[PATCH net-next] qed: fix the allocation of the chains with an external PBL

[Alexander Lobakin]

Dan reports static checker warning:

"The patch 9b6ee3cf95d3: "qed: sanitize PBL chains allocation" from Jul
23, 2020, leads to the following static checker warning:

        drivers/net/ethernet/qlogic/qed/qed_chain.c:299 qed_chain_alloc_pbl()
        error: uninitialized symbol 'pbl_virt'.

drivers/net/ethernet/qlogic/qed/qed_chain.c
   249  static int qed_chain_alloc_pbl(struct qed_dev *cdev, struct qed_chain 
*chain)
   250  {
   251          struct device *dev = &cdev->pdev->dev;
   252          struct addr_tbl_entry *addr_tbl;
   253          dma_addr_t phys, pbl_phys;
   254          __le64 *pbl_virt;
                ^^^^^^^^^^^^^^^^
[...]
   271          if (chain->b_external_pbl)
   272                  goto alloc_pages;
                        ^^^^^^^^^^^^^^^^ uninitialized
[...]
   298                  /* Fill the PBL table with the physical address of the 
page */
   299                  pbl_virt[i] = cpu_to_le64(phys);
                        ^^^^^^^^^^^
[...]
"

This issue was introduced with commit c3a321b06a80 ("qed: simplify
initialization of the chains with an external PBL"), when
chain->pbl_sp.table_virt initialization was moved up to
qed_chain_init_params().
Fix it by initializing pbl_virt with an already filled chain struct field.

Fixes: c3a321b06a80 ("qed: simplify initialization of the chains with an 
external PBL")
Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
Signed-off-by: Alexander Lobakin <aloba...@marvell.com>
---
 drivers/net/ethernet/qlogic/qed/qed_chain.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qlogic/qed/qed_chain.c 
b/drivers/net/ethernet/qlogic/qed/qed_chain.c
index f8efd36d66e0..b83d17b14e85 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_chain.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_chain.c
@@ -268,8 +268,10 @@ static int qed_chain_alloc_pbl(struct qed_dev *cdev, 
struct qed_chain *chain)
 
        chain->pbl.pp_addr_tbl = addr_tbl;
 
-       if (chain->b_external_pbl)
+       if (chain->b_external_pbl) {
+               pbl_virt = chain->pbl_sp.table_virt;
                goto alloc_pages;
+       }
 
        size = array_size(page_cnt, sizeof(*pbl_virt));
        if (unlikely(size == SIZE_MAX))
-- 
2.25.1