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<title>user/sven/linux.git/kernel, branch v6.1.49</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2023-08-23T15:52:41Z</updated>
<entry>
<title>sched/fair: Remove capacity inversion detection</title>
<updated>2023-08-23T15:52:41Z</updated>
<author>
<name>Vincent Guittot</name>
<email>vincent.guittot@linaro.org</email>
</author>
<published>2023-02-01T14:36:28Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8517d739923e054d774d6004e1c60e9793588502'/>
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<content type='text'>
commit a2e90611b9f425adbbfcdaa5b5e49958ddf6f61b upstream.

Remove the capacity inversion detection which is now handled by
util_fits_cpu() returning -1 when we need to continue to look for a
potential CPU with better performance.

This ends up almost reverting patches below except for some comments:
commit da07d2f9c153 ("sched/fair: Fixes for capacity inversion detection")
commit aa69c36f31aa ("sched/fair: Consider capacity inversion in util_fits_cpu()")
commit 44c7b80bffc3 ("sched/fair: Detect capacity inversion")

Signed-off-by: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20230201143628.270912-3-vincent.guittot@linaro.org
Signed-off-by: Qais Yousef (Google) &lt;qyousef@layalina.io&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>sched/fair: unlink misfit task from cpu overutilized</title>
<updated>2023-08-23T15:52:41Z</updated>
<author>
<name>Vincent Guittot</name>
<email>vincent.guittot@linaro.org</email>
</author>
<published>2023-02-01T14:36:27Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e8acf9971fbe52b7e22d458edb843649d6206565'/>
<id>urn:sha1:e8acf9971fbe52b7e22d458edb843649d6206565</id>
<content type='text'>
commit e5ed0550c04c5469ecdc1634d8aa18c8609590f0 upstream.

By taking into account uclamp_min, the 1:1 relation between task misfit
and cpu overutilized is no more true as a task with a small util_avg may
not fit a high capacity cpu because of uclamp_min constraint.

Add a new state in util_fits_cpu() to reflect the case that task would fit
a CPU except for the uclamp_min hint which is a performance requirement.

Use -1 to reflect that a CPU doesn't fit only because of uclamp_min so we
can use this new value to take additional action to select the best CPU
that doesn't match uclamp_min hint.

When util_fits_cpu() returns -1, we will continue to look for a possible
CPU with better performance, which replaces Capacity Inversion detection
with capacity_orig_of() - thermal_load_avg to detect a capacity inversion.

Signed-off-by: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
Reviewed-and-tested-by: Qais Yousef &lt;qyousef@layalina.io&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Dietmar Eggemann &lt;dietmar.eggemann@arm.com&gt;
Tested-by: Kajetan Puchalski &lt;kajetan.puchalski@arm.com&gt;
Link: https://lore.kernel.org/r/20230201143628.270912-2-vincent.guittot@linaro.org
Signed-off-by: Qais Yousef (Google) &lt;qyousef@layalina.io&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ring-buffer: Do not swap cpu_buffer during resize process</title>
<updated>2023-08-23T15:52:27Z</updated>
<author>
<name>Chen Lin</name>
<email>chen.lin5@zte.com.cn</email>
</author>
<published>2023-07-19T07:58:47Z</published>
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<id>urn:sha1:128c06a34cfe55212632533a706b050d54552741</id>
<content type='text'>
[ Upstream commit 8a96c0288d0737ad77882024974c075345c72011 ]

When ring_buffer_swap_cpu was called during resize process,
the cpu buffer was swapped in the middle, resulting in incorrect state.
Continuing to run in the wrong state will result in oops.

This issue can be easily reproduced using the following two scripts:
/tmp # cat test1.sh
//#! /bin/sh
for i in `seq 0 100000`
do
         echo 2000 &gt; /sys/kernel/debug/tracing/buffer_size_kb
         sleep 0.5
         echo 5000 &gt; /sys/kernel/debug/tracing/buffer_size_kb
         sleep 0.5
done
/tmp # cat test2.sh
//#! /bin/sh
for i in `seq 0 100000`
do
        echo irqsoff &gt; /sys/kernel/debug/tracing/current_tracer
        sleep 1
        echo nop &gt; /sys/kernel/debug/tracing/current_tracer
        sleep 1
done
/tmp # ./test1.sh &amp;
/tmp # ./test2.sh &amp;

A typical oops log is as follows, sometimes with other different oops logs.

