Question: WebAssembly support

[ghost]

Is WebAssembly supported on

1. iOS
2. Android

If supported, can you please comment on pthread support. See this for context - SharedArrayBuffer may cause issues for browsers, but enabling it in node for mobile should be perfectly safe as the sandboxing is done by the host OS (either iOS or Android)

[jaimecbernardo]

Hi @writepubapp,

The iOS runtime is based on the ChakraCore engine, which at the version we currently have (node-chakracore 8.6.0) has WebAssembly disabled for cross-platform builds, so WebAssembly is not on in the released binary.

WebAssembly is working for Android, confirmed by trying to run this test: nodejs/node@74e7a4a

In terms of working features for WebAssembly, unit tests for WebAssembly features on node were added after the current fork version, so we don't have more in-depth information of what's working or not.

Please let us know if you give it a try and what results you have.

In terms of safety for mobile devices, it seems to have been disabled for Android mobile browsers as well. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer#Browser_compatibility (See implementation notes)
While not my area of expertise, so take it with a grain of salt, these sorts of attacks were able to sidestep the OS-provided sandbox features at the time they were discovered, since the exploits targeted the CPU. Security patches were issued for Android, which may not be applied by every vendor. https://security.googleblog.com/2018/01/todays-cpu-vulnerability-what-you-need.html
There's work being done now to also mitigate it on the browser side: https://www.chromium.org/Home/chromium-security/ssca

[ghost]

@jaimecbernardo - thank you for the detailed response.

1. Does your roadmap for iOS include enabling WASM?
2. As for enabling sharedArrayBuffer, browsers need to execute un-trusted code from the open wild-web. I believe enabling sharedArrayBuffers for the back-end on trusted code from the app store is (in my opinion) safe. Maybe you can make this a run-time option for app developers?

Thank you for all the clarifications. Great product!

Cheers

[jaimecbernardo]

Hi @writepubapp ,

1. WASM seems to have been turned on by default on more recent node-chakracore versions, so it should come as an engine update, unless there's some reason we may need to disable it (if it depends on JIT, that's not allowed in iOS, for example).
2. It's hard to tell right now. From the source you shared, it seems that there will be engine flags to enable the feature, so in that case those will be available to pass when starting node.

Thank you! I hope this is helpful.

[mjp0]

Any news regarding this? I've a project where I need to compute en/decryption with nodejs and I'm already grinding my teeth about how much pain it will be performance-wise. WASM could help with these types of workloads a lot.

[jaimecbernardo]

Hi @markopolojarvi , This can be re-evaluated once the update to 10.x LTS hits: #156

[notatestuser]

Hey everyone. Now that this release has happened, WebAssembly still does not appear to be available in iOS. It would be great to be able to use WebAssembly in the node environment!

[jaimecbernardo]

Hi @notatestuser,

On iOS, WebAssembly is not supported yet, since ChakraCore currently enables WASM only if running on x86/x86_64 and JIT is enabled. This didn't change with the 10.x LTS release.

https://github.com/janeasystems/nodejs-mobile/blob/2101f2096d59d2a081f64da2f10fd7385222ac8a/deps/chakrashim/core/lib/Common/CommonDefines.h#L714-L722

[notatestuser]

Understood. Thank you!

…

________________________________ From: Jaime Bernardo <notifications@github.com> Sent: Monday, September 23, 2019 9:08 pm To: JaneaSystems/nodejs-mobile Cc: Luke Plaster; Mention Subject: Re: [JaneaSystems/nodejs-mobile] Question: WebAssembly support (#107) Hi @notatestuser<https://github.com/notatestuser>, On iOS, WebAssembly is not supported yet, since ChakraCore currently enables WASM only if running on x86/x86_64 and JIT is enabled. This didn't change with the 10.x LTS release. https://github.com/janeasystems/nodejs-mobile/blob/2101f2096d59d2a081f64da2f10fd7385222ac8a/deps/chakrashim/core/lib/Common/CommonDefines.h#L714-L722 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#107?email_source=notifications&email_token=AAJST5RP22SAAX3RU2CNYTDQLC5VHA5CNFSM4FPHFIA2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7KZKAQ#issuecomment-534091010>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AAJST5Q5H27BV72CXBKWYNTQLC5VHANCNFSM4FPHFIAQ>.

[navneetgulati]

Hey Any updates on wether web Assembly will be available on iOS. Or if not can anyone point me to some alternative for webAssembly.

[jaimecbernardo]

Even on V8, WebAssembly functionalities depend on JIT being enabled. And iOS Guidelines forbid use of JIT.