Restore of huge page shm regions will require that the restarting process temporarily shmat-attach to regions which are not in the current ipc namespace. Add an ipc_namespace argument to do_shmat_pgoff; convert callers to pass current->nsproxy->ipc_ns.
This depends on the patch "support ipc shm regions which are partially mapped" posted to the containers list on 6 August. Signed-off-by: Nathan Lynch <[email protected]> --- include/linux/shm.h | 8 +++++--- ipc/shm.c | 15 ++++++++------- 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/include/linux/shm.h b/include/linux/shm.h index 1f6af8c..9ca3196 100644 --- a/include/linux/shm.h +++ b/include/linux/shm.h @@ -104,10 +104,12 @@ struct shmid_kernel /* private to the kernel */ #define SHM_NORESERVE 010000 /* don't check for reservations */ #ifdef CONFIG_SYSVIPC +struct ipc_namespace; + long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr); -long do_shmat_pgoff(int shmid, char __user *shmaddr, - int shmflg, unsigned long *addr, - unsigned long shmsize, unsigned long shmpgoff); +long do_shmat_ns_pgoff(struct ipc_namespace *ns, int shmid, + char __user *shmaddr, int shmflg, unsigned long *addr, + unsigned long shmsize, unsigned long shmpgoff); extern int is_file_shm_hugepages(struct file *file); #else static inline long do_shmat(int shmid, char __user *shmaddr, diff --git a/ipc/shm.c b/ipc/shm.c index 1ba9193..6768fe4 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -321,6 +321,7 @@ static int ipcshm_checkpoint(struct ckpt_ctx *ctx, struct vm_area_struct *vma) int ipcshm_restore(struct ckpt_ctx *ctx, struct mm_struct *mm, struct ckpt_hdr_vma *h) { + struct ipc_namespace *ipcns = current->nsproxy->ipc_ns; struct file *file; int shmid, shmflg = 0; unsigned long start; @@ -348,8 +349,8 @@ int ipcshm_restore(struct ckpt_ctx *ctx, struct mm_struct *mm, /* do_shmat() below handles partial and offset mapping */ start = (unsigned long) h->vm_start; size = min(h->ino_size, h->vm_end - h->vm_start); - ret = do_shmat_pgoff(shmid, (char __user *) start, shmflg, - &addr, size, h->vm_pgoff << PAGE_SHIFT); + ret = do_shmat_ns_pgoff(ipcns, shmid, (char __user *) start, shmflg, + &addr, size, h->vm_pgoff << PAGE_SHIFT); BUG_ON(ret >= 0 && addr != h->vm_start); return ret; @@ -880,8 +881,9 @@ out: * "raddr" thing points to kernel space, and there has to be a wrapper around * this. */ -long do_shmat_pgoff(int shmid, char __user *shmaddr, int shmflg, - ulong *raddr, ulong shmsize, ulong shmpgoff) +long do_shmat_ns_pgoff(struct ipc_namespace *ns, int shmid, + char __user *shmaddr, int shmflg, ulong *raddr, + ulong shmsize, ulong shmpgoff) { struct shmid_kernel *shp; unsigned long addr; @@ -893,7 +895,6 @@ long do_shmat_pgoff(int shmid, char __user *shmaddr, int shmflg, unsigned long prot; int acc_mode; unsigned long user_addr; - struct ipc_namespace *ns; struct shm_file_data *sfd; struct path path; fmode_t f_mode; @@ -937,7 +938,6 @@ long do_shmat_pgoff(int shmid, char __user *shmaddr, int shmflg, * We cannot rely on the fs check since SYSV IPC does have an * additional creator id... */ - ns = current->nsproxy->ipc_ns; shp = shm_lock_check(ns, shmid); if (IS_ERR(shp)) { err = PTR_ERR(shp); @@ -1045,7 +1045,8 @@ out_put_dentry: */ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) { - return do_shmat_pgoff(shmid, shmaddr, shmflg, raddr, 0, 0); + return do_shmat_ns_pgoff(current->nsproxy->ipc_ns, shmid, shmaddr, + shmflg, raddr, 0, 0); } SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) -- 1.7.2.2 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
