[0/4] Use new infrastructure to fix deadlocks in execve

Message

Bernd Edlinger March 10, 2020, 1:43 p.m. UTC

This is a follow up on Eric's patch series to
fix the deadlocks observed with ptracing when execve
in multi-threaded applications.

This fixes the simple and most important case where
the cred_guard_mutex causes strace to deadlock.

This also adds a test case (which is only partially
fixed so far, the rest of the fixes will follow
soon).

Two trivial comment fixes are also included.

Bernd Edlinger (4):
  exec: Fix a deadlock in ptrace
  selftests/ptrace: add test cases for dead-locks
  mm: docs: Fix a comment in process_vm_rw_core
  kernel: doc: remove outdated comment in prepare_kernel_cred

 kernel/cred.c                             |  2 -
 kernel/fork.c                             |  4 +-
 mm/process_vm_access.c                    |  2 +-
 tools/testing/selftests/ptrace/Makefile   |  4 +-
 tools/testing/selftests/ptrace/vmaccess.c | 86 +++++++++++++++++++++++++++++++
 5 files changed, 91 insertions(+), 7 deletions(-)
 create mode 100644 tools/testing/selftests/ptrace/vmaccess.c

Comments

Eric W. Biederman March 10, 2020, 3:35 p.m. UTC | #1

Bernd Edlinger <[e-mail]> writes:

> This is a follow up on Eric's patch series to
> fix the deadlocks observed with ptracing when execve
> in multi-threaded applications.
>
> This fixes the simple and most important case where
> the cred_guard_mutex causes strace to deadlock.
>
> This also adds a test case (which is only partially
> fixed so far, the rest of the fixes will follow
> soon).
>
> Two trivial comment fixes are also included.
>
> Bernd Edlinger (4):
>   exec: Fix a deadlock in ptrace
>   selftests/ptrace: add test cases for dead-locks
>   mm: docs: Fix a comment in process_vm_rw_core
>   kernel: doc: remove outdated comment in prepare_kernel_cred
>
>  kernel/cred.c                             |  2 -
>  kernel/fork.c                             |  4 +-
>  mm/process_vm_access.c                    |  2 +-
>  tools/testing/selftests/ptrace/Makefile   |  4 +-
>  tools/testing/selftests/ptrace/vmaccess.c | 86 +++++++++++++++++++++++++++++++
>  5 files changed, 91 insertions(+), 7 deletions(-)
>  create mode 100644 tools/testing/selftests/ptrace/vmaccess.c

Applied.

Thank you,
Eric