files by the syscall table generation script invoked by
xtensa/Makefile and the generated files against the removed
files must be identical.

The generated uapi header file will be included in uapi/-
asm/unistd.h and generated system call table header file
will be included by kernel/syscall.c file.

Signed-off-by: Firoz Khan &lt;firoz.khan@linaro.org&gt;
Signed-off-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
</content>
</entry>
<entry>
<title>xtensa: add __NR_syscalls along with __NR_syscall_count</title>
<updated>2018-12-03T07:45:21+00:00</updated>
<author>
<name>Firoz Khan</name>
<email>firoz.khan@linaro.org</email>
</author>
<published>2018-11-13T10:19:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=a86067f587a9460e5f004469d183a76d3a2ab068'/>
<id>urn:sha1:a86067f587a9460e5f004469d183a76d3a2ab068</id>
<content type='text'>
__NR_syscall_count macro holds the number of system call
exist in xtensa architecture. We have to change the value
of __NR_syscall_count, if we add or delete a system call.

One of the patch in this patch series has a script which
will generate a uapi header based on syscall.tbl file.
The syscall.tbl file contains the total number of system
calls information. So we have two option to update __NR-
_syscall_count value.

1. Update __NR_syscall_count in asm/unistd.h manually by
   counting the no.of system calls. No need to update __NR-
   _syscall_count until we either add a new system call or
   delete existing system call.

2. We can keep this feature it above mentioned script,
   that will count the number of syscalls and keep it in
   a generated file. In this case we don't need to expli-
   citly update __NR_syscall_count in asm/unistd.h file.

The 2nd option will be the recommended one. For that, I
added the __NR_syscalls macro in uapi/asm/unistd.h.
The macro __NR_syscalls also added for making the name
convention same across all architecture. While __NR_syscalls
isn't strictly part of the uapi, having it as part of the
generated header to simplifies the implementation. We also
need to enclose this macro with #ifdef __KERNEL__ to avoid
side effects.

Signed-off-by: Firoz Khan &lt;firoz.khan@linaro.org&gt;
Signed-off-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
[Max: Drop __NR_syscall_count completely, use __NR_syscalls instead]
</content>
</entry>
<entry>
<title>tty/serial_core: add ISO7816 infrastructure</title>
<updated>2018-10-02T20:38:55+00:00</updated>
<author>
<name>Nicolas Ferre</name>
<email>nicolas.ferre@microchip.com</email>
</author>
<published>2018-09-26T12:58:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=ad8c0eaa0a418ae8ef3f9217638bb86439399eac'/>
<id>urn:sha1:ad8c0eaa0a418ae8ef3f9217638bb86439399eac</id>
<content type='text'>
Add the ISO7816 ioctl and associated accessors and data structure.
Drivers can then use this common implementation to handle ISO7816
(smart cards).

Signed-off-by: Nicolas Ferre &lt;nicolas.ferre@microchip.com&gt;
[ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes]
Signed-off-by: Ludovic Desroches &lt;ludovic.desroches@microchip.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net: Add a new socket option for a future transmit time.</title>
<updated>2018-07-04T13:30:27+00:00</updated>
<author>
<name>Richard Cochran</name>
<email>rcochran@linutronix.de</email>
</author>
<published>2018-07-03T22:42:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=80b14dee2bea128928537d61c333f24cb8cbb62f'/>
<id>urn:sha1:80b14dee2bea128928537d61c333f24cb8cbb62f</id>
<content type='text'>
This patch introduces SO_TXTIME. User space enables this option in
order to pass a desired future transmit time in a CMSG when calling
sendmsg(2). The argument to this socket option is a 8-bytes long struct
provided by the uapi header net_tstamp.h defined as:

struct sock_txtime {
	clockid_t 	clockid;
	u32		flags;
};

Note that new fields were added to struct sock by filling a 2-bytes
hole found in the struct. For that reason, neither the struct size or
number of cachelines were altered.

