<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/gpu/drm/arm, branch linux-5.10.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>minmax: add in_range() macro</title>
<updated>2025-10-29T13:01:15+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2025-10-17T09:04:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e1fade4cc73c1ccd78c210b5ca0266a63370d978'/>
<id>e1fade4cc73c1ccd78c210b5ca0266a63370d978</id>
<content type='text'>
[ Upstream commit f9bff0e31881d03badf191d3b0005839391f5f2b ]

Patch series "New page table range API", v6.

This patchset changes the API used by the MM to set up page table entries.
The four APIs are:

    set_ptes(mm, addr, ptep, pte, nr)
    update_mmu_cache_range(vma, addr, ptep, nr)
    flush_dcache_folio(folio)
    flush_icache_pages(vma, page, nr)

flush_dcache_folio() isn't technically new, but no architecture
implemented it, so I've done that for them.  The old APIs remain around
but are mostly implemented by calling the new interfaces.

The new APIs are based around setting up N page table entries at once.
The N entries belong to the same PMD, the same folio and the same VMA, so
ptep++ is a legitimate operation, and locking is taken care of for you.
Some architectures can do a better job of it than just a loop, but I have
hesitated to make too deep a change to architectures I don't understand
well.

One thing I have changed in every architecture is that PG_arch_1 is now a
per-folio bit instead of a per-page bit when used for dcache clean/dirty
tracking.  This was something that would have to happen eventually, and it
makes sense to do it now rather than iterate over every page involved in a
cache flush and figure out if it needs to happen.

The point of all this is better performance, and Fengwei Yin has measured
improvement on x86.  I suspect you'll see improvement on your architecture
too.  Try the new will-it-scale test mentioned here:
https://lore.kernel.org/linux-mm/20230206140639.538867-5-fengwei.yin@intel.com/
You'll need to run it on an XFS filesystem and have
CONFIG_TRANSPARENT_HUGEPAGE set.

This patchset is the basis for much of the anonymous large folio work
being done by Ryan, so it's received quite a lot of testing over the last
few months.

This patch (of 38):

Determine if a value lies within a range more efficiently (subtraction +
comparison vs two comparisons and an AND).  It also has useful (under some
circumstances) behaviour if the range exceeds the maximum value of the
type.  Convert all the conflicting definitions of in_range() within the
kernel; some can use the generic definition while others need their own
definition.

Link: https://lkml.kernel.org/r/20230802151406.3735276-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230802151406.3735276-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Eliav Farber &lt;farbere@amazon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f9bff0e31881d03badf191d3b0005839391f5f2b ]

Patch series "New page table range API", v6.

This patchset changes the API used by the MM to set up page table entries.
The four APIs are:

    set_ptes(mm, addr, ptep, pte, nr)
    update_mmu_cache_range(vma, addr, ptep, nr)
    flush_dcache_folio(folio)
    flush_icache_pages(vma, page, nr)

flush_dcache_folio() isn't technically new, but no architecture
implemented it, so I've done that for them.  The old APIs remain around
but are mostly implemented by calling the new interfaces.

The new APIs are based around setting up N page table entries at once.
The N entries belong to the same PMD, the same folio and the same VMA, so
ptep++ is a legitimate operation, and locking is taken care of for you.
Some architectures can do a better job of it than just a loop, but I have
hesitated to make too deep a change to architectures I don't understand
well.

One thing I have changed in every architecture is that PG_arch_1 is now a
per-folio bit instead of a per-page bit when used for dcache clean/dirty
tracking.  This was something that would have to happen eventually, and it
makes sense to do it now rather than iterate over every page involved in a
cache flush and figure out if it needs to happen.

The point of all this is better performance, and Fengwei Yin has measured
improvement on x86.  I suspect you'll see improvement on your architecture
too.  Try the new will-it-scale test mentioned here:
https://lore.kernel.org/linux-mm/20230206140639.538867-5-fengwei.yin@intel.com/
You'll need to run it on an XFS filesystem and have
CONFIG_TRANSPARENT_HUGEPAGE set.

This patchset is the basis for much of the anonymous large folio work
being done by Ryan, so it's received quite a lot of testing over the last
few months.

This patch (of 38):

Determine if a value lies within a range more efficiently (subtraction +
comparison vs two comparisons and an AND).  It also has useful (under some
circumstances) behaviour if the range exceeds the maximum value of the
type.  Convert all the conflicting definitions of in_range() within the
kernel; some can use the generic definition while others need their own
definition.

