Now we can use snprintf to do the UTF-16 to UTF-8 translation for the
command line.
Drop the special "zero" trick to handle an empty command line. This was
unnecessary even before this since with options_chars == 0,
efi_utf16_to_utf8 would not have accessed options at all. snprintf won't
access it either with a precision of 0.
Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx>
---
.../firmware/efi/libstub/efi-stub-helper.c | 68 ++-----------------
1 file changed, 7 insertions(+), 61 deletions(-)
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 01476d8f8edf..e3324f7b38b8 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -205,46 +205,6 @@ efi_status_t efi_parse_options(char const *cmdline)
return EFI_SUCCESS;
}
-/*
- * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
- */
-static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n)
-{
- unsigned int c;
-
- while (n--) {
- c = *src++;
- if (n && c >= 0xd800 && c <= 0xdbff &&
- *src >= 0xdc00 && *src <= 0xdfff) {
- c = 0x10000 + ((c & 0x3ff) << 10) + (*src & 0x3ff);
- src++;
- n--;
- }
- if (c >= 0xd800 && c <= 0xdfff)
- c = 0xfffd; /* Unmatched surrogate */
- if (c < 0x80) {
- *dst++ = c;
- continue;
- }
- if (c < 0x800) {
- *dst++ = 0xc0 + (c >> 6);
- goto t1;
- }
- if (c < 0x10000) {
- *dst++ = 0xe0 + (c >> 12);
- goto t2;
- }
- *dst++ = 0xf0 + (c >> 18);
- *dst++ = 0x80 + ((c >> 12) & 0x3f);
- t2:
- *dst++ = 0x80 + ((c >> 6) & 0x3f);
- t1:
- *dst++ = 0x80 + (c & 0x3f);
- }
-
- return dst;
-}
-
/*
* Convert the unicode UEFI command line to ASCII to pass to kernel.
* Size of memory allocated return in *cmd_line_len.
@@ -254,18 +214,15 @@ char *efi_convert_cmdline(efi_loaded_image_t *image,
int *cmd_line_len, unsigned long max_addr)
{
const u16 *s2;
- u8 *s1 = NULL;
unsigned long cmdline_addr = 0;
- int load_options_chars = efi_table_attr(image, load_options_size) / 2;
+ int options_chars = efi_table_attr(image, load_options_size) / 2;
const u16 *options = efi_table_attr(image, load_options);
int options_bytes = 0; /* UTF-8 bytes */
- int options_chars = 0; /* UTF-16 chars */
efi_status_t status;
- u16 zero = 0;
if (options) {
s2 = options;
- while (options_chars < load_options_chars) {
+ while (options_chars--) {
u16 c = *s2++;
if (c == L'\0' || c == L'\n')
@@ -276,7 +233,6 @@ char *efi_convert_cmdline(efi_loaded_image_t *image,
* 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
@@ -288,35 +244,25 @@ char *efi_convert_cmdline(efi_loaded_image_t *image,
* we must ignore it since we can't access the
* low surrogate.
*/
- if (options_chars == load_options_chars) {
+ if (!options_chars)
options_bytes -= 3;
- options_chars--;
- break;
- } else if ((*s2 & 0xfc00) == 0xdc00) {
+ else if ((*s2 & 0xfc00) == 0xdc00) {
options_bytes++;
- options_chars++;
+ options_chars--;
s2++;
}
}
}
}
- if (!options_chars) {
- /* No command line options, so return empty string*/
- options = &zero;
- }
-
options_bytes++; /* NUL termination */
status = efi_allocate_pages(options_bytes, &cmdline_addr, max_addr);
if (status != EFI_SUCCESS)
return NULL;
- s1 = (u8 *)cmdline_addr;
- s2 = (const u16 *)options;
-
- s1 = efi_utf16_to_utf8(s1, s2, options_chars);
- *s1 = '\0';
+ snprintf((char *)cmdline_addr, options_bytes,
+ "%.*ls", options_bytes-1, options);
*cmd_line_len = options_bytes;
return (char *)cmdline_addr;
--
2.26.2
