[tor-bugs] #21514 [Applications/Tor Browser]: Deal with W^X backport bustage in upcoming ESR release

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#21514: Deal with W^X backport bustage in upcoming ESR release
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 Reporter:  gk                        |          Owner:  arthuredelstein
     Type:  task                      |         Status:  needs_review
 Priority:  Very High                 |      Milestone:
Component:  Applications/Tor Browser  |        Version:
 Severity:  Critical                  |     Resolution:
 Keywords:  TorBrowserTeam201702      |  Actual Points:
Parent ID:                            |         Points:
 Reviewer:                            |        Sponsor:
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Changes (by arthuredelstein):

 * status:  accepted => needs_review


Comment:

 I believe I have finally got it working:

 https://github.com/arthuredelstein/tor-browser/commit/21514+4

 Thanks to Jan de Mooij for looking it over and helpful advice.

 So far I have tested on Linux, but this will need testing on Windows and
 Mac at least to show that it doesn't cause a crash. I am reasonably
 confident the code covers all three platforms.

 Jan also suggested we could examine the memory maps with and without the
 patch, using `gdb` or `/proc/pid/maps` on Linux and `VMMap` on Windows. He
 points out that without the patch we should hopefully observe multiple rwx
 regions.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21514#comment:5>
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