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>

diff --git a/include/efi_api.h b/include/efi_api.h
index bea19a5..e850b95 100644 (file)
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -914,9 +914,9 @@ struct efi_file_handle {
        efi_status_t (EFIAPI *write)(struct efi_file_handle *file,
                        efi_uintn_t *buffer_size, void *buffer);
        efi_status_t (EFIAPI *getpos)(struct efi_file_handle *file,
-                       efi_uintn_t *pos);
+                                     u64 *pos);
        efi_status_t (EFIAPI *setpos)(struct efi_file_handle *file,
-                       efi_uintn_t pos);
+                                     u64 pos);
        efi_status_t (EFIAPI *getinfo)(struct efi_file_handle *file,
                        const efi_guid_t *info_type, efi_uintn_t *buffer_size,
                        void *buffer);

diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index 0753a36..c1e285e 100644 (file)
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -436,28 +436,51 @@ error:
        return EFI_EXIT(ret);
 }
 
+/**
+ * efi_file_getpos() - get current position in file
+ *
+ * This function implements the GetPosition service of the EFI file protocol.
+ * See the UEFI spec for details.
+ *
+ * @file:      file handle
+ * @pos:       pointer to file position
+ * Return:     status code
+ */
 static efi_status_t EFIAPI efi_file_getpos(struct efi_file_handle *file,
-                                          efi_uintn_t *pos)
+                                          u64 *pos)
 {
+       efi_status_t ret = EFI_SUCCESS;
        struct file_handle *fh = to_fh(file);
 
        EFI_ENTRY("%p, %p", file, pos);
 
-       if (fh->offset <= SIZE_MAX) {
-               *pos = fh->offset;
-               return EFI_EXIT(EFI_SUCCESS);
-       } else {
-               return EFI_EXIT(EFI_DEVICE_ERROR);
+       if (fh->isdir) {
+               ret = EFI_UNSUPPORTED;
+               goto out;
        }
+
+       *pos = fh->offset;
+out:
+       return EFI_EXIT(ret);
 }
 
+/**
+ * efi_file_setpos() - set current position in file
+ *
+ * This function implements the SetPosition service of the EFI file protocol.
+ * See the UEFI spec for details.
+ *
+ * @file:      file handle
+ * @pos:       new file position
+ * Return:     status code
+ */
 static efi_status_t EFIAPI efi_file_setpos(struct efi_file_handle *file,
-               efi_uintn_t pos)
+                                          u64 pos)
 {
        struct file_handle *fh = to_fh(file);
        efi_status_t ret = EFI_SUCCESS;
 
-       EFI_ENTRY("%p, %zu", file, pos);
+       EFI_ENTRY("%p, %llu", file, pos);
 
        if (fh->isdir) {
                if (pos != 0) {

diff --git a/lib/efi_selftest/efi_selftest_block_device.c b/lib/efi_selftest/efi_selftest_block_device.c
index 1cd1304..d4e4fac 100644 (file)
--- 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);