Revert "RDMA/rxe: Create duplicate mapping tables for FMRs"

Below 2 commits will be reverted:
 commit 8ff5f5d9d8cf ("RDMA/rxe: Prevent double freeing rxe_map_set()")
 commit 647bf13ce944 ("RDMA/rxe: Create duplicate mapping tables for FMRs")

The community has a few bug reports which pointed this commit at last.
Some proposals are raised up in the meantime but all of them have no
follow-up operation.

The previous commit led the map_set of FMR to be not available any more if
the MR is registered again after invalidating. Although the mentioned
patch try to fix a potential race in building/accessing the same table
for fast memory regions, it broke rtrs etc ULPs. Since the latter could
be worse, revert this patch.

With previous commit, it's observed that a same MR in rnbd server will
trigger below code path:
 -> rxe_mr_init_fast()
 |-> alloc map_set() # map_set is uninitialized
 |...-> rxe_map_mr_sg() # build the map_set
     |-> rxe_mr_set_page()
 |...-> rxe_reg_fast_mr() # mr->state change to VALID from FREE that means
                          # we can access host memory(such rxe_mr_copy)
 |...-> rxe_invalidate_mr() # mr->state change to FREE from VALID
 |...-> rxe_reg_fast_mr() # mr->state change to VALID from FREE,
                          # but map_set was not built again
 |...-> rxe_mr_copy() # kernel crash due to access wild addresses
                      # that lookup from the map_set

The backtraces are not always identical.
[1st]----------
  RIP: 0010:lookup_iova+0x66/0xa0 [rdma_rxe]
  Code: 00 00 00 48 d3 ee 89 32 c3 4c 8b 18 49 8b 3b 48 8b 47 08 48 39 c6 72 38 48 29 c6 45 31 d2 b8 01 00 00 00 48 63 c8 48 c1 e1 04 <48> 8b 4c 0f 08 48 39 f1 77 21 83 c0 01 48 29 ce 3d 00 01 00 00 75
  RSP: 0018:ffffb7ff80063bf0 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff9b9949d86800 RCX: 0000000000000000
  RDX: ffffb7ff80063c00 RSI: 0000000049f6b378 RDI: 002818da00000004
  RBP: 0000000000000120 R08: ffffb7ff80063c08 R09: ffffb7ff80063c04
  R10: 0000000000000002 R11: ffff9b9916f7eef8 R12: ffff9b99488a0038
  R13: ffff9b99488a0038 R14: ffff9b9914fb346a R15: ffff9b990ab27000
  FS:  0000000000000000(0000) GS:ffff9b997dc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007efc33a98ed0 CR3: 0000000014f32004 CR4: 00000000001706f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   rxe_mr_copy.part.0+0x6f/0x140 [rdma_rxe]
   rxe_responder+0x12ee/0x1b60 [rdma_rxe]
   ? rxe_icrc_check+0x7e/0x100 [rdma_rxe]
   ? rxe_rcv+0x1d0/0x780 [rdma_rxe]
   ? rxe_icrc_hdr.isra.0+0xf6/0x160 [rdma_rxe]
   rxe_do_task+0x67/0xb0 [rdma_rxe]
   rxe_xmit_packet+0xc7/0x210 [rdma_rxe]
   rxe_requester+0x680/0xee0 [rdma_rxe]
   ? update_load_avg+0x5f/0x690
   ? update_load_avg+0x5f/0x690
   ? rtrs_clt_recv_done+0x1b/0x30 [rtrs_client]