Link: https://lkml.kernel.org/r/20230802151406.3735276-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230802151406.3735276-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Eliav Farber &lt;farbere@amazon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/komeda: Add check for komeda_get_layer_fourcc_list()</title>
<updated>2025-03-13T11:47:06+00:00</updated>
<author>
<name>Haoxiang Li</name>
<email>haoxiang_li2024@163.com</email>
</author>
<published>2024-12-19T09:02:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=05e510e25a56d45632f1a39515eb903aad342937'/>
<id>05e510e25a56d45632f1a39515eb903aad342937</id>
<content type='text'>
commit 79fc672a092d93a7eac24fe20a571d4efd8fa5a4 upstream.

Add check for the return value of komeda_get_layer_fourcc_list()
to catch the potential exception.

Fixes: 5d51f6c0da1b ("drm/komeda: Add writeback support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li &lt;haoxiang_li2024@163.com&gt;
Acked-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/r/20241219090256.146424-1-haoxiang_li2024@163.com
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 79fc672a092d93a7eac24fe20a571d4efd8fa5a4 upstream.

Add check for the return value of komeda_get_layer_fourcc_list()
to catch the potential exception.

Fixes: 5d51f6c0da1b ("drm/komeda: Add writeback support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li &lt;haoxiang_li2024@163.com&gt;
Acked-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/r/20241219090256.146424-1-haoxiang_li2024@163.com
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: komeda: Fix an issue related to normalized zpos</title>
<updated>2024-10-17T13:07:35+00:00</updated>
<author>
<name>hongchi.peng</name>
<email>hongchi.peng@siengine.com</email>
</author>
<published>2024-08-26T02:45:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=040511d9f28263bfd01313b16c0609aa32724fa7'/>
<id>040511d9f28263bfd01313b16c0609aa32724fa7</id>
<content type='text'>
[ Upstream commit 258905cb9a6414be5c9ca4aa20ef855f8dc894d4 ]

We use komeda_crtc_normalize_zpos to normalize zpos of affected planes
to their blending zorder in CU. If there's only one slave plane in
affected planes and its layer_split property is enabled, order++ for
its split layer, so that when calculating the normalized_zpos
of master planes, the split layer of the slave plane is included, but
the max_slave_zorder does not include the split layer and keep zero
because there's only one slave plane in affacted planes, although we
actually use two slave layers in this commit.

In most cases, this bug does not result in a commit failure, but assume
the following situation:
    slave_layer 0: zpos = 0, layer split enabled, normalized_zpos =
    0;(use slave_layer 2 as its split layer)
    master_layer 0: zpos = 2, layer_split enabled, normalized_zpos =
    2;(use master_layer 2 as its split layer)
    master_layer 1: zpos = 4, normalized_zpos = 4;
    master_layer 3: zpos = 5, normalized_zpos = 5;
    kcrtc_st-&gt;max_slave_zorder = 0;
When we use master_layer 3 as a input of CU in function
komeda_compiz_set_input and check it with function
komeda_component_check_input, the parameter idx is equal to
normailzed_zpos minus max_slave_zorder, the value of idx is 5
and is euqal to CU's max_active_inputs, so that
komeda_component_check_input returns a -EINVAL value.

To fix the bug described above, when calculating the max_slave_zorder
with the layer_split enabled, count the split layer in this calculation
directly.

Signed-off-by: hongchi.peng &lt;hongchi.peng@siengine.com&gt;
Acked-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240826024517.3739-1-hongchi.peng@siengine.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 258905cb9a6414be5c9ca4aa20ef855f8dc894d4 ]

We use komeda_crtc_normalize_zpos to normalize zpos of affected planes
to their blending zorder in CU. If there's only one slave plane in
affected planes and its layer_split property is enabled, order++ for
its split layer, so that when calculating the normalized_zpos
of master planes, the split layer of the slave plane is included, but
the max_slave_zorder does not include the split layer and keep zero
because there's only one slave plane in affacted planes, although we
actually use two slave layers in this commit.

In most cases, this bug does not result in a commit failure, but assume
the following situation:
    slave_layer 0: zpos = 0, layer split enabled, normalized_zpos =
    0;(use slave_layer 2 as its split layer)
    master_layer 0: zpos = 2, layer_split enabled, normalized_zpos =
    2;(use master_layer 2 as its split layer)
    master_layer 1: zpos = 4, normalized_zpos = 4;
    master_layer 3: zpos = 5, normalized_zpos = 5;
    kcrtc_st-&gt;max_slave_zorder = 0;
When we use master_layer 3 as a input of CU in function
komeda_compiz_set_input and check it with function
komeda_component_check_input, the parameter idx is equal to
normailzed_zpos minus max_slave_zorder, the value of idx is 5
and is euqal to CU's max_active_inputs, so that
komeda_component_check_input returns a -EINVAL value.

