Commit d69f3bad authored by Robin Holt's avatar Robin Holt Committed by Linus Torvalds

ipc: sysv shared memory limited to 8TiB

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: default avatarRobin Holt <holt@sgi.com>
Reported-by: default avatarAlex Thorlton <athorlton@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 41239fe8
......@@ -43,8 +43,8 @@ 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()
......
......@@ -462,7 +462,7 @@ 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;
......
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