🐞 fix(opensbi-1.2): Free memory

Add a sbi call to reclaim memory and clear pmp settings when uninstalling the fluffy module

opensbi-1.2/include/sm/platform/pmp/enclave_mm.h

@@ -75,6 +75,8 @@ void* mm_alloc(unsigned long req_size, unsigned long* resp_size);
 
 int mm_free(void* paddr, unsigned long size);
 
+int mm_free_clear(void* paddr, unsigned long size);
+
 void print_buddy_system();
 
 #endif /* _ENCLAVE_MM_H */

opensbi-1.2/include/sm/print.h

@@ -2,7 +2,7 @@
 #define SM_PRINT_H
 
 #include <sbi/sbi_console.h>
-#define PENGLAI_DEBUG
+// #define PENGLAI_DEBUG
 #ifdef PENGLAI_DEBUG
 #define printm(...) sbi_printf(__VA_ARGS__)
 #else

opensbi-1.2/include/sm/sm.h

@@ -29,6 +29,7 @@ extern uintptr_t _fw_start[], _fw_end[];
 #define SBI_ALLOC_ENCLAVE_MM    93
 #define SBI_MEMORY_EXTEND       92
 #define SBI_MEMORY_RECLAIM      91
+#define SBI_FREE_ENCLAVE_MEM    90
 #define SBI_DEBUG_PRINT         88
 
 //Enclave SBI numbers
@@ -52,6 +53,11 @@ extern uintptr_t _fw_start[], _fw_end[];
 #define RESUME_FROM_STOP         2003
 #define RESUME_FROM_OCALL        2
 
+#define FLAG_DESTROY                      0
+#define DIRECT_DESTROY                    1
+#define FREE_MAX_MEMORY                   2
+#define FREE_SPEC_MEMORY                  3
+
 void sm_init();
 
 uintptr_t sm_mm_init(uintptr_t paddr, unsigned long size);
@@ -60,6 +66,8 @@ uintptr_t sm_mm_extend(uintptr_t paddr, unsigned long size);
 
 uintptr_t sm_alloc_enclave_mem(uintptr_t mm_alloc_arg);
 
+uintptr_t sm_free_enclave_mem(uintptr_t size_ptr,unsigned long flag);
+
 uintptr_t sm_create_enclave(uintptr_t enclave_create_args);
 
 uintptr_t sm_attest_enclave(uintptr_t enclave_id, uintptr_t report, uintptr_t nonce);

opensbi-1.2/lib/sbi/sbi_ecall_penglai.c

@@ -51,6 +51,9 @@ static int sbi_ecall_penglai_host_handler(unsigned long extid, unsigned long fun
 		case SBI_DESTROY_ENCLAVE:
 			ret = sm_destroy_enclave((uintptr_t *)regs, regs->a0);
 			break;
+		case SBI_FREE_ENCLAVE_MEM:
+			ret= sm_free_enclave_mem(regs->a0, regs->a1);
+			break;
 		default:
 			sbi_printf("[Penglai@Monitor] host interface(funcid:%ld) not supported yet\n", funcid);
 			ret = SBI_ENOTSUPP;

opensbi-1.2/lib/sbi/sm/enclave.c

@@ -113,7 +113,7 @@ struct link_mem_t* add_link_mem(struct link_mem_t** tail)
 	return new_link_mem;
 }
 
-int remove_link_mem(struct link_mem_t** head, struct link_mem_t* ptr)
+int remove_link_mem(struct link_mem_t** head, struct link_mem_t* ptr,bool clear)
 {
 	struct link_mem_t *cur_link_mem, *tmp_link_mem;
 	int retval =0;
@@ -122,7 +122,12 @@ int remove_link_mem(struct link_mem_t** head, struct link_mem_t* ptr)
 	if (cur_link_mem == ptr)
 	{
 		*head = cur_link_mem->next_link_mem;
-		mm_free(cur_link_mem, cur_link_mem->mem_size);
+		if (clear)
+		{
+			mm_free_clear(cur_link_mem, cur_link_mem->mem_size);
+		}else{
+			mm_free(cur_link_mem, cur_link_mem->mem_size);
+		}
 		return 1;
 	}
 
@@ -133,7 +138,12 @@ int remove_link_mem(struct link_mem_t** head, struct link_mem_t* ptr)
 			tmp_link_mem = cur_link_mem->next_link_mem;
 			cur_link_mem->next_link_mem = cur_link_mem->next_link_mem->next_link_mem;
 			//FIXME
-			mm_free(tmp_link_mem, tmp_link_mem->mem_size);
+			if (clear)
+			{
+				mm_free_clear(tmp_link_mem, tmp_link_mem->mem_size);
+			}else{
+				mm_free(tmp_link_mem, tmp_link_mem->mem_size);
+			}
 			return retval;
 		}
 	}
@@ -207,7 +217,7 @@ static struct enclave_t* alloc_enclave()
 	return enclave;
 }
 