To fix the bug described above, when calculating the max_slave_zorder
with the layer_split enabled, count the split layer in this calculation
directly.

Signed-off-by: hongchi.peng &lt;hongchi.peng@siengine.com&gt;
Acked-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240826024517.3739-1-hongchi.peng@siengine.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/komeda: check for error-valued pointer</title>
<updated>2024-07-05T07:12:28+00:00</updated>
<author>
<name>Amjad Ouled-Ameur</name>
<email>amjad.ouled-ameur@arm.com</email>
</author>
<published>2024-06-10T10:20:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bda7cdaeebf57e46c1a488ae7a15f6f264691f59'/>
<id>bda7cdaeebf57e46c1a488ae7a15f6f264691f59</id>
<content type='text'>
[ Upstream commit b880018edd3a577e50366338194dee9b899947e0 ]

komeda_pipeline_get_state() may return an error-valued pointer, thus
check the pointer for negative or null value before dereferencing.

Fixes: 502932a03fce ("drm/komeda: Add the initial scaler support for CORE")
Signed-off-by: Amjad Ouled-Ameur &lt;amjad.ouled-ameur@arm.com&gt;
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240610102056.40406-1-amjad.ouled-ameur@arm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b880018edd3a577e50366338194dee9b899947e0 ]

komeda_pipeline_get_state() may return an error-valued pointer, thus
check the pointer for negative or null value before dereferencing.

Fixes: 502932a03fce ("drm/komeda: Add the initial scaler support for CORE")
Signed-off-by: Amjad Ouled-Ameur &lt;amjad.ouled-ameur@arm.com&gt;
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240610102056.40406-1-amjad.ouled-ameur@arm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/arm/malidp: fix a possible null pointer dereference</title>
<updated>2024-06-16T11:32:12+00:00</updated>
<author>
<name>Huai-Yuan Liu</name>
<email>qq810974084@gmail.com</email>
</author>
<published>2024-04-07T06:30:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a5fa5b40a278a3ca978fed64707bd27614adb1eb'/>
<id>a5fa5b40a278a3ca978fed64707bd27614adb1eb</id>
<content type='text'>
[ Upstream commit a1f95aede6285dba6dd036d907196f35ae3a11ea ]

In malidp_mw_connector_reset, new memory is allocated with kzalloc, but
no check is performed. In order to prevent null pointer dereferencing,
ensure that mw_state is checked before calling
__drm_atomic_helper_connector_reset.

Fixes: 8cbc5caf36ef ("drm: mali-dp: Add writeback connector")
Signed-off-by: Huai-Yuan Liu &lt;qq810974084@gmail.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240407063053.5481-1-qq810974084@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a1f95aede6285dba6dd036d907196f35ae3a11ea ]

In malidp_mw_connector_reset, new memory is allocated with kzalloc, but
no check is performed. In order to prevent null pointer dereferencing,
ensure that mw_state is checked before calling
__drm_atomic_helper_connector_reset.

Fixes: 8cbc5caf36ef ("drm: mali-dp: Add writeback connector")
Signed-off-by: Huai-Yuan Liu &lt;qq810974084@gmail.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240407063053.5481-1-qq810974084@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/komeda: drop all currently held locks if deadlock happens</title>
<updated>2023-11-28T16:54:50+00:00</updated>
<author>
<name>baozhu.liu</name>
<email>lucas.liu@siengine.com</email>
</author>
<published>2023-08-04T02:05:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2810a9c40b6fff590c92c9f5e1fc8cc137662581'/>
<id>2810a9c40b6fff590c92c9f5e1fc8cc137662581</id>
<content type='text'>
[ Upstream commit 19ecbe8325a2a7ffda5ff4790955b84eaccba49f ]

If komeda_pipeline_unbound_components() returns -EDEADLK,
it means that a deadlock happened in the locking context.
Currently, komeda is not dealing with the deadlock properly,producing the
following output when CONFIG_DEBUG_WW_MUTEX_SLOWPATH is enabled:

