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2 commits

Author SHA1 Message Date
Tiezhu Yang
29d44cce32 selftests/bpf: Use asm constraint "m" for LoongArch
Currently, LoongArch LLVM does not support the constraint "o" and no plan
to support it, it only supports the similar constraint "m", so change the
constraints from "nor" in the "else" case to arch-specific "nmr" to avoid
the build error such as "unexpected asm memory constraint" for LoongArch.

Fixes: 630301b0d5 ("selftests/bpf: Add basic USDT selftests")
Suggested-by: Weining Lu <luweining@loongson.cn>
Suggested-by: Li Chen <chenli@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Cc: stable@vger.kernel.org
Link: https://llvm.org/docs/LangRef.html#supported-constraint-code-list
Link: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/LoongArch/LoongArchISelDAGToDAG.cpp#L172
Link: https://lore.kernel.org/bpf/20241219111506.20643-1-yangtiezhu@loongson.cn
2024-12-19 13:15:52 +01:00
Andrii Nakryiko
630301b0d5 selftests/bpf: Add basic USDT selftests
Add semaphore-based USDT to test_progs itself and write basic tests to
valicate both auto-attachment and manual attachment logic, as well as
BPF-side functionality.

Also add subtests to validate that libbpf properly deduplicates USDT
specs and handles spec overflow situations correctly, as well as proper
"rollback" of partially-attached multi-spec USDT.

BPF-side of selftest intentionally consists of two files to validate
that usdt.bpf.h header can be included from multiple source code files
that are subsequently linked into final BPF object file without causing
any symbol duplication or other issues. We are validating that __weak
maps and bpf_usdt_xxx() API functions defined in usdt.bpf.h do work as
intended.

USDT selftests utilize sys/sdt.h header that on Ubuntu systems comes
from systemtap-sdt-devel package. But to simplify everyone's life,
including CI but especially casual contributors to bpf/bpf-next that
are trying to build selftests, I've checked in sys/sdt.h header from [0]
directly. This way it will work on all architectures and distros without
having to figure it out for every relevant combination and adding any
extra implicit package dependencies.

  [0] https://sourceware.org/git?p=systemtap.git;a=blob_plain;f=includes/sys/sdt.h;h=ca0162b4dc57520b96638c8ae79ad547eb1dd3a1;hb=HEAD

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-7-andrii@kernel.org
2022-04-05 13:16:08 -07:00