[2nd]----------
  RIP: 0010:rxe_mr_copy.part.0+0xa8/0x140 [rdma_rxe]
  Code: 00 00 49 c1 e7 04 48 8b 00 4c 8d 2c d0 48 8b 44 24 10 4d 03 7d 00 85 ed 7f 10 eb 6c 89 54 24 0c 49 83 c7 10 31 c0 85 ed 7e 5e <49> 8b 3f 8b 14 24 4c 89 f6 48 01 c7 85 d2 74 06 48 89 fe 4c 89 f7
  RSP: 0018:ffffae3580063bf8 EFLAGS: 00010202
  RAX: 0000000000018978 RBX: ffff9d7ef7a03600 RCX: 0000000000000008
  RDX: 000000000000007c RSI: 000000000000007c RDI: ffff9d7ef7a03600
  RBP: 0000000000000120 R08: ffffae3580063c08 R09: ffffae3580063c04
  R10: ffff9d7efece0038 R11: ffff9d7ec4b1db00 R12: ffff9d7efece0038
  R13: ffff9d7ef4098260 R14: ffff9d7f11e23c6a R15: 4c79500065708144
  FS:  0000000000000000(0000) GS:ffff9d7f3dc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fce47276c60 CR3: 0000000003f66004 CR4: 00000000001706f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   rxe_responder+0x12ee/0x1b60 [rdma_rxe]
   ? rxe_icrc_check+0x7e/0x100 [rdma_rxe]
   ? rxe_rcv+0x1d0/0x780 [rdma_rxe]
   ? rxe_icrc_hdr.isra.0+0xf6/0x160 [rdma_rxe]
   rxe_do_task+0x67/0xb0 [rdma_rxe]
   rxe_xmit_packet+0xc7/0x210 [rdma_rxe]
   rxe_requester+0x680/0xee0 [rdma_rxe]
   ? update_load_avg+0x5f/0x690
   ? update_load_avg+0x5f/0x690
   ? rtrs_clt_recv_done+0x1b/0x30 [rtrs_client]
   rxe_do_task+0x67/0xb0 [rdma_rxe]
   tasklet_action_common.constprop.0+0x92/0xc0
   __do_softirq+0xe1/0x2d8
   run_ksoftirqd+0x21/0x30
   smpboot_thread_fn+0x183/0x220
   ? sort_range+0x20/0x20
   kthread+0xe2/0x110
   ? kthread_complete_and_exit+0x20/0x20
   ret_from_fork+0x22/0x30

Link: https://lore.kernel.org/r/1658805386-2-1-git-send-email-lizhijian@fujitsu.com
Link: https://lore.kernel.org/all/20220210073655.42281-1-guoqing.jiang@linux.dev/T/
Link: https://www.spinics.net/lists/linux-rdma/msg110836.html
Link: https://lore.kernel.org/lkml/94a5ea93-b8bb-3a01-9497-e2021f29598a@linux.dev/t/
Tested-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

1 files changed, 66 insertions, 133 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 6fdbd7929ccc..850b80f5ad8b 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -24,7 +24,7 @@ u8 rxe_get_next_key(u32 last_key)
 
 int mr_check_range(struct rxe_mr *mr, u64 iova, size_t length)
 {
-	struct rxe_map_set *set = mr->cur_map_set;
+
 
 	switch (mr->type) {
 	case IB_MR_TYPE_DMA:
@@ -32,8 +32,8 @@ int mr_check_range(struct rxe_mr *mr, u64 iova, size_t length)
 
 	case IB_MR_TYPE_USER:
 	case IB_MR_TYPE_MEM_REG:
-		if (iova < set->iova || length > set->length ||
-		    iova > set->iova + set->length - length)
+		if (iova < mr->iova || length > mr->length ||
+		    iova > mr->iova + mr->length - length)
 			return -EFAULT;
 		return 0;
 
@@ -65,89 +65,41 @@ static void rxe_mr_init(int access, struct rxe_mr *mr)
 	mr->map_shift = ilog2(RXE_BUF_PER_MAP);
 }
 
-static void rxe_mr_free_map_set(int num_map, struct rxe_map_set *set)
-{
-	int i;
-
-	for (i = 0; i < num_map; i++)
-		kfree(set->map[i]);
-
-	kfree(set->map);
-	kfree(set);
-}
-
-static int rxe_mr_alloc_map_set(int num_map, struct rxe_map_set **setp)
+static int rxe_mr_alloc(struct rxe_mr *mr, int num_buf)
 {
 	int i;
-	struct rxe_map_set *set;
+	int num_map;
+	struct rxe_map **map = mr->map;
 