 ------------[ cut here ]------------
[   26.103984] WARNING: CPU: 2 PID: 345 at drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c:1248
	       komeda_release_unclaimed_resources+0x13c/0x170
[   26.117453] Modules linked in:
[   26.120511] CPU: 2 PID: 345 Comm: composer@2.1-se Kdump: loaded Tainted: G   W  5.10.110-SE-SDK1.8-dirty #16
[   26.131374] Hardware name: Siengine Se1000 Evaluation board (DT)
[   26.137379] pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
[   26.143385] pc : komeda_release_unclaimed_resources+0x13c/0x170
[   26.149301] lr : komeda_release_unclaimed_resources+0xbc/0x170
[   26.155130] sp : ffff800017b8b8d0
[   26.158442] pmr_save: 000000e0
[   26.161493] x29: ffff800017b8b8d0 x28: ffff000cf2f96200
[   26.166805] x27: ffff000c8f5a8800 x26: 0000000000000000
[   26.172116] x25: 0000000000000038 x24: ffff8000116a0140
[   26.177428] x23: 0000000000000038 x22: ffff000cf2f96200
[   26.182739] x21: ffff000cfc300300 x20: ffff000c8ab77080
[   26.188051] x19: 0000000000000003 x18: 0000000000000000
[   26.193362] x17: 0000000000000000 x16: 0000000000000000
[   26.198672] x15: b400e638f738ba38 x14: 0000000000000000
[   26.203983] x13: 0000000106400a00 x12: 0000000000000000
[   26.209294] x11: 0000000000000000 x10: 0000000000000000
[   26.214604] x9 : ffff800012f80000 x8 : ffff000ca3308000
[   26.219915] x7 : 0000000ff3000000 x6 : ffff80001084034c
[   26.225226] x5 : ffff800017b8bc40 x4 : 000000000000000f
[   26.230536] x3 : ffff000ca3308000 x2 : 0000000000000000
[   26.235847] x1 : 0000000000000000 x0 : ffffffffffffffdd
[   26.241158] Call trace:
[   26.243604] komeda_release_unclaimed_resources+0x13c/0x170
[   26.249175] komeda_crtc_atomic_check+0x68/0xf0
[   26.253706] drm_atomic_helper_check_planes+0x138/0x1f4
[   26.258929] komeda_kms_check+0x284/0x36c
[   26.262939] drm_atomic_check_only+0x40c/0x714
[   26.267381] drm_atomic_nonblocking_commit+0x1c/0x60
[   26.272344] drm_mode_atomic_ioctl+0xa3c/0xb8c
[   26.276787] drm_ioctl_kernel+0xc4/0x120
[   26.280708] drm_ioctl+0x268/0x534
[   26.284109] __arm64_sys_ioctl+0xa8/0xf0
[   26.288030] el0_svc_common.constprop.0+0x80/0x240
[   26.292817] do_el0_svc+0x24/0x90
[   26.296132] el0_svc+0x20/0x30
[   26.299185] el0_sync_handler+0xe8/0xf0
[   26.303018] el0_sync+0x1a4/0x1c0
[   26.306330] irq event stamp: 0
[   26.309384] hardirqs last  enabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.315650] hardirqs last disabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.323825] softirqs last  enabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.331997] softirqs last disabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.338261] ---[ end trace 20ae984fa860184a ]---
[   26.343021] ------------[ cut here ]------------
[   26.347646] WARNING: CPU: 3 PID: 345 at drivers/gpu/drm/drm_modeset_lock.c:228 drm_modeset_drop_locks+0x84/0x90
[   26.357727] Modules linked in:
[   26.360783] CPU: 3 PID: 345 Comm: composer@2.1-se Kdump: loaded Tainted: G   W  5.10.110-SE-SDK1.8-dirty #16
[   26.371645] Hardware name: Siengine Se1000 Evaluation board (DT)
[   26.377647] pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
[   26.383649] pc : drm_modeset_drop_locks+0x84/0x90
[   26.388351] lr : drm_mode_atomic_ioctl+0x860/0xb8c
[   26.393137] sp : ffff800017b8bb10
[   26.396447] pmr_save: 000000e0
[   26.399497] x29: ffff800017b8bb10 x28: 0000000000000001
[   26.404807] x27: 0000000000000038 x26: 0000000000000002
[   26.410115] x25: ffff000cecbefa00 x24: ffff000cf2f96200
[   26.415423] x23: 0000000000000001 x22: 0000000000000018
[   26.420731] x21: 0000000000000001 x20: ffff800017b8bc10
[   26.426039] x19: 0000000000000000 x18: 0000000000000000
[   26.431347] x17: 0000000002e8bf2c x16: 0000000002e94c6b
[   26.436655] x15: 0000000002ea48b9 x14: ffff8000121f0300
[   26.441963] x13: 0000000002ee2ca8 x12: ffff80001129cae0
[   26.447272] x11: ffff800012435000 x10: ffff000ed46b5e88
[   26.452580] x9 : ffff000c9935e600 x8 : 0000000000000000
[   26.457888] x7 : 000000008020001e x6 : 000000008020001f
[   26.463196] x5 : ffff80001085fbe0 x4 : fffffe0033a59f20
[   26.468504] x3 : 000000008020001e x2 : 0000000000000000
[   26.473813] x1 : 0000000000000000 x0 : ffff000c8f596090
[   26.479122] Call trace:
[   26.481566] drm_modeset_drop_locks+0x84/0x90
[   26.485918] drm_mode_atomic_ioctl+0x860/0xb8c
[   26.490359] drm_ioctl_kernel+0xc4/0x120
[   26.494278] drm_ioctl+0x268/0x534
[   26.497677] __arm64_sys_ioctl+0xa8/0xf0
[   26.501598] el0_svc_common.constprop.0+0x80/0x240
[   26.506384] do_el0_svc+0x24/0x90
[   26.509697] el0_svc+0x20/0x30
[   26.512748] el0_sync_handler+0xe8/0xf0
[   26.516580] el0_sync+0x1a4/0x1c0
[   26.519891] irq event stamp: 0
[   26.522943] hardirqs last  enabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.529207] hardirqs last disabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.537379] softirqs last  enabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.545550] softirqs last disabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.551812] ---[ end trace 20ae984fa860184b ]---

