From def9faea5ebf63e195f65949c4b6aae89cdb22d9 Mon Sep 17 00:00:00 2001
From: Devin Moore <devinmoore@google.com>
Date: Thu, 5 Aug 2021 19:05:45 +0000
Subject: dumpsys: display the client PIDs of all of the services

When gathering info on a service, get the BpBinder handle to look up the
node number of the binder service in binder_logs/proc/<pid>.
Look up the node number in binder_logs/state from the binder service.
That entry in the state file has the client PIDs.

Example output:
$ adb shell dumpsys --clients android.hardware.power.IPower/default
Client PIDs: 437, 708, 203

Test: adb root && adb shell dumpsys --clients
Test: adb shell dumpsys --clients power
Test: adb shell dumpsys --clients --pid
Change-Id: I0daebc18cb9f47925ccec5a3eb0b09c4b1e43fe4
---
 libs/binderdebug/BinderDebug.cpp | 57 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

(limited to 'libs/binderdebug/BinderDebug.cpp')

diff --git a/libs/binderdebug/BinderDebug.cpp b/libs/binderdebug/BinderDebug.cpp
index b435dba197..d086b49a7b 100644
--- a/libs/binderdebug/BinderDebug.cpp
+++ b/libs/binderdebug/BinderDebug.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/strings.h>
 #include <binder/Binder.h>
@@ -116,4 +117,60 @@ status_t getBinderPidInfo(BinderDebugContext context, pid_t pid, BinderPidInfo*
     return ret;
 }
 
+status_t getBinderClientPids(BinderDebugContext context, pid_t pid, pid_t servicePid,
+                             int32_t handle, std::vector<pid_t>* pids) {
+    std::smatch match;
+    static const std::regex kNodeNumber("^\\s+ref \\d+:\\s+desc\\s+(\\d+)\\s+node\\s+(\\d+).*");
+    std::string contextStr = contextToString(context);
+    int32_t node;
+    status_t ret = scanBinderContext(pid, contextStr, [&](const std::string& line) {
+        if (std::regex_search(line, match, kNodeNumber)) {
+            const std::string& descString = match.str(1);
+            int32_t desc;
+            if (!::android::base::ParseInt(descString.c_str(), &desc)) {
+                LOG(ERROR) << "Failed to parse desc int: " << descString;
+                return;
+            }
+            if (handle != desc) {
+                return;
+            }
+            const std::string& nodeString = match.str(2);
+            if (!::android::base::ParseInt(nodeString.c_str(), &node)) {
+                LOG(ERROR) << "Failed to parse node int: " << nodeString;
+                return;
+            }
+            return;
+        }
+        return;
+    });
+    if (ret != OK) {
+        return ret;
+    }
+    static const std::regex kClients("^\\s+node\\s+(\\d+).*proc\\s+([\\d+\\s*]*)");
+    ret = scanBinderContext(servicePid, contextStr, [&](const std::string& line) {
+        if (std::regex_search(line, match, kClients)) {
+            const std::string nodeString = match.str(1);
+            int32_t matchedNode;
+            if (!::android::base::ParseInt(nodeString.c_str(), &matchedNode)) {
+                LOG(ERROR) << "Failed to parse node int: " << nodeString;
+                return;
+            }
+            if (node != matchedNode) {
+                return;
+            }
+            const std::string clients = match.str(2);
+            for (const std::string& pidStr : base::Split(clients, " ")) {
+                int32_t pid;
+                if (!::android::base::ParseInt(pidStr, &pid)) {
+                    return;
+                }
+                pids->push_back(pid);
+            }
+            return;
+        }
+        return;
+    });
+    return ret;
+}
+
 } // namespace  android
-- 
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