iorap: Add iorap.inode2filename command line binary

Maps a list of inodes into their filenames by scanning the filesystem.

This is a separate binary that will be fork+execd by iorapd as a background
job when it occasionally needs to map ftrace events (from perfetto)
from inode numbers into actual filenames.

The inode scanning is following a security requirement to be in a separate
process, and an sepolicy CL will be added in a follow-up to grant limit
file scanning privileges to this binary.

Test: atest iorapd-tests # and also manual
Bug: 72170747

Change-Id: I280aa62ce3cc1d7efdadc22b40bd1435496b7086

1 files changed, 44 insertions, 0 deletions

diff --git a/Android.bp b/Android.bp
index c81e41c..5209683 100644
--- a/Android.bp
+++ b/Android.bp
@@ -63,8 +63,11 @@ cc_defaults {
         "libutils",
         "libcutils", // tracing.
 
+        "libfruit",  // dependency injection.
         // TODO: remove these annoying dependencies by hiding them in the main library code.
     ],
+
+    header_libs: ["librxcpp"],
 }
 
 cc_library_shared {
@@ -117,9 +120,48 @@ cc_binary {
     ],
 }
 
+cc_library_static {
+    name: "libiorap-inode2filename",
+    defaults: [
+        "iorap-default-flags",
+        "iorap-default-dependencies",
+    ],
+
+    srcs: [
+        "src/inode2filename/**/*.cc",
+    ],
+}
+
+cc_binary {
+  name: "iorap.inode2filename",
+  defaults: [
+      "iorap-default-flags",
+      "iorap-default-dependencies",
+  ],
+  srcs: [
+      "src/inode2filename/**/*.cc",
+  ],
+  // Easier debugging. TODO: make a separate debug config.
+  // XX: Using -O0 seems to completely hide some errors.
+  cflags: ["-O2", "-UNDEBUG", "-DIORAP_INODE2FILENAME_MAIN=1"],
+  sanitize: {
+    undefined: true,
+    all_undefined: true,
+    // Pretty print when ubsan detects a problem.
+    // Otherwise it just calls abort().
+
+/*
+    diag: {
+      undefined: true,
+    },
+    */ // don't use the diag when you want it to crash.
+  },
+}
+
 cc_test {
     name: "iorapd-tests",
     test_suites: ["device-tests"],
+    gtest: false,  // we use gtest *and* gmock.
     defaults: [
         "iorap-default-flags",
         "iorap-default-dependencies",
@@ -127,4 +169,6 @@ cc_test {
     srcs: [
         "tests/src/**/*.cc",
     ],
+    cflags: ["-O2", "-UNDEBUG"],
+    static_libs: ["libgmock_main", "libgmock", "libgtest", "libiorap-inode2filename"],
 }