According to the call trace information,it can be located to be
WARN_ON(IS_ERR(c_st)) in the komeda_pipeline_unbound_components function;
Then follow the function.
komeda_pipeline_unbound_components
-&gt; komeda_component_get_state_and_set_user
  -&gt; komeda_pipeline_get_state_and_set_crtc
    -&gt; komeda_pipeline_get_state
      -&gt;drm_atomic_get_private_obj_state
        -&gt; drm_atomic_get_private_obj_state
          -&gt; drm_modeset_lock

komeda_pipeline_unbound_components
-&gt; komeda_component_get_state_and_set_user
  -&gt; komeda_component_get_state
    -&gt; drm_atomic_get_private_obj_state
     -&gt; drm_modeset_lock

ret = drm_modeset_lock(&amp;obj-&gt;lock, state-&gt;acquire_ctx); if (ret)
	return ERR_PTR(ret);
Here it return -EDEADLK.

deal with the deadlock as suggested by [1], using the
function drm_modeset_backoff().
[1] https://docs.kernel.org/gpu/drm-kms.html?highlight=kms#kms-locking

Therefore, handling this problem can be solved
by adding return -EDEADLK back to the drm_modeset_backoff processing flow
in the drm_mode_atomic_ioctl function.

Signed-off-by: baozhu.liu &lt;lucas.liu@siengine.com&gt;
Signed-off-by: menghui.huang &lt;menghui.huang@siengine.com&gt;
Reviewed-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230804013117.6870-1-menghui.huang@siengine.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 19ecbe8325a2a7ffda5ff4790955b84eaccba49f ]

If komeda_pipeline_unbound_components() returns -EDEADLK,
it means that a deadlock happened in the locking context.
Currently, komeda is not dealing with the deadlock properly,producing the
following output when CONFIG_DEBUG_WW_MUTEX_SLOWPATH is enabled:

