X86: Make successive anonymous mmaps move down in 32 bit SE mode Linux.

src/arch/x86/linux/linux.hh

@@ -190,7 +190,9 @@ class X86Linux32 : public Linux
        uint32_t totalhigh; /* Total high memory size */
        uint32_t freehigh;  /* Available high memory size */
        uint32_t mem_unit;  /* Memory unit size in bytes */
-   } tgt_sysinfo;
+    } tgt_sysinfo;
+
+    static bool mmapGrowsDown() { return true; }
 };
 
 #endif

src/arch/x86/process.cc

@@ -184,7 +184,7 @@ I386LiveProcess::I386LiveProcess(LiveProcessParams *params,
 
     // Set up region for mmaps. This was determined empirically and may not
     // always be correct.
-    mmap_start = mmap_end = (Addr)0xf7ffd000ULL;
+    mmap_start = mmap_end = (Addr)0xf7ffe000ULL;
 }
 
 SyscallDesc*