Refactor: handle in-output errors for string functions (Part 1) #11854
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Yuhta
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czentgr
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Dec 13, 2024
| int result = snprintf(entry.label, entry.kLabelCapacity, "%s", label_.c_str()); | ||
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| if (result < 0) { | ||
| throw std::runtime_error("Encoding error in snprintf"); |
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On error I suggest to set the first byte to null byte. That's all that is needed to ensure the buffer doesn't contains anything bad. I think the buffer itself is not initialized prior so could contain random data which is overwritten or on error we set the null byte at the beginning. This should take care of errors and use of an uninitialized buffer.
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Yes we can do that. This virtually never happens though so we should wrap the condition inside FOLLY_UNLIKELY so CPU don't waste time decoding the unused instructions.
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PR Description:
Detect and address input/output errors that can result in undefined behavior. Ensure proper error handling for I/O functions that may fail and leave variables uninitialized. Neglecting to check the status of these functions before using their outputs (e.g., memory buffers, file descriptors, etc.) can lead to undefined program behavior. This update enforces checks on commonly used I/O functions to validate their return values and prevent improper usage.
This is first of the several changes for this refactoring.