syscall_emul: move mmapGrowsDown() to LiveProcess

The mmapGrowsDown() method was a static method on the OperatingSystem
class (and derived classes), which worked OK for the templated syscall
emulation methods, but made it hard to access elsewhere.  This patch
moves the method to be a virtual function on the LiveProcess method,
where it can be overridden for specific platforms (for now, Alpha).

This patch also changes the value of mmapGrowsDown() from being false
by default and true only on X86Linux32 to being true by default and
false only on Alpha, which seems closer to reality (though in reality
most people use ASLR and this doesn't really matter anymore).

In the process, also got rid of the unused mmap_start field on
LiveProcess and OperatingSystem mmapGrowsUp variable.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index a859fbe43..71c0dd090 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -1297,8 +1297,8 @@ mmapImpl(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc,
     // Extend global mmap region if necessary. Note that we ignore the
     // start address unless MAP_FIXED is specified.
     if (!(tgt_flags & OS::TGT_MAP_FIXED)) {
-        start = (OS::mmapGrowsDown()) ? p->mmap_end - length : p->mmap_end;
-        p->mmap_end = (OS::mmapGrowsDown()) ? start : p->mmap_end + length;
+        start = p->mmapGrowsDown() ? p->mmap_end - length : p->mmap_end;
+        p->mmap_end = p->mmapGrowsDown() ? start : p->mmap_end + length;
     }
 
     DPRINTF_SYSCALL(Verbose, " mmap range is 0x%x - 0x%x\n",