simpleperf: support kernel etm data in inject cmd.

1. Refactor KernelDso class to handle kernel address randomization.
2. Add Dso::IpToFileOffset() to convert ip addresses to file offsets,
   and use special operation for KernelDso.
3. Search for vmlinux in symbol dirs.
4. Delay creating KernelDso to use the kernel build id in recording
   files.

Bug: 172933381
Test: run simpleperf_unit_test
Test: run `simpleperf inject` manually to inject kernel etm data.
Change-Id: Ice7f465a6f1e870740cc8ceaf8da76220026adef

1 files changed, 41 insertions, 0 deletions

diff --git a/simpleperf/dso_test.cpp b/simpleperf/dso_test.cpp
index 566d76b9..96663d6b 100644
--- a/simpleperf/dso_test.cpp
+++ b/simpleperf/dso_test.cpp
@@ -24,6 +24,7 @@
 
 #include "get_test_data.h"
 #include "read_apk.h"
+#include "thread_tree.h"
 #include "utils.h"
 
 using namespace simpleperf_dso_impl;
@@ -210,6 +211,46 @@ TEST(dso, IpToVaddrInFile) {
   ASSERT_EQ(0xa5140, dso->IpToVaddrInFile(0xe9201140, 0xe9201000, 0xa5000));
 }
 
+TEST(dso, kernel_address_randomization) {
+  // Use ELF_FILE as a fake kernel vmlinux.
+  const std::string vmlinux_path = GetTestData(ELF_FILE);
+  Dso::SetVmlinux(vmlinux_path);
+  std::unique_ptr<Dso> dso = Dso::CreateDso(DSO_KERNEL, DEFAULT_KERNEL_MMAP_NAME);
+  ASSERT_TRUE(dso);
+  ASSERT_EQ(dso->GetDebugFilePath(), vmlinux_path);
+  // When map_start = 0, can't fix kernel address randomization. So vmlinux isn't used.
+  ASSERT_EQ(dso->IpToVaddrInFile(0x800500, 0, 0), 0x800500);
+  ASSERT_FALSE(dso->IpToFileOffset(0x800500, 0, 0));
+  ASSERT_TRUE(dso->FindSymbol(0x400510) == nullptr);
+
+  dso = Dso::CreateDso(DSO_KERNEL, DEFAULT_KERNEL_MMAP_NAME);
+  ASSERT_TRUE(dso);
+  ASSERT_EQ(dso->GetDebugFilePath(), vmlinux_path);
+  // When map_start != 0, can fix kernel address randomization. So vmlinux is used.
+  ASSERT_EQ(dso->IpToVaddrInFile(0x800500, 0x800400, 0), 0x400500);
+  ASSERT_EQ(dso->IpToFileOffset(0x800500, 0x800400, 0).value(), 0x500);
+  const Symbol* symbol = dso->FindSymbol(0x400510);
+  ASSERT_TRUE(symbol != nullptr);
+  ASSERT_STREQ(symbol->Name(), "GlobalFunc");
+}
+
+TEST(dso, find_vmlinux_in_symdirs) {
+  // Create a symdir.
+  TemporaryDir tmpdir;
+  std::string vmlinux_path = std::string(tmpdir.path) + OS_PATH_SEPARATOR + "elf";
+  std::string data;
+  ASSERT_TRUE(android::base::ReadFileToString(GetTestData(ELF_FILE), &data));
+  ASSERT_TRUE(android::base::WriteStringToFile(data, vmlinux_path));
+
+  // Find vmlinux in symbol dirs.
+  Dso::SetVmlinux("");
+  Dso::AddSymbolDir(tmpdir.path);
+  Dso::SetBuildIds({std::make_pair(DEFAULT_KERNEL_MMAP_NAME, BuildId(ELF_FILE_BUILD_ID))});
+  std::unique_ptr<Dso> dso = Dso::CreateDso(DSO_KERNEL, DEFAULT_KERNEL_MMAP_NAME);
+  ASSERT_TRUE(dso);
+  ASSERT_EQ(dso->GetDebugFilePath(), vmlinux_path);
+}
+
 TEST(dso, kernel_module) {
   // Test finding debug files for kernel modules.
   Dso::SetSymFsDir(GetTestDataDir());