<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arm64/include/asm, 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 'syscalls-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic</title>
<updated>2019-04-23T20:34:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-04-23T20:34:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d286e13d53f54b00bcd7443eedd067cd432cf547'/>
<id>d286e13d53f54b00bcd7443eedd067cd432cf547</id>
<content type='text'>
Pull syscall numbering updates from Arnd Bergmann:
 "arch: add pidfd and io_uring syscalls everywhere

  This comes a bit late, but should be in 5.1 anyway: we want the newly
  added system calls to be synchronized across all architectures in the
  release.

  I hope that in the future, any newly added system calls can be added
  to all architectures at the same time, and tested there while they are
  in linux-next, avoiding dependencies between the architecture
  maintainer trees and the tree that contains the new system call"

* tag 'syscalls-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  arch: add pidfd and io_uring syscalls everywhere
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull syscall numbering updates from Arnd Bergmann:
 "arch: add pidfd and io_uring syscalls everywhere

  This comes a bit late, but should be in 5.1 anyway: we want the newly
  added system calls to be synchronized across all architectures in the
  release.

  I hope that in the future, any newly added system calls can be added
  to all architectures at the same time, and tested there while they are
  in linux-next, avoiding dependencies between the architecture
  maintainer trees and the tree that contains the new system call"

* tag 'syscalls-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  arch: add pidfd and io_uring syscalls everywhere
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: futex: Restore oldval initialization to work around buggy compilers</title>
<updated>2019-04-18T17:17:08+00:00</updated>
<author>
<name>Nathan Chancellor</name>
<email>natechancellor@gmail.com</email>
</author>
<published>2019-04-17T07:21:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ff8acf929014b7f87315588e0daf8597c8aa9d1c'/>
<id>ff8acf929014b7f87315588e0daf8597c8aa9d1c</id>
<content type='text'>
Commit 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with
non-zero result value") removed oldval's zero initialization in
arch_futex_atomic_op_inuser because it is not necessary. Unfortunately,
Android's arm64 GCC 4.9.4 [1] does not agree:

../kernel/futex.c: In function 'do_futex':
../kernel/futex.c:1658:17: warning: 'oldval' may be used uninitialized
in this function [-Wmaybe-uninitialized]
   return oldval == cmparg;
                 ^
In file included from ../kernel/futex.c:73:0:
../arch/arm64/include/asm/futex.h:53:6: note: 'oldval' was declared here
  int oldval, ret, tmp;
      ^

GCC fails to follow that when ret is non-zero, futex_atomic_op_inuser
returns right away, avoiding the uninitialized use that it claims.
Restoring the zero initialization works around this issue.

[1]: https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/

Cc: stable@vger.kernel.org
Fixes: 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value")
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with
non-zero result value") removed oldval's zero initialization in
arch_futex_atomic_op_inuser because it is not necessary. Unfortunately,
Android's arm64 GCC 4.9.4 [1] does not agree:

../kernel/futex.c: In function 'do_futex':
../kernel/futex.c:1658:17: warning: 'oldval' may be used uninitialized
in this function [-Wmaybe-uninitialized]
   return oldval == cmparg;
                 ^
In file included from ../kernel/futex.c:73:0:
../arch/arm64/include/asm/futex.h:53:6: note: 'oldval' was declared here
  int oldval, ret, tmp;
      ^

GCC fails to follow that when ret is non-zero, futex_atomic_op_inuser
returns right away, avoiding the uninitialized use that it claims.
Restoring the zero initialization works around this issue.

[1]: https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/

Cc: stable@vger.kernel.org
Fixes: 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value")
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: add pidfd and io_uring syscalls everywhere</title>
<updated>2019-04-15T14:31:17+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2019-02-28T12:59:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=39036cd2727395c3369b1051005da74059a85317'/>
<id>39036cd2727395c3369b1051005da74059a85317</id>
<content type='text'>
Add the io_uring and pidfd_send_signal system calls to all architectures.