 ------------[ cut here ]------------
[   26.103984] WARNING: CPU: 2 PID: 345 at drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c:1248
	       komeda_release_unclaimed_resources+0x13c/0x170
[   26.117453] Modules linked in:
[   26.120511] CPU: 2 PID: 345 Comm: composer@2.1-se Kdump: loaded Tainted: G   W  5.10.110-SE-SDK1.8-dirty #16
[   26.131374] Hardware name: Siengine Se1000 Evaluation board (DT)
[   26.137379] pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
[   26.143385] pc : komeda_release_unclaimed_resources+0x13c/0x170
[   26.149301] lr : komeda_release_unclaimed_resources+0xbc/0x170
[   26.155130] sp : ffff800017b8b8d0
[   26.158442] pmr_save: 000000e0
[   26.161493] x29: ffff800017b8b8d0 x28: ffff000cf2f96200
[   26.166805] x27: ffff000c8f5a8800 x26: 0000000000000000
[   26.172116] x25: 0000000000000038 x24: ffff8000116a0140
[   26.177428] x23: 0000000000000038 x22: ffff000cf2f96200
[   26.182739] x21: ffff000cfc300300 x20: ffff000c8ab77080
[   26.188051] x19: 0000000000000003 x18: 0000000000000000
[   26.193362] x17: 0000000000000000 x16: 0000000000000000
[   26.198672] x15: b400e638f738ba38 x14: 0000000000000000
[   26.203983] x13: 0000000106400a00 x12: 0000000000000000
[   26.209294] x11: 0000000000000000 x10: 0000000000000000
[   26.214604] x9 : ffff800012f80000 x8 : ffff000ca3308000
[   26.219915] x7 : 0000000ff3000000 x6 : ffff80001084034c
[   26.225226] x5 : ffff800017b8bc40 x4 : 000000000000000f
[   26.230536] x3 : ffff000ca3308000 x2 : 0000000000000000
[   26.235847] x1 : 0000000000000000 x0 : ffffffffffffffdd
[   26.241158] Call trace:
[   26.243604] komeda_release_unclaimed_resources+0x13c/0x170
[   26.249175] komeda_crtc_atomic_check+0x68/0xf0
[   26.253706] drm_atomic_helper_check_planes+0x138/0x1f4
[   26.258929] komeda_kms_check+0x284/0x36c
[   26.262939] drm_atomic_check_only+0x40c/0x714
[   26.267381] drm_atomic_nonblocking_commit+0x1c/0x60
[   26.272344] drm_mode_atomic_ioctl+0xa3c/0xb8c
[   26.276787] drm_ioctl_kernel+0xc4/0x120
[   26.280708] drm_ioctl+0x268/0x534
[   26.284109] __arm64_sys_ioctl+0xa8/0xf0
[   26.288030] el0_svc_common.constprop.0+0x80/0x240
[   26.292817] do_el0_svc+0x24/0x90
[   26.296132] el0_svc+0x20/0x30
[   26.299185] el0_sync_handler+0xe8/0xf0
[   26.303018] el0_sync+0x1a4/0x1c0
[   26.306330] irq event stamp: 0
[   26.309384] hardirqs last  enabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.315650] hardirqs last disabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.323825] softirqs last  enabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.331997] softirqs last disabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.338261] ---[ end trace 20ae984fa860184a ]---
[   26.343021] ------------[ cut here ]------------
[   26.347646] WARNING: CPU: 3 PID: 345 at drivers/gpu/drm/drm_modeset_lock.c:228 drm_modeset_drop_locks+0x84/0x90
[   26.357727] Modules linked in:
[   26.360783] CPU: 3 PID: 345 Comm: composer@2.1-se Kdump: loaded Tainted: G   W  5.10.110-SE-SDK1.8-dirty #16
[   26.371645] Hardware name: Siengine Se1000 Evaluation board (DT)
[   26.377647] pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
[   26.383649] pc : drm_modeset_drop_locks+0x84/0x90
[   26.388351] lr : drm_mode_atomic_ioctl+0x860/0xb8c
[   26.393137] sp : ffff800017b8bb10
[   26.396447] pmr_save: 000000e0
[   26.399497] x29: ffff800017b8bb10 x28: 0000000000000001
[   26.404807] x27: 0000000000000038 x26: 0000000000000002
[   26.410115] x25: ffff000cecbefa00 x24: ffff000cf2f96200
[   26.415423] x23: 0000000000000001 x22: 0000000000000018
[   26.420731] x21: 0000000000000001 x20: ffff800017b8bc10
[   26.426039] x19: 0000000000000000 x18: 0000000000000000
[   26.431347] x17: 0000000002e8bf2c x16: 0000000002e94c6b
[   26.436655] x15: 0000000002ea48b9 x14: ffff8000121f0300
[   26.441963] x13: 0000000002ee2ca8 x12: ffff80001129cae0
[   26.447272] x11: ffff800012435000 x10: ffff000ed46b5e88
[   26.452580] x9 : ffff000c9935e600 x8 : 0000000000000000
[   26.457888] x7 : 000000008020001e x6 : 000000008020001f
[   26.463196] x5 : ffff80001085fbe0 x4 : fffffe0033a59f20
[   26.468504] x3 : 000000008020001e x2 : 0000000000000000
[   26.473813] x1 : 0000000000000000 x0 : ffff000c8f596090
[   26.479122] Call trace:
[   26.481566] drm_modeset_drop_locks+0x84/0x90
[   26.485918] drm_mode_atomic_ioctl+0x860/0xb8c
[   26.490359] drm_ioctl_kernel+0xc4/0x120
[   26.494278] drm_ioctl+0x268/0x534
[   26.497677] __arm64_sys_ioctl+0xa8/0xf0
[   26.501598] el0_svc_common.constprop.0+0x80/0x240
[   26.506384] do_el0_svc+0x24/0x90
[   26.509697] el0_svc+0x20/0x30
[   26.512748] el0_sync_handler+0xe8/0xf0
[   26.516580] el0_sync+0x1a4/0x1c0
[   26.519891] irq event stamp: 0
[   26.522943] hardirqs last  enabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.529207] hardirqs last disabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.537379] softirqs last  enabled at (0): [&lt;ffff800010056d34&gt;] copy_process+0x5d0/0x183c
[   26.545550] softirqs last disabled at (0): [&lt;0000000000000000&gt;] 0x0
[   26.551812] ---[ end trace 20ae984fa860184b ]---

