[U-Boot] [PATCH v2 1/1] efi_loader: optional data in load options are binary

Takahiro Akashi takahiro.akashi at linaro.org
Tue May 7 07:30:47 UTC 2019


On Tue, May 07, 2019 at 09:12:56AM +0200, Heinrich Schuchardt wrote:
> On 5/7/19 8:16 AM, Takahiro Akashi wrote:
> > On Tue, May 07, 2019 at 08:04:26AM +0200, Heinrich Schuchardt wrote:
> >> On 5/7/19 7:16 AM, Heinrich Schuchardt wrote:
> >>> On 5/7/19 3:53 AM, Takahiro Akashi wrote:
> >>>> On Tue, Apr 30, 2019 at 08:11:15AM +0200, Heinrich Schuchardt wrote:
> >>>>> The field boot OptionalData in structure _EFI_LOAD_OPTIONS is for binary
> >>>>> data.
> >>>>>
> >>>>> When we use `efidebug boot add` we should convert the 5th argument from
> >>>>> UTF-8 to UTF-16 before putting it into the BootXXXX variable.
> >>>>
> >>>> While optional_data holds u8 string in calling
> >>>> efi_serialize_load_option(),
> >>>> it holds u16 string in leaving from efi_deserialize_load_option().
> >>>> We should handle it in a consistent way if you want to keep optional_data
> >>>> as "const u8."
> >>
> >> When communicating with Linux optional data may contain a u16 string.
> >> But I cannot see were our coding is inconsistent.
> >
> > I don't get your point.
> > Do you want to allow 'u8 *' variable to hold u16 string?#
> 
> Yes, optional data may contain anything, in the case of Linux the
> command line parameters as an u16 string.
> 
> Other operating systems may use the field in other ways, e.g. store an
> ASCII string.

The problem is that with your patch optional_data is *always* converted
to utf-16 as far as we use efidebug.
My efidebug is not for linux only.

