Fix truncated exe file name in .NET core mini dump file name

src/coreclr/debug/createdump/crashinfounix.cpp

@@ -12,7 +12,7 @@ extern uint8_t g_debugHeaderCookie[4];
 
 int g_readProcessMemoryErrno = 0;
 
-bool GetStatus(pid_t pid, pid_t* ppid, pid_t* tgid, std::string* name);
+bool GetProcessInfo(pid_t pid, pid_t* ppid, pid_t* tgid, std::string* name);
 
 bool
 CrashInfo::Initialize()
@@ -65,8 +65,7 @@ CrashInfo::Initialize()
         m_fdPagemap = -1;
     }
 
-    // Get the process info
-    if (!GetStatus(m_pid, &m_ppid, &m_tgid, &m_name))
+    if (!GetProcessInfo(m_pid, &m_ppid, &m_tgid, &m_name))
     {
         return false;
     }
@@ -600,6 +599,42 @@ GetStatus(pid_t pid, pid_t* ppid, pid_t* tgid, std::string* name)
     return true;
 }
 
+bool
+GetProcessInfo(pid_t pid, pid_t* ppid, pid_t* tgid, std::string* name)
+{
+    if(!GetStatus(pid, ppid, tgid, name))
+    {
+        return false;
+    }
+
+    // Try reading the executable name from the /proc/<pid>/exe link. Prefer this name to the
+    // one reported by status if it is available because the status name is often truncated
+    char exePath[128];
+    int chars = snprintf(exePath, sizeof(exePath), "/proc/%d/exe", pid);
+    if (chars > 0 && (size_t)chars < sizeof(exePath))
+    {
+        struct stat sb;
+        if (lstat(exePath, &sb) != -1)
+        {
+            ssize_t bufSize = sb.st_size == 0 ? 4096 : sb.st_size + 1;
+            char *buf = static_cast<char*>(malloc(bufSize));
+            if (buf != nullptr)
+            {
+                ssize_t nbytes = readlink(exePath, buf, bufSize - 1);
+                if (nbytes != -1)
+                {
+                    buf[nbytes] = '\0';
+                    char* executableName = strrchr(buf, '/');
+                    *name = (executableName != nullptr) ? (executableName + 1) : buf;
+                }
+                free(buf);
+            }
+        }
+    }
+
+    return true;
+}
+
 void
 ModuleInfo::LoadModule()
 {