Implement debugger vm access for userptrs.
When bind is done, take ref to current task so that
we know from which vm the address was bound. Then during
debugger pread/pwrite we use this target task as
parameter to access the debuggee vm with access_process_vm().
This is based on suggestions from Thomas, Joonas and Simona.
Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Simona Vetter <simona@xxxxxxxx>
Signed-off-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/xe/xe_eudebug.c | 12 ++++++++++++
drivers/gpu/drm/xe/xe_vm.c | 11 +++++++++++
drivers/gpu/drm/xe/xe_vm_types.h | 6 ++++++
3 files changed, 29 insertions(+)
diff --git a/drivers/gpu/drm/xe/xe_eudebug.c b/drivers/gpu/drm/xe/xe_eudebug.c
index 9d87df75348b..980b5a1383ad 100644
--- a/drivers/gpu/drm/xe/xe_eudebug.c
+++ b/drivers/gpu/drm/xe/xe_eudebug.c
@@ -3074,6 +3074,18 @@ static int xe_eudebug_vma_access(struct xe_vma *vma, u64 offset_in_vma,
xe_bo_put(bo);
return ret;
+ } else if (xe_vma_is_userptr(vma)) {
+ struct xe_userptr *userptr = &to_userptr_vma(vma)->userptr;
+
+ /*
+ * XXX: access_remote_vm() would fit as userptr notifier has
+ * mm ref so we would not need to carry task ref at all.
+ * But access_remote_vm is not exported. access_process_vm()
+ * is exported so use it instead.
+ */
+ return access_process_vm(userptr->eudebug.task,
+ xe_vma_userptr(vma), buf, bytes,
+ write ? FOLL_WRITE : 0);
}
return -EINVAL;
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 0f17bc8b627b..c23bb4547d66 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -999,6 +999,14 @@ static struct xe_vma *xe_vma_create(struct xe_vm *vm,
}
userptr->notifier_seq = LONG_MAX;
+#if IS_ENABLED(CONFIG_DRM_XE_EUDEBUG)
+ /*
+ * We could use the mm which is on notifier. But
+ * the access_remote_vm() is not exported. Thus
+ * we get reference to task for access_process_vm()
+ */
+ userptr->eudebug.task = get_task_struct(current);
+#endif
}
xe_vm_get(vm);
@@ -1023,6 +1031,9 @@ static void xe_vma_destroy_late(struct xe_vma *vma)
if (userptr->sg)
xe_hmm_userptr_free_sg(uvma);
+#if IS_ENABLED(CONFIG_DRM_XE_EUDEBUG)
+ put_task_struct(userptr->eudebug.task);
+#endif
/*
* Since userptr pages are not pinned, we can't remove
* the notifer until we're sure the GPU is not accessing
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index 557b047ebdd7..26176ccbcbbc 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -68,6 +68,12 @@ struct xe_userptr {
#if IS_ENABLED(CONFIG_DRM_XE_USERPTR_INVAL_INJECT)
u32 divisor;
#endif
+
+#if IS_ENABLED(CONFIG_DRM_XE_EUDEBUG)
+ struct {
+ struct task_struct *task;
+ } eudebug;
+#endif
};
struct xe_vma {
--
2.43.0
