<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arm/include, 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>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: export &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt; iif KVM is supported</title>
<updated>2019-03-28T16:27:42+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-03-18T09:08:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3d9683cf3bfb6d4e4605a153958dfca7e18b52f2'/>
<id>3d9683cf3bfb6d4e4605a153958dfca7e18b52f2</id>
<content type='text'>
I do not see any consistency about headers_install of &lt;linux/kvm_para.h&gt;
and &lt;asm/kvm_para.h&gt;.

According to my analysis of Linux 5.1-rc1, there are 3 groups:

 [1] Both &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt; are exported

    alpha, arm, hexagon, mips, powerpc, s390, sparc, x86

 [2] &lt;asm/kvm_para.h&gt; is exported, but &lt;linux/kvm_para.h&gt; is not

    arc, arm64, c6x, h8300, ia64, m68k, microblaze, nios2, openrisc,
    parisc, sh, unicore32, xtensa

 [3] Neither &lt;linux/kvm_para.h&gt; nor &lt;asm/kvm_para.h&gt; is exported

    csky, nds32, riscv

This does not match to the actual KVM support. At least, [2] is
half-baked.

Nor do arch maintainers look like they care about this. For example,
commit 0add53713b1c ("microblaze: Add missing kvm_para.h to Kbuild")
exported &lt;asm/kvm_para.h&gt; to user-space in order to fix an in-kernel
build error.

We have two ways to make this consistent:

 [A] export both &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt; for all
     architectures, irrespective of the KVM support

 [B] Match the header export of &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt;
     to the KVM support

My first attempt was [A] because the code looks cleaner, but Paolo
suggested [B].

So, this commit goes with [B].

For most architectures, &lt;asm/kvm_para.h&gt; was moved to the kernel-space.
I changed include/uapi/linux/Kbuild so that it checks generated
asm/kvm_para.h as well as check-in ones.

After this commit, there will be two groups:

 [1] Both &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt; are exported

    arm, arm64, mips, powerpc, s390, x86

 [2] Neither &lt;linux/kvm_para.h&gt; nor &lt;asm/kvm_para.h&gt; is exported

    alpha, arc, c6x, csky, h8300, hexagon, ia64, m68k, microblaze,
    nds32, nios2, openrisc, parisc, riscv, sh, sparc, unicore32, xtensa

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Cornelia Huck &lt;cohuck@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I do not see any consistency about headers_install of &lt;linux/kvm_para.h&gt;
and &lt;asm/kvm_para.h&gt;.

According to my analysis of Linux 5.1-rc1, there are 3 groups:

 [1] Both &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt; are exported

    alpha, arm, hexagon, mips, powerpc, s390, sparc, x86

 [2] &lt;asm/kvm_para.h&gt; is exported, but &lt;linux/kvm_para.h&gt; is not

    arc, arm64, c6x, h8300, ia64, m68k, microblaze, nios2, openrisc,
    parisc, sh, unicore32, xtensa

 [3] Neither &lt;linux/kvm_para.h&gt; nor &lt;asm/kvm_para.h&gt; is exported

    csky, nds32, riscv

This does not match to the actual KVM support. At least, [2] is
half-baked.

Nor do arch maintainers look like they care about this. For example,
commit 0add53713b1c ("microblaze: Add missing kvm_para.h to Kbuild")
exported &lt;asm/kvm_para.h&gt; to user-space in order to fix an in-kernel
build error.

We have two ways to make this consistent:

 [A] export both &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt; for all
     architectures, irrespective of the KVM support

 [B] Match the header export of &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt;
     to the KVM support

My first attempt was [A] because the code looks cleaner, but Paolo
suggested [B].

So, this commit goes with [B].

For most architectures, &lt;asm/kvm_para.h&gt; was moved to the kernel-space.
I changed include/uapi/linux/Kbuild so that it checks generated
asm/kvm_para.h as well as check-in ones.

After this commit, there will be two groups:

 [1] Both &lt;linux/kvm_para.h&gt; and &lt;asm/kvm_para.h&gt; are exported

    arm, arm64, mips, powerpc, s390, x86

 [2] Neither &lt;linux/kvm_para.h&gt; nor &lt;asm/kvm_para.h&gt; is exported

    alpha, arc, c6x, csky, h8300, hexagon, ia64, m68k, microblaze,
    nds32, nios2, openrisc, parisc, riscv, sh, sparc, unicore32, xtensa

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Cornelia Huck &lt;cohuck@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: arm/arm64: Fix handling of stage2 huge mappings</title>
<updated>2019-03-20T17:29:55+00:00</updated>
<author>
<name>Suzuki K Poulose</name>
<email>suzuki.poulose@arm.com</email>
</author>
<published>2019-03-20T14:57:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3c3736cd32bf5197aed1410ae826d2d254a5b277'/>
<id>3c3736cd32bf5197aed1410ae826d2d254a5b277</id>
<content type='text'>
We rely on the mmu_notifier call backs to handle the split/merge
of huge pages and thus we are guaranteed that, while creating a
block mapping, either the entire block is unmapped at stage2 or it
is missing permission.

