<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/kernel, branch v5.15.34</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.15.34</id>
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<updated>2022-04-13T18:59:28Z</updated>
<entry>
<title>stacktrace: move filter_irq_stacks() to kernel/stacktrace.c</title>
<updated>2022-04-13T18:59:28Z</updated>
<author>
<name>Marco Elver</name>
<email>elver@google.com</email>
</author>
<published>2021-11-05T20:45:25Z</published>
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<id>urn:sha1:c9ea4fb1f3f356d7a04ebe15ac867ba3192c6d4f</id>
<content type='text'>
commit f39f21b3ddc7fc0f87eb6dc75ddc81b5bbfb7672 upstream.

filter_irq_stacks() has little to do with the stackdepot implementation,
except that it is usually used by users (such as KASAN) of stackdepot to
reduce the stack trace.

However, filter_irq_stacks() itself is not useful without a stack trace
as obtained by stack_trace_save() and friends.

Therefore, move filter_irq_stacks() to kernel/stacktrace.c, so that new
users of filter_irq_stacks() do not have to start depending on
STACKDEPOT only for filter_irq_stacks().

Link: https://lkml.kernel.org/r/20210923104803.2620285-1-elver@google.com
Signed-off-by: Marco Elver &lt;elver@google.com&gt;
Acked-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Aleksandr Nogikh &lt;nogikh@google.com&gt;
Cc: Taras Madan &lt;tarasmadan@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
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>static_call: Don't make __static_call_return0 static</title>
<updated>2022-04-13T18:59:28Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2022-03-14T11:49:36Z</published>
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<id>urn:sha1:68cea1e243b81e23e09b6822be6193321d9bf977</id>
<content type='text'>
commit 8fd4ddda2f49a66bf5dd3d0c01966c4b1971308b upstream.

System.map shows that vmlinux contains several instances of
__static_call_return0():

	c0004fc0 t __static_call_return0
	c0011518 t __static_call_return0
	c00d8160 t __static_call_return0

arch_static_call_transform() uses the middle one to check whether we are
setting a call to __static_call_return0 or not:

	c0011520 &lt;arch_static_call_transform&gt;:
	c0011520:       3d 20 c0 01     lis     r9,-16383	&lt;== r9 =  0xc001 &lt;&lt; 16
	c0011524:       39 29 15 18     addi    r9,r9,5400	&lt;== r9 += 0x1518
	c0011528:       7c 05 48 00     cmpw    r5,r9		&lt;== r9 has value 0xc0011518 here

So if static_call_update() is called with one of the other instances of
__static_call_return0(), arch_static_call_transform() won't recognise it.

In order to work properly, global single instance of __static_call_return0() is required.

Fixes: 3f2a8fc4b15d ("static_call/x86: Add __static_call_return0()")
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Link: https://lkml.kernel.org/r/30821468a0e7d28251954b578e5051dc09300d04.1647258493.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>sched: Teach the forced-newidle balancer about CPU affinity limitation.</title>
<updated>2022-04-13T18:59:27Z</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2022-03-17T14:51:32Z</published>
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<id>urn:sha1:ff6505766565616deb65a203e62d4ca63c6c277b</id>
<content type='text'>
commit 386ef214c3c6ab111d05e1790e79475363abaa05 upstream.

try_steal_cookie() looks at task_struct::cpus_mask to decide if the
task could be moved to `this' CPU. It ignores that the task might be in
a migration disabled section while not on the CPU. In this case the task
must not be moved otherwise per-CPU assumption are broken.

Use is_cpu_allowed(), as suggested by Peter Zijlstra, to decide if the a
task can be moved.

Fixes: d2dfa17bc7de6 ("sched: Trivial forced-newidle balancer")
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/YjNK9El+3fzGmswf@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf/core: Inherit event_caps</title>
<updated>2022-04-13T18:59:24Z</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2022-03-28T20:01:12Z</published>
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<id>urn:sha1:fcf9ccf9d26a13d4a10ee6b167e429d96db97fe4</id>
<content type='text'>
commit e3265a4386428d3d157d9565bb520aabff8b4bf0 upstream.

It was reported that some perf event setup can make fork failed on
ARM64.  It was the case of a group of mixed hw and sw events and it
failed in perf_event_init_task() due to armpmu_event_init().

The ARM PMU code checks if all the events in a group belong to the
same PMU except for software events.  But it didn't set the event_caps
of inherited events and no longer identify them as software events.
Therefore the test failed in a child process.

