[PATCH v8 11/18] cryptodisk: Add macros GRUB_TYPE_U_MAX/MIN(type) to replace literals

[Glenn Washburn]

Add GRUB_TYPE_U_MAX/MIN(type) macros to get the max/min values for an
unsigned number with size of type.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/disk/cryptodisk.c | 8 ++++----
 include/grub/types.h        | 7 +++++++
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index 0e955a020..5aa0c4720 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -284,23 +284,23 @@ grub_cryptodisk_endecrypt (struct grub_cryptodisk *dev,
          iv[1] = grub_cpu_to_le32 (sector >> GRUB_TYPE_BITS (iv[0]));
          /* FALLTHROUGH */
        case GRUB_CRYPTODISK_MODE_IV_PLAIN:
-         iv[0] = grub_cpu_to_le32 (sector & 0xFFFFFFFF);
+         iv[0] = grub_cpu_to_le32 (sector & GRUB_TYPE_U_MAX (iv[0]));
          break;
        case GRUB_CRYPTODISK_MODE_IV_BYTECOUNT64:
          iv[1] = grub_cpu_to_le32 (sector >> (GRUB_TYPE_BITS (iv[1])
                                               - dev->log_sector_size));
          iv[0] = grub_cpu_to_le32 ((sector << dev->log_sector_size)
-                                   & 0xFFFFFFFF);
+                                   & GRUB_TYPE_U_MAX (iv[0]));
          break;
        case GRUB_CRYPTODISK_MODE_IV_BENBI:
          {
            grub_uint64_t num = (sector << dev->benbi_log) + 1;
            iv[sz - 2] = grub_cpu_to_be32 (num >> GRUB_TYPE_BITS (iv[0]));
-           iv[sz - 1] = grub_cpu_to_be32 (num & 0xFFFFFFFF);
+           iv[sz - 1] = grub_cpu_to_be32 (num & GRUB_TYPE_U_MAX (iv[0]));
          }
          break;
        case GRUB_CRYPTODISK_MODE_IV_ESSIV:
-         iv[0] = grub_cpu_to_le32 (sector & 0xFFFFFFFF);
+         iv[0] = grub_cpu_to_le32 (sector & GRUB_TYPE_U_MAX (iv[0]));
          err = grub_crypto_ecb_encrypt (dev->essiv_cipher, iv, iv,
                                         dev->cipher->cipher->blocksize);
          if (err)
diff --git a/include/grub/types.h b/include/grub/types.h
index 9989e3a16..b36b26a79 100644
--- a/include/grub/types.h
+++ b/include/grub/types.h
@@ -161,6 +161,13 @@ typedef grub_int32_t       grub_ssize_t;
 #endif
 # define GRUB_LONG_MIN (-GRUB_LONG_MAX - 1)
 
+/*
+ * Cast to unsigned long long so that the "return value" is always a consistent
+ * type and to ensure an unsigned value regardless of type parameter.
+ */
+#define GRUB_TYPE_U_MAX(type) ((unsigned long long)((typeof (type))(~0)))
+#define GRUB_TYPE_U_MIN(type) 0ULL
+
 typedef grub_uint64_t grub_properly_aligned_t;
 
 #define GRUB_PROPERLY_ALIGNED_ARRAY(name, size) grub_properly_aligned_t 
name[((size) + sizeof (grub_properly_aligned_t) - 1) / sizeof 
(grub_properly_aligned_t)]
-- 
2.27.0