Use sudo if /proc/cpuinfo isn't readable in the start-tor-browser script

On Linux, the start-tor-browser script checks for SSE2 support by grepping /proc/cpuinfo. On some systems, /proc/cpuinfo isn't readable to ordinary users (Whonix may implement this) so it will fail with an error saying "Tor Browser requires a CPU with SSE2 support.".

It would be better if the script checked if the file is not readable and if it isn't, it tries to grep it with sudo --noninteractive so people can add sudoers exceptions for the Tor Browser.

added TorBrowserTeam201910R actualpoints::0.1 component::applications/tor browser owner::tbb-team priority::medium resolution::fixed severity::normal status::closed tbb-rbm type::enhancement labels

I am not overly thrilled having any sudo incantations in our start script. But maybe there is an other way to check for SSE2 support in the start script? Or maybe we just declare that there aren't any CPUs in daily use anymore without SSE2 support and just remove the check? Or...

But maybe there is an other way to check for SSE2 support in the start script?

All methods probably stem from /proc/cpuinfo or /sys (which Whonix may also restrict).

Or maybe we just declare that there aren't any CPUs in daily use anymore without SSE2 support and just remove the check?

That would be reasonable. SSE2 has been a thing for around 18 years now. Any non-ancient CPU would have it. The Tor Browser not working would probably be the least of their issues with hardware that old.

An other option is to check for SSE2 support only if /proc/cpuinfo is readable, and if not assume that SSE2 is available.

Replying to boklm:

An other option is to check for SSE2 support only if /proc/cpuinfo is readable, and if not assume that SSE2 is available.

This is what the patch in branch bug_31968 is doing: https://gitweb.torproject.org/user/boklm/tor-browser-build.git/commit/?h=bug_31968&id=6cf4e6eabc5eb559baf9721a3caf0544b7480093

@cypherpunks: could you check if applying this change to your Browser/start-tor-browser script solves the issue?

Trac:
Keywords: N/A deleted, TorBrowserTeam201910R, tbb-rbm added
Actualpoints: N/A to 0.1
Status: new to needs_review

Looks good to me in any case. Merged to master (commit 6cf4e6eabc5eb559baf9721a3caf0544b7480093).

Trac:
Status: needs_review to closed
Resolution: N/A to fixed

closed

added 48m of time spent

moved to tpo/applications/tor-browser#31968 (closed)