-Takahiro Akashi


> Regards
> 
> Heinrich
> 
> >
> > -Takahiro Akashi
> >
> >> Regards
> >>
> >> Heinrich
> >>
> >>>
> >>> The patch is already merged so I will have to create a follow up patch.
> >>>
> >>> The UEFI spec has EFI_LOAD_OPTION.OptionalData as UINT8. So an odd
> >>> number of bytes is a possibility.
> >>>
> >>> Best regards
> >>>
> >>> Heinrich
> >>>
> >>>>
> >>>> Thanks,
> >>>> -Takahiro Akashi
> >>>>
> >>>>> When printing boot variables with `efidebug boot dump` we should support
> >>>>> the OptionalData being arbitrary binary data. So let's dump the data as
> >>>>> hexadecimal values.
> >>>>>
> >>>>> Here is an example session protocol:
> >>>>>
> >>>>> => efidebug boot add 00a1 label1 scsi 0:1 doit1 'my option'
> >>>>> => efidebug boot add 00a2 label2 scsi 0:1 doit2
> >>>>> => efidebug boot dump
> >>>>> Boot00A0:
> >>>>>    attributes: A-- (0x00000001)
> >>>>>    label: label1
> >>>>>    file_path: .../HD(1,MBR,0xeac4e18b,0x800,0x3fffe)/doit1
> >>>>>    data:
> >>>>>      00000000: 6d 00 79 00 20 00 6f 00 70 00 74 00 69 00 6f 00  m.y.
> >>>>> .o.p.t.i.o.
> >>>>>      00000010: 6e 00 00 00                                      n...
> >>>>> Boot00A1:
> >>>>>    attributes: A-- (0x00000001)
> >>>>>    label: label2
> >>>>>    file_path: .../HD(1,MBR,0xeac4e18b,0x800,0x3fffe)/doit2
> >>>>>    data:
> >>>>>
> >>>>> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> >>>>> ---
> >>>>> v2:
> >>>>>     remove statement without effect in efi_serialize_load_option()
> >>>>> ---
> >>>>>   cmd/efidebug.c               | 27 +++++++++++++++++----------
> >>>>>   include/efi_loader.h         |  2 +-
> >>>>>   lib/efi_loader/efi_bootmgr.c | 15 ++++++++-------
> >>>>>   3 files changed, 26 insertions(+), 18 deletions(-)
> >>>>>
> >>>>> diff --git a/cmd/efidebug.c b/cmd/efidebug.c
> >>>>> index efe4ea873e..c4ac9dd634 100644
> >>>>> --- a/cmd/efidebug.c
> >>>>> +++ b/cmd/efidebug.c
> >>>>> @@ -11,6 +11,7 @@
> >>>>>   #include <efi_loader.h>
> >>>>>   #include <environment.h>
> >>>>>   #include <exports.h>
> >>>>> +#include <hexdump.h>
> >>>>>   #include <malloc.h>
> >>>>>   #include <search.h>
> >>>>>   #include <linux/ctype.h>
> >>>>> @@ -545,7 +546,10 @@ static int do_efi_boot_add(cmd_tbl_t *cmdtp, int
> >>>>> flag,
> >>>>>                   + sizeof(struct efi_device_path); /* for END */
> >>>>>
> >>>>>       /* optional data */
> >>>>> -    lo.optional_data = (u8 *)(argc == 6 ? "" : argv[6]);
> >>>>> +    if (argc < 6)
> >>>>> +        lo.optional_data = NULL;
> >>>>> +    else
> >>>>> +        lo.optional_data = (const u8 *)argv[6];
> >>>>>
> >>>>>       size = efi_serialize_load_option(&lo, (u8 **)&data);
> >>>>>       if (!size) {
> >>>>> @@ -615,12 +619,13 @@ static int do_efi_boot_rm(cmd_tbl_t *cmdtp, int
> >>>>> flag,
> >>>>>   /**
> >>>>>    * show_efi_boot_opt_data() - dump UEFI load option
> >>>>>    *
> >>>>> - * @id:        Load option number
> >>>>> - * @data:    Value of UEFI load option variable
> >>>>> + * @id:        load option number
> >>>>> + * @data:    value of UEFI load option variable
> >>>>> + * @size:    size of the boot option
> >>>>>    *
> >>>>>    * Decode the value of UEFI load option variable and print
> >>>>> information.
> >>>>>    */
> >>>>> -static void show_efi_boot_opt_data(int id, void *data)
> >>>>> +static void show_efi_boot_opt_data(int id, void *data, size_t size)
> >>>>>   {
> >>>>>       struct efi_load_option lo;
> >>>>>       char *label, *p;
> >>>>> @@ -638,7 +643,7 @@ static void show_efi_boot_opt_data(int id, void
> >>>>> *data)
> >>>>>       utf16_utf8_strncpy(&p, lo.label, label_len16);
> >>>>>
> >>>>>       printf("Boot%04X:\n", id);
> >>>>> -    printf("\tattributes: %c%c%c (0x%08x)\n",
> >>>>> +    printf("  attributes: %c%c%c (0x%08x)\n",
> >>>>>              /* ACTIVE */