These system calls are designed to handle both native and compat tasks,
so all entries are the same across architectures, only arm-compat and
the generic tale still use an old format.

Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Acked-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt; (s390)
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>
Add the io_uring and pidfd_send_signal system calls to all architectures.

These system calls are designed to handle both native and compat tasks,
so all entries are the same across architectures, only arm-compat and
the generic tale still use an old format.

Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Acked-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt; (s390)
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>arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value</title>
<updated>2019-04-12T14:04:33+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2019-04-08T11:45:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=045afc24124d80c6998d9c770844c67912083506'/>
<id>045afc24124d80c6998d9c770844c67912083506</id>
<content type='text'>
Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
explicitly set the return value on the non-faulting path and instead
leaves it holding the result of the underlying atomic operation. This
means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
value will be reported as having failed. Regrettably, I wrote the buggy
code back in 2011 and it was upstreamed as part of the initial arm64
support in 2012.

The reasons we appear to get away with this are:

  1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
     exercised by futex() test applications

  2. If the result of the atomic operation is zero, the system call
     behaves correctly

  3. Prior to version 2.25, the only operation used by GLIBC set the
     futex to zero, and therefore worked as expected. From 2.25 onwards,
     FUTEX_WAKE_OP is not used by GLIBC at all.

Fix the implementation by ensuring that the return value is either 0
to indicate that the atomic operation completed successfully, or -EFAULT
if we encountered a fault when accessing the user mapping.

Cc: &lt;stable@kernel.org&gt;
Fixes: 6170a97460db ("arm64: Atomic operations")
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
explicitly set the return value on the non-faulting path and instead
leaves it holding the result of the underlying atomic operation. This
means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
value will be reported as having failed. Regrettably, I wrote the buggy
code back in 2011 and it was upstreamed as part of the initial arm64
support in 2012.

The reasons we appear to get away with this are:

  1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
     exercised by futex() test applications

  2. If the result of the atomic operation is zero, the system call
     behaves correctly

  3. Prior to version 2.25, the only operation used by GLIBC set the
     futex to zero, and therefore worked as expected. From 2.25 onwards,
     FUTEX_WAKE_OP is not used by GLIBC at all.

Fix the implementation by ensuring that the return value is either 0
to indicate that the atomic operation completed successfully, or -EFAULT
if we encountered a fault when accessing the user mapping.

Cc: &lt;stable@kernel.org&gt;
Fixes: 6170a97460db ("arm64: Atomic operations")
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64/ftrace: fix inadvertent BUG() in trampoline check</title>
<updated>2019-04-08T15:58:13+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2019-04-07T19:06:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5a3ae7b314a2259b1188b22b392f5eba01e443ee'/>
<id>5a3ae7b314a2259b1188b22b392f5eba01e443ee</id>
<content type='text'>
The ftrace trampoline code (which deals with modules loaded out of
BL range of the core kernel) uses plt_entries_equal() to check whether
the per-module trampoline equals a zero buffer, to decide whether the
trampoline has already been initialized.

This triggers a BUG() in the opcode manipulation code, since we end
up checking the ADRP offset of a 0x0 opcode, which is not an ADRP
instruction.

So instead, add a helper to check whether a PLT is initialized, and
call that from the frace code.

Cc: &lt;stable@vger.kernel.org&gt; # v5.0
Fixes: bdb85cd1d206 ("arm64/module: switch to ADRP/ADD sequences for PLT entries")
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ftrace trampoline code (which deals with modules loaded out of
BL range of the core kernel) uses plt_entries_equal() to check whether
the per-module trampoline equals a zero buffer, to decide whether the
trampoline has already been initialized.

This triggers a BUG() in the opcode manipulation code, since we end
up checking the ADRP offset of a 0x0 opcode, which is not an ADRP
instruction.

So instead, add a helper to check whether a PLT is initialized, and
call that from the frace code.