[  231.711293] WARNING: CPU: 0 PID: 9 at kernel/trace/ring_buffer.c:2026 rb_update_pages+0x378/0x3f8
[  231.713375] Modules linked in:
[  231.714735] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G        W          6.5.0-rc1-00276-g20edcec23f92 #15
[  231.716750] Hardware name: linux,dummy-virt (DT)
[  231.718152] Workqueue: events update_pages_handler
[  231.719714] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  231.721171] pc : rb_update_pages+0x378/0x3f8
[  231.722212] lr : rb_update_pages+0x25c/0x3f8
[  231.723248] sp : ffff800082b9bd50
[  231.724169] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[  231.726102] x26: 0000000000000001 x25: fffffffffffff010 x24: 0000000000000ff0
[  231.728122] x23: ffff0000c3a0b600 x22: ffff0000c3a0b5c0 x21: fffffffffffffe0a
[  231.730203] x20: ffff0000c3a0b600 x19: ffff0000c0102400 x18: 0000000000000000
[  231.732329] x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffe7aa8510
[  231.734212] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000002
[  231.736291] x11: ffff8000826998a8 x10: ffff800082b9baf0 x9 : ffff800081137558
[  231.738195] x8 : fffffc00030e82c8 x7 : 0000000000000000 x6 : 0000000000000001
[  231.740192] x5 : ffff0000ffbafe00 x4 : 0000000000000000 x3 : 0000000000000000
[  231.742118] x2 : 00000000000006aa x1 : 0000000000000001 x0 : ffff0000c0007208
[  231.744196] Call trace:
[  231.744892]  rb_update_pages+0x378/0x3f8
[  231.745893]  update_pages_handler+0x1c/0x38
[  231.746893]  process_one_work+0x1f0/0x468
[  231.747852]  worker_thread+0x54/0x410
[  231.748737]  kthread+0x124/0x138
[  231.749549]  ret_from_fork+0x10/0x20
[  231.750434] ---[ end trace 0000000000000000 ]---
[  233.720486] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  233.721696] Mem abort info:
[  233.721935]   ESR = 0x0000000096000004
[  233.722283]   EC = 0x25: DABT (current EL), IL = 32 bits
[  233.722596]   SET = 0, FnV = 0
[  233.722805]   EA = 0, S1PTW = 0
[  233.723026]   FSC = 0x04: level 0 translation fault
[  233.723458] Data abort info:
[  233.723734]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  233.724176]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  233.724589]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  233.725075] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000104943000
[  233.725592] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[  233.726231] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[  233.726720] Modules linked in:
[  233.727007] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G        W          6.5.0-rc1-00276-g20edcec23f92 #15
[  233.727777] Hardware name: linux,dummy-virt (DT)
[  233.728225] Workqueue: events update_pages_handler
[  233.728655] pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  233.729054] pc : rb_update_pages+0x1a8/0x3f8
[  233.729334] lr : rb_update_pages+0x154/0x3f8
[  233.729592] sp : ffff800082b9bd50
[  233.729792] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[  233.730220] x26: 0000000000000000 x25: ffff800082a8b840 x24: ffff0000c0102418
[  233.730653] x23: 0000000000000000 x22: fffffc000304c880 x21: 0000000000000003
[  233.731105] x20: 00000000000001f4 x19: ffff0000c0102400 x18: ffff800082fcbc58
[  233.731727] x17: 0000000000000000 x16: 0000000000000001 x15: 0000000000000001
[  233.732282] x14: ffff8000825fe0c8 x13: 0000000000000001 x12: 0000000000000000
[  233.732709] x11: ffff8000826998a8 x10: 0000000000000ae0 x9 : ffff8000801b760c
[  233.733148] x8 : fefefefefefefeff x7 : 0000000000000018 x6 : ffff0000c03298c0
[  233.733553] x5 : 0000000000000002 x4 : 0000000000000000 x3 : 0000000000000000
[  233.733972] x2 : ffff0000c3a0b600 x1 : 0000000000000000 x0 : 0000000000000000
[  233.734418] Call trace:
[  233.734593]  rb_update_pages+0x1a8/0x3f8
[  233.734853]  update_pages_handler+0x1c/0x38
[  233.735148]  process_one_work+0x1f0/0x468
[  233.735525]  worker_thread+0x54/0x410
[  233.735852]  kthread+0x124/0x138
[  233.736064]  ret_from_fork+0x10/0x20
[  233.736387] Code: 92400000 910006b5 aa000021 aa0303f7 (f9400060)
[  233.736959] ---[ end trace 0000000000000000 ]---

