diff options
Diffstat (limited to 'lib/packing.c')
| -rw-r--r-- | lib/packing.c | 26 |
1 files changed, 10 insertions, 16 deletions
diff --git a/lib/packing.c b/lib/packing.c index f237b8af99f5f..09a2d195b9433 100644 --- a/lib/packing.c +++ b/lib/packing.c @@ -59,8 +59,17 @@ static void __pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, */ int plogical_first_u8 = startbit / BITS_PER_BYTE; int plogical_last_u8 = endbit / BITS_PER_BYTE; + int value_width = startbit - endbit + 1; int box; + /* Check if "uval" fits in "value_width" bits. + * The test only works for value_width < 64, but in the latter case, + * any 64-bit uval will surely fit. + */ + WARN(value_width < 64 && uval >= (1ull << value_width), + "Cannot store 0x%llx inside bits %zu-%zu - will truncate\n", + uval, startbit, endbit); + /* Iterate through an idealistic view of the pbuf as an u64 with * no quirks, u8 by u8 (aligned at u8 boundaries), from high to low * logical bit significance. "box" denotes the current logical u8. @@ -143,9 +152,6 @@ static void __pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen, u8 quirks) { - /* width of the field to access in the pbuf */ - u64 value_width; - /* startbit is expected to be larger than endbit, and both are * expected to be within the logically addressable range of the buffer. */ @@ -153,19 +159,7 @@ int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen, /* Invalid function call */ return -EINVAL; - value_width = startbit - endbit + 1; - if (unlikely(value_width > 64)) - return -ERANGE; - - /* Check if "uval" fits in "value_width" bits. - * If value_width is 64, the check will fail, but any - * 64-bit uval will surely fit. - */ - if (value_width < 64 && uval >= (1ull << value_width)) - /* Cannot store "uval" inside "value_width" bits. - * Truncating "uval" is most certainly not desirable, - * so simply erroring out is appropriate. - */ + if (unlikely(startbit - endbit >= 64)) return -ERANGE; __pack(pbuf, uval, startbit, endbit, pbuflen, quirks); |