diff options
Diffstat (limited to 'libdw/memory-access.h')
| -rw-r--r-- | libdw/memory-access.h | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/libdw/memory-access.h b/libdw/memory-access.h index 16c8c851..6d79343c 100644 --- a/libdw/memory-access.h +++ b/libdw/memory-access.h @@ -64,7 +64,7 @@ __libdw_max_len_sleb128 (const unsigned char *addr, const unsigned char *end) #define get_uleb128_step(var, addr, nth) \ do { \ unsigned char __b = *(addr)++; \ - (var) |= (typeof (var)) (__b & 0x7f) << ((nth) * 7); \ + (var) |= (__typeof (var)) (__b & 0x7f) << ((nth) * 7); \ if (likely ((__b & 0x80) == 0)) \ return (var); \ } while (0) @@ -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 @@ -112,11 +115,11 @@ __libdw_get_uleb128_unchecked (const unsigned char **addrp) #define get_sleb128_step(var, addr, nth) \ do { \ unsigned char __b = *(addr)++; \ - (var) |= (typeof (var)) (__b & 0x7f) << ((nth) * 7); \ + (var) |= (__typeof (var)) (__b & 0x7f) << ((nth) * 7); \ if (likely ((__b & 0x80) == 0)) \ { \ if ((__b & 0x40) != 0) \ - (var) |= - ((typeof (var)) 1 << (((nth) + 1) * 7)); \ + (var) |= - ((__typeof (var)) 1 << (((nth) + 1) * 7)); \ return (var); \ } \ } while (0) @@ -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) @@ -146,7 +152,7 @@ __libdw_get_sleb128 (const unsigned char **addrp, const unsigned char *end) { /* We only need the low bit of the final byte, and as it is the sign bit, we don't need to do anything else here. */ - acc |= ((typeof (acc)) b) << 7 * max; + acc |= ((__typeof (acc)) b) << 7 * max; return acc; } @@ -179,7 +185,7 @@ __libdw_get_sleb128_unchecked (const unsigned char **addrp) { /* We only need the low bit of the final byte, and as it is the sign bit, we don't need to do anything else here. */ - acc |= ((typeof (acc)) b) << 7 * max; + acc |= ((__typeof (acc)) b) << 7 * max; return acc; } |