fix(manifest): ignore memory regions with size 0

This patch modifies check_and_record_mem_regions() to return an error on
regions with size '0' when parsing a secure partition's manifest.

Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I9d9ee97357440849ec51bd88db5296069abc322e
diff --git a/inc/hf/manifest.h b/inc/hf/manifest.h
index c7a6869..15f415d 100644
--- a/inc/hf/manifest.h
+++ b/inc/hf/manifest.h
@@ -249,6 +249,7 @@
 	MANIFEST_ERROR_MEMORY_REGION_NODE_EMPTY,
 	MANIFEST_ERROR_DEVICE_REGION_NODE_EMPTY,
 	MANIFEST_ERROR_RXTX_SIZE_MISMATCH,
+	MANIFEST_ERROR_MEM_REGION_EMPTY,
 	MANIFEST_ERROR_MEM_REGION_OVERLAP,
 	MANIFEST_ERROR_INVALID_MEM_PERM,
 	MANIFEST_ERROR_INTERRUPT_ID_REPEATED,
diff --git a/src/manifest.c b/src/manifest.c
index be9689a..4875e12 100644
--- a/src/manifest.c
+++ b/src/manifest.c
@@ -414,11 +414,18 @@
 	return MANIFEST_SUCCESS;
 }
 
-static bool check_and_record_mem_regions(uintptr_t base_address,
-					 uint32_t page_count)
+static enum manifest_return_code check_and_record_mem_regions(
+	uintptr_t base_address, uint32_t page_count)
 {
 	uintptr_t limit = base_address + (page_count * PAGE_SIZE) - 1U;
 
+	if (page_count == 0U) {
+		dlog_error(
+			"Empty memory region defined with base address: %x\n",
+			base_address);
+		return MANIFEST_ERROR_MEM_REGION_EMPTY;
+	}
+
 	for (size_t i = 0; i < allocated_mem_regions_index; i++) {
 		uintptr_t mem_region_base = manifest_data->mem_regions[i].base;
 		uintptr_t mem_region_limit =
@@ -433,7 +440,7 @@
 				"Overlapping region %#x - %#x\n",
 				base_address, limit, mem_region_base,
 				mem_region_limit);
-			return false;
+			return MANIFEST_ERROR_MEM_REGION_OVERLAP;
 		}
 	}
 
@@ -442,7 +449,7 @@
 	manifest_data->mem_regions[allocated_mem_regions_index].limit = limit;
 	allocated_mem_regions_index++;
 
-	return true;
+	return MANIFEST_SUCCESS;
 }
 
 static enum manifest_return_code parse_ffa_memory_region_node(
@@ -481,10 +488,8 @@
 		dlog_verbose("      Pages_count:  %u\n",
 			     mem_regions[i].page_count);
 
-		if (!check_and_record_mem_regions(mem_regions[i].base_address,
-						  mem_regions[i].page_count)) {
-			return MANIFEST_ERROR_MEM_REGION_OVERLAP;
-		}
+		TRY(check_and_record_mem_regions(mem_regions[i].base_address,
+						 mem_regions[i].page_count));
 
 		TRY(read_uint32(mem_node, "attributes",
 				&mem_regions[i].attributes));
@@ -1271,6 +1276,8 @@
 		return "Device-region node should have at least one entry";
 	case MANIFEST_ERROR_RXTX_SIZE_MISMATCH:
 		return "RX and TX buffers should be of same size";
+	case MANIFEST_ERROR_MEM_REGION_EMPTY:
+		return "Memory region should have at least one page";
 	case MANIFEST_ERROR_MEM_REGION_OVERLAP:
 		return "Memory region overlaps with one already allocated";
 	case MANIFEST_ERROR_INVALID_MEM_PERM:
diff --git a/src/manifest_test.cc b/src/manifest_test.cc
index 04d97cf..e5d03d6 100644
--- a/src/manifest_test.cc
+++ b/src/manifest_test.cc
@@ -1132,6 +1132,38 @@
 		  MANIFEST_ERROR_PROPERTY_NOT_FOUND);
 	manifest_dealloc();
 
+	/* Empty memory region */
+	/* clang-format off */
+	dtb = ManifestDtBuilder()
+		.FfaValidManifest()
+		.StartChild("memory-regions")
+			.Compatible({ "arm,ffa-manifest-memory-regions" })
+			.Label("rx")
+			.StartChild("rx")
+				.Description("rx-buffer")
+				.Property("base-address", "<0x7300000>")
+				.Property("pages-count", "<0>")
+				.Property("attributes", "<1>")
+			.EndChild()
+			.Label("tx")
+			.StartChild("tx")
+				.Description("tx-buffer")
+				.Property("base-address", "<0x7310000>")
+				.Property("pages-count", "<2>")
+				.Property("attributes", "<3>")
+			.EndChild()
+		.EndChild()
+		.StartChild("rx_tx-info")
+			.Compatible({ "arm,ffa-manifest-rx_tx-buffer" })
+			.Property("rx-buffer", "<&rx>")
+			.Property("tx-buffer", "<&tx>")
+		.EndChild()
+		.Build();
+	/* clang-format on */
+	ASSERT_EQ(ffa_manifest_from_vec(&m, dtb),
+		  MANIFEST_ERROR_MEM_REGION_EMPTY);
+	manifest_dealloc();
+
 	/* Overlapping memory regions */
 	/* clang-format off */
 	dtb = ManifestDtBuilder()