efi/libstub: Get the exact UTF-8 length (15c316bc) · Commits · 戴 / test

drivers/firmware/efi/libstub/efi-stub-helper.c

+32 −12

Original line number	Diff line number	Diff line
		@@ -205,15 +205,6 @@ efi_status_t efi_parse_options(char const *cmdline)
		return EFI_SUCCESS;
		}

		/*
		* Get the number of UTF-8 bytes corresponding to an UTF-16 character.
		* This overestimates for surrogates, but that is okay.
		*/
		static int efi_utf8_bytes(u16 c)
		{
		return 1 + (c >= 0x80) + (c >= 0x800);
		}

		/*
		* Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
		*/
		@@ -274,10 +265,39 @@ char efi_convert_cmdline(efi_loaded_image_t image,

		if (options) {
		s2 = options;
		while (s2 && s2 != '\n'
		&& options_chars < load_options_chars) {
		options_bytes += efi_utf8_bytes(*s2++);
		while (options_chars < load_options_chars) {
		u16 c = *s2++;

		if (c == L'\0' \|\| c == L'\n')
		break;
		/*
		* Get the number of UTF-8 bytes corresponding to a
		* UTF-16 character.
		* The first part handles everything in the BMP.
		*/
		options_bytes += 1 + (c >= 0x80) + (c >= 0x800);
		options_chars++;
		/*
		* Add one more byte for valid surrogate pairs. Invalid
		* surrogates will be replaced with 0xfffd and take up
		* only 3 bytes.
		*/
		if ((c & 0xfc00) == 0xd800) {
		/*
		* If the very last word is a high surrogate,
		* we must ignore it since we can't access the
		* low surrogate.
		*/
		if (options_chars == load_options_chars) {
		options_bytes -= 3;
		options_chars--;
		break;
		} else if ((*s2 & 0xfc00) == 0xdc00) {
		options_bytes++;
		options_chars++;
		s2++;
		}
		}
		}
		}