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

src/kern/SConscript

@@ -47,3 +47,6 @@ if env['FULL_SYSTEM']:
         Source('tru64/tru64_events.cc')
         Source('tru64/tru64_syscalls.cc')
         TraceFlag('BADADDR')
+else:
+    Source('linux/linux.cc')
+    Source('operatingsystem.cc')

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);
+}
+

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
 
 

src/kern/operatingsystem.cc

@@ -0,0 +1,44 @@
+/*
+ * 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 "kern/operatingsystem.hh"
+#include "base/misc.hh"
+
+int
+OperatingSystem::openSpecialFile(std::string path, LiveProcess *process, ThreadContext *tc)
+{
+    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;
+}
+
+

src/kern/operatingsystem.hh

@@ -40,6 +40,10 @@
 class OperatingSystem {};
 
 #else //!FULL_SYSTEM
+#include <string>
+
+class LiveProcess;
+class ThreadContext;
 
 /// This struct is used to build an target-OS-dependent table that
 /// maps the target's open() flags to the host open() flags.
@@ -117,6 +121,8 @@ class OperatingSystem {
         int64_t ru_nivcsw;              //!< involuntary "
     } rusage;
 
+    static int openSpecialFile(std::string path, LiveProcess *process, ThreadContext *tc);
+
 };  // class OperatingSystem
 
 

src/sim/syscall_emul.hh

@@ -537,10 +537,18 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
 
     DPRINTF(SyscallVerbose, "opening file %s\n", path.c_str());
 
-    // open the file
-    int fd = open(path.c_str(), hostFlags, mode);
+    int fd;
+    if (!path.compare(0, 6, "/proc/") || !path.compare(0, 8, "/system/") ||
+        !path.compare(0, 10, "/platform/") || !path.compare(0, 5, "/sys/")) {
+        // It's a proc/sys entery and requires special handling
+        fd = OS::openSpecialFile(path, process, tc);
+        return (fd == -1) ? -1 : process->alloc_fd(fd,path.c_str(),hostFlags,mode, false);
+     } else {
+        // open the file
+        fd = open(path.c_str(), hostFlags, mode);
+        return (fd == -1) ? -errno : process->alloc_fd(fd,path.c_str(),hostFlags,mode, false);
+     }
 
-    return (fd == -1) ? -errno : process->alloc_fd(fd,path.c_str(),hostFlags,mode, false);
 }
 
 

src/sim/system.cc

@@ -244,6 +244,19 @@ System::new_page()
         fatal("Out of memory, please increase size of physical memory.");
     return return_addr;
 }
+
+Addr
+System::memSize()
+{
+    return physmem->size();
+}
+
+Addr
+System::freeMemSize()
+{
+   return physmem->size() - (page_ptr << LogVMPageSize);
+}
+
 #endif
 
 void

src/sim/system.hh

@@ -139,6 +139,12 @@ class System : public SimObject
         return next_PID++;
     }
 
+    /** Amount of physical memory that is still free */
+    Addr freeMemSize();
+
+    /** Amount of physical memory that exists */
+    Addr memSize();
+
 
 #endif // FULL_SYSTEM