SIGSEGV in fxRunID in xsnap when running ses test-global-object-mutability.js test

[dckc]

Steps to Reproduce

https://gist.github.com/dckc/19451649697bb7cb231ab5a776fde0d1 has a Makefile that automates these steps as well as a transcript of a run and a backtrace:

1. clone https://github.com/endojs/endo and check out v f84387457a35; cd endo
2. yarn; yarn build
3. cd packages/ses; yarn test:xs --debug test/test-global-object-mutability.js
   • the --debug is optional; it crashes either way. But --debug gives a useful backtrace.
4. see Error#1: test-global-object-mutability.js exited due to signal SIGSEGV
5. gdb on the resulting core file shows that it crashed at xsRun.c:4065 in fxRunID

Build environment: Linux
Target device: agoric xsnap in the endo repo

Other information

This is using the current moddable SDK 0b451c9

I noted this in #604 (comment) but this looks like a separate issue from #604 .

The ses test is test-global-object-mutability.js.

Getting the SES test suite to run on XS is endojs/endo#508 .

[phoddie]

@dckc - thanks for writing this up separately. That backtrace has nearly all of our favorite things: Promise, Reflect, async functions, eval, and Proxy. ;) Do you happen to know if this issue happen reliably across your development systems?

[dckc]

Yes, I just tried it on one other machine (AMD Opteron(tm) Processor 6128 HE w 32GB RAM) and it fails there too.

[dckc]

Trace info (using mxTrace) shows it died in createScopeHandler around one of the calls to reflectGet. The if (prop === 'eval') test evidently failed, but I'm not sure whether the if (prop in localObject) test passed or failed.

1032135 is a line number from less; yes, it was >1M bytecodes into the execution when it crashed.

1032133 336: begin_strict
1032134 336: reserve 5
1032135 341: retrieve 3 [sloppyGlobalsMode] [localObject] [globalObject]
1032136 341: new_local [_shadow] 3
1032137 341: new_local [prop] 4
1032138 341: argument 0
1032139 342: var_local_1 3
1032140 342: pop
1032141 341: argument 1
1032142 342: var_local_1 4
1032143 342: pop
1032144 341: get_closure 0
1032145 342: dub
1032146 343: branch_if_2
1032147 342: pop
1032148 341: get_local 4
1032149 342: string "eval"
1032150 343: strict_equal
1032151 342: dub
1032152 343: branch_if_2
1032153 342: pop
1032154 341: get_local 4
1032155 342: get_closure 1
1032156 343: in
1032157 342: dub
1032158 343: branch_if_2
1032159 342: pop
1032160 341: get_local 4
1032161 342: get_closure 2
1032162 343: in
1032163 342: dub
1032164 343: branch_if_2
1032165 342: branch_else_2
1032166 341: true
1032167 342: result
1032168 341: end
1032169 328: function_environment(Error#1)
1032170 Error#1: test-global-object-mutability.js exited due to signal SIGSEGV

[dckc]

oh! nice to see you've got a fix I can try.

Unfortunately, adding a label doesn't notify me. In the future, please add a comment and/or tag @dckc when you have something for me to verify.

[dckc]

fix confirmed. Thanks!

connolly@jambox:~/projects/agoric/endo-mod-up/packages/ses$ yarn test:xs test/test-global-object-mutability.js 
yarn run v1.22.0
$ ava-xs test/test-global-object-mutability.js
2 tests passed
Done in 1.76s.