efi: pstore: Return proper errors on UEFI failures

Right now efi-pstore either returns 0 (success) or -EIO; but we
do have a function to convert UEFI errors in different standard
error codes, helping to narrow down potential issues more accurately.

So, let's use this helper here.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 5b9dc26e6bcb963289debaee0084ed9494782d71..552c78f5f05902a20f78ad7671bbb36d5542a7f2 100644 (file)
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -136,7 +136,7 @@ static int efi_pstore_read_func(struct pstore_record *record,
                                     &size, record->buf);
        if (status != EFI_SUCCESS) {
                kfree(record->buf);
-               return -EIO;
+               return efi_status_to_err(status);
        }
 
        /*
@@ -189,7 +189,7 @@ static ssize_t efi_pstore_read(struct pstore_record *record)
                        return 0;
 
                if (status != EFI_SUCCESS)
-                       return -EIO;
+                       return efi_status_to_err(status);
 
                /* skip variables that don't concern us */
                if (efi_guidcmp(guid, LINUX_EFI_CRASH_GUID))
@@ -227,7 +227,7 @@ static int efi_pstore_write(struct pstore_record *record)
                                            record->size, record->psi->buf,
                                            true);
        efivar_unlock();
-       return status == EFI_SUCCESS ? 0 : -EIO;
+       return efi_status_to_err(status);
 };
 
 static int efi_pstore_erase(struct pstore_record *record)
@@ -238,7 +238,7 @@ static int efi_pstore_erase(struct pstore_record *record)
                                     PSTORE_EFI_ATTRIBUTES, 0, NULL);
 
        if (status != EFI_SUCCESS && status != EFI_NOT_FOUND)
-               return -EIO;
+               return efi_status_to_err(status);
        return 0;
 }