tree fb220c3c9777456da896159d8b77d4cbeca3961e
parent 95d29eb9e1cabfde6f68d95e3ed590a1d58196e0
author Cody Schuffelen <schuffelen@google.com> 1567021605 -0700
committer Cody Schuffelen <schuffelen@google.com> 1576197689 -0800

Implement SharedFD::MemfdCreate.

This makes it convenient to create SharedFDs for in-memory-only files.

Android currently has host prebuilts of glibc 2.15 and 2.17, but
memfd_create was only added in glibc 2.27. It was defined in Linux 3.17,
so we consider it safe to use the low-level arbitrary syscall wrapper.

Test: N/A
Change-Id: Id7de8f89537b2b8d0ed9b171bfb37bf770596386