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-rw-r--r--fs/ubifs/lpt.c45
1 files changed, 38 insertions, 7 deletions
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index cd11b23a187..db8bd0e518b 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);