media: verisilicon: Fix kernel panic due to __initconst misuse

Fix a kernel panic when probing the driver as a module:

  Unable to handle kernel paging request at virtual address
  ffffd9c18eb05000
  of_find_matching_node_and_match+0x5c/0x1a0
  hantro_probe+0x2f4/0x7d0 [hantro_vpu]

The imx8mq_vpu_shared_resources array is referenced by variant
structures through their shared_devices field. When built as a
module, __initconst causes this data to be freed after module
init, but it's later accessed during probe, causing a page fault.

The imx8mq_vpu_shared_resources is referenced from non-init code,
so keeping __initconst or __initconst_or_module here is wrong.

Drop the __initconst annotation and let it live in the normal .rodata
section.

A bug of __initconst called from regular non-init probe code
leading to bugs during probe deferrals or during unbind-bind cycles.

Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Closes: https://lore.kernel.org/all/68ef934f-baa0-4bf6-93d8-834bbc441e66@kernel.org/
Reported-by: Franz Schnyder <franz.schnyder@toradex.com>
Closes: https://lore.kernel.org/all/n3qmcb62tepxltoskpf7ws6yiirc2so62ia23b42rj3wlmpl67@rvkbuirx7kkp/
Fixes: e0203ddf9af7 ("media: verisilicon: Avoid G2 bus error while decoding H.264 and HEVC")
Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Suggested-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Ming Qian <ming.qian@oss.nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Cc: stable@kernel.org
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/platform/verisilicon/imx8m_vpu_hw.c b/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
index 6f8e43b7f1575bb6daa728de846b2c03398dca93..fa4224de4b996aeea92ce68d327725e2c15c3090 100644 (file)
--- a/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
+++ b/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
@@ -343,7 +343,7 @@ const struct hantro_variant imx8mq_vpu_variant = {
        .num_regs = ARRAY_SIZE(imx8mq_reg_names)
 };
 
-static const struct of_device_id imx8mq_vpu_shared_resources[] __initconst = {
+static const struct of_device_id imx8mq_vpu_shared_resources[] = {
        { .compatible = "nxp,imx8mq-vpu-g1", },
        { .compatible = "nxp,imx8mq-vpu-g2", },
        { /* sentinel */ }