Signed-off-by: Richard Cochran &lt;rcochran@linutronix.de&gt;
Signed-off-by: Jesus Sanchez-Palencia &lt;jesus.sanchez-palencia@intel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>y2038: xtensa: Extend sysvipc data structures</title>
<updated>2018-04-20T14:20:15+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2015-05-05T21:19:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=b497ef570ecdeeaef4335ecc4f712cbaae0918a5'/>
<id>urn:sha1:b497ef570ecdeeaef4335ecc4f712cbaae0918a5</id>
<content type='text'>
xtensa, uses a nonstandard variation of the generic sysvipc
data structures, intended to have the padding moved around
so it can deal with big-endian 32-bit user space that has
64-bit time_t.

xtensa tries hard to define the structures so they work
in both big-endian and little-endian systems with padding
on the right side.
However, they only succeeded for for two of the three structures,
and their struct shmid64_ds ended up being defined in two
identical copies, and the big-endian one is wrong.

This takes just take the same approach here that we have for
the asm-generic headers and adds separate 32-bit fields for the
upper halves of the timestamps, to let libc deal with the mess
in user space.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
</entry>
<entry>
<title>mm: introduce MAP_FIXED_NOREPLACE</title>
<updated>2018-04-11T17:28:38+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2018-04-10T23:35:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=a4ff8e8620d3f4f50ac4b41e8067b7d395056843'/>
<id>urn:sha1:a4ff8e8620d3f4f50ac4b41e8067b7d395056843</id>
<content type='text'>
Patch series "mm: introduce MAP_FIXED_NOREPLACE", v2.

This has started as a follow up discussion [3][4] resulting in the
runtime failure caused by hardening patch [5] which removes MAP_FIXED
from the elf loader because MAP_FIXED is inherently dangerous as it
might silently clobber an existing underlying mapping (e.g.  stack).
The reason for the failure is that some architectures enforce an
alignment for the given address hint without MAP_FIXED used (e.g.  for
shared or file backed mappings).

One way around this would be excluding those archs which do alignment
tricks from the hardening [6].  The patch is really trivial but it has
been objected, rightfully so, that this screams for a more generic
solution.  We basically want a non-destructive MAP_FIXED.

The first patch introduced MAP_FIXED_NOREPLACE which enforces the given
address but unlike MAP_FIXED it fails with EEXIST if the given range
conflicts with an existing one.  The flag is introduced as a completely
new one rather than a MAP_FIXED extension because of the backward
compatibility.  We really want a never-clobber semantic even on older
kernels which do not recognize the flag.  Unfortunately mmap sucks
wrt flags evaluation because we do not EINVAL on unknown flags.  On
those kernels we would simply use the traditional hint based semantic so
the caller can still get a different address (which sucks) but at least
not silently corrupt an existing mapping.  I do not see a good way
around that.  Except we won't export expose the new semantic to the
userspace at all.

It seems there are users who would like to have something like that.
Jemalloc has been mentioned by Michael Ellerman [7]

Florian Weimer has mentioned the following:
: glibc ld.so currently maps DSOs without hints.  This means that the kernel
: will map right next to each other, and the offsets between them a completely
: predictable.  We would like to change that and supply a random address in a
: window of the address space.  If there is a conflict, we do not want the
: kernel to pick a non-random address. Instead, we would try again with a
: random address.

John Hubbard has mentioned CUDA example
: a) Searches /proc/&lt;pid&gt;/maps for a "suitable" region of available
: VA space.  "Suitable" generally means it has to have a base address
: within a certain limited range (a particular device model might
: have odd limitations, for example), it has to be large enough, and
: alignment has to be large enough (again, various devices may have
: constraints that lead us to do this).
:
: This is of course subject to races with other threads in the process.
:
: Let's say it finds a region starting at va.
:
: b) Next it does:
:     p = mmap(va, ...)
:
: *without* setting MAP_FIXED, of course (so va is just a hint), to
: attempt to safely reserve that region. If p != va, then in most cases,
: this is a failure (almost certainly due to another thread getting a
: mapping from that region before we did), and so this layer now has to
: call munmap(), before returning a "failure: retry" to upper layers.
:
:     IMPROVEMENT: --&gt; if instead, we could call this:
:
:             p = mmap(va, ... MAP_FIXED_NOREPLACE ...)
:
:         , then we could skip the munmap() call upon failure. This
:         is a small thing, but it is useful here. (Thanks to Piotr
:         Jaroszynski and Mark Hairgrove for helping me get that detail
:         exactly right, btw.)
:
: c) After that, CUDA suballocates from p, via:
:
:      q = mmap(sub_region_start, ... MAP_FIXED ...)
:
: Interestingly enough, "freeing" is also done via MAP_FIXED, and
: setting PROT_NONE to the subregion. Anyway, I just included (c) for
: general interest.

