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lib: uuid: alignment error in gen_rand_uuid()

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Packed structures like struct uuid are not aligned. GCC 9.1 therefore
throws an error when trying to compile gen_rand_uuid().

lib/uuid.c: In function ‘gen_rand_uuid’:
lib/uuid.c:244:2: error: converting a packed ‘struct uuid’ pointer
(alignment 1) to a ‘unsigned int’ pointer (alignment 4) may result in
an unaligned pointer value [-Werror=address-of-packed-member]
  244 |  unsigned int *ptr = (unsigned int *)&uuid;
      |  ^~~~~~~~

Generate the uuid in a properly aligned buffer.

The byte order of a random number should not matter. Do not call
cpu_to_be32() to change the byte order.

Reported-by: Ramon Fried <rfried.dev@gmail.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
Heinrich Schuchardt 2019-07-14 23:31:50 +02:00 committed by Tom Rini
parent 0c4e81e0eb
commit a1b633df55
1 changed files with 7 additions and 7 deletions
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14
lib/uuid.c
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@ -240,25 +240,25 @@ void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
#if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
void gen_rand_uuid(unsigned char *uuid_bin)
{
struct uuid uuid;
unsigned int *ptr = (unsigned int *)&uuid;
u32 ptr[4];
struct uuid *uuid = (struct uuid *)ptr;
int i;
srand(get_ticks() + rand());
/* Set all fields randomly */
for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++)
*(ptr + i) = cpu_to_be32(rand());
for (i = 0; i < 4; i++)
ptr[i] = rand();
clrsetbits_be16(&uuid.time_hi_and_version,
clrsetbits_be16(&uuid->time_hi_and_version,
UUID_VERSION_MASK,
UUID_VERSION << UUID_VERSION_SHIFT);
clrsetbits_8(&uuid.clock_seq_hi_and_reserved,
clrsetbits_8(&uuid->clock_seq_hi_and_reserved,
UUID_VARIANT_MASK,
UUID_VARIANT << UUID_VARIANT_SHIFT);
memcpy(uuid_bin, &uuid, sizeof(struct uuid));
memcpy(uuid_bin, uuid, 16);
}
/*