<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux, branch v5.4.38</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.4.38</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.4.38'/>
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<updated>2020-05-02T06:49:01Z</updated>
<entry>
<title>qed: Fix use after free in qed_chain_free</title>
<updated>2020-05-02T06:49:01Z</updated>
<author>
<name>Yuval Basson</name>
<email>ybason@marvell.com</email>
</author>
<published>2020-03-29T17:32:49Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=93af898b251fd6386e874f8803661cece1e45657'/>
<id>urn:sha1:93af898b251fd6386e874f8803661cece1e45657</id>
<content type='text'>
commit 8063f761cd7c17fc1d0018728936e0c33a25388a upstream.

The qed_chain data structure was modified in
commit 1a4a69751f4d ("qed: Chain support for external PBL") to support
receiving an external pbl (due to iWARP FW requirements).
The pages pointed to by the pbl are allocated in qed_chain_alloc
and their virtual address are stored in an virtual addresses array to
enable accessing and freeing the data. The physical addresses however
weren't stored and were accessed directly from the external-pbl
during free.

Destroy-qp flow, leads to freeing the external pbl before the chain is
freed, when the chain is freed it tries accessing the already freed
external pbl, leading to a use-after-free. Therefore we need to store
the physical addresses in additional to the virtual addresses in a
new data structure.

Fixes: 1a4a69751f4d ("qed: Chain support for external PBL")
Signed-off-by: Michal Kalderon &lt;mkalderon@marvell.com&gt;
Signed-off-by: Yuval Bason &lt;ybason@marvell.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>PCI: Add Zhaoxin Vendor ID</title>
<updated>2020-05-02T06:48:50Z</updated>
<author>
<name>Raymond Pang</name>
<email>RaymondPang-oc@zhaoxin.com</email>
</author>
<published>2020-03-27T09:11:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=17d166e9535cde1276f7d2dd2c7c3b962d96a623'/>
<id>urn:sha1:17d166e9535cde1276f7d2dd2c7c3b962d96a623</id>
<content type='text'>
commit 3375590623e4a132b19a8740512f4deb95728933 upstream.

Add Zhaoxin Vendor ID to pci_ids.h

Link: https://lore.kernel.org/r/20200327091148.5190-2-RaymondPang-oc@zhaoxin.com
Signed-off-by: Raymond Pang &lt;RaymondPang-oc@zhaoxin.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>svcrdma: Fix leak of svc_rdma_recv_ctxt objects</title>
<updated>2020-05-02T06:48:48Z</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2020-03-31T21:02:33Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b4284efb1e14495c9198f15504164b44009d1821'/>
<id>urn:sha1:b4284efb1e14495c9198f15504164b44009d1821</id>
<content type='text'>
commit 23cf1ee1f1869966b75518c59b5cbda4c6c92450 upstream.

Utilize the xpo_release_rqst transport method to ensure that each
rqstp's svc_rdma_recv_ctxt object is released even when the server
cannot return a Reply for that rqstp.

Without this fix, each RPC whose Reply cannot be sent leaks one
svc_rdma_recv_ctxt. This is a 2.5KB structure, a 4KB DMA-mapped
Receive buffer, and any pages that might be part of the Reply
message.

The leak is infrequent unless the network fabric is unreliable or
Kerberos is in use, as GSS sequence window overruns, which result
in connection loss, are more common on fast transports.

Fixes: 3a88092ee319 ("svcrdma: Preserve Receive buffer until svc_rdma_sendto")
Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>printk: queue wake_up_klogd irq_work only if per-CPU areas are ready</title>
<updated>2020-05-02T06:48:42Z</updated>
<author>
<name>Sergey Senozhatsky</name>
<email>sergey.senozhatsky@gmail.com</email>
</author>
<published>2020-03-03T11:30:02Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4a5c9ae67b12f628fdc8f9ffac7e5677d510dd5e'/>
<id>urn:sha1:4a5c9ae67b12f628fdc8f9ffac7e5677d510dd5e</id>
<content type='text'>
commit ab6f762f0f53162d41497708b33c9a3236d3609e upstream.

printk_deferred(), similarly to printk_safe/printk_nmi, does not
immediately attempt to print a new message on the consoles, avoiding
calls into non-reentrant kernel paths, e.g. scheduler or timekeeping,
which potentially can deadlock the system.

Those printk() flavors, instead, rely on per-CPU flush irq_work to print
messages from safer contexts.  For same reasons (recursive scheduler or
timekeeping calls) printk() uses per-CPU irq_work in order to wake up
user space syslog/kmsg readers.

