efi_loader: correct signature of GetPosition, SetPosition

The UEFI spec requires that file positions are passed as u64 in
GetPosition() and SetPosition().

Check if the file handle points to a directory in GetPosition().

Provide a unit test for GetPosition() and SetPosition().

Fix Coverity warning CID 184079 (CONSTANT_EXPRESSION_RESULT).

Add comments.

Fixes: b6dd57773719 ("efi_loader: use correct types in EFI_FILE_PROTOCOL")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 28 insertions, 2 deletions

diff --git a/lib/efi_selftest/efi_selftest_block_device.c b/lib/efi_selftest/efi_selftest_block_device.c
index 1cd13042e9..d4e4fac1c7 100644
--- a/lib/efi_selftest/efi_selftest_block_device.c
+++ b/lib/efi_selftest/efi_selftest_block_device.c
@@ -308,6 +308,7 @@ static int execute(void)
 	} system_info;
 	efi_uintn_t buf_size;
 	char buf[16] __aligned(ARCH_DMA_MINALIGN);
+	u64 pos;
 
 	/* Connect controller to virtual disk */
 	ret = boottime->connect_controller(disk_handle, NULL, NULL, 1);
@@ -392,21 +393,36 @@ static int execute(void)
 		efi_st_error("Failed to open file\n");
 		return EFI_ST_FAILURE;
 	}
+	ret = file->setpos(file, 1);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("SetPosition failed\n");
+		return EFI_ST_FAILURE;
+	}
 	buf_size = sizeof(buf) - 1;
 	ret = file->read(file, &buf_size, buf);
 	if (ret != EFI_SUCCESS) {
 		efi_st_error("Failed to read file\n");
 		return EFI_ST_FAILURE;
 	}
-	if (buf_size != 13) {
+	if (buf_size != 12) {
 		efi_st_error("Wrong number of bytes read: %u\n",
 			     (unsigned int)buf_size);
 		return EFI_ST_FAILURE;
 	}
-	if (efi_st_memcmp(buf, "Hello world!", 12)) {
+	if (efi_st_memcmp(buf, "ello world!", 11)) {
 		efi_st_error("Unexpected file content\n");
 		return EFI_ST_FAILURE;
 	}
+	ret = file->getpos(file, &pos);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("GetPosition failed\n");
+		return EFI_ST_FAILURE;
+	}
+	if (pos != 13) {
+		efi_st_error("GetPosition returned %u, expected 13\n",
+			     (unsigned int)pos);
+		return EFI_ST_FAILURE;
+	}
 	ret = file->close(file);
 	if (ret != EFI_SUCCESS) {
 		efi_st_error("Failed to close file\n");
@@ -434,6 +450,16 @@ static int execute(void)
 		efi_st_error("Failed to close file\n");
 		return EFI_ST_FAILURE;
 	}
+	ret = file->getpos(file, &pos);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("GetPosition failed\n");
+		return EFI_ST_FAILURE;
+	}
+	if (pos != 7) {
+		efi_st_error("GetPosition returned %u, expected 7\n",
+			     (unsigned int)pos);
+		return EFI_ST_FAILURE;
+	}
 
 	/* Verify file */
 	boottime->set_mem(buf, sizeof(buf), 0);