From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
patches@lists.linux.dev, Joel Fernandes <joelagnelf@nvidia.com>,
Dave Airlie <airlied@redhat.com>,
intel-xe@lists.freedesktop.org,
Peter Senna Tschudin <peter.senna@linux.intel.com>,
Koen Koning <koen.koning@linux.intel.com>
Subject: [PATCH 6.18 674/675] gpu: Fix uninitialized buddy for built-in drivers
Date: Thu, 30 Jul 2026 16:16:44 +0200 [thread overview]
Message-ID: <20260730141459.487176866@linuxfoundation.org> (raw)
In-Reply-To: <20260730141445.110192266@linuxfoundation.org>
6.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Koen Koning <koen.koning@linux.intel.com>
commit cc27314c67516c138ee3829197d1c3b998e29fae upstream.
Move buddy to the start of the link order, so its __init runs before any
other built-in drivers that may depend on it. Otherwise, a built-in
driver that tries to use the buddy allocator will run into a kernel NULL
pointer dereference because slab_blocks is uninitialized.
Specifically, this fixes drm/xe (as built-in) running into a kernel
panic during boot, because it uses buddy during device probe.
Fixes: ba110db8e1bc ("gpu: Move DRM buddy allocator one level up (part two)")
Cc: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: intel-xe@lists.freedesktop.org
Reviewed-by: Dave Airlie <airlied@redhat.com>
Tested-by: Peter Senna Tschudin <peter.senna@linux.intel.com>
Signed-off-by: Koen Koning <koen.koning@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patch.msgid.link/20260213152047.179628-1-koen.koning@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/Makefile | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpu/Makefile
+++ b/drivers/gpu/Makefile
@@ -2,8 +2,9 @@
# drm/tegra depends on host1x, so if both drivers are built-in care must be
# taken to initialize them in the correct order. Link order is the only way
# to ensure this currently.
+# Similarly, buddy must come first since it is used by other drivers.
+obj-$(CONFIG_GPU_BUDDY) += buddy.o
obj-y += host1x/ drm/ vga/ tests/
obj-$(CONFIG_IMX_IPUV3_CORE) += ipu-v3/
obj-$(CONFIG_TRACE_GPU_MEM) += trace/
obj-$(CONFIG_NOVA_CORE) += nova-core/
-obj-$(CONFIG_GPU_BUDDY) += buddy.o
parent reply other threads:[~2026-07-30 15:27 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20260730141445.110192266@linuxfoundation.org>]
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