After analysis, the seq of the error is as follows [1-5]:

int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
			int cpu_id)
{
	for_each_buffer_cpu(buffer, cpu) {
		cpu_buffer = buffer-&gt;buffers[cpu];
		//1. get cpu_buffer, aka cpu_buffer(A)
		...
		...
		schedule_work_on(cpu,
		 &amp;cpu_buffer-&gt;update_pages_work);
		//2. 'update_pages_work' is queue on 'cpu', cpu_buffer(A) is passed to
		// update_pages_handler, do the update process, set 'update_done' in
		// complete(&amp;cpu_buffer-&gt;update_done) and to wakeup resize process.
	//----&gt;
		//3. Just at this moment, ring_buffer_swap_cpu is triggered,
		//cpu_buffer(A) be swaped to cpu_buffer(B), the max_buffer.
		//ring_buffer_swap_cpu is called as the 'Call trace' below.

		Call trace:
		 dump_backtrace+0x0/0x2f8
		 show_stack+0x18/0x28
		 dump_stack+0x12c/0x188
		 ring_buffer_swap_cpu+0x2f8/0x328
		 update_max_tr_single+0x180/0x210
		 check_critical_timing+0x2b4/0x2c8
		 tracer_hardirqs_on+0x1c0/0x200
		 trace_hardirqs_on+0xec/0x378
		 el0_svc_common+0x64/0x260
		 do_el0_svc+0x90/0xf8
		 el0_svc+0x20/0x30
		 el0_sync_handler+0xb0/0xb8
		 el0_sync+0x180/0x1c0
	//&lt;----

	/* wait for all the updates to complete */
	for_each_buffer_cpu(buffer, cpu) {
		cpu_buffer = buffer-&gt;buffers[cpu];
		//4. get cpu_buffer, cpu_buffer(B) is used in the following process,
		//the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong.
		//for example, cpu_buffer(A)-&gt;update_done will leave be set 1, and will
		//not 'wait_for_completion' at the next resize round.
		  if (!cpu_buffer-&gt;nr_pages_to_update)
			continue;

		if (cpu_online(cpu))
			wait_for_completion(&amp;cpu_buffer-&gt;update_done);
		cpu_buffer-&gt;nr_pages_to_update = 0;
	}
	...
}
	//5. the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong,
	//Continuing to run in the wrong state, then oops occurs.

Link: https://lore.kernel.org/linux-trace-kernel/202307191558478409990@zte.com.cn

Signed-off-by: Chen Lin &lt;chen.lin5@zte.com.cn&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>dma-remap: use kvmalloc_array/kvfree for larger dma memory remap</title>
<updated>2023-08-23T15:52:21Z</updated>
<author>
<name>gaoxu</name>
<email>gaoxu2@hihonor.com</email>
</author>
<published>2023-06-06T12:47:37Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b7a34e30d42fcd756f9ffad41def454e4a0474fd'/>
<id>urn:sha1:b7a34e30d42fcd756f9ffad41def454e4a0474fd</id>
<content type='text'>
[ Upstream commit 51ff97d54f02b4444dfc42e380ac4c058e12d5dd ]

If dma_direct_alloc() alloc memory in size of 64MB, the inner function
dma_common_contiguous_remap() will allocate 128KB memory by invoking
the function kmalloc_array(). and the kmalloc_array seems to fail to try to
allocate 128KB mem.