-static int free_enclave(int eid)
+static int free_enclave(int eid, bool clear)
 {
 	struct link_mem_t *cur;
 	struct enclave_t *enclave = NULL;
@@ -226,6 +236,7 @@ static int free_enclave(int eid)
 			enclave->state = INVALID;
 			found = 1;
 			ret_val = 0;
+			remove_link_mem(&enclave_metadata_head,cur,clear);
 			break;
 		}
 		count += cur->slab_num;
@@ -462,7 +473,7 @@ uintptr_t create_enclave(struct enclave_sbi_param_t create_args)
 	spin_unlock(&enclave_metadata_lock);
 
 	//free enclave struct
-	free_enclave(eid); //the enclave state will be set INVALID here
+	free_enclave(eid,0); //the enclave state will be set INVALID here
 	return ENCLAVE_ERROR;
 }
 
@@ -602,7 +613,7 @@ uintptr_t destroy_enclave(uintptr_t* regs, unsigned int eid)
 		spin_unlock(&enclave_metadata_lock);
 
 		//free enclave struct
-		retval = free_enclave(eid); //the enclave state will be set INVALID here
+		retval = free_enclave(eid,0); //the enclave state will be set INVALID here
 		return retval;
 	}
 	//FIXME: what if the enclave->state is RUNNABLE now?
@@ -680,7 +691,7 @@ uintptr_t resume_enclave(uintptr_t* regs, unsigned int eid)
 		spin_unlock(&enclave_metadata_lock);
 
 		//free enclave struct
-		free_enclave(eid); //the enclave state will be set INVALID here
+		free_enclave(eid,0); //the enclave state will be set INVALID here
 		return ENCLAVE_SUCCESS; //this will break the infinite loop in the enclave-driver
 	}
 
@@ -771,8 +782,7 @@ uintptr_t exit_enclave(uintptr_t* regs, unsigned long retval)
 	spin_unlock(&enclave_metadata_lock);
 
 	//free enclave struct
-	free_enclave(eid);
-
+	free_enclave(eid, 0);
 	return 0;
 }
 
@@ -947,7 +957,7 @@ uintptr_t do_timer_irq(uintptr_t *regs, uintptr_t mcause, uintptr_t mepc)
 		spin_unlock(&enclave_metadata_lock);
 
 		//free enclave struct
-		retval = free_enclave(eid); //the enclave state will be set INVALID here
+		retval = free_enclave(eid,0); //the enclave state will be set INVALID here
 
 		retval = ENCLAVE_SUCCESS; //this means we will not run any more
 		goto timer_irq_out;

opensbi-1.2/lib/sbi/sm/platform/pmp/enclave_mm.c

@@ -1102,6 +1102,104 @@ int mm_free(void* req_paddr, unsigned long free_size)
 	//printm("after mm_free\r\n");
 	//print_buddy_system();
 