However, only printk_safe/printk_nmi do make sure that per-CPU areas
have been initialised and that it's safe to modify per-CPU irq_work.
This means that, for instance, should printk_deferred() be invoked "too
early", that is before per-CPU areas are initialised, printk_deferred()
will perform illegal per-CPU access.

Lech Perczak [0] reports that after commit 1b710b1b10ef ("char/random:
silence a lockdep splat with printk()") user-space syslog/kmsg readers
are not able to read new kernel messages.

The reason is printk_deferred() being called too early (as was pointed
out by Petr and John).

Fix printk_deferred() and do not queue per-CPU irq_work before per-CPU
areas are initialized.

Link: https://lore.kernel.org/lkml/aa0732c6-5c4e-8a8b-a1c1-75ebe3dca05b@camlintechnologies.com/
Reported-by: Lech Perczak &lt;l.perczak@camlintechnologies.com&gt;
Signed-off-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Tested-by: Jann Horn &lt;jannh@google.com&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: John Ogness &lt;john.ogness@linutronix.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>KVM: Check validity of resolved slot when searching memslots</title>
<updated>2020-04-29T14:33:16Z</updated>
<author>
<name>Sean Christopherson</name>
<email>sean.j.christopherson@intel.com</email>
</author>
<published>2020-04-08T06:40:58Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=878127ac8b7013d7d7fad9d160654da5b6195902'/>
<id>urn:sha1:878127ac8b7013d7d7fad9d160654da5b6195902</id>
<content type='text'>
commit b6467ab142b708dd076f6186ca274f14af379c72 upstream.

Check that the resolved slot (somewhat confusingly named 'start') is a
valid/allocated slot before doing the final comparison to see if the
specified gfn resides in the associated slot.  The resolved slot can be
invalid if the binary search loop terminated because the search index
was incremented beyond the number of used slots.

This bug has existed since the binary search algorithm was introduced,
but went unnoticed because KVM statically allocated memory for the max
number of slots, i.e. the access would only be truly out-of-bounds if
all possible slots were allocated and the specified gfn was less than
the base of the lowest memslot.  Commit 36947254e5f98 ("KVM: Dynamically
size memslot array based on number of used slots") eliminated the "all
possible slots allocated" condition and made the bug embarrasingly easy
to hit.

Fixes: 9c1a5d38780e6 ("kvm: optimize GFN to memslot lookup with large slots amount")
Reported-by: syzbot+d889b59b2bb87d4047a2@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Message-Id: &lt;20200408064059.8957-2-sean.j.christopherson@intel.com&gt;
Reviewed-by: Cornelia Huck &lt;cohuck@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>vmalloc: fix remap_vmalloc_range() bounds checks</title>
<updated>2020-04-29T14:33:14Z</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2020-04-21T01:14:11Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=f4f235309b5cc8e6217774279ae2b263345f5f6a'/>
<id>urn:sha1:f4f235309b5cc8e6217774279ae2b263345f5f6a</id>
<content type='text'>
commit bdebd6a2831b6fab69eb85cee74a8ba77f1a1cc2 upstream.

remap_vmalloc_range() has had various issues with the bounds checks it
promises to perform ("This function checks that addr is a valid
vmalloc'ed area, and that it is big enough to cover the vma") over time,
e.g.:

 - not detecting pgoff&lt;&lt;PAGE_SHIFT overflow

 - not detecting (pgoff&lt;&lt;PAGE_SHIFT)+usize overflow

 - not checking whether addr and addr+(pgoff&lt;&lt;PAGE_SHIFT) are the same
   vmalloc allocation

 - comparing a potentially wildly out-of-bounds pointer with the end of
   the vmalloc region

In particular, since commit fc9702273e2e ("bpf: Add mmap() support for
BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer
dereferences by calling mmap() on a BPF map with a size that is bigger
than the distance from the start of the BPF map to the end of the
address space.

This could theoretically be used as a kernel ASLR bypass, by using
whether mmap() with a given offset oopses or returns an error code to
perform a binary search over the possible address range.

To allow remap_vmalloc_range_partial() to verify that addr and
addr+(pgoff&lt;&lt;PAGE_SHIFT) are in the same vmalloc region, pass the offset
to remap_vmalloc_range_partial() instead of adding it to the pointer in
remap_vmalloc_range().

In remap_vmalloc_range_partial(), fix the check against
get_vm_area_size() by using size comparisons instead of pointer
comparisons, and add checks for pgoff.