Call trace:
[14977.928623] qcrosvm: page allocation failure: order:5, mode:0x40cc0
[14977.928638] dump_backtrace.cfi_jt+0x0/0x8
[14977.928647] dump_stack_lvl+0x80/0xb8
[14977.928652] warn_alloc+0x164/0x200
[14977.928657] __alloc_pages_slowpath+0x9f0/0xb4c
[14977.928660] __alloc_pages+0x21c/0x39c
[14977.928662] kmalloc_order+0x48/0x108
[14977.928666] kmalloc_order_trace+0x34/0x154
[14977.928668] __kmalloc+0x548/0x7e4
[14977.928673] dma_direct_alloc+0x11c/0x4f8
[14977.928678] dma_alloc_attrs+0xf4/0x138
[14977.928680] gh_vm_ioctl_set_fw_name+0x3c4/0x610 [gunyah]
[14977.928698] gh_vm_ioctl+0x90/0x14c [gunyah]
[14977.928705] __arm64_sys_ioctl+0x184/0x210

work around by doing kvmalloc_array instead.

Signed-off-by: Gao Xu &lt;gaoxu2@hihonor.com&gt;
Reviewed-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf, cpumap: Make sure kthread is running before map update returns</title>
<updated>2023-08-11T10:08:23Z</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2023-07-29T09:51:06Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7a1178a3671b40746830d355836b72e47ceb2490'/>
<id>urn:sha1:7a1178a3671b40746830d355836b72e47ceb2490</id>
<content type='text'>
commit 640a604585aa30f93e39b17d4d6ba69fcb1e66c9 upstream.

The following warning was reported when running stress-mode enabled
xdp_redirect_cpu with some RT threads:

  ------------[ cut here ]------------
  WARNING: CPU: 4 PID: 65 at kernel/bpf/cpumap.c:135
  CPU: 4 PID: 65 Comm: kworker/4:1 Not tainted 6.5.0-rc2+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
  Workqueue: events cpu_map_kthread_stop
  RIP: 0010:put_cpu_map_entry+0xda/0x220
  ......
  Call Trace:
   &lt;TASK&gt;
   ? show_regs+0x65/0x70
   ? __warn+0xa5/0x240
   ......
   ? put_cpu_map_entry+0xda/0x220
   cpu_map_kthread_stop+0x41/0x60
   process_one_work+0x6b0/0xb80
   worker_thread+0x96/0x720
   kthread+0x1a5/0x1f0
   ret_from_fork+0x3a/0x70
   ret_from_fork_asm+0x1b/0x30
   &lt;/TASK&gt;

The root cause is the same as commit 436901649731 ("bpf: cpumap: Fix memory
leak in cpu_map_update_elem"). The kthread is stopped prematurely by
kthread_stop() in cpu_map_kthread_stop(), and kthread() doesn't call
cpu_map_kthread_run() at all but XDP program has already queued some
frames or skbs into ptr_ring. So when __cpu_map_ring_cleanup() checks
the ptr_ring, it will find it was not emptied and report a warning.

An alternative fix is to use __cpu_map_ring_cleanup() to drop these
pending frames or skbs when kthread_stop() returns -EINTR, but it may
confuse the user, because these frames or skbs have been handled
correctly by XDP program. So instead of dropping these frames or skbs,
just make sure the per-cpu kthread is running before
__cpu_map_entry_alloc() returns.

After apply the fix, the error handle for kthread_stop() will be
unnecessary because it will always return 0, so just remove it.

Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP")
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Reviewed-by: Pu Lehui &lt;pulehui@huawei.com&gt;
Acked-by: Jesper Dangaard Brouer &lt;hawk@kernel.org&gt;
Link: https://lore.kernel.org/r/20230729095107.1722450-2-houtao@huaweicloud.com
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>bpf: Disable preemption in bpf_event_output</title>
<updated>2023-08-11T10:08:21Z</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2023-07-25T08:42:06Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=36dd8ca330b76585640ed32255a3c99f901e1502'/>
<id>urn:sha1:36dd8ca330b76585640ed32255a3c99f901e1502</id>
<content type='text'>
commit d62cc390c2e99ae267ffe4b8d7e2e08b6c758c32 upstream.

