>From 7d6cf630c1adbb9787a24c2994230373c2b20a8f Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 20 Sep 2013 09:55:39 -0500 Subject: [PATCH] efi: Handle arbitrary Unicode characters Instead of truncating UTF-16 assuming all characters is ASCII, properly convert it to UTF-8. Signed-off-by: H. Peter Anvin --- arch/x86/boot/compressed/eboot.c | 3 +- drivers/firmware/efi/efi-stub-helper.c | 89 ++++++++++++++++++++++++++-------- 2 files changed, 71 insertions(+), 21 deletions(-) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index bf56206..aacbe50 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -488,8 +488,7 @@ struct boot_params *make_boot_params(void *handle, efi_system_table_t *_table) hdr->type_of_loader = 0x21; /* Convert unicode cmdline to ascii */ - cmdline_ptr = efi_convert_cmdline_to_ascii(sys_table, image, - &options_size); + cmdline_ptr = efi_convert_cmdline(sys_table, image, &options_size); if (!cmdline_ptr) goto fail; hdr->cmd_line_ptr = (unsigned long)cmdline_ptr; diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c index c91e757..7d4c1a4 100644 --- a/drivers/firmware/efi/efi-stub-helper.c +++ b/drivers/firmware/efi/efi-stub-helper.c @@ -567,20 +567,72 @@ static efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg, return status; } -/* Convert the unicode UEFI command line to ASCII to pass to kernel. + +/* + * 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. + */ +static u8 *efi_utf8_to_utf16(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. */ -static char *efi_convert_cmdline_to_ascii(efi_system_table_t *sys_table_arg, - efi_loaded_image_t *image, - int *cmd_line_len) +static char *efi_convert_cmdline(efi_system_table_t *sys_table_arg, + efi_loaded_image_t *image, + int *cmd_line_len) { - u16 *s2; + const u16 *s2; u8 *s1 = NULL; unsigned long cmdline_addr = 0; int load_options_size = image->load_options_size / 2; /* ASCII */ - void *options = image->load_options; - int options_size = 0; + const void *options = image->load_options; + int options_bytes = 0; /* UTF-8 bytes */ + int options_chars = 0; /* UTF-16 chars */ efi_status_t status; int i; u16 zero = 0; @@ -588,40 +640,39 @@ static char *efi_convert_cmdline_to_ascii(efi_system_table_t *sys_table_arg, if (options) { s2 = options; while (*s2 && *s2 != '\n' && options_size < load_options_size) { + options_bytes += efi_utf8_bytes(*s2); s2++; - options_size++; } + options_chars = s2 - options; } - if (options_size == 0) { - /* No command line options, so return empty string*/ - options_size = 1; + if (!options_chars) { + /* No command line options, so return empty string */ options = &zero; } - options_size++; /* NUL termination */ + options_bytes++; /* NUL termination */ + #ifdef CONFIG_ARM /* For ARM, allocate at a high address to avoid reserved * regions at low addresses that we don't know the specfics of * at the time we are processing the command line. */ - status = efi_high_alloc(sys_table_arg, options_size, 0, + status = efi_high_alloc(sys_table_arg, options_bytes, 0, &cmdline_addr, 0xfffff000); #else - status = efi_low_alloc(sys_table_arg, options_size, 0, + status = efi_low_alloc(sys_table_arg, options_bytes, 0, &cmdline_addr); #endif if (status != EFI_SUCCESS) return NULL; s1 = (u8 *)cmdline_addr; - s2 = (u16 *)options; - - for (i = 0; i < options_size - 1; i++) - *s1++ = *s2++; + s2 = (const u16 *)options; + s1 = efi_utf16_to_utf8(s1, s2, options_chars); *s1 = '\0'; - *cmd_line_len = options_size; + *cmd_line_len = options_bytes; return (char *)cmdline_addr; } -- 1.7.11.7