Re: [RFC] selftests/x86: Add test_vsyscall

[Borislav Petkov]

On Thu, Jan 04, 2018 at 09:38:37PM -0800, Andy Lutomirski wrote:
> It's RFC because I want to re-read it myself first.  It's also missing
> a test that will reliably make sure that vsyscall=none prevents use of
> vsyscalls.

With my patch ontop of 4.4 from yesterday:

# ./test_vsyscall_32
Warning: failed to find getcpu in vDSO
[RUN]   test gettimeofday()
        vDSO time offsets: 0.000001 0.000001
[OK]    vDSO gettimeofday()'s timeval was okay
[RUN]   test time()
[OK]    vDSO time() is okay
[RUN]   getcpu() on CPU 0
[RUN]   getcpu() on CPU 1
# ./test_vsyscall_64
        vsyscall map: ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]
        vsyscall permissions are r-x
[RUN]   test gettimeofday()
        vDSO time offsets: 0.000000 0.000005
[OK]    vDSO gettimeofday()'s timeval was okay
        vsyscall time offsets: 0.000004 0.000001
[OK]    vsyscall gettimeofday()'s timeval was okay
[RUN]   test time()
[OK]    vDSO time() is okay
[OK]    vsyscall time() is okay
[RUN]   getcpu() on CPU 0
[OK]    vDSO reported correct CPU
[OK]    vDSO reported correct node
[OK]    vsyscall reported correct CPU
[OK]    vsyscall reported correct node
[RUN]   getcpu() on CPU 1
[OK]    vDSO reported correct CPU
[OK]    vDSO reported correct node
[OK]    vsyscall reported correct CPU
[OK]    vsyscall reported correct node
[RUN]   Checking read access to the vsyscall page
[FAIL]  We don't have read access, but we should

Do I really need the read access? :-)

I have CONFIG_LEGACY_VSYSCALL_EMULATE=y

Thx.

-- 
Regards/Gruss,
    Boris.

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