We received report [1] of kernel crash, which is caused by
using nesting protection without disabled preemption.

The bpf_event_output can be called by programs executed by
bpf_prog_run_array_cg function that disabled migration but
keeps preemption enabled.

This can cause task to be preempted by another one inside the
nesting protection and lead eventually to two tasks using same
perf_sample_data buffer and cause crashes like:

  BUG: kernel NULL pointer dereference, address: 0000000000000001
  #PF: supervisor instruction fetch in kernel mode
  #PF: error_code(0x0010) - not-present page
  ...
  ? perf_output_sample+0x12a/0x9a0
  ? finish_task_switch.isra.0+0x81/0x280
  ? perf_event_output+0x66/0xa0
  ? bpf_event_output+0x13a/0x190
  ? bpf_event_output_data+0x22/0x40
  ? bpf_prog_dfc84bbde731b257_cil_sock4_connect+0x40a/0xacb
  ? xa_load+0x87/0xe0
  ? __cgroup_bpf_run_filter_sock_addr+0xc1/0x1a0
  ? release_sock+0x3e/0x90
  ? sk_setsockopt+0x1a1/0x12f0
  ? udp_pre_connect+0x36/0x50
  ? inet_dgram_connect+0x93/0xa0
  ? __sys_connect+0xb4/0xe0
  ? udp_setsockopt+0x27/0x40
  ? __pfx_udp_push_pending_frames+0x10/0x10
  ? __sys_setsockopt+0xdf/0x1a0
  ? __x64_sys_connect+0xf/0x20
  ? do_syscall_64+0x3a/0x90
  ? entry_SYSCALL_64_after_hwframe+0x72/0xdc

Fixing this by disabling preemption in bpf_event_output.

[1] https://github.com/cilium/cilium/issues/26756
Cc: stable@vger.kernel.org
Reported-by: Oleg "livelace" Popov &lt;o.popov@livelace.ru&gt;
Closes: https://github.com/cilium/cilium/issues/26756
Fixes: 2a916f2f546c ("bpf: Use migrate_disable/enable in array macros and cgroup/lirc code.")
Acked-by: Hou Tao &lt;houtao1@huawei.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/r/20230725084206.580930-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>bpf: Disable preemption in bpf_perf_event_output</title>
<updated>2023-08-11T10:08:20Z</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2023-07-25T08:42:05Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3654ed5daf492463c3faa434c7000d45c2da2ace'/>
<id>urn:sha1:3654ed5daf492463c3faa434c7000d45c2da2ace</id>
<content type='text'>
commit f2c67a3e60d1071b65848efaa8c3b66c363dd025 upstream.

The nesting protection in bpf_perf_event_output relies on disabled
preemption, which is guaranteed for kprobes and tracepoints.

However bpf_perf_event_output can be also called from uprobes context
through bpf_prog_run_array_sleepable function which disables migration,
but keeps preemption enabled.

This can cause task to be preempted by another one inside the nesting
protection and lead eventually to two tasks using same perf_sample_data
buffer and cause crashes like:

  kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
  BUG: unable to handle page fault for address: ffffffff82be3eea
  ...
  Call Trace:
   ? __die+0x1f/0x70
   ? page_fault_oops+0x176/0x4d0
   ? exc_page_fault+0x132/0x230
   ? asm_exc_page_fault+0x22/0x30
   ? perf_output_sample+0x12b/0x910
   ? perf_event_output+0xd0/0x1d0
   ? bpf_perf_event_output+0x162/0x1d0
   ? bpf_prog_c6271286d9a4c938_krava1+0x76/0x87
   ? __uprobe_perf_func+0x12b/0x540
   ? uprobe_dispatcher+0x2c4/0x430
   ? uprobe_notify_resume+0x2da/0xce0
   ? atomic_notifier_call_chain+0x7b/0x110
   ? exit_to_user_mode_prepare+0x13e/0x290
   ? irqentry_exit_to_user_mode+0x5/0x30
   ? asm_exc_int3+0x35/0x40

Fixing this by disabling preemption in bpf_perf_event_output.

