From 0bf2650bb1a3d5dc0702ad75413aff3eb60fd206 Mon Sep 17 00:00:00 2001
From: Matthias Baesken <mbaesken@openjdk.org>
Date: Wed, 5 Jun 2019 16:53:52 +0200
Subject: [PATCH] 8224958: add os::dll_load calls to event log

Reviewed-by: dholmes, mdoerr, stuefe
---
 src/hotspot/os/aix/os_aix.cpp         |  9 ++++++--
 src/hotspot/os/bsd/os_bsd.cpp         | 30 ++++++++++++++++++++-------
 src/hotspot/os/linux/os_linux.cpp     | 13 ++++++++++--
 src/hotspot/os/solaris/os_solaris.cpp | 15 ++++++++++----
 src/hotspot/os/windows/os_windows.cpp | 13 ++++++------
 5 files changed, 59 insertions(+), 21 deletions(-)

diff --git a/src/hotspot/os/aix/os_aix.cpp b/src/hotspot/os/aix/os_aix.cpp
index 9762e0787dd..0117f121950 100644
--- a/src/hotspot/os/aix/os_aix.cpp
+++ b/src/hotspot/os/aix/os_aix.cpp
@@ -1327,16 +1327,21 @@ void *os::dll_load(const char *filename, char *ebuf, int ebuflen) {
   // RTLD_LAZY is currently not implemented. The dl is loaded immediately with all its dependants.
   void * result= ::dlopen(filename, RTLD_LAZY);
   if (result != NULL) {
+    Events::log(NULL, "Loaded shared library %s", filename);
     // Reload dll cache. Don't do this in signal handling.
     LoadedLibraries::reload();
     return result;
   } else {
     // error analysis when dlopen fails
-    const char* const error_report = ::dlerror();
-    if (error_report && ebuf && ebuflen > 0) {
+    const char* error_report = ::dlerror();
+    if (error_report == NULL) {
+      error_report = "dlerror returned no error description";
+    }
+    if (ebuf != NULL && ebuflen > 0) {
       snprintf(ebuf, ebuflen - 1, "%s, LIBPATH=%s, LD_LIBRARY_PATH=%s : %s",
                filename, ::getenv("LIBPATH"), ::getenv("LD_LIBRARY_PATH"), error_report);
     }
+    Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
   }
   return NULL;
 }
diff --git a/src/hotspot/os/bsd/os_bsd.cpp b/src/hotspot/os/bsd/os_bsd.cpp
index a707fe38452..713a9c0842c 100644
--- a/src/hotspot/os/bsd/os_bsd.cpp
+++ b/src/hotspot/os/bsd/os_bsd.cpp
@@ -1265,13 +1265,21 @@ void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
 #else
   void * result= ::dlopen(filename, RTLD_LAZY);
   if (result != NULL) {
+    Events::log(NULL, "Loaded shared library %s", filename);
     // Successful loading
     return result;
   }
 
-  // Read system error message into ebuf
-  ::strncpy(ebuf, ::dlerror(), ebuflen-1);
-  ebuf[ebuflen-1]='\0';
+  const char* error_report = ::dlerror();
+  if (error_report == NULL) {
+    error_report = "dlerror returned no error description";
+  }
+  if (ebuf != NULL && ebuflen > 0) {
+    // Read system error message into ebuf
+    ::strncpy(ebuf, error_report, ebuflen-1);
+    ebuf[ebuflen-1]='\0';
+  }
+  Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
 
   return NULL;
 #endif // STATIC_BUILD
@@ -1283,16 +1291,24 @@ void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
 #else
   void * result= ::dlopen(filename, RTLD_LAZY);
   if (result != NULL) {
+    Events::log(NULL, "Loaded shared library %s", filename);
     // Successful loading
     return result;
   }
 
   Elf32_Ehdr elf_head;
 
