On 11/11/22 19:04, Ilias Apalodimas wrote:
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 <[email protected]>
---
lib/efi_loader/efi_file.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index 750d380ad967..ff731db6cb8c 100644
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -1128,6 +1128,7 @@ struct efi_file_handle *efi_file_from_path(struct
efi_device_path *fp)
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");
@@ -1140,9 +1141,14 @@ struct efi_file_handle *efi_file_from_path(struct
efi_device_path *fp)
* 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 = calloc(1, filename_sz);
As we copy filename_sz bytes there is not need for zeroing out. We can
use malloc() here.
Otherwise:
Reviewed-by: Heinrich Schuchardt <[email protected]>
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);
