> -----Original Message----- > From: Arvind Sankar <nivedita@xxxxxxxxxxxx> > Sent: Saturday, September 12, 2020 12:51 > To: Jacobo Pantoja > Cc: Limonciello, Mario; Ard Biesheuvel; Peter Jones; linux-efi > Subject: [RFC PATCH 1/2] efi/x86: Add a quirk to support command line > arguments on Dell EFI firmware > > > [EXTERNAL EMAIL] > > At least some versions of Dell EFI firmware pass the entire > EFI_LOAD_OPTION descriptor, rather than just the OptionalData part, to > the loaded image. > > To handle this, add a quirk to check if the options look like a valid > EFI_LOAD_OPTION descriptor, and if so, use the OptionalData part as the > command line. I think it would be useful to document in the commit message the specifics of at least the failure reported by Jacobo (Precision T3620 FW 2.15.0). > > Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> > Reported-by: Jacobo Pantoja <jacobopantoja@xxxxxxxxx> > Link: https://lore.kernel.org/linux- > efi/20200907170021.GA2284449@xxxxxxxxxxxxxxxxxx/ > --- > .../firmware/efi/libstub/efi-stub-helper.c | 99 ++++++++++++++++++- > drivers/firmware/efi/libstub/efistub.h | 31 ++++++ > drivers/firmware/efi/libstub/file.c | 5 +- > 3 files changed, 133 insertions(+), 2 deletions(-) > > diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c > b/drivers/firmware/efi/libstub/efi-stub-helper.c > index f735db55adc0..294958ff1ee6 100644 > --- a/drivers/firmware/efi/libstub/efi-stub-helper.c > +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c > @@ -238,6 +238,100 @@ efi_status_t efi_parse_options(char const *cmdline) > return EFI_SUCCESS; > } > > +/* > + * The EFI_LOAD_OPTION descriptor has the following layout: > + * u32 Attributes; > + * u16 FilePathListLength; > + * u16 Description[]; > + * efi_device_path_protocol_t FilePathList[]; > + * u8 OptionalData[]; > + * > + * This function validates and unpacks the variable-size data fields. > + */ > +static > +bool efi_load_option_unpack(efi_load_option_unpacked_t *dest, > + const efi_load_option_t *src, size_t size) > +{ > + > + const void *pos; > + u16 c; > + efi_device_path_protocol_t header; > + const efi_char16_t *description; > + const efi_device_path_protocol_t *file_path_list; Should re-order to reverse xmas tree order. > + > + if (size < offsetof(efi_load_option_t, variable_data)) > + return false; > + pos = src->variable_data; > + size -= offsetof(efi_load_option_t, variable_data); > + > + if ((src->attributes & ~EFI_LOAD_OPTION_MASK) != 0) > + return false; > + > + /* Scan description. */ > + description = pos; > + do { > + if (size < sizeof(c)) > + return false; > + c = *(const u16 *)pos; > + pos += sizeof(c); > + size -= sizeof(c); > + } while (c != L'\0'); > + > + /* Scan file_path_list. */ > + file_path_list = pos; > + do { > + if (size < sizeof(header)) > + return false; > + header = *(const efi_device_path_protocol_t *)pos; > + if (header.length < sizeof(header)) > + return false; > + if (size < header.length) > + return false; > + pos += header.length; > + size -= header.length; > + } while ((header.type != EFI_DEV_END_PATH && header.type != > EFI_DEV_END_PATH2) || > + (header.sub_type != EFI_DEV_END_ENTIRE)); > + if (pos != (const void *)file_path_list + src->file_path_list_length) > + return false; > + > + dest->attributes = src->attributes; > + dest->file_path_list_length = src->file_path_list_length; > + dest->description = description; > + dest->file_path_list = file_path_list; > + dest->optional_data_size = size; > + dest->optional_data = size ? pos : NULL; > + > + return true; > +} > + > +/* > + * At least some versions of Dell firmware pass the entire contents of the > + * Boot#### variable, i.e. the EFI_LOAD_OPTION descriptor, rather than just > the > + * OptionalData field. > + * > + * Detect this case and extract OptionalData. > + */ > +void efi_apply_loadoptions_quirk(const void **load_options, int > *load_options_size) > +{ > + const efi_load_option_t *load_option = *load_options; > + efi_load_option_unpacked_t load_option_unpacked; > + > + if (!IS_ENABLED(CONFIG_X86)) > + return; > + if (!load_option) > + return; > + if (*load_options_size < sizeof(*load_option)) > + return; > + if ((load_option->attributes & ~EFI_LOAD_OPTION_BOOT_MASK) != 0) > + return; > + > + if (!efi_load_option_unpack(&load_option_unpacked, load_option, > *load_options_size)) > + return; > + In case this was ever to be attributed to a cause for someone to fail to boot, it may be useful to drop a pr_debug here that could be easily turned on. > + *load_options = load_option_unpacked.optional_data; > + *load_options_size = load_option_unpacked.optional_data_size; > +} > + > /* > * Convert the unicode UEFI command line to ASCII to pass to kernel. > * Size of memory allocated return in *cmd_line_len. > @@ -247,12 +341,15 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int > *cmd_line_len) > { > const u16 *s2; > unsigned long cmdline_addr = 0; > - int options_chars = efi_table_attr(image, load_options_size) / 2; > + int options_chars = efi_table_attr(image, load_options_size); > const u16 *options = efi_table_attr(image, load_options); > int options_bytes = 0, safe_options_bytes = 0; /* UTF-8 bytes */ > bool in_quote = false; > efi_status_t status; > > + efi_apply_loadoptions_quirk((const void **)&options, &options_chars); > + options_chars /= sizeof(*options); > + > if (options) { > s2 = options; > while (options_bytes < COMMAND_LINE_SIZE && options_chars--) { > diff --git a/drivers/firmware/efi/libstub/efistub.h > b/drivers/firmware/efi/libstub/efistub.h > index 85050f5a1b28..589d07acb22d 100644 > --- a/drivers/firmware/efi/libstub/efistub.h > +++ b/drivers/firmware/efi/libstub/efistub.h > @@ -688,6 +688,35 @@ union efi_load_file_protocol { > } mixed_mode; > }; > > +typedef struct { > + u32 attributes; > + u16 file_path_list_length; > + u8 variable_data[]; > + // efi_char16_t description[]; > + // efi_device_path_protocol_t file_path_list[]; > + // u8 optional_data[]; > +} __packed efi_load_option_t; > + > +#define EFI_LOAD_OPTION_ACTIVE 0x0001U > +#define EFI_LOAD_OPTION_FORCE_RECONNECT 0x0002U > +#define EFI_LOAD_OPTION_HIDDEN 0x0008U > +#define EFI_LOAD_OPTION_CATEGORY 0x1f00U > +#define EFI_LOAD_OPTION_CATEGORY_BOOT 0x0000U > +#define EFI_LOAD_OPTION_CATEGORY_APP 0x0100U > + > +#define EFI_LOAD_OPTION_BOOT_MASK \ > + (EFI_LOAD_OPTION_ACTIVE|EFI_LOAD_OPTION_HIDDEN|EFI_LOAD_OPTION_CATEGORY) > +#define EFI_LOAD_OPTION_MASK > (EFI_LOAD_OPTION_FORCE_RECONNECT|EFI_LOAD_OPTION_BOOT_MASK) > + > +typedef struct { > + u32 attributes; > + u16 file_path_list_length; > + const efi_char16_t *description; > + const efi_device_path_protocol_t *file_path_list; > + size_t optional_data_size; > + const void *optional_data; > +} efi_load_option_unpacked_t; > + > void efi_pci_disable_bridge_busmaster(void); > > typedef efi_status_t (*efi_exit_boot_map_processing)( > @@ -730,6 +759,8 @@ __printf(1, 2) int efi_printk(char const *fmt, ...); > > void efi_free(unsigned long size, unsigned long addr); > > +void efi_apply_loadoptions_quirk(const void **load_options, int > *load_options_size); > + > char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len); > > efi_status_t efi_get_memory_map(struct efi_boot_memmap *map); > diff --git a/drivers/firmware/efi/libstub/file.c > b/drivers/firmware/efi/libstub/file.c > index 630caa6b1f4c..4e81c6077188 100644 > --- a/drivers/firmware/efi/libstub/file.c > +++ b/drivers/firmware/efi/libstub/file.c > @@ -136,7 +136,7 @@ efi_status_t handle_cmdline_files(efi_loaded_image_t > *image, > unsigned long *load_size) > { > const efi_char16_t *cmdline = image->load_options; > - int cmdline_len = image->load_options_size / 2; > + int cmdline_len = image->load_options_size; > unsigned long efi_chunk_size = ULONG_MAX; > efi_file_protocol_t *volume = NULL; > efi_file_protocol_t *file; > @@ -148,6 +148,9 @@ efi_status_t handle_cmdline_files(efi_loaded_image_t > *image, > if (!load_addr || !load_size) > return EFI_INVALID_PARAMETER; > > + efi_apply_loadoptions_quirk((const void **)&cmdline, &cmdline_len); > + cmdline_len /= sizeof(*cmdline); > + > if (IS_ENABLED(CONFIG_X86) && !efi_nochunk) > efi_chunk_size = EFI_READ_CHUNK_SIZE; > > -- > 2.26.2
