diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/vppinfra/hash.c | 47 |
1 files changed, 28 insertions, 19 deletions
diff --git a/src/vppinfra/hash.c b/src/vppinfra/hash.c index b3db9f82b9c..121fa385705 100644 --- a/src/vppinfra/hash.c +++ b/src/vppinfra/hash.c @@ -80,27 +80,33 @@ static u8 *hash_format_pair_default (u8 * s, va_list * args); #if uword_bits == 64 static inline u64 -get_unaligned_as_u64 (void const *data, int n) +zap64 (u64 x, word n) { - int i; - u64 r = 0; - u8 const *p = (u8 const *) data; - +#define _(n) (((u64) 1 << (u64) (8*(n))) - (u64) 1) + static u64 masks_little_endian[] = { + 0, _(1), _(2), _(3), _(4), _(5), _(6), _(7), + }; + static u64 masks_big_endian[] = { + 0, ~_(7), ~_(6), ~_(5), ~_(4), ~_(3), ~_(2), ~_(1), + }; +#undef _ if (clib_arch_is_big_endian) - { - for (i = 0; i < n; i++) - r |= ((u64) ((*(p + i)) << (u8) (1 << (8 - i)))); - } + return x & masks_big_endian[n]; else - { - for (i = 0; i < n; i++) - r |= ((u64) ((*(p + i)) << (u8) (1 << i))); - } - - return r; + return x & masks_little_endian[n]; } -static inline u64 +/** + * make address-sanitizer skip this: + * clib_mem_unaligned + zap64 casts its input as u64, computes a mask + * according to the input length, and returns the casted maked value. + * Therefore all the 8 Bytes of the u64 are systematically read, which + * rightfully causes address-sanitizer to raise an error on smaller inputs. + * + * However the invalid Bytes are discarded within zap64(), whicj is why + * this can be silenced safely. + */ +static inline u64 __attribute__ ((no_sanitize_address)) hash_memory64 (void *p, word n_bytes, u64 state) { u64 *q = p; @@ -126,16 +132,19 @@ hash_memory64 (void *p, word n_bytes, u64 state) case 2: a += clib_mem_unaligned (q + 0, u64); b += clib_mem_unaligned (q + 1, u64); - c += get_unaligned_as_u64 (q + 2, n % sizeof (u64)) << 8; + if (n % sizeof (u64)) + c += zap64 (clib_mem_unaligned (q + 2, u64), n % sizeof (u64)) << 8; break; case 1: a += clib_mem_unaligned (q + 0, u64); - b += get_unaligned_as_u64 (q + 1, n % sizeof (u64)); + if (n % sizeof (u64)) + b += zap64 (clib_mem_unaligned (q + 1, u64), n % sizeof (u64)); break; case 0: - a += get_unaligned_as_u64 (q + 0, n % sizeof (u64)); + if (n % sizeof (u64)) + a += zap64 (clib_mem_unaligned (q + 0, u64), n % sizeof (u64)); break; } |