-  // Read system error message into ebuf
-  // It may or may not be overwritten below
-  ::strncpy(ebuf, ::dlerror(), ebuflen-1);
-  ebuf[ebuflen-1]='\0';
+  const char* const error_report = ::dlerror();
+  if (error_report == NULL) {
+    error_report = "dlerror returned no error description";
+  }
+  if (ebuf != NULL && ebuflen > 0) {
+    // Read system error message into ebuf
+    ::strncpy(ebuf, error_report, ebuflen-1);
+    ebuf[ebuflen-1]='\0';
+  }
+  Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
+
   int diag_msg_max_length=ebuflen-strlen(ebuf);
   char* diag_msg_buf=ebuf+strlen(ebuf);
 
diff --git a/src/hotspot/os/linux/os_linux.cpp b/src/hotspot/os/linux/os_linux.cpp
index 8cb3221214f..439f6b781d1 100644
--- a/src/hotspot/os/linux/os_linux.cpp
+++ b/src/hotspot/os/linux/os_linux.cpp
@@ -1881,8 +1881,17 @@ void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
                                 int ebuflen) {
   void * result = ::dlopen(filename, RTLD_LAZY);
   if (result == NULL) {
-    ::strncpy(ebuf, ::dlerror(), ebuflen - 1);
-    ebuf[ebuflen-1] = '\0';
+    const char* error_report = ::dlerror();
+    if (error_report == NULL) {
+      error_report = "dlerror returned no error description";
+    }
+    if (ebuf != NULL && ebuflen > 0) {
+      ::strncpy(ebuf, error_report, ebuflen-1);
+      ebuf[ebuflen-1]='\0';
+    }
+    Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
+  } else {
+    Events::log(NULL, "Loaded shared library %s", filename);
   }
   return result;
 }
diff --git a/src/hotspot/os/solaris/os_solaris.cpp b/src/hotspot/os/solaris/os_solaris.cpp
index 9c85277a037..4c0ade1d760 100644
--- a/src/hotspot/os/solaris/os_solaris.cpp
+++ b/src/hotspot/os/solaris/os_solaris.cpp
@@ -1528,15 +1528,22 @@ void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
   void * result= ::dlopen(filename, RTLD_LAZY);
   if (result != NULL) {
     // Successful loading
+    Events::log(NULL, "Loaded shared library %s", filename);
     return result;
   }
 
   Elf32_Ehdr elf_head;
+  const char* error_report = ::dlerror();
+  if (error_report == NULL) {
+    error_report = "dlerror returned no error description";
+  }
+  if (ebuf != NULL && ebuflen > 0) {
+    ::strncpy(ebuf, error_report, ebuflen-1);
+    ebuf[ebuflen-1]='\0';
+  }
+
+  Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
 
-  // Read system error message into ebuf
-  // It may or may not be overwritten below
-  ::strncpy(ebuf, ::dlerror(), ebuflen-1);
-  ebuf[ebuflen-1]='\0';
   int diag_msg_max_length=ebuflen-strlen(ebuf);
   char* diag_msg_buf=ebuf+strlen(ebuf);
 
diff --git a/src/hotspot/os/windows/os_windows.cpp b/src/hotspot/os/windows/os_windows.cpp
index 2a300e1e0d6..b3c89df7c50 100644
--- a/src/hotspot/os/windows/os_windows.cpp
+++ b/src/hotspot/os/windows/os_windows.cpp
@@ -1367,12 +1367,18 @@ static int _print_module(const char* fname, address base_address,
 void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
   void * result = LoadLibrary(name);
   if (result != NULL) {
+    Events::log(NULL, "Loaded shared library %s", name);
     // Recalculate pdb search path if a DLL was loaded successfully.
     SymbolEngine::recalc_search_path();
     return result;
   }
-
   DWORD errcode = GetLastError();
+  // Read system error message into ebuf
+  // It may or may not be overwritten below (in the for loop and just above)
+  lasterror(ebuf, (size_t) ebuflen);
+  ebuf[ebuflen - 1] = '\0';
+  Events::log(NULL, "Loading shared library %s failed, error code %lu", name, errcode);
+
   if (errcode == ERROR_MOD_NOT_FOUND) {
     strncpy(ebuf, "Can't find dependent libraries", ebuflen - 1);
     ebuf[ebuflen - 1] = '\0';
@@ -1384,11 +1390,6 @@ void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
   // for an architecture other than Hotspot is running in
   // - then print to buffer "DLL was built for a different architecture"
   // else call os::lasterror to obtain system error message
-
-  // Read system error message into ebuf
-  // It may or may not be overwritten below (in the for loop and just above)
-  lasterror(ebuf, (size_t) ebuflen);
-  ebuf[ebuflen - 1] = '\0';
   int fd = ::open(name, O_RDONLY | O_BINARY, 0);
   if (fd < 0) {
     return NULL;