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chamibuddhika
searching PlanetScale…
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chamibuddhika
11y ago
For userspace probes DTrace uses INT3 AFAIK. Taking a signal each time a probe gets hit can be high overhead for certain usages though (like low overhead profiling as opposed to intrusive debugging).
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chamibuddhika
11y ago
This works since x86 guarantees atomicity for aligned reads and writes w.rt. instruction fetch. LOCK prefix can be used for unaligned reads/writes to ensure atomicity of data reads and writes. But Intel SDM says (in 8.1.2 Volume 3A) &q