According to the call trace information,it can be located to be
WARN_ON(IS_ERR(c_st)) in the komeda_pipeline_unbound_components function;
Then follow the function.
komeda_pipeline_unbound_components
-&gt; komeda_component_get_state_and_set_user
  -&gt; komeda_pipeline_get_state_and_set_crtc
    -&gt; komeda_pipeline_get_state
      -&gt;drm_atomic_get_private_obj_state
        -&gt; drm_atomic_get_private_obj_state
          -&gt; drm_modeset_lock

komeda_pipeline_unbound_components
-&gt; komeda_component_get_state_and_set_user
  -&gt; komeda_component_get_state
    -&gt; drm_atomic_get_private_obj_state
     -&gt; drm_modeset_lock

ret = drm_modeset_lock(&amp;obj-&gt;lock, state-&gt;acquire_ctx); if (ret)
	return ERR_PTR(ret);
Here it return -EDEADLK.

deal with the deadlock as suggested by [1], using the
function drm_modeset_backoff().
[1] https://docs.kernel.org/gpu/drm-kms.html?highlight=kms#kms-locking

Therefore, handling this problem can be solved
by adding return -EDEADLK back to the drm_modeset_backoff processing flow
in the drm_mode_atomic_ioctl function.

Signed-off-by: baozhu.liu &lt;lucas.liu@siengine.com&gt;
Signed-off-by: menghui.huang &lt;menghui.huang@siengine.com&gt;
Reviewed-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230804013117.6870-1-menghui.huang@siengine.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>malidp: Fix NULL vs IS_ERR() checking</title>
<updated>2023-03-11T15:40:21+00:00</updated>
<author>
<name>Miaoqian Lin</name>
<email>linmq006@gmail.com</email>
</author>
<published>2021-12-13T07:21:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a5bbea50d622b8f49ab8ee3b0eb283107febcf1a'/>
<id>a5bbea50d622b8f49ab8ee3b0eb283107febcf1a</id>
<content type='text'>
commit 15342f930ebebcfe36f2415049736a77d7d2e045 upstream.

The get_sg_table() function does not return NULL.
It returns error pointers.

Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/dri-devel/20211213072115.18098-1-linmq006@gmail.com/
Signed-off-by: Stefan Ghinea &lt;stefan.ghinea@windriver.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 15342f930ebebcfe36f2415049736a77d7d2e045 upstream.

The get_sg_table() function does not return NULL.
It returns error pointers.

Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/dri-devel/20211213072115.18098-1-linmq006@gmail.com/
Signed-off-by: Stefan Ghinea &lt;stefan.ghinea@windriver.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: mali-dp: potential dereference of null pointer</title>
<updated>2022-06-09T08:21:01+00:00</updated>
<author>
<name>Jiasheng Jiang</name>
<email>jiasheng@iscas.ac.cn</email>
</author>
<published>2021-12-14T10:08:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4c7dd0037e6aeecad9b947b30f0d9eaeda11762'/>
<id>b4c7dd0037e6aeecad9b947b30f0d9eaeda11762</id>
<content type='text'>
[ Upstream commit 73c3ed7495c67b8fbdc31cf58e6ca8757df31a33 ]

The return value of kzalloc() needs to be checked.
To avoid use of null pointer '&amp;state-&gt;base' in case of the
failure of alloc.

Fixes: 99665d072183 ("drm: mali-dp: add malidp_crtc_state struct")
Signed-off-by: Jiasheng Jiang &lt;jiasheng@iscas.ac.cn&gt;
Reviewed-by: Brian Starkey &lt;brian.starkey@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20211214100837.46912-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 73c3ed7495c67b8fbdc31cf58e6ca8757df31a33 ]

The return value of kzalloc() needs to be checked.
To avoid use of null pointer '&amp;state-&gt;base' in case of the
failure of alloc.