-	set = kmalloc(sizeof(*set), GFP_KERNEL);
-	if (!set)
-		goto err_out;
+	num_map = (num_buf + RXE_BUF_PER_MAP - 1) / RXE_BUF_PER_MAP;
 
-	set->map = kmalloc_array(num_map, sizeof(struct rxe_map *), GFP_KERNEL);
-	if (!set->map)
-		goto err_free_set;
+	mr->map = kmalloc_array(num_map, sizeof(*map), GFP_KERNEL);
+	if (!mr->map)
+		goto err1;
 
 	for (i = 0; i < num_map; i++) {
-		set->map[i] = kmalloc(sizeof(struct rxe_map), GFP_KERNEL);
-		if (!set->map[i])
-			goto err_free_map;
+		mr->map[i] = kmalloc(sizeof(**map), GFP_KERNEL);
+		if (!mr->map[i])
+			goto err2;
 	}
 
-	*setp = set;
-
-	return 0;
-
-err_free_map:
-	for (i--; i >= 0; i--)
-		kfree(set->map[i]);
-
-	kfree(set->map);
-err_free_set:
-	kfree(set);
-err_out:
-	return -ENOMEM;
-}
-
-/**
- * rxe_mr_alloc() - Allocate memory map array(s) for MR
- * @mr: Memory region
- * @num_buf: Number of buffer descriptors to support
- * @both: If non zero allocate both mr->map and mr->next_map
- *	  else just allocate mr->map. Used for fast MRs
- *
- * Return: 0 on success else an error
- */
-static int rxe_mr_alloc(struct rxe_mr *mr, int num_buf, int both)
-{
-	int ret;
-	int num_map;
-
 	BUILD_BUG_ON(!is_power_of_2(RXE_BUF_PER_MAP));
-	num_map = (num_buf + RXE_BUF_PER_MAP - 1) / RXE_BUF_PER_MAP;
 
 	mr->map_shift = ilog2(RXE_BUF_PER_MAP);
 	mr->map_mask = RXE_BUF_PER_MAP - 1;
+
 	mr->num_buf = num_buf;
-	mr->max_buf = num_map * RXE_BUF_PER_MAP;
 	mr->num_map = num_map;
-
-	ret = rxe_mr_alloc_map_set(num_map, &mr->cur_map_set);
-	if (ret)
-		return -ENOMEM;
-
-	if (both) {
-		ret = rxe_mr_alloc_map_set(num_map, &mr->next_map_set);
-		if (ret)
-			goto err_free;
-	}
+	mr->max_buf = num_map * RXE_BUF_PER_MAP;
 
 	return 0;
 
-err_free:
-	rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
-	mr->cur_map_set = NULL;
+err2:
+	for (i--; i >= 0; i--)
+		kfree(mr->map[i]);
+
+	kfree(mr->map);
+err1:
 	return -ENOMEM;
 }
 
@@ -164,7 +116,6 @@ void rxe_mr_init_dma(struct rxe_pd *pd, int access, struct rxe_mr *mr)
 int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 		     int access, struct rxe_mr *mr)
 {
-	struct rxe_map_set	*set;
 	struct rxe_map		**map;
 	struct rxe_phys_buf	*buf = NULL;
 	struct ib_umem		*umem;
@@ -172,6 +123,7 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 	int			num_buf;
 	void			*vaddr;
 	int err;
+	int i;
 
 	umem = ib_umem_get(pd->ibpd.device, start, length, access);
 	if (IS_ERR(umem)) {
@@ -185,20 +137,18 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 
 	rxe_mr_init(access, mr);
 
-	err = rxe_mr_alloc(mr, num_buf, 0);
+	err = rxe_mr_alloc(mr, num_buf);
 	if (err) {
 		pr_warn("%s: Unable to allocate memory for map\n",
 				__func__);
 		goto err_release_umem;
 	}
 
-	set = mr->cur_map_set;
-	set->page_shift = PAGE_SHIFT;
-	set->page_mask = PAGE_SIZE - 1;
-
-	num_buf = 0;
-	map = set->map;
+	mr->page_shift = PAGE_SHIFT;
+	mr->page_mask = PAGE_SIZE - 1;
 