Cc: stable@vger.kernel.org
Fixes: 8c7dcb84e3b7 ("bpf: implement sleepable uprobes by chaining gps")
Acked-by: Hou Tao &lt;houtao1@huawei.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/r/20230725084206.580930-2-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>bpf, cpumap: Handle skb as well when clean up ptr_ring</title>
<updated>2023-08-11T10:08:15Z</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2023-07-29T09:51:07Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=cbd000451885801e9bbfd9cf7a7946806a85cb5e'/>
<id>urn:sha1:cbd000451885801e9bbfd9cf7a7946806a85cb5e</id>
<content type='text'>
[ Upstream commit 7c62b75cd1a792e14b037fa4f61f9b18914e7de1 ]

The following warning was reported when running xdp_redirect_cpu with
both skb-mode and stress-mode enabled:

  ------------[ cut here ]------------
  Incorrect XDP memory type (-2128176192) usage
  WARNING: CPU: 7 PID: 1442 at net/core/xdp.c:405
  Modules linked in:
  CPU: 7 PID: 1442 Comm: kworker/7:0 Tainted: G  6.5.0-rc2+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
  Workqueue: events __cpu_map_entry_free
  RIP: 0010:__xdp_return+0x1e4/0x4a0
  ......
  Call Trace:
   &lt;TASK&gt;
   ? show_regs+0x65/0x70
   ? __warn+0xa5/0x240
   ? __xdp_return+0x1e4/0x4a0
   ......
   xdp_return_frame+0x4d/0x150
   __cpu_map_entry_free+0xf9/0x230
   process_one_work+0x6b0/0xb80
   worker_thread+0x96/0x720
   kthread+0x1a5/0x1f0
   ret_from_fork+0x3a/0x70
   ret_from_fork_asm+0x1b/0x30
   &lt;/TASK&gt;

The reason for the warning is twofold. One is due to the kthread
cpu_map_kthread_run() is stopped prematurely. Another one is
__cpu_map_ring_cleanup() doesn't handle skb mode and treats skbs in
ptr_ring as XDP frames.

Prematurely-stopped kthread will be fixed by the preceding patch and
ptr_ring will be empty when __cpu_map_ring_cleanup() is called. But
as the comments in __cpu_map_ring_cleanup() said, handling and freeing
skbs in ptr_ring as well to "catch any broken behaviour gracefully".

Fixes: 11941f8a8536 ("bpf: cpumap: Implement generic cpumap")
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Acked-by: Jesper Dangaard Brouer &lt;hawk@kernel.org&gt;
Link: https://lore.kernel.org/r/20230729095107.1722450-3-houtao@huaweicloud.com
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf: Fix function pointer case</title>
<updated>2023-08-11T10:08:09Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-11-16T21:40:17Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=15c22cd1de50f9489f9f1fd9cd5ec6eaccedc918'/>
<id>urn:sha1:15c22cd1de50f9489f9f1fd9cd5ec6eaccedc918</id>
<content type='text'>
commit 1af6239d1d3e61d33fd2f0ba53d3d1a67cc50574 upstream.

With the advent of CFI it is no longer acceptible to cast function
pointers.

The robot complains thusly:

  kernel-events-core.c:warning:cast-from-int-(-)(struct-perf_cpu_pmu_context-)-to-remote_function_f-(aka-int-(-)(void-)-)-converts-to-incompatible-function-type

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Cixi Geng &lt;cixi.geng1@unisoc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>mm: Move mm_cachep initialization to mm_init()</title>
<updated>2023-08-08T18:03:49Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-10-25T19:38:18Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e0fd83a193c530fdeced8b2e2ec83039ffdb884b'/>
<id>urn:sha1:e0fd83a193c530fdeced8b2e2ec83039ffdb884b</id>
<content type='text'>
commit af80602799681c78f14fbe20b6185a56020dedee upstream.

In order to allow using mm_alloc() much earlier, move initializing
mm_cachep into mm_init().

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20221025201057.751153381@infradead.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
