From f55f199b7d76a01e7ce9d1c3bb004327e075c327 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 29 Mar 2011 14:05:12 +0100 Subject: [PATCH] NOMMU: implement access_remote_vm Recent vm changes brought in a new function which the core procfs code utilizes. So implement it for nommu systems too to avoid link failures. Signed-off-by: Mike Frysinger Signed-off-by: David Howells Tested-by: Simon Horman Tested-by: Ithamar Adema Acked-by: Greg Ungerer --- mm/nommu.c | 52 +++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 13 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index cb86e7d5e7f5..c4c542c736a9 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1971,21 +1971,10 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) } EXPORT_SYMBOL(filemap_fault); -/* - * Access another process' address space. - * - source/target buffer must be kernel space - */ -int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, + unsigned long addr, void *buf, int len, int write) { struct vm_area_struct *vma; - struct mm_struct *mm; - - if (addr + len < addr) - return 0; - - mm = get_task_mm(tsk); - if (!mm) - return 0; down_read(&mm->mmap_sem); @@ -2010,6 +1999,43 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in } up_read(&mm->mmap_sem); + + return len; +} + +/** + * @access_remote_vm - access another process' address space + * @mm: the mm_struct of the target address space + * @addr: start address to access + * @buf: source or destination buffer + * @len: number of bytes to transfer + * @write: whether the access is a write + * + * The caller must hold a reference on @mm. + */ +int access_remote_vm(struct mm_struct *mm, unsigned long addr, + void *buf, int len, int write) +{ + return __access_remote_vm(NULL, mm, addr, buf, len, write); +} + +/* + * Access another process' address space. + * - source/target buffer must be kernel space + */ +int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +{ + struct mm_struct *mm; + + if (addr + len < addr) + return 0; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + len = __access_remote_vm(tsk, mm, addr, buf, len, write); + mmput(mm); return len; }