CxPlatTimespecToUs:Microsecond time conversion overflow on 32-bit unix platforms #4529
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CxPlatTimespecToUs:Microsecond time conversion overflow on 32-bit unix platforms
Description
Describe the purpose of and changes within this Pull Request.
The timespec structure is defined as follows
struct timespec
{
time_t tv_sec; // Seconds - >= 0
long tv_nsec; // Nanoseconds - [0, 999999999]
};
On a 32-bit platform, time_t t is usually defined as a 32-bit signed integer (int or long) .
Therefore, byte overflow occurs in the following calculation:
#define CXPLAT_MICROSEC_PER_SEC (1000000)
Time->tv_sec * CXPLAT_MICROSEC_PER_SEC
This will cause the calculated microsecond time to be discontinuous, and the time obtained after overflow is smaller than the last time obtained
Testing
Do any existing tests cover this change? Are new tests needed?
Documentation
Is there any documentation impact for this change?