Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 56 insertions, 0 deletions

diff --git a/tests/qtest/fuzz/fork_fuzz.ld b/tests/qtest/fuzz/fork_fuzz.ld
new file mode 100644
index 000000000..cfb88b7fd
--- /dev/null
+++ b/tests/qtest/fuzz/fork_fuzz.ld
@@ -0,0 +1,56 @@
+/*
+ * We adjust linker script modification to place all of the stuff that needs to
+ * persist across fuzzing runs into a contiguous section of memory. Then, it is
+ * easy to re-map the counter-related memory as shared.
+ */
+
+SECTIONS
+{
+  .data.fuzz_start : ALIGN(4K)
+  {
+      __FUZZ_COUNTERS_START = .;
+      __start___sancov_cntrs = .;
+      *(_*sancov_cntrs);
+      __stop___sancov_cntrs = .;
+
+      /* Lowest stack counter */
+      *(__sancov_lowest_stack);
+  }
+}
+INSERT AFTER .data;
+
+SECTIONS
+{
+  .data.fuzz_ordered :
+  {
+      /*
+       * Coverage counters. They're not necessary for fuzzing, but are useful
+       * for analyzing the fuzzing performance
+       */
+      __start___llvm_prf_cnts = .;
+      *(*llvm_prf_cnts);
+      __stop___llvm_prf_cnts = .;
+
+      /* Internal Libfuzzer TracePC object which contains the ValueProfileMap */
+      FuzzerTracePC*(.bss*);
+      /*
+       * In case the above line fails, explicitly specify the (mangled) name of
+       * the object we care about
+       */
+       *(.bss._ZN6fuzzer3TPCE);
+  }
+}
+INSERT AFTER .data.fuzz_start;
+
+SECTIONS
+{
+  .data.fuzz_end : ALIGN(4K)
+  {
+      __FUZZ_COUNTERS_END = .;
+  }
+}
+/*
+ * Don't overwrite the SECTIONS in the default linker script. Instead insert the
+ * above into the default script
+ */
+INSERT AFTER .data.fuzz_ordered;