go runtime_error ai_generated true

panic: runtime error: unaligned memory access

ID: go/cgo-struct-alignment

Also available as: JSON · Markdown · 中文
80%Fix Rate
82%Confidence
0Evidence
2024-12-03First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.19 active — — —
1.20 active — — —

Root Cause

Passing a Go struct with different alignment requirements to C, causing unaligned access on some architectures (e.g., ARM).

generic

中文

将具有不同对齐要求的Go结构体传递给C，在某些架构（如ARM）上导致未对齐访问。

Workarounds

  1. 80% success Ensure Go struct has same alignment as C using `unsafe.Alignof` 
    type MyStruct struct {
    A int32
    B int64
}
_ = unsafe.Alignof(MyStruct{}) // check alignment
  2. 90% success Use `C.struct_MyStruct` directly in Go 
    // #include <mylib.h>
// type GoStruct C.struct_MyStruct

Dead Ends

Common approaches that don't work:

  1. Adding `// #pragma pack(1)` in C code 50% fail

    Go struct may still be aligned differently.

  2. Ignoring the panic and hoping for the best 100% fail

    Will crash on strict alignment platforms.