diff options
Diffstat (limited to 'libdw/memory-access.h')
| -rw-r--r-- | libdw/memory-access.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/libdw/memory-access.h b/libdw/memory-access.h index fca4129a..6d79343c 100644 --- a/libdw/memory-access.h +++ b/libdw/memory-access.h @@ -72,13 +72,16 @@ __libdw_max_len_sleb128 (const unsigned char *addr, const unsigned char *end) static inline uint64_t __libdw_get_uleb128 (const unsigned char **addrp, const unsigned char *end) { + const size_t max = __libdw_max_len_uleb128 (*addrp, end); + if (unlikely (max == 0)) + return UINT64_MAX; + uint64_t acc = 0; /* Unroll the first step to help the compiler optimize for the common single-byte case. */ get_uleb128_step (acc, *addrp, 0); - const size_t max = __libdw_max_len_uleb128 (*addrp - 1, end); for (size_t i = 1; i < max; ++i) get_uleb128_step (acc, *addrp, i); /* Other implementations set VALUE to UINT_MAX in this @@ -124,6 +127,10 @@ __libdw_get_uleb128_unchecked (const unsigned char **addrp) static inline int64_t __libdw_get_sleb128 (const unsigned char **addrp, const unsigned char *end) { + const size_t max = __libdw_max_len_sleb128 (*addrp, end); + if (unlikely (max == 0)) + return INT64_MAX; + /* Do the work in an unsigned type, but use implementation-defined behavior to cast to signed on return. This avoids some undefined behavior when shifting. */ @@ -133,7 +140,6 @@ __libdw_get_sleb128 (const unsigned char **addrp, const unsigned char *end) for the common single-byte case. */ get_sleb128_step (acc, *addrp, 0); - const size_t max = __libdw_max_len_sleb128 (*addrp - 1, end); for (size_t i = 1; i < max; ++i) get_sleb128_step (acc, *addrp, i); if (*addrp == end) |