[PATCH AUTOSEL 6.10 033/121] drm/amdkfd: Check debug trap enable before write dbg_ev_file

Sasha Levin
2024-08-01T00:12:29Z

From: "Lin.Cao" <lincao12@amd.com>

[ Upstream commit 547033b593063eb85bfdf9b25a5f1b8fd1911be2 ]

In interrupt context, write dbg_ev_file will be run by work queue. It
will cause write dbg_ev_file execution after debug_trap_disable, which
will cause NULL pointer access.
v2: cancel work "debug_event_workarea" before set dbg_ev_file as NULL.

Signed-off-by: Lin.Cao <lincao12@amd.com>
Reviewed-by: Jonathan Kim <jonathan.kim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdkfd/kfd_debug.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
index d889e3545120a..6c2f6a26c479c 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
@@ -103,7 +103,8 @@ void debug_event_write_work_handler(struct work_struct *work)
struct kfd_process,
debug_event_workarea);

- kernel_write(process->dbg_ev_file, &write_data, 1, &pos);
+ if (process->debug_trap_enabled && process->dbg_ev_file)
+ kernel_write(process->dbg_ev_file, &write_data, 1, &pos);
}

/* update process/device/queue exception status, write to descriptor
@@ -645,6 +646,7 @@ int kfd_dbg_trap_disable(struct kfd_process *target)
else if (target->runtime_info.runtime_state != DEBUG_RUNTIME_STATE_DISABLED)
target->runtime_info.runtime_state = DEBUG_RUNTIME_STATE_ENABLED;

+ cancel_work_sync(&target->debug_event_workarea);
fput(target->dbg_ev_file);
target->dbg_ev_file = NULL;

--
2.43.0