3 files changed, 65 insertions, 35 deletions

diff --git a/src/mongo/util/log.cpp b/src/mongo/util/log.cpp
index 75720dbcf7f..b3c130bf264 100644
--- a/src/mongo/util/log.cpp
+++ b/src/mongo/util/log.cpp
@@ -54,6 +54,11 @@ using namespace std;
 
 namespace mongo {
 
+namespace {
+const char kUnknownMsg[] = "Unknown error";
+const int kBuflen = 256;  // strerror strings in non-English locales can be large.
+}
+
 static logger::ExtraLogContextFn _appendExtraLogContext;
 
 Status logger::registerExtraLogContextFn(logger::ExtraLogContextFn contextFn) {
@@ -81,50 +86,69 @@ bool rotateLogs(bool renameFiles) {
     return result.empty();
 }
 
-string errnoWithDescription(int x) {
+string errnoWithDescription(int errNumber) {
 #if defined(_WIN32)
-    if (x < 0)
-        x = GetLastError();
+    if (errNumber < 0)
+        errNumber = GetLastError();
 #else
-    if (x < 0)
-        x = errno;
+    if (errNumber < 0)
+        errNumber = errno;
 #endif
-    stringstream s;
-    s << "errno:" << x << ' ';
 
-#if defined(_WIN32)
-    LPWSTR errorText = NULL;
+    char buf[kBuflen];
+    char* msg{nullptr};
+
+#if defined(__GNUC__) && defined(_GNU_SOURCE)
+    msg = strerror_r(errNumber, buf, kBuflen);
+#elif defined(_WIN32)
+
+    LPWSTR errorText = nullptr;
     FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER |
                        FORMAT_MESSAGE_IGNORE_INSERTS,
-                   NULL,
-                   x,
+                   nullptr,
+                   errNumber,
                    0,
                    reinterpret_cast<LPWSTR>(&errorText),  // output
                    0,                                     // minimum size for output buffer
-                   NULL);
+                   nullptr);
+
     if (errorText) {
-        string x = toUtf8String(errorText);
-        for (string::iterator i = x.begin(); i != x.end(); i++) {
-            if (*i == '\n' || *i == '\r')
-                break;
-            s << *i;
+        string utf8ErrorText = toUtf8String(errorText);
+        auto size = utf8ErrorText.find_first_of("\r\n");
+        if (size == string::npos) {  // not found
+            size = utf8ErrorText.length();
+        }
+
+        if (size > kBuflen) {
+            size = kBuflen;
         }
+
+        memcpy(buf, utf8ErrorText.c_str(), size);
+        msg = buf;
         LocalFree(errorText);
-    } else
-        s << strerror(x);
-/*
-DWORD n = FormatMessage(
-    FORMAT_MESSAGE_ALLOCATE_BUFFER |
-    FORMAT_MESSAGE_FROM_SYSTEM |
-    FORMAT_MESSAGE_IGNORE_INSERTS,
-    NULL, x,
-    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-    (LPTSTR) &lpMsgBuf, 0, NULL);
-*/
+    } else if (strerror_s(buf, kBuflen, errNumber) != 0) {
+        msg = buf;
+    }
+#else /* XSI strerror_r */
+    if (strerror_r(errNumber, buf, kBuflen) == 0) {
+        msg = buf;
+    }
+#endif
+
+    if (!msg) {
+        return {kUnknownMsg};
+    }
+
+    return {msg};
+}
+
+std::pair<int, std::string> errnoAndDescription() {
+#if defined(_WIN32)
+    int errNumber = GetLastError();
 #else
-    s << strerror(x);
+    int errNumber = errno;
 #endif
-    return s.str();
+    return {errNumber, errnoWithDescription(errNumber)};
 }
 
 void logContext(const char* errmsg) {
diff --git a/src/mongo/util/log.h b/src/mongo/util/log.h
index b0f53a30b87..82a78b3cf99 100644
--- a/src/mongo/util/log.h
+++ b/src/mongo/util/log.h
@@ -217,6 +217,7 @@ extern Tee* const warnings;            // Things put here go in serverStatus
 extern Tee* const startupWarningsLog;  // Things put here get reported in MMS
 
 std::string errnoWithDescription(int errorcode = -1);
+std::pair<int, std::string> errnoAndDescription();
 
 /**
  * Write the current context (backtrace), along with the optional "msg".
diff --git a/src/mongo/util/processinfo.cpp b/src/mongo/util/processinfo.cpp
index 5a0e8dc798c..8afcb2f0eeb 100644
--- a/src/mongo/util/processinfo.cpp
+++ b/src/mongo/util/processinfo.cpp
@@ -58,6 +58,15 @@ public:
         path = p;
         ofstream out(path.c_str(), ios_base::out);
         out << ProcessId::getCurrent() << endl;
+        if (!out.good()) {
+            auto errAndStr = errnoAndDescription();
+            if (errAndStr.first == 0) {
+                log() << "ERROR: Cannot write pid file to " << path
+                      << ": Unable to determine OS error";
+            } else {
+                log() << "ERROR: Cannot write pid file to " << path << ": " << errAndStr.second;
+            }
+        }
         return out.good();
     }
 
@@ -65,11 +74,7 @@ public:
 } pidFileWiper;
 
 bool writePidFile(const string& path) {
-    bool e = pidFileWiper.write(path);
-    if (!e) {
-        log() << "ERROR: Cannot write pid file to " << path << ": " << strerror(errno);
-    }
-    return e;
+    return pidFileWiper.write(path);
 }
 
 ProcessInfo::SystemInfo* ProcessInfo::systemInfo = NULL;