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For example, an addition may produce an arithmetic overflow (it does not fulfill its contract of computing a good approximation to the mathematical sum); or a routine may fail to meet its postcondition. Exception: an abnormal event occurring during the execution of a routine (that routine is the "recipient" of the exception) during its execution.
Starting with Visual C++ 2005, the CRT uses a 64-bit time_t unless the _USE_32BIT_TIME_T preprocessor macro is defined. [36] However, the Windows API itself is unaffected by the year 2038 bug, as Windows internally tracks time as the number of 100-nanosecond intervals since 1 January 1601 in a 64-bit signed integer, which will not overflow ...
However, any overflow that occurs in a buffer from a previous stack frame will still overwrite a return pointer and allow for malicious exploitation of the bug. [11] For instance, in the example above, the return pointer for foo will not be overwritten because the overflow actually occurs within the stack frame for memcpy.
This can happen in multi-threaded environments, or even in single-threaded environments when other code (typically called in the destruction of some object) resets the global variable before the checking code. The following example shows a way to avoid this problem (see [dead link ] or ; cf. ). But at the cost of not being able to use return ...
A code sanitizer is a programming tool that detects bugs in the form of undefined or suspicious behavior by a compiler inserting instrumentation code at runtime. The class of tools was first introduced by Google's AddressSanitizer (or ASan) of 2012, which uses directly mapped shadow memory to detect memory corruption such as buffer overflows or accesses to a dangling pointer (use-after-free).
Integer overflow can be demonstrated through an odometer overflowing, a mechanical version of the phenomenon. All digits are set to the maximum 9 and the next increment of the white digit causes a cascade of carry-over additions setting all digits to 0, but there is no higher digit (1,000,000s digit) to change to a 1, so the counter resets to zero.
This is a common source of errors. Most implementations of the STL provide a debug mode that is slower, but can locate such errors if used. A similar problem exists in other languages, for example Java. Ranges have been proposed as a safer, more flexible alternative to iterators. [11]
Off-by-one errors are common in using the C library because it is not consistent with respect to whether one needs to subtract 1 byte – functions like fgets() and strncpy will never write past the length given them (fgets() subtracts 1 itself, and only retrieves (length − 1) bytes), whereas others, like strncat will write past the length given them.