From 6c21855928047d4f89300dacdc3aa896f3515a27 Mon Sep 17 00:00:00 2001
From: Steven Moreland <smoreland@google.com>
Date: Tue, 21 Jul 2020 17:47:32 +0000
Subject: tryRegistrationImpl: better error checking

ifstream is_open does not check for errors, so we use ifstream operator
bool instead, and we use it more frequently than strictly needed. Also,
the functions here are added to attribute noinline, so that stacktraces
will be more useful.

Test: boot and check names are fixed up in `ps -A -o comm`
Bug: 161271113

Change-Id: Ia451fa1b06c49def0fe8b3a3558af83fff18ec96
Merged-In: Ia451fa1b06c49def0fe8b3a3558af83fff18ec96
---
 transport/ServiceManagement.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/transport/ServiceManagement.cpp b/transport/ServiceManagement.cpp
index d7faa6db..7de5c787 100644
--- a/transport/ServiceManagement.cpp
+++ b/transport/ServiceManagement.cpp
@@ -87,7 +87,7 @@ static void waitForHwServiceManager() {
 static std::string binaryName() {
     std::ifstream ifs("/proc/self/cmdline");
     std::string cmdline;
-    if (!ifs.is_open()) {
+    if (!ifs) {
         return "";
     }
     ifs >> cmdline;
@@ -106,7 +106,7 @@ static std::string packageWithoutVersion(const std::string& packageAndVersion) {
     return packageAndVersion.substr(0, at);
 }
 
-static void tryShortenProcessName(const std::string& descriptor) {
+__attribute__((noinline)) static void tryShortenProcessName(const std::string& descriptor) {
     const static std::string kTasks = "/proc/self/task/";
 
     // make sure that this binary name is in the same package
@@ -135,17 +135,17 @@ static void tryShortenProcessName(const std::string& descriptor) {
         if (dp->d_name[0] == '.') continue;
 
         std::fstream fs(kTasks + dp->d_name + "/comm");
-        if (!fs.is_open()) {
+        if (!fs) {
             ALOGI("Could not rename process, failed read comm for %s.", dp->d_name);
             continue;
         }
 
         std::string oldComm;
-        fs >> oldComm;
+        if (!(fs >> oldComm)) continue;
 
         // don't rename if it already has an explicit name
         if (base::StartsWith(descriptor, oldComm)) {
-            fs.seekg(0, fs.beg);
+            if (!fs.seekg(0, fs.beg)) continue;
             fs << newName;
         }
     }
@@ -157,7 +157,7 @@ namespace details {
  * Returns the age of the current process by reading /proc/self/stat and comparing starttime to the
  * current time. This is useful for measuring how long it took a HAL to register itself.
  */
-static long getProcessAgeMs() {
+__attribute__((noinline)) static long getProcessAgeMs() {
     constexpr const int PROCFS_STAT_STARTTIME_INDEX = 21;
     std::string content;
     android::base::ReadFileToString("/proc/self/stat", &content, false);
-- 
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