diff options
| -rw-r--r-- | fs/ubifs/lpt.c | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c index cd11b23a1875..db8bd0e518b2 100644 --- a/fs/ubifs/lpt.c +++ b/fs/ubifs/lpt.c @@ -288,25 +288,56 @@ uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits) const int k = 32 - nrbits; uint8_t *p = *addr; int b = *pos; - uint32_t val; + uint32_t uninitialized_var(val); + const int bytes = (nrbits + b + 7) >> 3; ubifs_assert(nrbits > 0); ubifs_assert(nrbits <= 32); ubifs_assert(*pos >= 0); ubifs_assert(*pos < 8); if (b) { - val = p[1] | ((uint32_t)p[2] << 8) | ((uint32_t)p[3] << 16) | - ((uint32_t)p[4] << 24); + switch (bytes) { + case 2: + val = p[1]; + break; + case 3: + val = p[1] | ((uint32_t)p[2] << 8); + break; + case 4: + val = p[1] | ((uint32_t)p[2] << 8) | + ((uint32_t)p[3] << 16); + break; + case 5: + val = p[1] | ((uint32_t)p[2] << 8) | + ((uint32_t)p[3] << 16) | + ((uint32_t)p[4] << 24); + } val <<= (8 - b); val |= *p >> b; nrbits += b; - } else - val = p[0] | ((uint32_t)p[1] << 8) | ((uint32_t)p[2] << 16) | - ((uint32_t)p[3] << 24); + } else { + switch (bytes) { + case 1: + val = p[0]; + break; + case 2: + val = p[0] | ((uint32_t)p[1] << 8); + break; + case 3: + val = p[0] | ((uint32_t)p[1] << 8) | + ((uint32_t)p[2] << 16); + break; + case 4: + val = p[0] | ((uint32_t)p[1] << 8) | + ((uint32_t)p[2] << 16) | + ((uint32_t)p[3] << 24); + break; + } + } val <<= k; val >>= k; b = nrbits & 7; - p += nrbits / 8; + p += nrbits >> 3; *addr = p; *pos = b; ubifs_assert((val >> nrbits) == 0 || nrbits - b == 32); |