kselftest/arm64: Try harder to generate different keys during PAC tests

We very intermittently see failures in the single_thread_different_keys
PAC test. As noted in the comment in the test the PAC

kselftest/arm64: Try harder to generate different keys during PAC tests

We very intermittently see failures in the single_thread_different_keys
PAC test. As noted in the comment in the test the PAC field can be quite
narrow so there is a chance of collisions even with different keys with a
chance of 5% for 7 bit keys, and the potential for narrower keys. The test
tries to avoid this by running repeatedly, but only tries 10 times which
even with a 5% chance of collisions isn't enough.

Increase the number of times we attempt to look for collisions by a factor
of 100, this also affects other tests which are following a similar pattern
with running the test repeatedly and either don't care like with
pac_instruction_not_nop or potentially have the same issue like
exec_sign_all.

The PAC tests are very fast, running in a second or two even in emulation,
so the 100x increased cost is mildly irritating but not a huge issue. The
bulk of the overhead is in the exec_sign_all test which does a fork() and
exec() per iteration.

Signed-off-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all()

The PAC exec_sign_all() test spawns some child processes, creating pipes
to be stdin and stdout for the child. It cleans up most of the fi

kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all()

The PAC exec_sign_all() test spawns some child processes, creating pipes
to be stdin and stdout for the child. It cleans up most of the file
descriptors that are created as part of this but neglects to clean up the
parent end of the child stdin and stdout. Add the missing close() calls.

Signed-off-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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kselftest/arm64: Enable build of PAC tests with LLVM=1

Currently we don't build the PAC selftests when building with LLVM=1 since
we attempt to test for PAC support in the toolchain before we've set

kselftest/arm64: Enable build of PAC tests with LLVM=1

Currently we don't build the PAC selftests when building with LLVM=1 since
we attempt to test for PAC support in the toolchain before we've set up the
build system to point at LLVM in lib.mk, which has to be one of the last
things in the Makefile.

Since all versions of LLVM supported for use with the kernel have PAC
support we can just sidestep the issue by just assuming PAC is there when
doing a LLVM=1 build.

Signed-off-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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