Hello Oded Gabbay,
The patch c216477363a3: "habanalabs: add debugfs support" from Feb
16, 2019, leads to the following Smatch static checker warning:
drivers/accel/habanalabs/common/debugfs.c:272 vm_show()
warn: sleeping in atomic context
drivers/accel/habanalabs/common/debugfs.c
241 static int vm_show(struct seq_file *s, void *data)
242 {
243 struct hl_debugfs_entry *entry = s->private;
244 struct hl_dbg_device_entry *dev_entry = entry->dev_entry;
245 struct hl_vm_hw_block_list_node *lnode;
246 struct hl_ctx *ctx;
247 struct hl_vm *vm;
248 struct hl_vm_hash_node *hnode;
249 struct hl_userptr *userptr;
250 struct hl_vm_phys_pg_pack *phys_pg_pack = NULL;
251 struct hl_va_range *va_range;
252 struct hl_vm_va_block *va_block;
253 enum vm_type *vm_type;
254 bool once = true;
255 u64 j;
256 int i;
257
258 if (!dev_entry->hdev->mmu_enable)
259 return 0;
260
261 spin_lock(&dev_entry->ctx_mem_hash_spinlock);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This is holding a spinlock.
262
263 list_for_each_entry(ctx, &dev_entry->ctx_mem_hash_list, debugfs_list) {
264 once = false;
265 seq_puts(s, "\n\n----------------------------------------------------");
266 seq_puts(s, "\n----------------------------------------------------\n\n");
267 seq_printf(s, "ctx asid: %u\n", ctx->asid);
268
269 seq_puts(s, "\nmappings:\n\n");
270 seq_puts(s, " virtual address size handle\n");
271 seq_puts(s, "----------------------------------------------------\n");
--> 272 mutex_lock(&ctx->mem_hash_lock);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
so it can't take a mutex or it leads to a sleeping in atomic bug. These
can be detected at runtime by enabling CONFIG_DEBUG_ATOMIC_SLEEP.
regards,
dan carpenter
