IB/usnic: Update with bug fixes from core code

usnic has a modified version of the core codes' ib_umem_get() and
related, and the copy misses many of the bug fixes done over the years:

Commit bc3e53f6 ("mm: distinguish between mlocked and pinned pages")
Commit 87773dd5 ("IB: ib_umem_release() should decrement mm->pinned_vm
                      from ib_umem_get")
Commit 8494057a ("IB/uverbs: Prevent integer overflow in ib_umem_get
                      address arithmetic")
Commit 8abaae62 ("IB/core: disallow registering 0-sized memory region")
Commit 66578b0b ("IB/core: don't disallow registering region starting
                      at 0x0")
Commit 53376fed ("RDMA/core: not to set page dirty bit if it's already
                      set.")
Commit 8e907ed4 ("IB/umem: Use the correct mm during ib_umem_release")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/usnic/usnic_ib_verbs.c

@@ -666,7 +666,7 @@ int usnic_ib_dereg_mr(struct ib_mr *ibmr)
 
 	usnic_dbg("va 0x%lx length 0x%zx\n", mr->umem->va, mr->umem->length);
 
-	usnic_uiom_reg_release(mr->umem, ibmr->pd->uobject->context->closing);
+	usnic_uiom_reg_release(mr->umem, ibmr->uobject->context);
 	kfree(mr);
 	return 0;
 }

drivers/infiniband/hw/usnic/usnic_uiom.c

@@ -41,6 +41,7 @@
 #include <linux/workqueue.h>
 #include <linux/list.h>
 #include <linux/pci.h>
+#include <rdma/ib_verbs.h>
 
 #include "usnic_log.h"
 #include "usnic_uiom.h"
@@ -88,7 +89,7 @@ static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty)
 		for_each_sg(chunk->page_list, sg, chunk->nents, i) {
 			page = sg_page(sg);
 			pa = sg_phys(sg);
-			if (dirty)
+			if (!PageDirty(page) && dirty)
 				set_page_dirty_lock(page);
 			put_page(page);
 			usnic_dbg("pa: %pa\n", &pa);
@@ -114,6 +115,16 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 	dma_addr_t pa;
 	unsigned int gup_flags;
 
+	/*
+	 * If the combination of the addr and size requested for this memory
+	 * region causes an integer overflow, return error.
+	 */
+	if (((addr + size) < addr) || PAGE_ALIGN(addr + size) < (addr + size))
+		return -EINVAL;
+
+	if (!size)
+		return -EINVAL;
+
 	if (!can_do_mlock())
 		return -EPERM;
 
@@ -127,7 +138,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 
 	down_write(&current->mm->mmap_sem);
 
-	locked = npages + current->mm->locked_vm;
+	locked = npages + current->mm->pinned_vm;
 	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 
 	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
@@ -143,7 +154,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 	ret = 0;
 
 	while (npages) {
-		ret = get_user_pages(cur_base,
+		ret = get_user_pages_longterm(cur_base,
 					min_t(unsigned long, npages,
 					PAGE_SIZE / sizeof(struct page *)),
 					gup_flags, page_list, NULL);
@@ -186,7 +197,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 	if (ret < 0)
 		usnic_uiom_put_pages(chunk_list, 0);
 	else
-		current->mm->locked_vm = locked;
+		current->mm->pinned_vm = locked;
 
 	up_write(&current->mm->mmap_sem);
 	free_page((unsigned long) page_list);
@@ -420,18 +431,22 @@ struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
 	return ERR_PTR(err);
 }
 
-void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr, int closing)
+void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr,
+			    struct ib_ucontext *ucontext)
 {
+	struct task_struct *task;
 	struct mm_struct *mm;
 	unsigned long diff;
 
 	__usnic_uiom_reg_release(uiomr->pd, uiomr, 1);
 
-	mm = get_task_mm(current);
-	if (!mm) {
-		kfree(uiomr);
-		return;
-	}
+	task = get_pid_task(ucontext->tgid, PIDTYPE_PID);
+	if (!task)
+		goto out;
+	mm = get_task_mm(task);
+	put_task_struct(task);
+	if (!mm)
+		goto out;
 
 	diff = PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
 
@@ -443,7 +458,7 @@ void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr, int closing)
 	 * up here and not be able to take the mmap_sem.  In that case
 	 * we defer the vm_locked accounting to the system workqueue.
 	 */
-	if (closing) {
+	if (ucontext->closing) {
 		if (!down_write_trylock(&mm->mmap_sem)) {
 			INIT_WORK(&uiomr->work, usnic_uiom_reg_account);
 			uiomr->mm = mm;
@@ -455,9 +470,10 @@ void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr, int closing)
 	} else
 		down_write(&mm->mmap_sem);
 
-	current->mm->locked_vm -= diff;
+	mm->pinned_vm -= diff;
 	up_write(&mm->mmap_sem);
 	mmput(mm);
+out:
 	kfree(uiomr);
 }
 

drivers/infiniband/hw/usnic/usnic_uiom.h

@@ -39,6 +39,8 @@
 
 #include "usnic_uiom_interval_tree.h"
 
+struct ib_ucontext;
+
 #define USNIC_UIOM_READ			(1)
 #define USNIC_UIOM_WRITE		(2)
 
@@ -89,7 +91,8 @@ void usnic_uiom_free_dev_list(struct device **devs);
 struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
 						unsigned long addr, size_t size,
 						int access, int dmasync);
-void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr, int closing);
+void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr,
+			    struct ib_ucontext *ucontext);
 int usnic_uiom_init(char *drv_name);
 void usnic_uiom_fini(void);
 #endif /* USNIC_UIOM_H_ */