Revert "Use the libc clone wrapper in sys_clone."
This reverts commit d8a593bceaf0a4b38d06a8c13b948202d205f1b6.
Reason for revert: see crbug.com/442817
> Previously, we directly invoked the syscall, which would not update
> libc's PID cache in the child. Although the libc wrapper function
> updates the PID cache, it unfortunately requires that the child run on a
> different stack, even if CLONE_VM is not specified. We work around this
> by briefly switching stacks in the child, then using longjmp to switch
> back. This gives us a version of clone with fork-like behavior, which is
> what we need for starting processes in new namespaces.
>
> BUG=312380
> Committed: https://crrev.com/d8a593bceaf0a4b38d06a8c13b948202d205f1b6
> Cr-Commit-Position: refs/heads/master@{#308510}
BUG=312380, 442817
TBR=rickyz@chromium.org
Review URL: https://codereview.chromium.org/807213002
Cr-Commit-Position: refs/heads/master@{#308636}
3 files changed