Fixes: 99665d072183 ("drm: mali-dp: add malidp_crtc_state struct")
Signed-off-by: Jiasheng Jiang &lt;jiasheng@iscas.ac.cn&gt;
Reviewed-by: Brian Starkey &lt;brian.starkey@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20211214100837.46912-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/komeda: Fix an undefined behavior bug in komeda_plane_add()</title>
<updated>2022-06-09T08:21:01+00:00</updated>
<author>
<name>Zhou Qingyang</name>
<email>zhou1615@umn.edu</email>
</author>
<published>2021-12-01T03:37:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=78a3e9fcdb7b1712de30d9d248bf19cee6a890b0'/>
<id>78a3e9fcdb7b1712de30d9d248bf19cee6a890b0</id>
<content type='text'>
[ Upstream commit f5e284bb74ab296f98122673c7ecd22028b2c200 ]

In komeda_plane_add(), komeda_get_layer_fourcc_list() is assigned to
formats and used in drm_universal_plane_init().
drm_universal_plane_init() passes formats to
__drm_universal_plane_init(). __drm_universal_plane_init() further
passes formats to memcpy() as src parameter, which could lead to an
undefined behavior bug on failure of komeda_get_layer_fourcc_list().

Fix this bug by adding a check of formats.

This bug was found by a static analyzer. The analysis employs
differential checking to identify inconsistent security operations
(e.g., checks or kfrees) between two code paths and confirms that the
inconsistent operations are not recovered in the current function or
the callers, so they constitute bugs.

Note that, as a bug found by static analysis, it can be a false
positive or hard to trigger. Multiple researchers have cross-reviewed
the bug.

Builds with CONFIG_DRM_KOMEDA=m show no new warnings,
and our static analyzer no longer warns about this code.

Fixes: 61f1c4a8ab75 ("drm/komeda: Attach komeda_dev to DRM-KMS")
Signed-off-by: Zhou Qingyang &lt;zhou1615@umn.edu&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/dri-devel/20211201033704.32054-1-zhou1615@umn.edu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f5e284bb74ab296f98122673c7ecd22028b2c200 ]

In komeda_plane_add(), komeda_get_layer_fourcc_list() is assigned to
formats and used in drm_universal_plane_init().
drm_universal_plane_init() passes formats to
__drm_universal_plane_init(). __drm_universal_plane_init() further
passes formats to memcpy() as src parameter, which could lead to an
undefined behavior bug on failure of komeda_get_layer_fourcc_list().

Fix this bug by adding a check of formats.

This bug was found by a static analyzer. The analysis employs
differential checking to identify inconsistent security operations
(e.g., checks or kfrees) between two code paths and confirms that the
inconsistent operations are not recovered in the current function or
the callers, so they constitute bugs.

Note that, as a bug found by static analysis, it can be a false
positive or hard to trigger. Multiple researchers have cross-reviewed
the bug.

Builds with CONFIG_DRM_KOMEDA=m show no new warnings,
and our static analyzer no longer warns about this code.

Fixes: 61f1c4a8ab75 ("drm/komeda: Attach komeda_dev to DRM-KMS")
Signed-off-by: Zhou Qingyang &lt;zhou1615@umn.edu&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/dri-devel/20211201033704.32054-1-zhou1615@umn.edu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/komeda: return early if drm_universal_plane_init() fails.</title>
<updated>2022-06-09T08:20:50+00:00</updated>
<author>
<name>Liviu Dudau</name>
<email>liviu.dudau@arm.com</email>
</author>
<published>2021-12-02T17:00:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c977d63b8cc45a1ca4ce438c072af43af6f4aa6b'/>
<id>c977d63b8cc45a1ca4ce438c072af43af6f4aa6b</id>
<content type='text'>
[ Upstream commit c8f76c37cc3668ee45e081e76a15f24a352ebbdd ]

If drm_universal_plane_init() fails early we jump to the common cleanup code
that calls komeda_plane_destroy() which in turn could access the uninitalised
drm_plane and crash. Return early if an error is detected without going through
the common code.

Reported-by: Steven Price &lt;steven.price@arm.com&gt;
Reviewed-by: Steven Price &lt;steven.price@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/dri-devel/20211203100946.2706922-1-liviu.dudau@arm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c8f76c37cc3668ee45e081e76a15f24a352ebbdd ]

If drm_universal_plane_init() fails early we jump to the common cleanup code
that calls komeda_plane_destroy() which in turn could access the uninitalised
drm_plane and crash. Return early if an error is detected without going through
the common code.

Reported-by: Steven Price &lt;steven.price@arm.com&gt;
Reviewed-by: Steven Price &lt;steven.price@arm.com&gt;
Signed-off-by: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Link: https://lore.kernel.org/dri-devel/20211203100946.2706922-1-liviu.dudau@arm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