A simple reproducer is:

  $ perf stat -e '{cycles,cs,instructions}' perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  perf: fork(): Invalid argument

The perf stat was fine but the perf bench failed in fork().  Let's
inherit the event caps from the parent.

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: https://lkml.kernel.org/r/20220328200112.457740-1-namhyung@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>swiotlb: Support aligned swiotlb buffers</title>
<updated>2022-04-08T12:24:17Z</updated>
<author>
<name>David Stevens</name>
<email>stevensd@chromium.org</email>
</author>
<published>2021-09-29T02:32:59Z</published>
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<id>urn:sha1:3e44e136560cb66dd5156889f811b870789b9499</id>
<content type='text'>
commit e81e99bacc9f9347bda7808a949c1ce9fcc2bbf4 upstream.

Add an argument to swiotlb_tbl_map_single that specifies the desired
alignment of the allocated buffer. This is used by dma-iommu to ensure
the buffer is aligned to the iova granule size when using swiotlb with
untrusted sub-granule mappings. This addresses an issue where adjacent
slots could be exposed to the untrusted device if IO_TLB_SIZE &lt; iova
granule &lt; PAGE_SIZE.

Signed-off-by: David Stevens &lt;stevensd@chromium.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20210929023300.335969-7-stevensd@google.com
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Cc: Mario Limonciello &lt;Mario.Limonciello@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>bpf: Adjust BPF stack helper functions to accommodate skip &gt; 0</title>
<updated>2022-04-08T12:24:14Z</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2022-03-14T18:20:41Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=398ac11f4425d1e52aaf0d05d4fc90524e1a5b5e'/>
<id>urn:sha1:398ac11f4425d1e52aaf0d05d4fc90524e1a5b5e</id>
<content type='text'>
commit ee2a098851bfbe8bcdd964c0121f4246f00ff41e upstream.

Let's say that the caller has storage for num_elem stack frames.  Then,
the BPF stack helper functions walk the stack for only num_elem frames.
This means that if skip &gt; 0, one keeps only 'num_elem - skip' frames.

This is because it sets init_nr in the perf_callchain_entry to the end
of the buffer to save num_elem entries only.  I believe it was because
the perf callchain code unwound the stack frames until it reached the
global max size (sysctl_perf_event_max_stack).

However it now has perf_callchain_entry_ctx.max_stack to limit the
iteration locally.  This simplifies the code to handle init_nr in the
BPF callstack entries and removes the confusion with the perf_event's
__PERF_SAMPLE_CALLCHAIN_EARLY which sets init_nr to 0.

Also change the comment on bpf_get_stack() in the header file to be
more explicit what the return value means.

Fixes: c195651e565a ("bpf: add bpf_get_stack helper")
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/bpf/30a7b5d5-6726-1cc2-eaee-8da2828a9a9c@oracle.com
Link: https://lore.kernel.org/bpf/20220314182042.71025-1-namhyung@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

Based-on-patch-by: Eugene Loh &lt;eugene.loh@oracle.com&gt;
</content>
</entry>
<entry>
<title>tracing: Have type enum modifications copy the strings</title>
<updated>2022-04-08T12:24:13Z</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-03-18T19:34:32Z</published>
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<id>urn:sha1:14d552ab31ede4027e8a7d2eb3dd7670e2bdc007</id>
<content type='text'>
commit 795301d3c28996219d555023ac6863401b6076bc upstream.

When an enum is used in the visible parts of a trace event that is
exported to user space, the user space applications like perf and
trace-cmd do not have a way to know what the value of the enum is. To
solve this, at boot up (or module load) the printk formats are modified to
replace the enum with their numeric value in the string output.

Array fields of the event are defined by [&lt;nr-elements&gt;] in the type
portion of the format file so that the user space parsers can correctly
parse the array into the appropriate size chunks. But in some trace
events, an enum is used in defining the size of the array, which once
again breaks the parsing of user space tooling.

This was solved the same way as the print formats were, but it modified
the type strings of the trace event. This caused crashes in some
architectures because, as supposed to the print string, is a const string
value. This was not detected on x86, as it appears that const strings are
still writable (at least in boot up), but other architectures this is not
the case, and writing to a const string will cause a kernel fault.

To fix this, use kstrdup() to copy the type before modifying it. If the
trace event is for the core kernel there's no need to free it because the
string will be in use for the life of the machine being on line. For
modules, create a link list to store all the strings being allocated for
modules and when the module is removed, free them.

