From 5a467624b1c06db5a47bf2fe58e41347686af512 Mon Sep 17 00:00:00 2001 From: Robin Holt Date: Tue, 30 Apr 2013 19:15:54 -0700 Subject: [PATCH] ipc: sysv shared memory limited to 8TiB commit d69f3bad4675ac519d41ca2b11e1c00ca115cecd upstream. Trying to run an application which was trying to put data into half of memory using shmget(), we found that having a shmall value below 8EiB-8TiB would prevent us from using anything more than 8TiB. By setting kernel.shmall greater than 8EiB-8TiB would make the job work. In the newseg() function, ns->shm_tot which, at 8TiB is INT_MAX. ipc/shm.c: 458 static int newseg(struct ipc_namespace *ns, struct ipc_params *params) 459 { ... 465 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; ... 474 if (ns->shm_tot + numpages > ns->shm_ctlall) 475 return -ENOSPC; [akpm@linux-foundation.org: make ipc/shm.c:newseg()'s numpages size_t, not int] Signed-off-by: Robin Holt Reported-by: Alex Thorlton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- include/linux/ipc_namespace.h | 2 +- ipc/shm.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h index 8a297a5e794c..497c6cc8848f 100644 --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -42,8 +42,8 @@ struct ipc_namespace { size_t shm_ctlmax; size_t shm_ctlall; + unsigned long shm_tot; int shm_ctlmni; - int shm_tot; /* * Defines whether IPC_RMID is forced for _all_ shm segments regardless * of shmctl() diff --git a/ipc/shm.c b/ipc/shm.c index b76be5bda6c2..326a20bdba3a 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -450,7 +450,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) size_t size = params->u.size; int error; struct shmid_kernel *shp; - int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; + size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; struct file * file; char name[13]; int id; -- 2.39.2