Secure __next_prime from overflowing git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@117650 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/src/hash.cpp b/src/hash.cpp index dd4e8e3..6bd9c3b 100644 --- a/src/hash.cpp +++ b/src/hash.cpp
@@ -9,6 +9,7 @@ #include "__hash_table" #include "algorithm" +#include "stdexcept" _LIBCPP_BEGIN_NAMESPACE_STD @@ -143,6 +144,26 @@ // are fewer potential primes to search, and fewer potential primes to divide // against. +inline _LIBCPP_INLINE_VISIBILITY +void +__check_for_overflow(size_t N, integral_constant<size_t, 32>) +{ +#ifndef _LIBCPP_NO_EXCEPTIONS + if (N > 0xFFFFFFFB) + throw overflow_error("__next_prime overflow"); +#endif +} + +inline _LIBCPP_INLINE_VISIBILITY +void +__check_for_overflow(size_t N, integral_constant<size_t, 64>) +{ +#ifndef _LIBCPP_NO_EXCEPTIONS + if (N > 0xFFFFFFFFFFFFFFC5ull) + throw overflow_error("__next_prime overflow"); +#endif +} + size_t __next_prime(size_t n) { @@ -152,6 +173,9 @@ if (n <= small_primes[N-1]) return *std::lower_bound(small_primes, small_primes + N, n); // Else n > largest small_primes + // Check for overflow + __check_for_overflow(n, integral_constant<size_t, + sizeof(n) * __CHAR_BIT__>()); // Start searching list of potential primes: L * k0 + indices[in] const size_t M = sizeof(indices) / sizeof(indices[0]); // Select first potential prime >= n 