+	num_buf			= 0;
+	map = mr->map;
 	if (length > 0) {
 		buf = map[0]->buf;
 
@@ -214,29 +164,33 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 				pr_warn("%s: Unable to get virtual address\n",
 						__func__);
 				err = -ENOMEM;
-				goto err_release_umem;
+				goto err_cleanup_map;
 			}
 
 			buf->addr = (uintptr_t)vaddr;
 			buf->size = PAGE_SIZE;
 			num_buf++;
 			buf++;
+
 		}
 	}
 
 	mr->ibmr.pd = &pd->ibpd;
 	mr->umem = umem;
 	mr->access = access;
+	mr->length = length;
+	mr->iova = iova;
+	mr->va = start;
+	mr->offset = ib_umem_offset(umem);
 	mr->state = RXE_MR_STATE_VALID;
 	mr->type = IB_MR_TYPE_USER;
 
-	set->length = length;
-	set->iova = iova;
-	set->va = start;
-	set->offset = ib_umem_offset(umem);
-
 	return 0;
 
+err_cleanup_map:
+	for (i = 0; i < mr->num_map; i++)
+		kfree(mr->map[i]);
+	kfree(mr->map);
 err_release_umem:
 	ib_umem_release(umem);
 err_out:
@@ -250,7 +204,7 @@ int rxe_mr_init_fast(struct rxe_pd *pd, int max_pages, struct rxe_mr *mr)
 	/* always allow remote access for FMRs */
 	rxe_mr_init(IB_ACCESS_REMOTE, mr);
 
-	err = rxe_mr_alloc(mr, max_pages, 1);
+	err = rxe_mr_alloc(mr, max_pages);
 	if (err)
 		goto err1;
 
@@ -268,24 +222,21 @@ err1:
 static void lookup_iova(struct rxe_mr *mr, u64 iova, int *m_out, int *n_out,
 			size_t *offset_out)
 {
-	struct rxe_map_set *set = mr->cur_map_set;
-	size_t offset = iova - set->iova + set->offset;
+	size_t offset = iova - mr->iova + mr->offset;
 	int			map_index;
 	int			buf_index;
 	u64			length;
-	struct rxe_map *map;
 
-	if (likely(set->page_shift)) {
-		*offset_out = offset & set->page_mask;
-		offset >>= set->page_shift;
+	if (likely(mr->page_shift)) {
+		*offset_out = offset & mr->page_mask;
+		offset >>= mr->page_shift;
 		*n_out = offset & mr->map_mask;
 		*m_out = offset >> mr->map_shift;
 	} else {
 		map_index = 0;
 		buf_index = 0;
 
-		map = set->map[map_index];
-		length = map->buf[buf_index].size;
+		length = mr->map[map_index]->buf[buf_index].size;
 
 		while (offset >= length) {
 			offset -= length;
@@ -295,8 +246,7 @@ static void lookup_iova(struct rxe_mr *mr, u64 iova, int *m_out, int *n_out,
 				map_index++;
 				buf_index = 0;
 			}
-			map = set->map[map_index];
-			length = map->buf[buf_index].size;
+			length = mr->map[map_index]->buf[buf_index].size;
 		}
 
 		*m_out = map_index;
@@ -317,7 +267,7 @@ void *iova_to_vaddr(struct rxe_mr *mr, u64 iova, int length)
 		goto out;
 	}
 
-	if (!mr->cur_map_set) {
+	if (!mr->map) {
 		addr = (void *)(uintptr_t)iova;
 		goto out;
 	}
@@ -330,13 +280,13 @@ void *iova_to_vaddr(struct rxe_mr *mr, u64 iova, int length)
 
 	lookup_iova(mr, iova, &m, &n, &offset);
 
-	if (offset + length > mr->cur_map_set->map[m]->buf[n].size) {
+	if (offset + length > mr->map[m]->buf[n].size) {
 		pr_warn("crosses page boundary\n");
 		addr = NULL;
 		goto out;
 	}
 