Atomic address range probing in the multithreaded programs in general
sounds like an interesting thing to me.

The second patch simply replaces MAP_FIXED use in elf loader by
MAP_FIXED_NOREPLACE.  I believe other places which rely on MAP_FIXED
should follow.  Actually real MAP_FIXED usages should be docummented
properly and they should be more of an exception.

[1] http://lkml.kernel.org/r/20171116101900.13621-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/20171129144219.22867-1-mhocko@kernel.org
[3] http://lkml.kernel.org/r/20171107162217.382cd754@canb.auug.org.au
[4] http://lkml.kernel.org/r/1510048229.12079.7.camel@abdul.in.ibm.com
[5] http://lkml.kernel.org/r/20171023082608.6167-1-mhocko@kernel.org
[6] http://lkml.kernel.org/r/20171113094203.aofz2e7kueitk55y@dhcp22.suse.cz
[7] http://lkml.kernel.org/r/87efp1w7vy.fsf@concordia.ellerman.id.au

This patch (of 2):

MAP_FIXED is used quite often to enforce mapping at the particular range.
The main problem of this flag is, however, that it is inherently dangerous
because it unmaps existing mappings covered by the requested range.  This
can cause silent memory corruptions.  Some of them even with serious
security implications.  While the current semantic might be really
desiderable in many cases there are others which would want to enforce the
given range but rather see a failure than a silent memory corruption on a
clashing range.  Please note that there is no guarantee that a given range
is obeyed by the mmap even when it is free - e.g.  arch specific code is
allowed to apply an alignment.

Introduce a new MAP_FIXED_NOREPLACE flag for mmap to achieve this
behavior.  It has the same semantic as MAP_FIXED wrt.  the given address
request with a single exception that it fails with EEXIST if the requested
address is already covered by an existing mapping.  We still do rely on
get_unmaped_area to handle all the arch specific MAP_FIXED treatment and
check for a conflicting vma after it returns.

The flag is introduced as a completely new one rather than a MAP_FIXED
extension because of the backward compatibility.  We really want a
never-clobber semantic even on older kernels which do not recognize the
flag.  Unfortunately mmap sucks wrt.  flags evaluation because we do not
EINVAL on unknown flags.  On those kernels we would simply use the
traditional hint based semantic so the caller can still get a different
address (which sucks) but at least not silently corrupt an existing
mapping.  I do not see a good way around that.

[mpe@ellerman.id.au: fix whitespace]
[fail on clashing range with EEXIST as per Florian Weimer]
[set MAP_FIXED before round_hint_to_min as per Khalid Aziz]
Link: http://lkml.kernel.org/r/20171213092550.2774-2-mhocko@kernel.org
Reviewed-by: Khalid Aziz &lt;khalid.aziz@oracle.com&gt;
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Khalid Aziz &lt;khalid.aziz@oracle.com&gt;
Cc: Russell King - ARM Linux &lt;linux@armlinux.org.uk&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Florian Weimer &lt;fweimer@redhat.com&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Abdul Haleem &lt;abdhalee@linux.vnet.ibm.com&gt;
Cc: Joel Stanley &lt;joel@jms.id.au&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Jason Evans &lt;jasone@google.com&gt;
Cc: David Goldblatt &lt;davidtgoldblatt@gmail.com&gt;
Cc: Edward Tomasz Napierała &lt;trasz@FreeBSD.org&gt;
Cc: Anshuman Khandual &lt;khandual@linux.vnet.ibm.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>unify {de,}mangle_poll(), get rid of kernel-side POLL...</title>
<updated>2018-02-11T22:37:22+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2018-02-01T20:13:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-obmc-linux/commit/?id=7a163b2195cda0cddf47b5caf14a7229d4e2bea3'/>
<id>urn:sha1:7a163b2195cda0cddf47b5caf14a7229d4e2bea3</id>
<content type='text'>
except, again, POLLFREE and POLL_BUSY_LOOP.

With this, we finally get to the promised end result:

 - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any
   stray instances of -&gt;poll() still using those will be caught by
   sparse.

 - eventpoll.c and select.c warning-free wrt __poll_t

 - no more kernel-side definitions of POLL... - userland ones are
   visible through the entire kernel (and used pretty much only for
   mangle/demangle)

 - same behavior as after the first series (i.e. sparc et.al. epoll(2)
   working correctly).

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
