6.12-stable review patch. If anyone has any objections, please let me know.
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From: Lucas De Marchi lucas.demarchi@intel.com
[ Upstream commit fe39b222a4139354d32ff9d46b88757f63f71d63 ]
If userspace holds an fd open, unbinds the device and then closes it, the driver shouldn't try to access the hardware. Protect it by using drm_dev_enter()/drm_dev_exit(). This fixes the following page fault:
<6> [IGT] xe_wedged: exiting, ret=98 <1> BUG: unable to handle page fault for address: ffffc901bc5e508c <1> #PF: supervisor read access in kernel mode <1> #PF: error_code(0x0000) - not-present page ... <4> xe_lrc_update_timestamp+0x1c/0xd0 [xe] <4> xe_exec_queue_update_run_ticks+0x50/0xb0 [xe] <4> xe_exec_queue_fini+0x16/0xb0 [xe] <4> __guc_exec_queue_fini_async+0xc4/0x190 [xe] <4> guc_exec_queue_fini_async+0xa0/0xe0 [xe] <4> guc_exec_queue_fini+0x23/0x40 [xe] <4> xe_exec_queue_destroy+0xb3/0xf0 [xe] <4> xe_file_close+0xd4/0x1a0 [xe] <4> drm_file_free+0x210/0x280 [drm] <4> drm_close_helper.isra.0+0x6d/0x80 [drm] <4> drm_release_noglobal+0x20/0x90 [drm]
Fixes: 514447a12190 ("drm/xe: Stop accumulating LRC timestamp on job_free") Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3421 Reviewed-by: Umesh Nerlige Ramappa umesh.nerlige.ramappa@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20241218053122.2730195-1-lucas... Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com (cherry picked from commit 4ca1fd418338d4d135428a0eb1e16e3b3ce17ee8) Signed-off-by: Thomas Hellström thomas.hellstrom@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/xe/xe_exec_queue.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c index fd0f3b3c9101..268cd3123be9 100644 --- a/drivers/gpu/drm/xe/xe_exec_queue.c +++ b/drivers/gpu/drm/xe/xe_exec_queue.c @@ -8,6 +8,7 @@ #include <linux/nospec.h>
#include <drm/drm_device.h> +#include <drm/drm_drv.h> #include <drm/drm_file.h> #include <uapi/drm/xe_drm.h>
@@ -762,9 +763,11 @@ bool xe_exec_queue_is_idle(struct xe_exec_queue *q) */ void xe_exec_queue_update_run_ticks(struct xe_exec_queue *q) { + struct xe_device *xe = gt_to_xe(q->gt); struct xe_file *xef; struct xe_lrc *lrc; u32 old_ts, new_ts; + int idx;
/* * Jobs that are run during driver load may use an exec_queue, but are @@ -774,6 +777,10 @@ void xe_exec_queue_update_run_ticks(struct xe_exec_queue *q) if (!q->vm || !q->vm->xef) return;
+ /* Synchronize with unbind while holding the xe file open */ + if (!drm_dev_enter(&xe->drm, &idx)) + return; + xef = q->vm->xef;
/* @@ -787,6 +794,8 @@ void xe_exec_queue_update_run_ticks(struct xe_exec_queue *q) lrc = q->lrc[0]; new_ts = xe_lrc_update_timestamp(lrc, &old_ts); xef->run_ticks[q->class] += (new_ts - old_ts) * q->width; + + drm_dev_exit(idx); }
/**