audit syscall information.

Debora Velarde dvelarde at us.ibm.com
Thu Apr 28 20:39:09 UTC 2005






In our syscalls, we are currently checking the expected values of some of
the syscall parameters.  We do not always check a0, a1, a2, and a3.  One
syscall may check a0, a1, and a2.  Another may only check a0, and a1.

When we compile our syscalls in 32bit mode on a 64bit system, the a0, a1,
a2, a3 values are no longer what we expected them to be.

For example, in our access syscall test
      a0 = pathname
      a1 = mode

When we compile and run in 64bit mode:
The audit record looks like:
type=KERNEL msg=audit(1114696605.916:2151478): item=0 name="./mytest.9825"
inode=6062205 dev=fd:00 mode=0100004 uid=0 gid=0 rdev=00:00
type=KERNEL msg=audit(1114696605.916:2151478): syscall=21 arch=c000003e
success=yes exit=0 a0=50a460 a1=4 a2=3cb762ea03 a3=0 items=1 pid=9825
loginuid=500 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0
comm="access_test"
exe=/deb/rhcc/eal4/tests/LTP/ltp-full/testcases/audit/filters/access_test

>From our test:
access_test    0  INFO  :  expected (pfilename) a0 s=./mytest.9825 h=50a460
d=5284960 u=5284960.  (expected a0 printed as a string, hex, decimal,
unsigned values)
            Note audit record a0=50a460 which matches expected value
printed in hex

access_test    0  INFO  :  expected (access_mode) a1 h=4 d=4 u=4.
(expected a1 printed as a hex, decimal, and unsigned value)
            Note audit record a1=4 which matches expected (printed in %x,
%d, and %u)

access_test    0  INFO  :  expected (pfilename) objectname s=./mytest.9825.
            Matches "name" in audit record"

access_test    1  PASS  :  Expected record found!


When we compile and run in 32bit mode:
type=KERNEL msg=audit(1114696996.822:2260436): item=0 name="./mytest.10196"
inode=6062205 dev=fd:00 mode=0100004 uid=0 gid=0 rdev=00:00
type=KERNEL msg=audit(1114696996.822:2260436): syscall=33 arch=40000003
success=yes exit=0 a0=80510e0 a1=76c378 a2=0 a3=0 items=1 pid=10196
loginuid=500 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0
comm="access_test"
exe=/deb/rhcc/eal4/tests/LTP/ltp-full/testcases/audit/filters/access_test

>From our test
access_test    0  INFO  :  expected (pfilename) a0 s=./mytest.10196
h=8051260 d=134550112 u=134550112.
      Note audit record a0=80510e0 does NOT match expected (in %x, %d, or
%u format).

access_test    0  INFO  :  expected (access_mode) a1 h=4 d=4 u=4.
      Note audit record a1=76c378.  does NOT match expected (in %x , %d, or
%u format).

access_test    0  INFO  :  expected (pfilename) objectname
s=./mytest.10196.

access_test    1  FAIL  :  Expected record not found.


I know David put some hooks in for the ipc syscalls, I haven't been able to
test those to see if that corrects this problem for those or not.  I'm not
sure when that fix was introduced.  I'm currently running on
kernel.2.6.9-5.0.3.EL.audit.20 and this problem is true for the ipc
syscalls as well.

If that does fix the problem, should our tests only check a0, a1, a2, a3
values for the syscalls which David is adding these hooks?

Thanks,
debbie
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