3  * linux/ipc/shm.c
7  * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli.
9  * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
11  * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr>
31 #include <linux/shm.h>
32 #include <uapi/linux/shm.h>
67 	 * The task created the shm object, for
158 	ipc_init_proc_interface("sysvipc/shm",  in shm_init()
301 /* This is called by fork, once for every shm attach. */
347  * shm_may_destroy - identifies whether shm segment should be destroyed now
375 	/* remove from the list of attaches of the shm segment */  in __shm_close()
476 		 *    the shm objects will be free by free_ipc_work().  in exit_shm()
494 		 * 5) unlink the shm segment from the list of segments  in exit_shm()
595 	 * IPC ID that was removed, and possibly even reused by another shm  in shm_mmap()
926  * Calculate and add used RSS and swap pages of a shm.
1508  * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
1601 	 * We need to take a reference to the real shm file to prevent the  in do_shmat()
1603 	 * file extends beyond that of the shm segment.  It's not usually  in do_shmat()
1606 	 * We'll deny the ->mmap() if the shm segment was since removed, but to  in do_shmat()
1607 	 * detect shm ID reuse we need to compare the file pointers.  in do_shmat()
1742 	 * This function tries to be smart and unmap shm segments that  in ksys_shmdt()
1744 	 * - It first determines the size of the shm segment that should be  in ksys_shmdt()
1745 	 *   unmapped: It searches for a vma that is backed by shm and that  in ksys_shmdt()
1748 	 * - Then it unmaps all shm vmas that started at shmaddr and that  in ksys_shmdt()
1750 	 *   same shm segment from which we determined the size.  in ksys_shmdt()
1774 			 * Record the file of the shm segment being  in ksys_shmdt()
1784 			 * We discovered the size of the shm segment, so  in ksys_shmdt()