However, we miss a case where the block mapping is split for dirty
logging case and then could later be made block mapping, if we cancel the
dirty logging. This not only creates inconsistent TLB entries for
the pages in the the block, but also leakes the table pages for
PMD level.

Handle this corner case for the huge mappings at stage2 by
unmapping the non-huge mapping for the block. This could potentially
release the upper level table. So we need to restart the table walk
once we unmap the range.

Fixes : ad361f093c1e31d ("KVM: ARM: Support hugetlbfs backed huge pages")
Reported-by: Zheng Xiang &lt;zhengxiang9@huawei.com&gt;
Cc: Zheng Xiang &lt;zhengxiang9@huawei.com&gt;
Cc: Zenghui Yu &lt;yuzenghui@huawei.com&gt;
Cc: Christoffer Dall &lt;christoffer.dall@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We rely on the mmu_notifier call backs to handle the split/merge
of huge pages and thus we are guaranteed that, while creating a
block mapping, either the entire block is unmapped at stage2 or it
is missing permission.

However, we miss a case where the block mapping is split for dirty
logging case and then could later be made block mapping, if we cancel the
dirty logging. This not only creates inconsistent TLB entries for
the pages in the the block, but also leakes the table pages for
PMD level.

Handle this corner case for the huge mappings at stage2 by
unmapping the non-huge mapping for the block. This could potentially
release the upper level table. So we need to restart the table walk
once we unmap the range.

Fixes : ad361f093c1e31d ("KVM: ARM: Support hugetlbfs backed huge pages")
Reported-by: Zheng Xiang &lt;zhengxiang9@huawei.com&gt;
Cc: Zheng Xiang &lt;zhengxiang9@huawei.com&gt;
Cc: Zenghui Yu &lt;yuzenghui@huawei.com&gt;
Cc: Christoffer Dall &lt;christoffer.dall@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
</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>Merge tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2019-03-17T20:25:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-17T20:25:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=28d747f266fb73cd28a1b9a174cc3738fc177b00'/>
<id>28d747f266fb73cd28a1b9a174cc3738fc177b00</id>
<content type='text'>
Pull more Kbuild updates from Masahiro Yamada:

 - add more Build-Depends to Debian source package

 - prefix header search paths with $(srctree)/

 - make modpost show verbose section mismatch warnings

 - avoid hard-coded CROSS_COMPILE for h8300

 - fix regression for Debian make-kpkg command

 - add semantic patch to detect missing put_device()

 - fix some warnings of 'make deb-pkg'

 - optimize NOSTDINC_FLAGS evaluation

 - add warnings about redundant generic-y

 - clean up Makefiles and scripts

* tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: remove stale lxdialog/.gitignore
  kbuild: force all architectures except um to include mandatory-y
  kbuild: warn redundant generic-y
  Revert "modsign: Abort modules_install when signing fails"
  kbuild: Make NOSTDINC_FLAGS a simply expanded variable
  kbuild: deb-pkg: avoid implicit effects
  coccinelle: semantic code search for missing put_device()
  kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIG
  kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddeb
  kbuild: deb-pkg: add CONFIG_ prefix to kernel config options
  kbuild: add workaround for Debian make-kpkg
  kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG}
  unicore32: simplify linker script generation for decompressor
  h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux-
  kbuild: move archive command to scripts/Makefile.lib
  modpost: always show verbose warning for section mismatch
  ia64: prefix header search path with $(srctree)/
  libfdt: prefix header search paths with $(srctree)/
  deb-pkg: generate correct build dependencies
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more Kbuild updates from Masahiro Yamada:

 - add more Build-Depends to Debian source package

 - prefix header search paths with $(srctree)/

 - make modpost show verbose section mismatch warnings

 - avoid hard-coded CROSS_COMPILE for h8300

 - fix regression for Debian make-kpkg command

 - add semantic patch to detect missing put_device()

 - fix some warnings of 'make deb-pkg'

