efi_loader: replace a u16_strdup with alloc + memcpy
Heinrich reports that on RISC-V unaligned access is emulated by OpenSBI
which is very slow. Performance wise it's better if we skip the calls
to u16_strdup() -- which in turn calls u16_strsize() and just allocate/copy the
memory directly. The access to dp.length may still be unaligned, but that's
way less than what u16_strsize() would do
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Use malloc() instead of calloc().
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index d6dc823..520c730 100644
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -1137,6 +1137,7 @@
container_of(fp, struct efi_device_path_file_path, dp);
struct efi_file_handle *f2;
u16 *filename;
+ size_t filename_sz;
if (!EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) {
printf("bad file path!\n");
@@ -1149,9 +1150,14 @@
* protocol member functions to be aligned. So memcpy it
* unconditionally
*/
- filename = u16_strdup(fdp->str);
+ if (fdp->dp.length <= offsetof(struct efi_device_path_file_path, str))
+ return NULL;
+ filename_sz = fdp->dp.length -
+ offsetof(struct efi_device_path_file_path, str);
+ filename = malloc(filename_sz);
if (!filename)
return NULL;
+ memcpy(filename, fdp->str, filename_sz);
EFI_CALL(ret = f->open(f, &f2, filename,
EFI_FILE_MODE_READ, 0));
free(filename);