diff options
author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-05-18 22:07:16 +0300 |
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committer | Ard Biesheuvel <ardb@kernel.org> | 2020-05-20 20:09:20 +0300 |
commit | 04b24409b42a9fcae2379a6ddcf9c827b9af7a45 (patch) | |
tree | dabfaad46777b92ff88edf4dfffcc840f4414a64 /drivers/firmware/efi/libstub/efi-stub-helper.c | |
parent | 15c316bcbc23b777eae4e21f129526190aa20af1 (diff) | |
download | linux-04b24409b42a9fcae2379a6ddcf9c827b9af7a45.tar.xz |
efi/libstub: Use snprintf with %ls to convert the command line
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@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-25-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'drivers/firmware/efi/libstub/efi-stub-helper.c')
-rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 66 |
1 files changed, 6 insertions, 60 deletions
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 4d544f395403..9fb107e9355b 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -206,46 +206,6 @@ efi_status_t efi_parse_options(char const *cmdline) } /* - * 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. * Returns NULL on error. @@ -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) { 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; |