diff options
| -rw-r--r-- | fs/ext4/hash.c | 64 |
1 files changed, 42 insertions, 22 deletions
diff --git a/fs/ext4/hash.c b/fs/ext4/hash.c index 72645bd92582..978bd92da0ad 100644 --- a/fs/ext4/hash.c +++ b/fs/ext4/hash.c @@ -9,6 +9,7 @@ #include <linux/unicode.h> #include <linux/compiler.h> #include <linux/bitops.h> +#include <linux/unaligned.h> #include "ext4.h" #define DELTA 0x9E3779B9 @@ -141,21 +142,28 @@ static void str2hashbuf_signed(const char *msg, int len, __u32 *buf, int num) pad = (__u32)len | ((__u32)len << 8); pad |= pad << 16; - val = pad; if (len > num*4) len = num * 4; - for (i = 0; i < len; i++) { - val = ((int) scp[i]) + (val << 8); - if ((i % 4) == 3) { - *buf++ = val; - val = pad; - num--; - } + + while (len >= 4) { + val = ((__u32)scp[0] << 24) + ((__u32)scp[1] << 16) + ((__u32)scp[2] << 8) + scp[3]; + *buf++ = val; + scp += 4; + len -= 4; + num--; } + + val = pad; + + for (i = 0; i < len; i++) + val = scp[i] + (val << 8); + if (--num >= 0) *buf++ = val; + while (--num >= 0) *buf++ = pad; + } static void str2hashbuf_unsigned(const char *msg, int len, __u32 *buf, int num) @@ -167,21 +175,28 @@ static void str2hashbuf_unsigned(const char *msg, int len, __u32 *buf, int num) pad = (__u32)len | ((__u32)len << 8); pad |= pad << 16; - val = pad; if (len > num*4) len = num * 4; - for (i = 0; i < len; i++) { - val = ((int) ucp[i]) + (val << 8); - if ((i % 4) == 3) { - *buf++ = val; - val = pad; - num--; - } + + while (len >= 4) { + val = get_unaligned_be32(ucp); + *buf++ = val; + ucp += 4; + len -= 4; + num--; } + + val = pad; + + for (i = 0; i < len; i++) + val = ucp[i] + (val << 8); + if (--num >= 0) *buf++ = val; + while (--num >= 0) *buf++ = pad; + } /* @@ -205,8 +220,7 @@ static int __ext4fs_dirhash(const struct inode *dir, const char *name, int len, const char *p; int i; __u32 in[8], buf[4]; - void (*str2hashbuf)(const char *, int, __u32 *, int) = - str2hashbuf_signed; + bool use_unsigned = false; /* Initialize the default seed for the hash checksum functions */ buf[0] = 0x67452301; @@ -232,12 +246,15 @@ static int __ext4fs_dirhash(const struct inode *dir, const char *name, int len, hash = dx_hack_hash_signed(name, len); break; case DX_HASH_HALF_MD4_UNSIGNED: - str2hashbuf = str2hashbuf_unsigned; + use_unsigned = true; fallthrough; case DX_HASH_HALF_MD4: p = name; while (len > 0) { - (*str2hashbuf)(p, len, in, 8); + if (use_unsigned) + str2hashbuf_unsigned(p, len, in, 8); + else + str2hashbuf_signed(p, len, in, 8); half_md4_transform(buf, in); len -= 32; p += 32; @@ -246,12 +263,15 @@ static int __ext4fs_dirhash(const struct inode *dir, const char *name, int len, hash = buf[1]; break; case DX_HASH_TEA_UNSIGNED: - str2hashbuf = str2hashbuf_unsigned; + use_unsigned = true; fallthrough; case DX_HASH_TEA: p = name; while (len > 0) { - (*str2hashbuf)(p, len, in, 4); + if (use_unsigned) + str2hashbuf_unsigned(p, len, in, 4); + else + str2hashbuf_signed(p, len, in, 4); TEA_transform(buf, in); len -= 16; p += 16; |