[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 06:16:11 UTC 2019


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?

-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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