NOMMU: Avoiding duplicate icache flushes of shared maps

[net-next-2.6.git] / mm / nommu.c

diff --git a/mm/nommu.c b/mm/nommu.c
index 6f9248f89bdefbd6470bb0c4b68fb50b134866d2..a8d17521624ab57b1066755d21a25bcc419550a5 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -432,6 +432,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
        /*
         * Ok, looks good - let it rip.
         */
+       flush_icache_range(mm->brk, brk);
        return mm->brk = brk;
 }
 
@@ -1353,10 +1354,14 @@ unsigned long do_mmap_pgoff(struct file *file,
 share:
        add_vma_to_mm(current->mm, vma);
 
-       up_write(&nommu_region_sem);
+       /* we flush the region from the icache only when the first executable
+        * mapping of it is made  */
+       if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) {
+               flush_icache_range(region->vm_start, region->vm_end);
+               region->vm_icache_flushed = true;
+       }
 
-       if (prot & PROT_EXEC)
-               flush_icache_range(result, result + len);
+       up_write(&nommu_region_sem);
 
        kleave(" = %lx", result);
        return result;