tree bfca8adb748c7396243bc1914c06758d23082c5f
parent 34ae543dc3b9c577c39eb9d7063e2f72747f5d26
author Josh Gao <jmgao@google.com> 1467321618 -0700
committer Josh Gao <jmgao@google.com> 1468453742 -0700

debuggerd: verify that traced threads belong to the right process.

Fix two races in debuggerd's PTRACE_ATTACH logic:
  1. The target thread in a crash dump request could exit between the
     /proc/<pid>/task/<tid> check and the PTRACE_ATTACH.
  2. Sibling threads could exit between listing /proc/<pid>/task and the
     PTRACE_ATTACH.

Bug: http://b/29555636
Change-Id: I4dfe1ea30e2c211d2389321bd66e3684dd757591