Cc: &lt;stable@vger.kernel.org&gt; # v5.0
Fixes: bdb85cd1d206 ("arm64/module: switch to ADRP/ADD sequences for PLT entries")
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>syscalls: Remove start and number from syscall_set_arguments() args</title>
<updated>2019-04-05T13:27:23+00:00</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2019-03-28T00:07:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=32d92586629a8b3637a3c9361709818e25f327ad'/>
<id>32d92586629a8b3637a3c9361709818e25f327ad</id>
<content type='text'>
After removing the start and count arguments of syscall_get_arguments() it
seems reasonable to remove them from syscall_set_arguments(). Note, as of
today, there are no users of syscall_set_arguments(). But we are told that
there will be soon. But for now, at least make it consistent with
syscall_get_arguments().

Link: http://lkml.kernel.org/r/20190327222014.GA32540@altlinux.org

Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Cc: Dave Martin &lt;dave.martin@arm.com&gt;
Cc: "Dmitry V. Levin" &lt;ldv@altlinux.org&gt;
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt; # For xtensa changes
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt; # For the arm64 bits
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt; # for x86
Reviewed-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After removing the start and count arguments of syscall_get_arguments() it
seems reasonable to remove them from syscall_set_arguments(). Note, as of
today, there are no users of syscall_set_arguments(). But we are told that
there will be soon. But for now, at least make it consistent with
syscall_get_arguments().

Link: http://lkml.kernel.org/r/20190327222014.GA32540@altlinux.org

Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Cc: Dave Martin &lt;dave.martin@arm.com&gt;
Cc: "Dmitry V. Levin" &lt;ldv@altlinux.org&gt;
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt; # For xtensa changes
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt; # For the arm64 bits
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt; # for x86
Reviewed-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>syscalls: Remove start and number from syscall_get_arguments() args</title>
<updated>2019-04-05T13:26:43+00:00</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2016-11-07T21:26:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b35f549df1d7520d37ba1e6d4a8d4df6bd52d136'/>
<id>b35f549df1d7520d37ba1e6d4a8d4df6bd52d136</id>
<content type='text'>
At Linux Plumbers, Andy Lutomirski approached me and pointed out that the
function call syscall_get_arguments() implemented in x86 was horribly
written and not optimized for the standard case of passing in 0 and 6 for
the starting index and the number of system calls to get. When looking at
all the users of this function, I discovered that all instances pass in only
0 and 6 for these arguments. Instead of having this function handle
different cases that are never used, simply rewrite it to return the first 6
arguments of a system call.

This should help out the performance of tracing system calls by ptrace,
ftrace and perf.

Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org

Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Cc: Dave Martin &lt;dave.martin@arm.com&gt;
Cc: "Dmitry V. Levin" &lt;ldv@altlinux.org&gt;
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Paul Burton &lt;paul.burton@mips.com&gt; # MIPS parts
Acked-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt; # For xtensa changes
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt; # For the arm64 bits
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt; # for x86
Reviewed-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Reported-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
At Linux Plumbers, Andy Lutomirski approached me and pointed out that the
function call syscall_get_arguments() implemented in x86 was horribly
written and not optimized for the standard case of passing in 0 and 6 for
the starting index and the number of system calls to get. When looking at
all the users of this function, I discovered that all instances pass in only
0 and 6 for these arguments. Instead of having this function handle
different cases that are never used, simply rewrite it to return the first 6
arguments of a system call.

This should help out the performance of tracing system calls by ptrace,
ftrace and perf.

Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org

Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Cc: Dave Martin &lt;dave.martin@arm.com&gt;
Cc: "Dmitry V. Levin" &lt;ldv@altlinux.org&gt;
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Paul Burton &lt;paul.burton@mips.com&gt; # MIPS parts
Acked-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt; # For xtensa changes
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt; # For the arm64 bits
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt; # for x86
Reviewed-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Reported-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'kvmarm-fixes-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master</title>
<updated>2019-03-28T18:07:30+00:00</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2019-03-28T18:07:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=690edec54cbaa0e98dc592aae6864272f48f3c84'/>
<id>690edec54cbaa0e98dc592aae6864272f48f3c84</id>
<content type='text'>
KVM/ARM fixes for 5.1

- Fix THP handling in the presence of pre-existing PTEs
- Honor request for PTE mappings even when THPs are available
- GICv4 performance improvement
- Take the srcu lock when writing to guest-controlled ITS data structures
- Reset the virtual PMU in preemptible context
- Various cleanups
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
KVM/ARM fixes for 5.1

- Fix THP handling in the presence of pre-existing PTEs
- Honor request for PTE mappings even when THPs are available
- GICv4 performance improvement
- Take the srcu lock when writing to guest-controlled ITS data structures
- Reset the virtual PMU in preemptible context
- Various cleanups
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: arm/arm64: vgic-its: Take the srcu lock when writing to guest memory</title>
<updated>2019-03-19T17:56:56+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>marc.zyngier@arm.com</email>
</author>
<published>2019-03-19T12:47:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a6ecfb11bf37743c1ac49b266595582b107b61d4'/>
<id>a6ecfb11bf37743c1ac49b266595582b107b61d4</id>
<content type='text'>
When halting a guest, QEMU flushes the virtual ITS caches, which
amounts to writing to the various tables that the guest has allocated.

When doing this, we fail to take the srcu lock, and the kernel
shouts loudly if running a lockdep kernel:

[   69.680416] =============================
[   69.680819] WARNING: suspicious RCU usage
[   69.681526] 5.1.0-rc1-00008-g600025238f51-dirty #18 Not tainted
[   69.682096] -----------------------------
[   69.682501] ./include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
[   69.683225]
[   69.683225] other info that might help us debug this:
[   69.683225]
[   69.683975]
[   69.683975] rcu_scheduler_active = 2, debug_locks = 1
[   69.684598] 6 locks held by qemu-system-aar/4097:
[   69.685059]  #0: 0000000034196013 (&amp;kvm-&gt;lock){+.+.}, at: vgic_its_set_attr+0x244/0x3a0
[   69.686087]  #1: 00000000f2ed935e (&amp;its-&gt;its_lock){+.+.}, at: vgic_its_set_attr+0x250/0x3a0
[   69.686919]  #2: 000000005e71ea54 (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.687698]  #3: 00000000c17e548d (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.688475]  #4: 00000000ba386017 (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.689978]  #5: 00000000c2c3c335 (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.690729]
[   69.690729] stack backtrace:
[   69.691151] CPU: 2 PID: 4097 Comm: qemu-system-aar Not tainted 5.1.0-rc1-00008-g600025238f51-dirty #18
[   69.691984] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[   69.692831] Call trace:
[   69.694072]  lockdep_rcu_suspicious+0xcc/0x110
[   69.694490]  gfn_to_memslot+0x174/0x190
[   69.694853]  kvm_write_guest+0x50/0xb0
[   69.695209]  vgic_its_save_tables_v0+0x248/0x330
[   69.695639]  vgic_its_set_attr+0x298/0x3a0
[   69.696024]  kvm_device_ioctl_attr+0x9c/0xd8
[   69.696424]  kvm_device_ioctl+0x8c/0xf8
[   69.696788]  do_vfs_ioctl+0xc8/0x960
[   69.697128]  ksys_ioctl+0x8c/0xa0
[   69.697445]  __arm64_sys_ioctl+0x28/0x38
[   69.697817]  el0_svc_common+0xd8/0x138
[   69.698173]  el0_svc_handler+0x38/0x78
[   69.698528]  el0_svc+0x8/0xc

The fix is to obviously take the srcu lock, just like we do on the
read side of things since bf308242ab98. One wonders why this wasn't
fixed at the same time, but hey...

Fixes: bf308242ab98 ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock")
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When halting a guest, QEMU flushes the virtual ITS caches, which
amounts to writing to the various tables that the guest has allocated.

