apkm, linus: this or something like it needs to go into 2.6.33 (& 32) to
fix 'ulimit -s'.  

Mikey

[PATCH] Restrict stack space reservation to rlimit

When reserving stack space for a new process, make sure we're not
attempting to allocate more than rlimit allows.

Also, reserve the same stack size independent of page size.

This fixes a bug unmasked by fc63cf237078c86214abcb2ee9926d8ad289da9b

Signed-off-by: Michael Neuling <mi...@neuling.org>
Cc: Anton Blanchard <an...@samba.org>
Cc: sta...@kernel.org
---
 fs/exec.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Index: clone1/fs/exec.c
===================================================================
--- clone1.orig/fs/exec.c
+++ clone1/fs/exec.c
@@ -554,7 +554,7 @@ static int shift_arg_pages(struct vm_are
        return 0;
 }
 
-#define EXTRA_STACK_VM_PAGES   20      /* random */
+#define EXTRA_STACK_VM_SIZE    81920UL /* randomly 20 4K pages */
 
 /*
  * Finalizes the stack vm_area_struct. The flags and permissions are updated,
@@ -627,10 +627,13 @@ int setup_arg_pages(struct linux_binprm 
                        goto out_unlock;
        }
 
+       stack_base = min(EXTRA_STACK_VM_SIZE,
+                        current->signal->rlim[RLIMIT_STACK].rlim_cur) -
+               PAGE_SIZE;
 #ifdef CONFIG_STACK_GROWSUP
-       stack_base = vma->vm_end + EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+       stack_base = vma->vm_end + stack_base;
 #else
-       stack_base = vma->vm_start - EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+       stack_base = vma->vm_start - stack_base;
 #endif
        ret = expand_stack(vma, stack_base);
        if (ret)
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Reply via email to