selftests/bpf: Add syscall ctx variable offset tests

Add various tests to exercise fixed and variable offsets on PTR_TO_CTX
for syscall programs, and cover disallowed cases for other program types
l

selftests/bpf: Add syscall ctx variable offset tests

Add various tests to exercise fixed and variable offsets on PTR_TO_CTX
for syscall programs, and cover disallowed cases for other program types
lacking convert_ctx_access callback. Load verifier_ctx with CAP_SYS_ADMIN
so that kfunc related logic can be tested. While at it, convert assembly
tests to C. Unfortunately, ctx_pointer_to_helper_2's unpriv case conflicts
with usage of kfuncs in the file and cannot be run.

Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: move trampoline_count to dedicated bpf_testmod target

trampoline_count fills all trampoline attachment slots for a single
target function and verifies that one extra attach fails with

selftests/bpf: move trampoline_count to dedicated bpf_testmod target

trampoline_count fills all trampoline attachment slots for a single
target function and verifies that one extra attach fails with -E2BIG.

It currently targets bpf_modify_return_test, which is also used by
other selftests such as modify_return, get_func_ip_test, and
get_func_args_test. When such tests run in parallel, they can contend
for the same per-function trampoline quota and cause unexpected attach
failures. This issue is currently masked by harness serialization.

Move trampoline_count to a dedicated bpf_testmod target and register it
for fmod_ret attachment. Also route the final trigger through
trigger_module_test_read(), so the execution path exercises the same
dedicated target.

This keeps the test semantics unchanged while isolating it from other
selftests, so it no longer needs to run in serial mode. Remove the
TODO comment as well.

Tested:
./test_progs -t trampoline_count -vv
./test_progs -j$(nproc) -t trampoline_count -vv
./test_progs -j$(nproc) -t \
trampoline_count,modify_return,get_func_ip_test,get_func_args_test -vv
20 runs of:
./test_progs -j$(nproc) -t \
trampoline_count,modify_return,get_func_ip_test,get_func_args_test

Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260324044949.869801-1-sun.jian.kdev@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: Add test for struct_ops __ref argument in any position

Add a selftest to verify that the verifier correctly identifies refcounted
arguments in struct_ops programs, even when they are

selftests/bpf: Add test for struct_ops __ref argument in any position

Add a selftest to verify that the verifier correctly identifies refcounted
arguments in struct_ops programs, even when they are not the first
argument. This ensures that the restriction on tail calls for programs
with __ref arguments is properly enforced regardless of which argument
they appear in.

This test verifies the fix for check_struct_ops_btf_id() proposed by
Keisuke Nishimura [0], which corrected a bug where only the first
argument was checked for the refcounted flag.
The test includes:
- An update to bpf_testmod to add 'test_refcounted_multi', an operator with
three arguments where the third is tagged with "__ref".
- A BPF program 'test_refcounted_multi' that attempts a tail call.
- A test runner that asserts the verifier rejects the program with
"program with __ref argument cannot tail call".

[0]: https://lore.kernel.org/bpf/20260320130219.63711-1-keisuke.nishimura@inria.fr/

Signed-off-by: Varun R Mallya <varunrmallya@gmail.com>
Link: https://lore.kernel.org/r/20260321214038.80479-1-varunrmallya@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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selftests/bpf: Improve test coverage for kfunc call

On powerpc, immediate load instructions are sign extended. In case
of unsigned types, arguments should be explicitly zero-extended by
the caller.

selftests/bpf: Improve test coverage for kfunc call

On powerpc, immediate load instructions are sign extended. In case
of unsigned types, arguments should be explicitly zero-extended by
the caller. For kfunc call, this needs to be handled in the JIT code.
In bpf_kfunc_call_test4(), that tests for sign-extension of signed
argument types in kfunc calls, add some additional failure checks.
And add bpf_kfunc_call_test5() to test zero-extension of unsigned
argument types in kfunc calls.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260312080113.843408-1-hbathini@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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