-	addr = (void *)(uintptr_t)mr->cur_map_set->map[m]->buf[n].addr + offset;
+	addr = (void *)(uintptr_t)mr->map[m]->buf[n].addr + offset;
 
 out:
 	return addr;
@@ -372,7 +322,7 @@ int rxe_mr_copy(struct rxe_mr *mr, u64 iova, void *addr, int length,
 		return 0;
 	}
 
-	WARN_ON_ONCE(!mr->cur_map_set);
+	WARN_ON_ONCE(!mr->map);
 
 	err = mr_check_range(mr, iova, length);
 	if (err) {
@@ -382,7 +332,7 @@ int rxe_mr_copy(struct rxe_mr *mr, u64 iova, void *addr, int length,
 
 	lookup_iova(mr, iova, &m, &i, &offset);
 
-	map = mr->cur_map_set->map + m;
+	map = mr->map + m;
 	buf	= map[0]->buf + i;
 
 	while (length > 0) {
@@ -628,9 +578,8 @@ err:
 int rxe_reg_fast_mr(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
 {
 	struct rxe_mr *mr = to_rmr(wqe->wr.wr.reg.mr);
-	u32 key = wqe->wr.wr.reg.key & 0xff;
+	u32 key = wqe->wr.wr.reg.key;
 	u32 access = wqe->wr.wr.reg.access;
-	struct rxe_map_set *set;
 
 	/* user can only register MR in free state */
 	if (unlikely(mr->state != RXE_MR_STATE_FREE)) {
@@ -646,36 +595,19 @@ int rxe_reg_fast_mr(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
 		return -EINVAL;
 	}
 
+	/* user is only allowed to change key portion of l/rkey */
+	if (unlikely((mr->lkey & ~0xff) != (key & ~0xff))) {
+		pr_warn("%s: key = 0x%x has wrong index mr->lkey = 0x%x\n",
+			__func__, key, mr->lkey);
+		return -EINVAL;
+	}
+
 	mr->access = access;
-	mr->lkey = (mr->lkey & ~0xff) | key;
-	mr->rkey = (access & IB_ACCESS_REMOTE) ? mr->lkey : 0;
+	mr->lkey = key;
+	mr->rkey = (access & IB_ACCESS_REMOTE) ? key : 0;
+	mr->iova = wqe->wr.wr.reg.mr->iova;
 	mr->state = RXE_MR_STATE_VALID;
 
-	set = mr->cur_map_set;
-	mr->cur_map_set = mr->next_map_set;
-	mr->cur_map_set->iova = wqe->wr.wr.reg.mr->iova;
-	mr->next_map_set = set;
-
-	return 0;
-}
-
-int rxe_mr_set_page(struct ib_mr *ibmr, u64 addr)
-{
-	struct rxe_mr *mr = to_rmr(ibmr);
-	struct rxe_map_set *set = mr->next_map_set;
-	struct rxe_map *map;
-	struct rxe_phys_buf *buf;
-
-	if (unlikely(set->nbuf == mr->num_buf))
-		return -ENOMEM;
-
-	map = set->map[set->nbuf / RXE_BUF_PER_MAP];
-	buf = &map->buf[set->nbuf % RXE_BUF_PER_MAP];
-
-	buf->addr = addr;
-	buf->size = ibmr->page_size;
-	set->nbuf++;
-
 	return 0;
 }
 
@@ -695,14 +627,15 @@ int rxe_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
 void rxe_mr_cleanup(struct rxe_pool_elem *elem)
 {
 	struct rxe_mr *mr = container_of(elem, typeof(*mr), elem);
+	int i;
 
 	rxe_put(mr_pd(mr));
-
 	ib_umem_release(mr->umem);
 
-	if (mr->cur_map_set)
-		rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
+	if (mr->map) {
+		for (i = 0; i < mr->num_map; i++)
+			kfree(mr->map[i]);
 
-	if (mr->next_map_set)
-		rxe_mr_free_map_set(mr->num_map, mr->next_map_set);
+		kfree(mr->map);
+	}
 }