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chore(tracer): add a workaround to allow running under race sanitizer #900

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Merged
merged 2 commits into from
Nov 4, 2025
+38 −1
Merged

chore(tracer): add a workaround to allow running under race sanitizer #900

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85a083f
chore(tracer): add a workaround to allow running under race sanitizer
korniltsev-grafanista Oct 29, 2025
956bfb5
Merge branch 'main' into tracer-race-workaround
korniltsev-grafanista Nov 3, 2025
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17 changes: 17 additions & 0 deletions tracer/norace.go
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Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
//go:build !race

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

// Package tracer
package tracer // import "go.opentelemetry.io/ebpf-profiler/tracer"

import (
"unsafe"

"go.opentelemetry.io/ebpf-profiler/support"
)

func traceFromRaw(raw []byte) *support.Trace {
return (*support.Trace)(unsafe.Pointer(unsafe.SliceData(raw)))
}
20 changes: 20 additions & 0 deletions tracer/race.go
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Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
//go:build race

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

// Package tracer
package tracer // import "go.opentelemetry.io/ebpf-profiler/tracer"

import (
"unsafe"

"go.opentelemetry.io/ebpf-profiler/support"
)

func traceFromRaw(raw []byte) *support.Trace {
// workaround for "fatal error: checkptr: converted pointer straddles multiple allocations"
fullSizeCopy := make([]byte, unsafe.Sizeof(support.Trace{}))
copy(fullSizeCopy, raw)
return (*support.Trace)(unsafe.Pointer(unsafe.SliceData(fullSizeCopy)))
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@christos68k christos68k Oct 29, 2025

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Compared to norace, this logic results in a different Trace.Hash (as the writes to raw through the pointer don't take effect) but since we don't use this hash at all anymore I opened #901 to remove it.

}
2 changes: 1 addition & 1 deletion tracer/tracer.go
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Original file line number Diff line number Diff line change
Expand Up @@ -886,7 +886,7 @@ func (t *Tracer) loadBpfTrace(raw []byte, cpu int) *host.Trace {
}

frameSize := support.Sizeof_Frame
ptr := (*support.Trace)(unsafe.Pointer(unsafe.SliceData(raw)))
ptr := traceFromRaw(raw)

// NOTE: can't do exact check here: kernel adds a few padding bytes to messages.
if len(raw) < frameListOffs+int(ptr.Stack_len)*frameSize {
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