Commit 5ddd36b9 authored by Stephen Wilson's avatar Stephen Wilson Committed by Al Viro
Browse files

mm: implement access_remote_vm 



Provide an alternative to access_process_vm that allows the caller to obtain a
reference to the supplied mm_struct.

Signed-off-by: default avatarStephen Wilson <wilsons@start.ca>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 206cb636

include/linux/mm.h

+2 −0
Original line number Diff line number Diff line
@@ -971,6 +971,8 @@ static inline int handle_mm_fault(struct mm_struct *mm, 


extern int make_pages_present(unsigned long addr, unsigned long end);

extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);

extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,

		void *buf, int len, int write);



int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,

		     unsigned long start, int len, unsigned int foll_flags,

mm/memory.c

+16 −0
Original line number Diff line number Diff line
@@ -3711,6 +3711,22 @@ static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, 
	return buf - old_buf;

}



/**

 * @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,