Introduce tests for Capability mode System calls and _exit(2)

[aniketp]

Summary

This revision introduces atf-c(3) tests for 2 Capability mode syscalls and _exit(2).

• cap_enter(2)
• cap_getmode(2)
• _exit(2)

Test Plan

Execute make && make install from test/sys/audit.
Execute kyua test from /usr/tests/sys/audit. All testcases should succeed.

[asomers]

For me cap_enter_success passes intermittently. On a case when it failed, the global audit trail showed the cap_enter call we were looking for (as well as the child's exit(2), which is also in class "pc"). But the auditpipe showed nothing after fork. I think we're looking at a buffering issue. When I run "./process_control cap_enter_success" the last thing I see is the fork record. Then the process pauses for 10 seconds. But while it's paused, if I run any command at all in another terminal, then the test immediately passes. So I think that the auditpipe(4) device is buffering up some amount of data before its read(2) returns.

[aniketp]

• Add the AUDITPIPE_FLUSH ioctl after calling cap_enter() to eliminate the buffering issue

[aniketp]

• Add tests for _exit(2) using the AUDITPIPE_FLUSH approach (for now)

[aniketp]

• Updates in _exit(2) test case comment

[asomers]

using AUDITPIPE_FLUSH doesn't work. You should remove that part and fix the bug in utils.c instead.

[aniketp]

• Disable I/O buffering from /dev/auditpipe for read operations for cap_enter(2) and _exit(2)

[aniketp]

• Forgot a comma in _exit(2) test case comments

[aniketp]

• Some more updates to the recent comments

[asomers]

There's nothing special about exit or cap_enter. You need to disable buffering everywhere, anytime you combine fread(3) with something like ppoll(2).

[aniketp]

• Disable I/O buffering for the whole test-suite

[aniketp]

• Remove redundant header includes that were added for ioctl operations which are not required anymore

[asomers]

tests/sys/audit/utils.c

216 ↗

(On Diff #45398)

Technically it's not possible, not since you use setvbuf. I would say something more like "disable stream buffering so fread(3) (called via au_read_rec(3)) doesn't buffer data unbeknownst to ppoll(2)"

[aniketp]

• Improvements in setvbuf's comments

[aniketp]

This comment was removed by aniketp.

[aniketp]

• Grammatical corrections in the same comment