linux-kernel - [PATCH] -mm: fix nommu path broken by procfs task exe symlink

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Date:	Tue, 19 Feb 2008 21:17:49 -0800
From:	Matt Helsley <matthltc@...ibm.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Mike Frysinger <vapier.adi@...il.com>,
	linux-mm <linux-mm@...ck.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Oleg Nesterov <oleg@...sign.ru>,
	David Howells <dhowells@...hat.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Christoph Hellwig <chellwig@...ibm.com>,
	Al Viro <viro@...iv.linux.org.uk>,
	Hugh Dickins <hugh@...itas.com>, Bryan Wu <Bryan.Wu@...log.com>
Subject: [PATCH] -mm: fix nommu path broken by procfs task exe symlink

Hi Andrew,

nommu configurations will not compile because the "mm" variable does not
exist. Replace usage of the mm variable and the empty vma->vm_mm field
with correct mm pointers.

Signed-off-by: Matt Helsley <matthltc@...ibm.com>
Cc: Mike Frysinger <vapier.adi@...il.com>
---
Needs testing on a nommu system. I am working on getting an emulated nommu
environment built but it is not coming together quickly.

 mm/nommu.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

Index: linux-2.6.24-mm1/mm/nommu.c
===================================================================
--- linux-2.6.24-mm1.orig/mm/nommu.c
+++ linux-2.6.24-mm1/mm/nommu.c
@@ -962,12 +962,14 @@ unsigned long do_mmap_pgoff(struct file 
 
 	INIT_LIST_HEAD(&vma->anon_vma_node);
 	atomic_set(&vma->vm_usage, 1);
 	if (file) {
 		get_file(file);
-		if (vm_flags & VM_EXECUTABLE)
-			added_exe_file_vma(mm);
+		if (vm_flags & VM_EXECUTABLE) {
+			added_exe_file_vma(current->mm);
+			vma->vm_mm = current->mm;
+		}
 	}
 	vma->vm_file	= file;
 	vma->vm_flags	= vm_flags;
 	vma->vm_start	= addr;
 	vma->vm_end	= addr + len;
@@ -1053,11 +1055,11 @@ unsigned long do_mmap_pgoff(struct file 
 EXPORT_SYMBOL(do_mmap_pgoff);
 
 /*
  * handle mapping disposal for uClinux
  */
-static void put_vma(struct vm_area_struct *vma)
+static void put_vma(struct mm_struct *mm, struct vm_area_struct *vma)
 {
 	if (vma) {
 		down_write(&nommu_vma_sem);
 
 		if (atomic_dec_and_test(&vma->vm_usage)) {
@@ -1078,11 +1080,11 @@ static void put_vma(struct vm_area_struc
 			askedalloc -= sizeof(*vma);
 
 			if (vma->vm_file) {
 				fput(vma->vm_file);
 				if (vma->vm_flags & VM_EXECUTABLE)
-					removed_exe_file_vma(vma->vm_mm);
+					removed_exe_file_vma(mm);
 			}
 			kfree(vma);
 		}
 
 		up_write(&nommu_vma_sem);
@@ -1116,11 +1118,11 @@ int do_munmap(struct mm_struct *mm, unsi
 	return -EINVAL;
 
  found:
 	vml = *parent;
 
-	put_vma(vml->vma);
+	put_vma(mm, vml->vma);
 
 	*parent = vml->next;
 	realalloc -= kobjsize(vml);
 	askedalloc -= sizeof(*vml);
 	kfree(vml);
@@ -1161,11 +1163,11 @@ void exit_mmap(struct mm_struct * mm)
 
 		mm->total_vm = 0;
 
 		while ((tmp = mm->context.vmlist)) {
 			mm->context.vmlist = tmp->next;
-			put_vma(tmp->vma);
+			put_vma(mm, tmp->vma);
 
 			realalloc -= kobjsize(tmp);
 			askedalloc -= sizeof(*tmp);
 			kfree(tmp);
 		}


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