Commit 8e907ed4 authored by Lidong Chen's avatar Lidong Chen Committed by Jason Gunthorpe

IB/umem: Use the correct mm during ib_umem_release

User-space may invoke ibv_reg_mr and ibv_dereg_mr in different threads.

If ibv_dereg_mr is called after the thread which invoked ibv_reg_mr has
exited, get_pid_task will return NULL and ib_umem_release will not
decrease mm->pinned_vm.

Instead of using threads to locate the mm, use the overall tgid from the
ib_ucontext struct instead. This matches the behavior of ODP and
disassociate in handling the mm of the process that called ibv_reg_mr.

Cc: <stable@vger.kernel.org>
Fixes: 87773dd5 ("IB: ib_umem_release() should decrement mm->pinned_vm from ib_umem_get")
Signed-off-by: default avatarLidong Chen <lidongchen@tencent.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 3d691910
...@@ -119,7 +119,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, ...@@ -119,7 +119,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
umem->length = size; umem->length = size;
umem->address = addr; umem->address = addr;
umem->page_shift = PAGE_SHIFT; umem->page_shift = PAGE_SHIFT;
umem->pid = get_task_pid(current, PIDTYPE_PID);
/* /*
* We ask for writable memory if any of the following * We ask for writable memory if any of the following
* access flags are set. "Local write" and "remote write" * access flags are set. "Local write" and "remote write"
...@@ -132,7 +131,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, ...@@ -132,7 +131,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND)); IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
if (access & IB_ACCESS_ON_DEMAND) { if (access & IB_ACCESS_ON_DEMAND) {
put_pid(umem->pid);
ret = ib_umem_odp_get(context, umem, access); ret = ib_umem_odp_get(context, umem, access);
if (ret) { if (ret) {
kfree(umem); kfree(umem);
...@@ -148,7 +146,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, ...@@ -148,7 +146,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
page_list = (struct page **) __get_free_page(GFP_KERNEL); page_list = (struct page **) __get_free_page(GFP_KERNEL);
if (!page_list) { if (!page_list) {
put_pid(umem->pid);
kfree(umem); kfree(umem);
return ERR_PTR(-ENOMEM); return ERR_PTR(-ENOMEM);
} }
...@@ -231,7 +228,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, ...@@ -231,7 +228,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
if (ret < 0) { if (ret < 0) {
if (need_release) if (need_release)
__ib_umem_release(context->device, umem, 0); __ib_umem_release(context->device, umem, 0);
put_pid(umem->pid);
kfree(umem); kfree(umem);
} else } else
current->mm->pinned_vm = locked; current->mm->pinned_vm = locked;
...@@ -274,8 +270,7 @@ void ib_umem_release(struct ib_umem *umem) ...@@ -274,8 +270,7 @@ void ib_umem_release(struct ib_umem *umem)
__ib_umem_release(umem->context->device, umem, 1); __ib_umem_release(umem->context->device, umem, 1);
task = get_pid_task(umem->pid, PIDTYPE_PID); task = get_pid_task(umem->context->tgid, PIDTYPE_PID);
put_pid(umem->pid);
if (!task) if (!task)
goto out; goto out;
mm = get_task_mm(task); mm = get_task_mm(task);
......
...@@ -48,7 +48,6 @@ struct ib_umem { ...@@ -48,7 +48,6 @@ struct ib_umem {
int writable; int writable;
int hugetlb; int hugetlb;
struct work_struct work; struct work_struct work;
struct pid *pid;
struct mm_struct *mm; struct mm_struct *mm;
unsigned long diff; unsigned long diff;
struct ib_umem_odp *odp_data; struct ib_umem_odp *odp_data;
......
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