evacchi
commented
1 year ago thanks for the detailed reproducer!
EDIT: confirmed on native arm64 (Apple M1) with any wasm file
EDIT2: wait no. It just SIGSEGVs because ExportedFunction() returns nil 🤔
EDIT3: finally, managed to reproduce with linux/riscv64
❯ docker run --platform linux/riscv64 -v $(pwd)/repro:/test -v $(pwd)/repro:/wazero -e WAZEROCLI=/wazero --tmpfs /tmp --rm -t wazero:test
```
❯ docker run --platform linux/riscv64 -v $(pwd)/repro:/test -v $(pwd)/repro:/wazero -e WAZEROCLI=/wazero --tmpfs /tmp --rm -t wazero:test
SIGILL: illegal instruction
PC=0x0 m=0 sigcode=1
instruction bytes: 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
goroutine 1 [running]:
runtime/internal/atomic.(*Uint32).Load(...)
/opt/homebrew/Cellar/go/1.20.7/libexec/src/runtime/internal/atomic/types.go:194
runtime.main()
/opt/homebrew/Cellar/go/1.20.7/libexec/src/runtime/proc.go:260 +0x218 fp=0xc000129e18 sp=0xc000129dc0 pc=0x45348
runtime: g 1: unexpected return pc for runtime.main called from 0xc0000a3050
stack: frame={sp:0xc000129e18, fp:0xc000129e70} stack=[0xc000122000,0xc00012a000)
0x000000c000129d18: 0x0000000000000000 0x0000000000000001
0x000000c000129d28: 0x00000000001bff84 But I can confirm it's only a mismanaged nil ptr.
f := mod.ExportedFunction("iDontExist")
if f == nil {
println("nope")
} else {
f.Call(ctx)
}prints nope.
EDIT4: @jerbob92 I think you found bug in the Go compiler
❯ cat reproducer.go
package main
type i interface {
f()
}
func main() {
var ii i
ii.f()
}⬇️
❯ GOARCH=riscv64 GOOS=linux go build -gcflags=all="-N -l" reproducer.go
❯ docker run --platform linux/riscv64 -v $(pwd)/reproducer:/test -v $(pwd)/reproducer:/wazero -e WAZEROCLI=/wazero --tmpfs /tmp --rm -t wazero:test💣💥
mathetake
Describe the bug This is a result of the issue we found when developing #1611, that code would try to call the exported function
stackRestore, but that function was not defined in our WASM, because we didn't expect the current tests to reach that code. On some platforms this willSIGILL: illegal instructionsome of the times, at least on arm64 and riscv64.To Reproduce First make sure you can run arm64 in Docker by install qemu:
Create a Dockerfile with the following:
Build the docker image:
Create the following main.go:
Build the binary and run it in Docker:
You might have to run it a few times to trigger it. If you first check the exported function for nil it doesn't have this behaviour.
Expected behavior
ExportedFunctionshould always return nil when the function doesn't exist.Environment (please complete the relevant information):
Additional context