[PATCH v6 00/16] Infrastructure to allow fixing exec deadlocks

[Bernd Edlinger]

This is an infrastructure change that makes way for fixing this issue.
Each patch was already posted previously so this is just a cleanup of
the original mailing list thread(s) which got out of control by now.

Everything started here:
https://lore.kernel.org/lkml/AM6PR03MB5170B06F3A2B75EFB98D071AE4E60@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/

I added reviewed-by tags from the mailing list threads, except when
withdrawn.

It took a lot longer than expected to collect everything from the
mailinglist threads, since several commit messages have been infected
with typos, and they got fixed without a new patch version.

- Correct the point of no return.
- Add two new mutexes to replace cred_guard_mutex.
- Fix each use of cred_guard_mutex.
- Update documentation.
- Add a test case.

Bernd Edlinger (11):
  exec: Fix a deadlock in strace
  selftests/ptrace: add test cases for dead-locks
  mm: docs: Fix a comment in process_vm_rw_core
  kernel: doc: remove outdated comment cred.c
  kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve
  proc: Use new infrastructure to fix deadlocks in execve
  proc: io_accounting: Use new infrastructure to fix deadlocks in execve
  perf: Use new infrastructure to fix deadlocks in execve
  pidfd: Use new infrastructure to fix deadlocks in execve
  exec: Fix dead-lock in de_thread with ptrace_attach
  doc: Update documentation of ->exec_*_mutex

Eric W. Biederman (5):
  exec: Only compute current once in flush_old_exec
  exec: Factor unshare_sighand out of de_thread and call it separately
  exec: Move cleanup of posix timers on exec out of de_thread
  exec: Move exec_mmap right after de_thread in flush_old_exec
  exec: Add exec_update_mutex to replace cred_guard_mutex

 Documentation/security/credentials.rst    |  29 +++++--
 fs/exec.c                                 | 122 ++++++++++++++++++++++--------
 fs/proc/base.c                            |  23 +++---
 include/linux/binfmts.h                   |   8 +-
 include/linux/sched/signal.h              |  17 ++++-
 init/init_task.c                          |   3 +-
 kernel/cred.c                             |   4 +-
 kernel/events/core.c                      |  12 +--
 kernel/fork.c                             |   7 +-
 kernel/kcmp.c                             |   8 +-
 kernel/pid.c                              |   4 +-
 kernel/ptrace.c                           |  20 ++++-
 kernel/seccomp.c                          |  15 ++--
 mm/process_vm_access.c                    |   2 +-
 tools/testing/selftests/ptrace/Makefile   |   4 +-
 tools/testing/selftests/ptrace/vmaccess.c |  86 +++++++++++++++++++++
 16 files changed, 278 insertions(+), 86 deletions(-)
 create mode 100644 tools/testing/selftests/ptrace/vmaccess.c

-- 
1.9.1