1 files changed, 40 insertions, 17 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 632b02e34ec7..e95c692ef0e4 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -571,6 +571,9 @@ int setup_arg_pages(struct linux_binprm *bprm,
         struct vm_area_struct *prev = NULL;
         unsigned long vm_flags;
         unsigned long stack_base;
+        unsigned long stack_size;
+        unsigned long stack_expand;
+        unsigned long rlim_stack;
 
 #ifdef CONFIG_STACK_GROWSUP
         /* Limit stack size to 1GB */
@@ -627,10 +630,24 @@ int setup_arg_pages(struct linux_binprm *bprm,
                         goto out_unlock;
         }
 
+        stack_expand = EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+        stack_size = vma->vm_end - vma->vm_start;
+        /*
+         * Align this down to a page boundary as expand_stack
+         * will align it up.
+         */
+        rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK;
+        rlim_stack = min(rlim_stack, stack_size);
 #ifdef CONFIG_STACK_GROWSUP
-        stack_base = vma->vm_end + EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+        if (stack_size + stack_expand > rlim_stack)
+                stack_base = vma->vm_start + rlim_stack;
+        else
+                stack_base = vma->vm_end + stack_expand;
 #else
-        stack_base = vma->vm_start - EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+        if (stack_size + stack_expand > rlim_stack)
+                stack_base = vma->vm_end - rlim_stack;
+        else
+                stack_base = vma->vm_start - stack_expand;
 #endif
         ret = expand_stack(vma, stack_base);
         if (ret)
@@ -941,9 +958,7 @@ void set_task_comm(struct task_struct *tsk, char *buf)
 
 int flush_old_exec(struct linux_binprm * bprm)
 {
-        char * name;
-        int i, ch, retval;
-        char tcomm[sizeof(current->comm)];
+        int retval;
 
         /*
          * Make sure we have a private signal table and that
@@ -964,6 +979,25 @@ int flush_old_exec(struct linux_binprm * bprm)
 
         bprm->mm = NULL;                /* We're using it now */
 
+        current->flags &= ~PF_RANDOMIZE;
+        flush_thread();
+        current->personality &= ~bprm->per_clear;
+
+        return 0;
+
+out:
+        return retval;
+}
+EXPORT_SYMBOL(flush_old_exec);
+
+void setup_new_exec(struct linux_binprm * bprm)
+{
+        int i, ch;
+        char * name;
+        char tcomm[sizeof(current->comm)];
+
+        arch_pick_mmap_layout(current->mm);
+
         /* This is the point of no return */
         current->sas_ss_sp = current->sas_ss_size = 0;
 
@@ -985,9 +1019,6 @@ int flush_old_exec(struct linux_binprm * bprm)
         tcomm[i] = '\0';
         set_task_comm(current, tcomm);
 
-        current->flags &= ~PF_RANDOMIZE;
-        flush_thread();
-
         /* Set the new mm task size. We have to do that late because it may
          * depend on TIF_32BIT which is only updated in flush_thread() on
          * some architectures like powerpc
@@ -1003,8 +1034,6 @@ int flush_old_exec(struct linux_binprm * bprm)
                 set_dumpable(current->mm, suid_dumpable);
         }
 
-        current->personality &= ~bprm->per_clear;
-
         /*
          * Flush performance counters when crossing a
          * security domain:
@@ -1019,14 +1048,8 @@ int flush_old_exec(struct linux_binprm * bprm)
                         
         flush_signal_handlers(current, 0);
         flush_old_files(current->files);
-
-        return 0;
-
-out:
-        return retval;
 }
-
-EXPORT_SYMBOL(flush_old_exec);
+EXPORT_SYMBOL(setup_new_exec);
 
 /*
  * Prepare credentials and lock ->cred_guard_mutex.