fanotify: Add test for permission event destruction

Test whether kernel's notification subsystem gets stuck when some fanotify permission events are not responded to. Also test destruction of fanotify instance while there are outstanding permission events. This can result in hanging of processes indefinitely in kernel or in kernel crashes.

Kernel crashes should be fixed by commit 96d41019e3ac "fanotify: fix list corruption in fanotify_get_response()", kernel hangs by 05f0e38724e8 "fanotify: Release SRCU lock when waiting for userspace response".

---
 runtest/syscalls                                |   1 +
 testcases/kernel/syscalls/fanotify/fanotify07.c | 245 ++++++++++++++++++++++++
 2 files changed, 246 insertions(+)
 create mode 100644 testcases/kernel/syscalls/fanotify/fanotify07.c

index 89abac5ff5f8..94232c6cf21e 100644
@@ -473,6 +473,7 @@ fanotify03 fanotify03
 fanotify04 fanotify04
 fanotify05 fanotify05
 fanotify06 fanotify06
+fanotify07 fanotify07
 
 ioperm01 ioperm01
 ioperm02 ioperm02

2.12.0

Hi!
Looks good, I will push it once we are done with the release and git is unfrozen again (likely end of this week).

Cyril Hrubis
[email protected]

Hi!
Pushed with minor changes, thanks.

What I did:

* Updated the copyright year to 2017

* Added the kernel commit ids to the top level comment in the test source

* Removed the fd_notify = -1 after SAFE_CLOSE(fd_notify) SAFE_CLOSE() sets the fd to -1 already

* Updated syscalls/.gitignore

Cyril Hrubis
[email protected]