Fixes: 833423143c3a ("[PATCH] mm: introduce remap_vmalloc_range()")
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: stable@vger.kernel.org
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: KP Singh &lt;kpsingh@chromium.org&gt;
Link: http://lkml.kernel.org/r/20200415222312.236431-1-jannh@google.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>iio: core: remove extra semi-colon from devm_iio_device_register() macro</title>
<updated>2020-04-29T14:33:12Z</updated>
<author>
<name>Lars Engebretsen</name>
<email>lars@engebretsen.ch</email>
</author>
<published>2020-04-15T10:10:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=14952589c9d8061a6592f025e40ea542c89e29cc'/>
<id>urn:sha1:14952589c9d8061a6592f025e40ea542c89e29cc</id>
<content type='text'>
commit a07479147be03d2450376ebaff9ea1a0682f25d6 upstream.

This change removes the semi-colon from the devm_iio_device_register()
macro which seems to have been added by accident.

Fixes: 63b19547cc3d9 ("iio: Use macro magic to avoid manual assign of driver_module")
Signed-off-by: Lars Engebretsen &lt;lars@engebretsen.ch&gt;
Cc: &lt;Stable@vger.kernel.org&gt;
Reviewed-by: Alexandru Ardelean &lt;alexandru.ardelean@analog.com&gt;
Signed-off-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>KEYS: Don't write out to userspace while holding key semaphore</title>
<updated>2020-04-23T08:36:45Z</updated>
<author>
<name>Waiman Long</name>
<email>longman@redhat.com</email>
</author>
<published>2020-03-22T01:11:24Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=f1afcf9488fc45765e20e2047d3b776981900e0b'/>
<id>urn:sha1:f1afcf9488fc45765e20e2047d3b776981900e0b</id>
<content type='text'>
commit d3ec10aa95819bff18a0d936b18884c7816d0914 upstream.

A lockdep circular locking dependency report was seen when running a
keyutils test:

