selftests/bpf: fexit_sleep: Fix stack allocation for arm64

[ Upstream commit e1ef78dce9b7b0fa7f9d88bb3554441d74d33b34 ]

On ARM64 the stack pointer should be aligned at a 16 byte boundary or
the SPA

selftests/bpf: fexit_sleep: Fix stack allocation for arm64

[ Upstream commit e1ef78dce9b7b0fa7f9d88bb3554441d74d33b34 ]

On ARM64 the stack pointer should be aligned at a 16 byte boundary or
the SPAlignmentFault can occur. The fexit_sleep selftest allocates the
stack for the child process as a character array, this is not guaranteed
to be aligned at 16 bytes.

Because of the SPAlignmentFault, the child process is killed before it
can do the nanosleep call and hence fentry_cnt remains as 0. This causes
the main thread to hang on the following line:

while (READ_ONCE(fexit_skel->bss->fentry_cnt) != 2);

Fix this by allocating the stack using mmap() as described in the
example in the man page of clone().

Remove the fexit_sleep test from the DENYLIST of arm64.

Fixes: eddbe8e65214 ("selftest/bpf: Add a test to check trampoline freeing logic.")
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240715173327.8657-1-puranjay@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

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selftests/bpf: Add weak/typeless ksym test for light skeleton

Also, avoid using CO-RE features, as lskel doesn't support CO-RE, yet.
Include both light and libbpf skeleton in same file to test both

selftests/bpf: Add weak/typeless ksym test for light skeleton

Also, avoid using CO-RE features, as lskel doesn't support CO-RE, yet.
Include both light and libbpf skeleton in same file to test both of them
together.

In c48e51c8b07a ("bpf: selftests: Add selftests for module kfunc support"),
I added support for generating both lskel and libbpf skel for a BPF
object, however the name parameter for bpftool caused collisions when
included in same file together. This meant that every test needed a
separate file for a libbpf/light skeleton separation instead of
subtests.

Change that by appending a "_lskel" suffix to the name for files using
light skeleton, and convert all existing users.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-7-memxor@gmail.com

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selftests/bpf: Convert few tests to light skeleton.

Convert few tests that don't use CO-RE to light skeleton.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <dani

selftests/bpf: Convert few tests to light skeleton.

Convert few tests that don't use CO-RE to light skeleton.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-19-alexei.starovoitov@gmail.com

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selftests/bpf: Silence clang compilation warnings

With clang compiler:
make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel
make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
Some linker fla

selftests/bpf: Silence clang compilation warnings

With clang compiler:
make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel
make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
Some linker flags are not used/effective for some binaries and
we have warnings like:
warning: -lelf: 'linker' input unused [-Wunused-command-line-argument]

We also have warnings like:
.../selftests/bpf/prog_tests/ns_current_pid_tgid.c:74:57: note: treat the string as an argument to avoid this
if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", strerror(errno)))
^
"%s",
.../selftests/bpf/test_progs.h:129:35: note: expanded from macro 'CHECK'
_CHECK(condition, tag, duration, format)
^
.../selftests/bpf/test_progs.h:108:21: note: expanded from macro '_CHECK'
fprintf(stdout, ##format); \
^
The first warning can be silenced with clang option -Wno-unused-command-line-argument.
For the second warning, source codes are modified as suggested by the compiler
to silence the warning. Since gcc does not support the option
-Wno-unused-command-line-argument and the warning only happens with clang
compiler, the option -Wno-unused-command-line-argument is enabled only when
clang compiler is used.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153429.3029377-1-yhs@fb.com

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selftest/bpf: Add a test to check trampoline freeing logic.

Add a selftest for commit e21aa341785c ("bpf: Fix fexit trampoline.")
to make sure that attaching fexit prog to a sleeping kernel function

selftest/bpf: Add a test to check trampoline freeing logic.

Add a selftest for commit e21aa341785c ("bpf: Fix fexit trampoline.")
to make sure that attaching fexit prog to a sleeping kernel function
will trigger appropriate trampoline and program destruction.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210318004523.55908-1-alexei.starovoitov@gmail.com

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