plat: avoid MAP_FIXED
authornotaz <notasas@gmail.com>
Tue, 24 Mar 2015 22:38:13 +0000 (00:38 +0200)
committernotaz <notasas@gmail.com>
Tue, 24 Mar 2015 22:38:13 +0000 (00:38 +0200)
linux/plat.c

index 660a095..06c315e 100644 (file)
@@ -178,8 +178,10 @@ void *plat_mmap(unsigned long addr, size_t size, int need_exec, int is_fixed)
        req = (void *)addr;
        if (need_exec)
                prot |= PROT_EXEC;
+       /* avoid MAP_FIXED, it overrides existing mappings..
        if (is_fixed)
                flags |= MAP_FIXED;
+       */
        if (size >= HUGETLB_THRESHOLD)
                flags |= MAP_HUGETLB;
 
@@ -197,9 +199,14 @@ void *plat_mmap(unsigned long addr, size_t size, int need_exec, int is_fixed)
        if (ret == MAP_FAILED)
                return NULL;
 
-       if (req != NULL && ret != req)
-               fprintf(stderr,
-                       "warning: mmaped to %p, requested %p\n", ret, req);
+       if (req != NULL && ret != req) {
+               fprintf(stderr, "%s: mmaped to %p, requested %p\n",
+                       is_fixed ? "error" : "warning", ret, req);
+               if (is_fixed) {
+                       munmap(ret, size);
+                       return NULL;
+               }
+       }
 
        return ret;
 }