7009098: SA cannot open core files larger than 2GB on Linux 32-bit

Summary: Added Large File Support by compiling libsaproc.so with -D_FILE_OFFSET_BITS=64, and a small change with which SA should first load libraries from the path specified with SA_ALTROOT.
Reviewed-by: dholmes, kevinw, dcubed, minqi

agent/src/os/linux/Makefile

 #
-# Copyright (c) 2002, 2009, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -40,7 +40,7 @@ OBJS     = $(SOURCES:.c=.o)
 
 LIBS     = -lthread_db
 
-CFLAGS   = -c -fPIC -g -D_GNU_SOURCE -D$(ARCH) $(INCLUDES)
+CFLAGS   = -c -fPIC -g -D_GNU_SOURCE -D$(ARCH) $(INCLUDES) -D_FILE_OFFSET_BITS=64
 
 LIBSA = $(ARCH)/libsaproc.so
 

agent/src/os/linux/libproc_impl.c

 /*
- * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -50,10 +50,6 @@ int pathmap_open(const char* name) {
    char alt_path[PATH_MAX + 1];
 
    init_alt_root();
-   fd = open(name, O_RDONLY);
-   if (fd >= 0) {
-      return fd;
-   }
 
    if (alt_root_len > 0) {
       strcpy(alt_path, alt_root);
@@ -73,6 +69,11 @@ int pathmap_open(const char* name) {
             return fd;
          }
       }
+   } else {
+      fd = open(name, O_RDONLY);
+      if (fd >= 0) {
+         return fd;
+      }
    }
 
    return -1;

make/linux/makefiles/saproc.make

 #
-# Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -75,6 +75,7 @@ $(LIBSAPROC): $(SASRCFILES) $(SAMAPFILE)
 	fi
 	@echo Making SA debugger back-end...
 	$(QUIETLY) $(CC) -D$(BUILDARCH) -D_GNU_SOURCE                   \
+		   -D_FILE_OFFSET_BITS=64                               \
                    $(SYMFLAG) $(ARCHFLAG) $(SHARED_FLAG) $(PICFLAG)     \
 	           -I$(SASRCDIR)                                        \
 	           -I$(GENERATED)                                       \