> >>>>>              lo.attributes & LOAD_OPTION_ACTIVE ? 'A' : '-',
> >>>>>              /* FORCE RECONNECT */
> >>>>> @@ -646,14 +651,16 @@ static void show_efi_boot_opt_data(int id, void
> >>>>> *data)
> >>>>>              /* HIDDEN */
> >>>>>              lo.attributes & LOAD_OPTION_HIDDEN ? 'H' : '-',
> >>>>>              lo.attributes);
> >>>>> -    printf("\tlabel: %s\n", label);
> >>>>> +    printf("  label: %s\n", label);
> >>>>>
> >>>>>       dp_str = efi_dp_str(lo.file_path);
> >>>>> -    printf("\tfile_path: %ls\n", dp_str);
> >>>>> +    printf("  file_path: %ls\n", dp_str);
> >>>>>       efi_free_pool(dp_str);
> >>>>>
> >>>>> -    printf("\tdata: %s\n", lo.optional_data);
> >>>>> -
> >>>>> +    printf("  data:\n");
> >>>>> +    print_hex_dump("    ", DUMP_PREFIX_OFFSET, 16, 1,
> >>>>> +               lo.optional_data, size + (u8 *)data -
> >>>>> +               (u8 *)lo.optional_data, true);
> >>>>>       free(label);
> >>>>>   }
> >>>>>
> >>>>> @@ -686,7 +693,7 @@ static void show_efi_boot_opt(int id)
> >>>>>                           data));
> >>>>>       }
> >>>>>       if (ret == EFI_SUCCESS)
> >>>>> -        show_efi_boot_opt_data(id, data);
> >>>>> +        show_efi_boot_opt_data(id, data, size);
> >>>>>       else if (ret == EFI_NOT_FOUND)
> >>>>>           printf("Boot%04X: not found\n", id);
> >>>>>
> >>>>> diff --git a/include/efi_loader.h b/include/efi_loader.h
> >>>>> index 39ed8a6fa5..07b913d256 100644
> >>>>> --- a/include/efi_loader.h
> >>>>> +++ b/include/efi_loader.h
> >>>>> @@ -560,7 +560,7 @@ struct efi_load_option {
> >>>>>       u16 file_path_length;
> >>>>>       u16 *label;
> >>>>>       struct efi_device_path *file_path;
> >>>>> -    u8 *optional_data;
> >>>>> +    const u8 *optional_data;
> >>>>>   };
> >>>>>
> >>>>>   void efi_deserialize_load_option(struct efi_load_option *lo, u8
> >>>>> *data);
> >>>>> diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> >>>>> index 4ccba22875..7bf51874c1 100644
> >>>>> --- a/lib/efi_loader/efi_bootmgr.c
> >>>>> +++ b/lib/efi_loader/efi_bootmgr.c
> >>>>> @@ -53,19 +53,20 @@ void efi_deserialize_load_option(struct
> >>>>> efi_load_option *lo, u8 *data)
> >>>>>    */
> >>>>>   unsigned long efi_serialize_load_option(struct efi_load_option *lo,
> >>>>> u8 **data)
> >>>>>   {
> >>>>> -    unsigned long label_len, option_len;
> >>>>> +    unsigned long label_len;
> >>>>>       unsigned long size;
> >>>>>       u8 *p;
> >>>>>
> >>>>>       label_len = (u16_strlen(lo->label) + 1) * sizeof(u16);
> >>>>> -    option_len = strlen((char *)lo->optional_data);
> >>>>>
> >>>>>       /* total size */
> >>>>>       size = sizeof(lo->attributes);
> >>>>>       size += sizeof(lo->file_path_length);
> >>>>>       size += label_len;
> >>>>>       size += lo->file_path_length;
> >>>>> -    size += option_len + 1;
> >>>>> +    if (lo->optional_data)
> >>>>> +        size += (utf8_utf16_strlen((const char *)lo->optional_data)
> >>>>> +                       + 1) * sizeof(u16);
> >>>>>       p = malloc(size);
> >>>>>       if (!p)
> >>>>>           return 0;
> >>>>> @@ -84,10 +85,10 @@ unsigned long efi_serialize_load_option(struct
> >>>>> efi_load_option *lo, u8 **data)
> >>>>>       memcpy(p, lo->file_path, lo->file_path_length);
> >>>>>       p += lo->file_path_length;
> >>>>>
> >>>>> -    memcpy(p, lo->optional_data, option_len);
> >>>>> -    p += option_len;
> >>>>> -    *(char *)p = '\0';
> >>>>> -
> >>>>> +    if (lo->optional_data) {
> >>>>> +        utf8_utf16_strcpy((u16 **)&p, (const char *)lo->optional_data);
> >>>>> +        p += sizeof(u16); /* size of trailing \0 */
> >>>>> +    }
> >>>>>       return size;
> >>>>>   }
> >>>>>
> >>>>> --
> >>>>> 2.20.1
> >>>>>
> >>>>
> >>>
> >>>
> >>
> >
> 


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