kselftest/arm64: Validate that GCS push and write permissions work

Add trivial assembly programs which give themselves the appropriate
permissions and then execute GCSPUSHM and GCSSTR, they will rep

kselftest/arm64: Validate that GCS push and write permissions work

Add trivial assembly programs which give themselves the appropriate
permissions and then execute GCSPUSHM and GCSSTR, they will report errors
by generating signals on the non-permitted instructions. Not using libc
minimises the interaction with any policy set for the system but we skip on
failure to get the permissions in case the system is locked down to make
them inaccessible.

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: Add a GCS stress test

Add a stress test which runs one more process than we have CPUs spinning
through a very recursive function with frequent syscalls immediately prior
to return a

kselftest/arm64: Add a GCS stress test

Add a stress test which runs one more process than we have CPUs spinning
through a very recursive function with frequent syscalls immediately prior
to return and signals being injected every 100ms. The goal is to flag up
any scheduling related issues, for example failure to ensure that barriers
are inserted when moving a GCS using task to another CPU. The test runs for
a configurable amount of time, defaulting to 10 seconds.

Reviewed-by: Thiago Jung Bauermann <[email protected]>
Tested-by: Thiago Jung Bauermann <[email protected]>
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: Add test coverage for GCS mode locking

Verify that we can lock individual GCS mode bits, that other modes
aren't affected and as a side effect also that every combination of
modes c

kselftest/arm64: Add test coverage for GCS mode locking

Verify that we can lock individual GCS mode bits, that other modes
aren't affected and as a side effect also that every combination of
modes can be enabled.

Normally the inability to reenable GCS after disabling it would be an
issue with testing but fortunately the kselftest_harness runs each test
within a fork()ed child. This can be inconvenient for some kinds of
testing but here it means that each test is in a separate thread and
therefore won't be affected by other tests in the suite.

Once we get toolchains with support for enabling GCS by default we will
need to take care to not do that in the build system but there are no
such toolchains yet so it is not yet an issue.

Reviewed-by: Thiago Jung Bauermann <[email protected]>
Tested-by: Thiago Jung Bauermann <[email protected]>
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: Add a GCS test program built with the system libc

There are things like threads which nolibc struggles with which we want
to add coverage for, and the ABI allows us to test most of

kselftest/arm64: Add a GCS test program built with the system libc

There are things like threads which nolibc struggles with which we want
to add coverage for, and the ABI allows us to test most of these even if
libc itself does not understand GCS so add a test application built
using the system libc.

Reviewed-by: Thiago Jung Bauermann <[email protected]>
Tested-by: Thiago Jung Bauermann <[email protected]>
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: Add very basic GCS test program

This test program just covers the basic GCS ABI, covering aspects of the
ABI as standalone features without attempting to integrate things.

Reviewed

kselftest/arm64: Add very basic GCS test program

This test program just covers the basic GCS ABI, covering aspects of the
ABI as standalone features without attempting to integrate things.

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

show more ...