selftests/bpf: Update bpf_cpumask_any* tests to use bpf_cpumask_any_distribute*

In a prior patch, we removed the bpf_cpumask_any() and
bpf_cpumask_any_and() kfuncs, and replaced them with
bpf_cpumas

selftests/bpf: Update bpf_cpumask_any* tests to use bpf_cpumask_any_distribute*

In a prior patch, we removed the bpf_cpumask_any() and
bpf_cpumask_any_and() kfuncs, and replaced them with
bpf_cpumask_any_distribute() and bpf_cpumask_any_distribute_and().
The advertised semantics between the two kfuncs were identical, with the
former always returning the first CPU, and the latter actually returning
any CPU.

This patch updates the selftests for these kfuncs to use the new names.

Signed-off-by: David Vernet <void@manifault.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230610035053.117605-4-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: Add test for new bpf_cpumask_first_and() kfunc

A prior patch added a new kfunc called bpf_cpumask_first_and() which
wraps cpumask_first_and(). This patch adds a selftest to validate i

selftests/bpf: Add test for new bpf_cpumask_first_and() kfunc

A prior patch added a new kfunc called bpf_cpumask_first_and() which
wraps cpumask_first_and(). This patch adds a selftest to validate its
behavior.

Signed-off-by: David Vernet <void@manifault.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230610035053.117605-2-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: Add test for non-NULLable PTR_TO_BTF_IDs

In a recent patch, we taught the verifier that trusted PTR_TO_BTF_ID can
never be NULL. This prevents the verifier from incorrectly failing to

selftests/bpf: Add test for non-NULLable PTR_TO_BTF_IDs

In a recent patch, we taught the verifier that trusted PTR_TO_BTF_ID can
never be NULL. This prevents the verifier from incorrectly failing to
load certain programs where it gets confused and thinks a reference
isn't dropped because it incorrectly assumes that a branch exists in
which a NULL PTR_TO_BTF_ID pointer is never released.

This patch adds a testcase that verifies this cannot happen.

Signed-off-by: David Vernet <void@manifault.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230602150112.1494194-2-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: Remove bpf_cpumask_kptr_get() kfunc

Now that struct bpf_cpumask is RCU safe, there's no need for this kfunc.
Rather than doing the following:

private(MASK) static struct bpf_cpumask __kptr *gl

bpf: Remove bpf_cpumask_kptr_get() kfunc

Now that struct bpf_cpumask is RCU safe, there's no need for this kfunc.
Rather than doing the following:

private(MASK) static struct bpf_cpumask __kptr *global;

int BPF_PROG(prog, s32 cpu, ...)
{
struct bpf_cpumask *cpumask;

bpf_rcu_read_lock();
cpumask = bpf_cpumask_kptr_get(&global);
if (!cpumask) {
bpf_rcu_read_unlock();
return -1;
}
bpf_cpumask_setall(cpumask);
...
bpf_cpumask_release(cpumask);
bpf_rcu_read_unlock();
}

Programs can instead simply do (assume same global cpumask):

int BPF_PROG(prog, ...)
{
struct bpf_cpumask *cpumask;

bpf_rcu_read_lock();
cpumask = global;
if (!cpumask) {
bpf_rcu_read_unlock();
return -1;
}
bpf_cpumask_setall(cpumask);
...
bpf_rcu_read_unlock();
}

In other words, no extra atomic acquire / release, and less boilerplate
code.

This patch removes both the kfunc, as well as its selftests and
documentation.

Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230316054028.88924-5-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf/selftests: Test using global cpumask kptr with RCU

Now that struct bpf_cpumask * is considered an RCU-safe type according
to the verifier, we should add tests that validate its common usages.
Th

bpf/selftests: Test using global cpumask kptr with RCU

Now that struct bpf_cpumask * is considered an RCU-safe type according
to the verifier, we should add tests that validate its common usages.
This patch adds those tests to the cpumask test suite. A subsequent
changes will remove bpf_cpumask_kptr_get(), and will adjust the selftest
and BPF documentation accordingly.

Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230316054028.88924-4-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: fix lots of silly mistakes pointed out by compiler

Once we enable -Wall for BPF sources, compiler will complain about lots
of unused variables, variables that are set but never read,

selftests/bpf: fix lots of silly mistakes pointed out by compiler

Once we enable -Wall for BPF sources, compiler will complain about lots
of unused variables, variables that are set but never read, etc.

Fix all these issues first before enabling -Wall in Makefile.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: Add selftest suite for cpumask kfuncs

A recent patch added a new set of kfuncs for allocating, freeing,
manipulating, and querying cpumasks. This patch adds a new 'cpumask'
selftest s

selftests/bpf: Add selftest suite for cpumask kfuncs

A recent patch added a new set of kfuncs for allocating, freeing,
manipulating, and querying cpumasks. This patch adds a new 'cpumask'
selftest suite which verifies their behavior.

Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230125143816.721952-5-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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