[12537.027242] ======================================================
[12537.059309] WARNING: possible circular locking dependency detected
[12537.088148] 4.18.0-147.7.1.el8_1.x86_64+debug #1 Tainted: G OE    --------- -  -
[12537.125253] ------------------------------------------------------
[12537.153189] keyctl/25598 is trying to acquire lock:
[12537.175087] 000000007c39f96c (&amp;mm-&gt;mmap_sem){++++}, at: __might_fault+0xc4/0x1b0
[12537.208365]
[12537.208365] but task is already holding lock:
[12537.234507] 000000003de5b58d (&amp;type-&gt;lock_class){++++}, at: keyctl_read_key+0x15a/0x220
[12537.270476]
[12537.270476] which lock already depends on the new lock.
[12537.270476]
[12537.307209]
[12537.307209] the existing dependency chain (in reverse order) is:
[12537.340754]
[12537.340754] -&gt; #3 (&amp;type-&gt;lock_class){++++}:
[12537.367434]        down_write+0x4d/0x110
[12537.385202]        __key_link_begin+0x87/0x280
[12537.405232]        request_key_and_link+0x483/0xf70
[12537.427221]        request_key+0x3c/0x80
[12537.444839]        dns_query+0x1db/0x5a5 [dns_resolver]
[12537.468445]        dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs]
[12537.496731]        cifs_reconnect+0xe04/0x2500 [cifs]
[12537.519418]        cifs_readv_from_socket+0x461/0x690 [cifs]
[12537.546263]        cifs_read_from_socket+0xa0/0xe0 [cifs]
[12537.573551]        cifs_demultiplex_thread+0x311/0x2db0 [cifs]
[12537.601045]        kthread+0x30c/0x3d0
[12537.617906]        ret_from_fork+0x3a/0x50
[12537.636225]
[12537.636225] -&gt; #2 (root_key_user.cons_lock){+.+.}:
[12537.664525]        __mutex_lock+0x105/0x11f0
[12537.683734]        request_key_and_link+0x35a/0xf70
[12537.705640]        request_key+0x3c/0x80
[12537.723304]        dns_query+0x1db/0x5a5 [dns_resolver]
[12537.746773]        dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs]
[12537.775607]        cifs_reconnect+0xe04/0x2500 [cifs]
[12537.798322]        cifs_readv_from_socket+0x461/0x690 [cifs]
[12537.823369]        cifs_read_from_socket+0xa0/0xe0 [cifs]
[12537.847262]        cifs_demultiplex_thread+0x311/0x2db0 [cifs]
[12537.873477]        kthread+0x30c/0x3d0
[12537.890281]        ret_from_fork+0x3a/0x50
[12537.908649]
[12537.908649] -&gt; #1 (&amp;tcp_ses-&gt;srv_mutex){+.+.}:
[12537.935225]        __mutex_lock+0x105/0x11f0
[12537.954450]        cifs_call_async+0x102/0x7f0 [cifs]
[12537.977250]        smb2_async_readv+0x6c3/0xc90 [cifs]
[12538.000659]        cifs_readpages+0x120a/0x1e50 [cifs]
[12538.023920]        read_pages+0xf5/0x560
[12538.041583]        __do_page_cache_readahead+0x41d/0x4b0
[12538.067047]        ondemand_readahead+0x44c/0xc10
[12538.092069]        filemap_fault+0xec1/0x1830
[12538.111637]        __do_fault+0x82/0x260
[12538.129216]        do_fault+0x419/0xfb0
[12538.146390]        __handle_mm_fault+0x862/0xdf0
[12538.167408]        handle_mm_fault+0x154/0x550
[12538.187401]        __do_page_fault+0x42f/0xa60
[12538.207395]        do_page_fault+0x38/0x5e0
[12538.225777]        page_fault+0x1e/0x30
[12538.243010]
[12538.243010] -&gt; #0 (&amp;mm-&gt;mmap_sem){++++}:
[12538.267875]        lock_acquire+0x14c/0x420
[12538.286848]        __might_fault+0x119/0x1b0
[12538.306006]        keyring_read_iterator+0x7e/0x170
[12538.327936]        assoc_array_subtree_iterate+0x97/0x280
[12538.352154]        keyring_read+0xe9/0x110
[12538.370558]        keyctl_read_key+0x1b9/0x220
[12538.391470]        do_syscall_64+0xa5/0x4b0
[12538.410511]        entry_SYSCALL_64_after_hwframe+0x6a/0xdf
[12538.435535]
[12538.435535] other info that might help us debug this:
[12538.435535]
[12538.472829] Chain exists of:
[12538.472829]   &amp;mm-&gt;mmap_sem --&gt; root_key_user.cons_lock --&gt; &amp;type-&gt;lock_class
[12538.472829]
[12538.524820]  Possible unsafe locking scenario:
[12538.524820]
[12538.551431]        CPU0                    CPU1
[12538.572654]        ----                    ----
[12538.595865]   lock(&amp;type-&gt;lock_class);
[12538.613737]                                lock(root_key_user.cons_lock);
[12538.644234]                                lock(&amp;type-&gt;lock_class);
[12538.672410]   lock(&amp;mm-&gt;mmap_sem);
[12538.687758]
[12538.687758]  *** DEADLOCK ***
[12538.687758]
[12538.714455] 1 lock held by keyctl/25598:
[12538.732097]  #0: 000000003de5b58d (&amp;type-&gt;lock_class){++++}, at: keyctl_read_key+0x15a/0x220
[12538.770573]
[12538.770573] stack backtrace:
[12538.790136] CPU: 2 PID: 25598 Comm: keyctl Kdump: loaded Tainted: G
[12538.844855] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015
[12538.881963] Call Trace:
[12538.892897]  dump_stack+0x9a/0xf0
[12538.907908]  print_circular_bug.isra.25.cold.50+0x1bc/0x279
[12538.932891]  ? save_trace+0xd6/0x250
[12538.948979]  check_prev_add.constprop.32+0xc36/0x14f0
[12538.971643]  ? keyring_compare_object+0x104/0x190
[12538.992738]  ? check_usage+0x550/0x550
[12539.009845]  ? sched_clock+0x5/0x10
[12539.025484]  ? sched_clock_cpu+0x18/0x1e0
[12539.043555]  __lock_acquire+0x1f12/0x38d0
[12539.061551]  ? trace_hardirqs_on+0x10/0x10
[12539.080554]  lock_acquire+0x14c/0x420
[12539.100330]  ? __might_fault+0xc4/0x1b0
[12539.119079]  __might_fault+0x119/0x1b0
[12539.135869]  ? __might_fault+0xc4/0x1b0
[12539.153234]  keyring_read_iterator+0x7e/0x170
[12539.172787]  ? keyring_read+0x110/0x110
[12539.190059]  assoc_array_subtree_iterate+0x97/0x280
[12539.211526]  keyring_read+0xe9/0x110
[12539.227561]  ? keyring_gc_check_iterator+0xc0/0xc0
[12539.249076]  keyctl_read_key+0x1b9/0x220
[12539.266660]  do_syscall_64+0xa5/0x4b0
[12539.283091]  entry_SYSCALL_64_after_hwframe+0x6a/0xdf

One way to prevent this deadlock scenario from happening is to not
allow writing to userspace while holding the key semaphore. Instead,
an internal buffer is allocated for getting the keys out from the
read method first before copying them out to userspace without holding
the lock.

