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Date:   Wed, 10 Aug 2022 11:14:21 +0200
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To:     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Gavin Shan <gshan@redhat.com>
Cc:     Florian Weimer <fweimer@redhat.com>, kvmarm@lists.cs.columbia.edu,
        kvm@vger.kernel.org, linux-kselftest@vger.kernel.org,
        linux-kernel@vger.kernel.org, maz@kernel.org,
        oliver upton <oliver.upton@linux.dev>,
        andrew jones <andrew.jones@linux.dev>, seanjc@google.com,
        yihyu@redhat.com, shan gavin <shan.gavin@gmail.com>
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From:   Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH 1/2] KVM: selftests: Make rseq compatible with glibc-2.35
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On 8/9/22 14:21, Mathieu Desnoyers wrote:
>> For kvm/selftests, there are 3 architectures involved actually. So we
>> just need consider 4 cases: aarch64, x86, s390 and other. For other
>> case, we just use __builtin_thread_pointer() to maintain code's
>> integrity, but it's not called at all.
>>
>> I think kvm/selftest is always relying on glibc if I'm correct.
> All those are handled in the rseq selftests and in librseq. Why duplicate all that logic again?

Yeah, rseq_test should reuse librseq code.  The simplest way,
if slightly hackish, is to do something like

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 690b499c3471..6c192b0ec304 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -37,6 +37,7 @@ ifeq ($(ARCH),riscv)
  	UNAME_M := riscv
  endif
  
  LIBKVM += lib/assert.c
  LIBKVM += lib/elf.c
  LIBKVM += lib/guest_modes.c
@@ -198,7 +199,7 @@ endif
  CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \
  	-fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \
  	-I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \
-	-I$(<D) -Iinclude/$(UNAME_M) -I.. $(EXTRA_CFLAGS) $(KHDR_INCLUDES)
+	-I$(<D) -Iinclude/$(UNAME_M) -I.. $(EXTRA_CFLAGS) $(KHDR_INCLUDES) -I../rseq
  
  no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \
          $(CC) -Werror -no-pie -x c - -o "$$TMP", -no-pie)


and just #include "../rseq/rseq.c" in rseq_test.c.

Thanks,

Paolo