Link: https://lore.kernel.org/all/yt9dr1706b4i.fsf@linux.ibm.com/
Link: https://lkml.kernel.org/r/20220318153432.3984b871@gandalf.local.home

Tested-by: Marc Zyngier &lt;maz@kernel.org&gt;
Tested-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Reported-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Fixes: b3bc8547d3be ("tracing: Have TRACE_DEFINE_ENUM affect trace event types as well")
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""</title>
<updated>2022-04-08T12:24:13Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-28T18:37:05Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7007c894631cf43041dcfa0da7142bbaa7eb673c'/>
<id>urn:sha1:7007c894631cf43041dcfa0da7142bbaa7eb673c</id>
<content type='text'>
commit 901c7280ca0d5e2b4a8929fbe0bfb007ac2a6544 upstream.

Halil Pasic points out [1] that the full revert of that commit (revert
in bddac7c1e02b), and that a partial revert that only reverts the
problematic case, but still keeps some of the cleanups is probably
better.  ￼

And that partial revert [2] had already been verified by Oleksandr
Natalenko to also fix the issue, I had just missed that in the long
discussion.

So let's reinstate the cleanups from commit aa6f8dcbab47 ("swiotlb:
rework "fix info leak with DMA_FROM_DEVICE""), and effectively only
revert the part that caused problems.

Link: https://lore.kernel.org/all/20220328013731.017ae3e3.pasic@linux.ibm.com/ [1]
Link: https://lore.kernel.org/all/20220324055732.GB12078@lst.de/ [2]
Link: https://lore.kernel.org/all/4386660.LvFx2qVVIh@natalenko.name/ [3]
Suggested-by: Halil Pasic &lt;pasic@linux.ibm.com&gt;
Tested-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
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>watch_queue: Free the page array when watch_queue is dismantled</title>
<updated>2022-04-08T12:24:11Z</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2022-03-28T17:07:04Z</published>
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<id>urn:sha1:4913daecd04addb41bc96a9175a885e1c19862a8</id>
<content type='text'>
commit b490207017ba237d97b735b2aa66dc241ccd18f5 upstream.

Commit 7ea1a0124b6d ("watch_queue: Free the alloc bitmap when the
watch_queue is torn down") took care of the bitmap, but not the page
array.

  BUG: memory leak
  unreferenced object 0xffff88810d9bc140 (size 32):
  comm "syz-executor335", pid 3603, jiffies 4294946994 (age 12.840s)
  hex dump (first 32 bytes):
    40 a7 40 04 00 ea ff ff 00 00 00 00 00 00 00 00  @.@.............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
     kmalloc_array include/linux/slab.h:621 [inline]
     kcalloc include/linux/slab.h:652 [inline]
     watch_queue_set_size+0x12f/0x2e0 kernel/watch_queue.c:251
     pipe_ioctl+0x82/0x140 fs/pipe.c:632
     vfs_ioctl fs/ioctl.c:51 [inline]
     __do_sys_ioctl fs/ioctl.c:874 [inline]
     __se_sys_ioctl fs/ioctl.c:860 [inline]
     __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860
     do_syscall_x64 arch/x86/entry/common.c:50 [inline]

Reported-by: syzbot+25ea042ae28f3888727a@syzkaller.appspotmail.com
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Link: https://lore.kernel.org/r/20220322004654.618274-1-eric.dumazet@gmail.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>tracing: Have TRACE_DEFINE_ENUM affect trace event types as well</title>
<updated>2022-04-08T12:24:02Z</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-03-11T04:27:38Z</published>
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<id>urn:sha1:7c6bd60999f32138e3b73fd97ea11ef47a94de25</id>
<content type='text'>
[ Upstream commit b3bc8547d3be60898818885f5bf22d0a62e2eb48 ]

The macro TRACE_DEFINE_ENUM is used to convert enums in the kernel to
their actual value when they are exported to user space via the trace
event format file.

Currently only the enums in the "print fmt" (TP_printk in the TRACE_EVENT
macro) have the enums converted. But the enums can be used to denote array
size:

        field:unsigned int fc_ineligible_rc[EXT4_FC_REASON_MAX]; offset:12;      size:36;        signed:0;

The EXT4_FC_REASON_MAX has no meaning to userspace but it needs to know
that information to know how to parse the array.

Have the array indexes also be parsed as well.

Link: https://lore.kernel.org/all/cover.1646922487.git.riteshh@linux.ibm.com/

Reported-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Tested-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
