linux-kernel - [PATCH drm-misc-next v2 4/4] drm/vc4: hvs: protect drm_print

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Date:   Fri, 19 Aug 2022 13:08:49 +0200
From:   Danilo Krummrich <dakr@...hat.com>
To:     daniel@...ll.ch, airlied@...ux.ie, tzimmermann@...e.de,
        mripard@...nel.org
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Danilo Krummrich <dakr@...hat.com>
Subject: [PATCH drm-misc-next v2 4/4] drm/vc4: hvs: protect drm_print_regset32()

In vc4_hvs_dump_state() potentially freed resources are protected from
being accessed with drm_dev_enter()/drm_dev_exit().

Also include drm_print_regset32() in the protected section, since
drm_print_regset32() does access memory that is typically mapped via
devm_* calls.

Fixes: 969cfae1f01d ("drm/vc4: hvs: Protect device resources after removal")
Signed-off-by: Danilo Krummrich <dakr@...hat.com>
---
 drivers/gpu/drm/vc4/vc4_hvs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index 9e823e0de197..4ac9f5a2d5f9 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -71,11 +71,11 @@ void vc4_hvs_dump_state(struct vc4_hvs *hvs)
 	struct drm_printer p = drm_info_printer(&hvs->pdev->dev);
 	int idx, i;
 
-	drm_print_regset32(&p, &hvs->regset);
-
 	if (!drm_dev_enter(drm, &idx))
 		return;
 
+	drm_print_regset32(&p, &hvs->regset);
+
 	DRM_INFO("HVS ctx:\n");
 	for (i = 0; i < 64; i += 4) {
 		DRM_INFO("0x%08x (%s): 0x%08x 0x%08x 0x%08x 0x%08x\n",
-- 
2.37.2