+mm_free_out:
+	spin_unlock(&pmp_bitmap_lock);
+	return ret_val;
+}
+//TODO:Reserved interfaces for calls to reclaim unused memory
+int mm_free_clear(void* req_paddr, unsigned long free_size)
+{
+	//check this paddr is 2^power aligned
+	uintptr_t paddr = (uintptr_t)req_paddr;
+	unsigned long order = ilog2(free_size-1) + 1;
+	unsigned long size = 1 << order;
+	if(check_mem_size(paddr, size) < 0)
+		return -1;
+
+	int ret_val = 0;
+	int region_idx = 0;
+	struct mm_list_t* mm_region = PADDR_2_MM_LIST(paddr);
+	mm_region->order = order;
+	mm_region->prev_mm = NULL;
+	mm_region->next_mm = NULL;
+
+	spin_lock(&pmp_bitmap_lock);
+
+	//print_buddy_system();
+
+	for(region_idx=0; region_idx < N_PMP_REGIONS; ++region_idx)
+	{
+		if(mm_regions[region_idx].valid && region_contain(mm_regions[region_idx].paddr, mm_regions[region_idx].size, paddr, size))
+		{
+			break;
+		}
+	}
+	if(region_idx >= N_PMP_REGIONS)
+	{
+		printm("mm_free: buddy system doesn't contain memory(addr 0x%lx, order %ld)\r\n", paddr, order);
+		ret_val = -1;
+		goto mm_free_out;
+	}
+
+	//check whether this region overlap with existing free mm_lists
+	struct mm_list_head_t* mm_list_head = mm_regions[region_idx].mm_list_head;
+	while(mm_list_head)
+	{
+		struct mm_list_t* mm_region = mm_list_head->mm_list;
+		while(mm_region)
+		{
+			uintptr_t region_paddr = (uintptr_t)MM_LIST_2_PADDR(mm_region);
+			unsigned long region_size = 1 << mm_region->order;
+			if(region_overlap(paddr, size, region_paddr, region_size))
+			{
+				printm("mm_free: memory(addr 0x%lx order %ld) overlap with free memory(addr 0x%lx order %d)\r\n", paddr, order, region_paddr, mm_region->order);
+				ret_val = -1;
+				break;
+			}
+			mm_region = mm_region->next_mm;
+		}
+		if(mm_region)
+			break;
+
+		mm_list_head = mm_list_head->next_list_head;
+	}
+	if(mm_list_head)
+	{
+		goto mm_free_out;
+	}
+
+	//insert with merge
+	ret_val = insert_mm_region(region_idx, mm_region, 1);
+	if(ret_val < 0)
+	{
+		printm("mm_free: failed to insert mm(addr 0x%lx, order %ld)\r\n in mm_regions[%d]\r\n", paddr, order, region_idx);
+	}
+
+	//printm("after mm_free\r\n");
+	//print_buddy_system();
+	int pmp_idx;
+	struct pmp_config_t pmp_config;
+	pmp_idx = REGION_TO_PMP(region_idx);
+	pmp_config	= get_pmp(pmp_idx);
+
+	struct mm_region_t mm_regiont = mm_regions[region_idx];
+	mm_list_head  = mm_regiont.mm_list_head;
+	struct mm_list_t *mm_list = mm_list_head->mm_list;
+	if (((long int *)MM_LIST_2_PADDR(mm_list) == (long int *)pmp_config.paddr)&&((pmp_config.size) == (1<<mm_list->order)))
+	{
+		delete_certain_region(region_idx,&mm_list_head,mm_list);
+		mm_regions[region_idx].valid	= 0;
+	    mm_regions[region_idx].paddr	= 0;
+	    mm_regions[region_idx].mm_list_head = NULL;
+		// release_big_emem_lock(__func__);
+		clear_pmp_and_sync(pmp_idx);
+		// acquire_big_emem_lock(__func__);
+	}
+
+	printm("***after mm_free***\r\n");
+	print_buddy_system();
+	dump_pmps();
+
 mm_free_out:
 	spin_unlock(&pmp_bitmap_lock);
 	return ret_val;

opensbi-1.2/lib/sbi/sm/sm.c

@@ -273,3 +273,52 @@ uintptr_t sm_do_timer_irq(uintptr_t *regs, uintptr_t mcause, uintptr_t mepc)
 	regs[11] = ret; //value
 	return ret;
 }
+
+uintptr_t sm_free_enclave_mem(uintptr_t size_ptr, unsigned long flag)
+{
+	uintptr_t ret	   = 0;
+	unsigned long size = 0;
+	dump_pmps();
+	switch (flag) {
+	case FREE_MAX_MEMORY:
+		for (size_t i = NPMP - 2; i >= 0; i--) {
+			int pmp_idx		       = i;
+			struct pmp_config_t pmp_config = get_pmp(pmp_idx);
+
+			if (pmp_config.paddr == 0 || pmp_config.size == 0) {
+				continue;
+			}
+
+			if (pmp_idx == 0) {
+				printm("M mode: sm_memory_reclaim: There is no mem to reclaim\r\n");
+				dump_pmps();
+				size = 0;
+				ret  = 0;
+				break;
+			}
+
+			clear_pmp_and_sync(pmp_idx);
+			ret  = pmp_config.paddr;
+			size = pmp_config.size;
+
+			break;
+		}
+		break;
+	case FREE_SPEC_MEMORY:
+		/*free */
+		{	//TODO:Reserved interfaces for calls to reclaim unused memory
+			struct pmp_config_t pmp_config = get_pmp(15);
+			clear_pmp_and_sync(15);
+			ret  = pmp_config.paddr;
+			size = 0;
+		}
+		break;
+	default:
+		ret  = 0;
+		size = 0;
+		break;
+	}
+
+	copy_to_host((void *)size_ptr, (void *)(&size), sizeof(unsigned long));
+	return ret;
+}