When doing this, we fail to take the srcu lock, and the kernel
shouts loudly if running a lockdep kernel:

[   69.680416] =============================
[   69.680819] WARNING: suspicious RCU usage
[   69.681526] 5.1.0-rc1-00008-g600025238f51-dirty #18 Not tainted
[   69.682096] -----------------------------
[   69.682501] ./include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
[   69.683225]
[   69.683225] other info that might help us debug this:
[   69.683225]
[   69.683975]
[   69.683975] rcu_scheduler_active = 2, debug_locks = 1
[   69.684598] 6 locks held by qemu-system-aar/4097:
[   69.685059]  #0: 0000000034196013 (&amp;kvm-&gt;lock){+.+.}, at: vgic_its_set_attr+0x244/0x3a0
[   69.686087]  #1: 00000000f2ed935e (&amp;its-&gt;its_lock){+.+.}, at: vgic_its_set_attr+0x250/0x3a0
[   69.686919]  #2: 000000005e71ea54 (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.687698]  #3: 00000000c17e548d (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.688475]  #4: 00000000ba386017 (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.689978]  #5: 00000000c2c3c335 (&amp;vcpu-&gt;mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.690729]
[   69.690729] stack backtrace:
[   69.691151] CPU: 2 PID: 4097 Comm: qemu-system-aar Not tainted 5.1.0-rc1-00008-g600025238f51-dirty #18
[   69.691984] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[   69.692831] Call trace:
[   69.694072]  lockdep_rcu_suspicious+0xcc/0x110
[   69.694490]  gfn_to_memslot+0x174/0x190
[   69.694853]  kvm_write_guest+0x50/0xb0
[   69.695209]  vgic_its_save_tables_v0+0x248/0x330
[   69.695639]  vgic_its_set_attr+0x298/0x3a0
[   69.696024]  kvm_device_ioctl_attr+0x9c/0xd8
[   69.696424]  kvm_device_ioctl+0x8c/0xf8
[   69.696788]  do_vfs_ioctl+0xc8/0x960
[   69.697128]  ksys_ioctl+0x8c/0xa0
[   69.697445]  __arm64_sys_ioctl+0x28/0x38
[   69.697817]  el0_svc_common+0xd8/0x138
[   69.698173]  el0_svc_handler+0x38/0x78
[   69.698528]  el0_svc+0x8/0xc

The fix is to obviously take the srcu lock, just like we do on the
read side of things since bf308242ab98. One wonders why this wasn't
fixed at the same time, but hey...

Fixes: bf308242ab98 ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock")
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Add MIDR encoding for HiSilicon Taishan CPUs</title>
<updated>2019-03-19T14:55:10+00:00</updated>
<author>
<name>Hanjun Guo</name>
<email>hanjun.guo@linaro.org</email>
</author>
<published>2019-03-05T13:40:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=efd00c722ca855745fcc35a7e6675b5a782a3fc8'/>
<id>efd00c722ca855745fcc35a7e6675b5a782a3fc8</id>
<content type='text'>
Adding the MIDR encodings for HiSilicon Taishan v110 CPUs,
which is used in Kunpeng ARM64 server SoCs. TSV110 is the
abbreviation of Taishan v110.

Signed-off-by: Hanjun Guo &lt;hanjun.guo@linaro.org&gt;
Reviewed-by: John Garry &lt;john.garry@huawei.com&gt;
Reviewed-by: Zhangshaokun &lt;zhangshaokun@hisilicon.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding the MIDR encodings for HiSilicon Taishan v110 CPUs,
which is used in Kunpeng ARM64 server SoCs. TSV110 is the
abbreviation of Taishan v110.

Signed-off-by: Hanjun Guo &lt;hanjun.guo@linaro.org&gt;
Reviewed-by: John Garry &lt;john.garry@huawei.com&gt;
Reviewed-by: Zhangshaokun &lt;zhangshaokun@hisilicon.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