That requires taking out the __user modifier from all the relevant
read methods as well as additional changes to not use any userspace
write helpers. That is,

  1) The put_user() call is replaced by a direct copy.
  2) The copy_to_user() call is replaced by memcpy().
  3) All the fault handling code is removed.

Compiling on a x86-64 system, the size of the rxrpc_read() function is
reduced from 3795 bytes to 2384 bytes with this patch.

Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
Signed-off-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>compiler.h: fix error in BUILD_BUG_ON() reporting</title>
<updated>2020-04-23T08:36:37Z</updated>
<author>
<name>Vegard Nossum</name>
<email>vegard.nossum@oracle.com</email>
</author>
<published>2020-04-07T03:09:37Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3910babeac1ab031f4e178042cbd1af9a9a0ec51'/>
<id>urn:sha1:3910babeac1ab031f4e178042cbd1af9a9a0ec51</id>
<content type='text'>
[ Upstream commit af9c5d2e3b355854ff0e4acfbfbfadcd5198a349 ]

compiletime_assert() uses __LINE__ to create a unique function name.  This
means that if you have more than one BUILD_BUG_ON() in the same source
line (which can happen if they appear e.g.  in a macro), then the error
message from the compiler might output the wrong condition.

For this source file:

	#include &lt;linux/build_bug.h&gt;

	#define macro() \
		BUILD_BUG_ON(1); \
		BUILD_BUG_ON(0);

	void foo()
	{
		macro();
	}

gcc would output:

./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_9' declared with attribute error: BUILD_BUG_ON failed: 0
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)

However, it was not the BUILD_BUG_ON(0) that failed, so it should say 1
instead of 0. With this patch, we use __COUNTER__ instead of __LINE__, so
each BUILD_BUG_ON() gets a different function name and the correct
condition is printed:

./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_0' declared with attribute error: BUILD_BUG_ON failed: 1
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

Signed-off-by: Vegard Nossum &lt;vegard.nossum@oracle.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Reviewed-by: Daniel Santos &lt;daniel.santos@pobox.com&gt;
Cc: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Cc: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Link: http://lkml.kernel.org/r/20200331112637.25047-1-vegard.nossum@oracle.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>percpu_counter: fix a data race at vm_committed_as</title>
<updated>2020-04-23T08:36:37Z</updated>
<author>
<name>Qian Cai</name>
<email>cai@lca.pw</email>
</author>
<published>2020-04-07T03:10:25Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b525f94f16e52e7833419ac3812f0d8afb032fe4'/>
<id>urn:sha1:b525f94f16e52e7833419ac3812f0d8afb032fe4</id>
<content type='text'>
[ Upstream commit 7e2345200262e4a6056580f0231cccdaffc825f3 ]

"vm_committed_as.count" could be accessed concurrently as reported by
KCSAN,

 BUG: KCSAN: data-race in __vm_enough_memory / percpu_counter_add_batch

 write to 0xffffffff9451c538 of 8 bytes by task 65879 on cpu 35:
  percpu_counter_add_batch+0x83/0xd0
  percpu_counter_add_batch at lib/percpu_counter.c:91
  __vm_enough_memory+0xb9/0x260
  dup_mm+0x3a4/0x8f0
  copy_process+0x2458/0x3240
  _do_fork+0xaa/0x9f0
  __do_sys_clone+0x125/0x160
  __x64_sys_clone+0x70/0x90
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffffffff9451c538 of 8 bytes by task 66773 on cpu 19:
  __vm_enough_memory+0x199/0x260
  percpu_counter_read_positive at include/linux/percpu_counter.h:81
  (inlined by) __vm_enough_memory at mm/util.c:839
  mmap_region+0x1b2/0xa10
  do_mmap+0x45c/0x700
  vm_mmap_pgoff+0xc0/0x130
  ksys_mmap_pgoff+0x6e/0x300
  __x64_sys_mmap+0x33/0x40
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The read is outside percpu_counter::lock critical section which results in
a data race.  Fix it by adding a READ_ONCE() in
percpu_counter_read_positive() which could also service as the existing
compiler memory barrier.

Signed-off-by: Qian Cai &lt;cai@lca.pw&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: Marco Elver &lt;elver@google.com&gt;
Link: http://lkml.kernel.org/r/1582302724-2804-1-git-send-email-cai@lca.pw
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
