Fix issue 326: glibc non-deterministic because it reads /proc

2 files changed, 73 insertions, 1 deletions

diff --git a/src/kern/linux/linux.cc b/src/kern/linux/linux.cc
new file mode 100644
index 000000000..b14e3c709
--- /dev/null
+++ b/src/kern/linux/linux.cc
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2009 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Ali Saidi
+ */
+
+#include <string>
+
+#include "cpu/thread_context.hh"
+#include "kern/linux/linux.hh"
+#include "sim/process.hh"
+#include "sim/system.hh"
+
+int
+Linux::openSpecialFile(std::string path, LiveProcess *process, ThreadContext *tc)
+{
+    DPRINTF(SyscallVerbose, "Opening special file: %s\n", path.c_str());
+    if (path.compare(0, 13, "/proc/meminfo") == 0) {
+        std::string data = Linux::procMeminfo(process, tc);
+        FILE *f = tmpfile();
+        int fd = fileno(f);
+        int ret M5_VAR_USED = fwrite(data.c_str(), 1, data.size(), f);
+        assert(ret == data.size());
+        rewind(f);
+        return fd;
+    }
+
+    warn("Attempting to open special file: %s. Ignorning. Simulation may"
+            " take un-expected code path or be non-deterministic until proper"
+            "  handling is implemented.\n", path.c_str());
+    return -1;
+}
+
+std::string
+Linux::procMeminfo(LiveProcess *process, ThreadContext *tc)
+{
+    return csprintf("MemTotal:%12d kB\nMemFree: %12d kB\n",
+            process->system->memSize() >> 10,
+            process->system->freeMemSize() >> 10);
+}
+
diff --git a/src/kern/linux/linux.hh b/src/kern/linux/linux.hh
index a41fac9a7..ad35fa726 100644
--- a/src/kern/linux/linux.hh
+++ b/src/kern/linux/linux.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004-2005 The Regents of The University of Michigan
+ * Copyright (c) 2004-2009 The Regents of The University of Michigan
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -39,9 +39,13 @@ class Linux {};
 #else //!FULL_SYSTEM
 
 #include <inttypes.h>
+#include <string>
 
 #include "kern/operatingsystem.hh"
 
+class ThreadContext;
+class LiveProcess;
+
 ///
 /// This class encapsulates the types, structures, constants,
 /// functions, and syscall-number mappings specific to the Alpha Linux
@@ -158,6 +162,9 @@ class Linux : public OperatingSystem
         int64_t ru_nivcsw;              //!< involuntary "
     };
 
+    static int openSpecialFile(std::string path, LiveProcess *process, ThreadContext *tc);
+    static std::string procMeminfo(LiveProcess *process, ThreadContext *tc);
+
 };  // class Linux