Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 11/16] misc: use ACCESS_ONCE for rlimits | Date | Wed, 18 Nov 2009 15:51:57 +0100 |
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Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented.
Signed-off-by: Jiri Slaby <jslaby@novell.com> Cc: James Morris <jmorris@namei.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Cc: linux-rdma@vger.kernel.org --- drivers/infiniband/core/umem.c | 3 ++- drivers/infiniband/hw/ipath/ipath_user_pages.c | 4 ++-- ipc/mqueue.c | 4 ++-- ipc/shm.c | 4 ++-- 4 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 6f7c096..90d806b 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -136,7 +136,8 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, down_write(¤t->mm->mmap_sem); locked = npages + current->mm->locked_vm; - lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT; + lock_limit = ACCESS_ONCE(current->signal-> + rlim[RLIMIT_MEMLOCK].rlim_cur) >> PAGE_SHIFT; if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) { ret = -ENOMEM; diff --git a/drivers/infiniband/hw/ipath/ipath_user_pages.c b/drivers/infiniband/hw/ipath/ipath_user_pages.c index 82878e3..f7db156 100644 --- a/drivers/infiniband/hw/ipath/ipath_user_pages.c +++ b/drivers/infiniband/hw/ipath/ipath_user_pages.c @@ -59,8 +59,8 @@ static int __get_user_pages(unsigned long start_page, size_t num_pages, size_t got; int ret; - lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> - PAGE_SHIFT; + lock_limit = ACCESS_ONCE(current->signal-> + rlim[RLIMIT_MEMLOCK].rlim_cur) >> PAGE_SHIFT; if (num_pages > lock_limit) { ret = -ENOMEM; diff --git a/ipc/mqueue.c b/ipc/mqueue.c index ee9d697..d04869f 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -152,8 +152,8 @@ static struct inode *mqueue_get_inode(struct super_block *sb, spin_lock(&mq_lock); if (u->mq_bytes + mq_bytes < u->mq_bytes || - u->mq_bytes + mq_bytes > - p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { + u->mq_bytes + mq_bytes > ACCESS_ONCE(p->signal-> + rlim[RLIMIT_MSGQUEUE].rlim_cur)) { spin_unlock(&mq_lock); goto out_inode; } diff --git a/ipc/shm.c b/ipc/shm.c index 464694e..99de87c 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -761,8 +761,8 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) if (euid != shp->shm_perm.uid && euid != shp->shm_perm.cuid) goto out_unlock; - if (cmd == SHM_LOCK && - !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) + if (cmd == SHM_LOCK && !ACCESS_ONCE(current->signal-> + rlim[RLIMIT_MEMLOCK].rlim_cur)) goto out_unlock; } -- 1.6.4.2
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