 - optimize NOSTDINC_FLAGS evaluation

 - add warnings about redundant generic-y

 - clean up Makefiles and scripts

* tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: remove stale lxdialog/.gitignore
  kbuild: force all architectures except um to include mandatory-y
  kbuild: warn redundant generic-y
  Revert "modsign: Abort modules_install when signing fails"
  kbuild: Make NOSTDINC_FLAGS a simply expanded variable
  kbuild: deb-pkg: avoid implicit effects
  coccinelle: semantic code search for missing put_device()
  kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIG
  kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddeb
  kbuild: deb-pkg: add CONFIG_ prefix to kernel config options
  kbuild: add workaround for Debian make-kpkg
  kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG}
  unicore32: simplify linker script generation for decompressor
  h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux-
  kbuild: move archive command to scripts/Makefile.lib
  modpost: always show verbose warning for section mismatch
  ia64: prefix header search path with $(srctree)/
  libfdt: prefix header search paths with $(srctree)/
  deb-pkg: generate correct build dependencies
</pre>
</div>
</content>
</entry>
<entry>
<title>kbuild: force all architectures except um to include mandatory-y</title>
<updated>2019-03-17T03:56:32+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-03-17T02:01:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=037fc3368be46dc1a2a90f6e50c8cbce49d75fd6'/>
<id>037fc3368be46dc1a2a90f6e50c8cbce49d75fd6</id>
<content type='text'>
Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated include directives
to scripts/Makefile.asm-generic so that no architecture would opt out
of the mandatory-y mechanism.

um is not forced to include mandatory-y since it is a very exceptional
case which does not support UAPI.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated include directives
to scripts/Makefile.asm-generic so that no architecture would opt out
of the mandatory-y mechanism.

um is not forced to include mandatory-y since it is a very exceptional
case which does not support UAPI.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kbuild: warn redundant generic-y</title>
<updated>2019-03-17T03:56:31+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-03-17T02:01:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7cbbbb8bc2974264bbbf326d9a4552fc8878d375'/>
<id>7cbbbb8bc2974264bbbf326d9a4552fc8878d375</id>
<content type='text'>
The generic-y is redundant under the following condition:

 - arch has its own implementation

 - the same header is added to generated-y

 - the same header is added to mandatory-y

If a redundant generic-y is found, the warning like follows is displayed:

  scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h

I fixed up arch Kbuild files found by this.

Suggested-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The generic-y is redundant under the following condition:

 - arch has its own implementation

 - the same header is added to generated-y

 - the same header is added to mandatory-y

If a redundant generic-y is found, the warning like follows is displayed:

  scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h

I fixed up arch Kbuild files found by this.

Suggested-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2019-03-15T22:00:28+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-15T22:00:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=636deed6c0bc137a7c4f4a97ae1fcf0ad75323da'/>
<id>636deed6c0bc137a7c4f4a97ae1fcf0ad75323da</id>
<content type='text'>
Pull KVM updates from Paolo Bonzini:
 "ARM:
   - some cleanups
   - direct physical timer assignment
   - cache sanitization for 32-bit guests

  s390:
   - interrupt cleanup
   - introduction of the Guest Information Block
   - preparation for processor subfunctions in cpu models

  PPC:
   - bug fixes and improvements, especially related to machine checks
     and protection keys

  x86:
   - many, many cleanups, including removing a bunch of MMU code for
     unnecessary optimizations
   - AVIC fixes

  Generic:
   - memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits)
  kvm: vmx: fix formatting of a comment
  KVM: doc: Document the life cycle of a VM and its resources
  MAINTAINERS: Add KVM selftests to existing KVM entry
  Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"
  KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()
  KVM: PPC: Fix compilation when KVM is not enabled
  KVM: Minor cleanups for kvm_main.c
  KVM: s390: add debug logging for cpu model subfunctions
  KVM: s390: implement subfunction processor calls
  arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
  KVM: arm/arm64: Remove unused timer variable
  KVM: PPC: Book3S: Improve KVM reference counting
  KVM: PPC: Book3S HV: Fix build failure without IOMMU support
  Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
  x86: kvmguest: use TSC clocksource if invariant TSC is exposed
  KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
  KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
  KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
  KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes()
  KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull KVM updates from Paolo Bonzini:
 "ARM:
   - some cleanups
   - direct physical timer assignment
   - cache sanitization for 32-bit guests

  s390:
   - interrupt cleanup
   - introduction of the Guest Information Block
   - preparation for processor subfunctions in cpu models

  PPC:
   - bug fixes and improvements, especially related to machine checks
     and protection keys

  x86:
   - many, many cleanups, including removing a bunch of MMU code for
     unnecessary optimizations
   - AVIC fixes

  Generic:
   - memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits)
  kvm: vmx: fix formatting of a comment
  KVM: doc: Document the life cycle of a VM and its resources
  MAINTAINERS: Add KVM selftests to existing KVM entry
  Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"
  KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()
  KVM: PPC: Fix compilation when KVM is not enabled
  KVM: Minor cleanups for kvm_main.c
  KVM: s390: add debug logging for cpu model subfunctions
  KVM: s390: implement subfunction processor calls
  arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
  KVM: arm/arm64: Remove unused timer variable
  KVM: PPC: Book3S: Improve KVM reference counting
  KVM: PPC: Book3S HV: Fix build failure without IOMMU support
  Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
  x86: kvmguest: use TSC clocksource if invariant TSC is exposed
  KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
  KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
  KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
  KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes()
  KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children
  ...
</pre>
</div>
</content>
</entry>
</feed>
