queue-5.1/scsi-lpfc-correct-rcu-unlock-issue-in-lpfc_nvme_info.patch

   1 From 9450c00c32b3d1caf45e04ee6be409093cc1db06 Mon Sep 17 00:00:00 2001
   2 From: James Smart <jsmart2021@gmail.com>
   3 Date: Mon, 6 May 2019 17:26:48 -0700
   4 Subject: scsi: lpfc: correct rcu unlock issue in lpfc_nvme_info_show
   5
   6 [ Upstream commit 79080d349f7f58a2e86c56043a3d04184d5f294a ]
   7
   8 Many of the exit cases were not releasing the rcu read lock.  Corrected the
   9 exit paths.
  10
  11 Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
  12 Signed-off-by: James Smart <jsmart2021@gmail.com>
  13 Tested-by: Bart Van Assche <bvanassche@acm.org>
  14 Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
  15 Signed-off-by: Sasha Levin <sashal@kernel.org>
  16 ---
  17  drivers/scsi/lpfc/lpfc_attr.c | 32 +++++++++++++++++++-------------
  18  1 file changed, 19 insertions(+), 13 deletions(-)
  19
  20 diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
  21 index f30cb0fb9a82..26a22e41204e 100644
  22 --- a/drivers/scsi/lpfc/lpfc_attr.c
  23 +++ b/drivers/scsi/lpfc/lpfc_attr.c
  24 @@ -338,7 +338,7 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
  25                   phba->sli4_hba.io_xri_max,
  26                   lpfc_sli4_get_els_iocb_cnt(phba));
  27         if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
  28 -               goto buffer_done;
  29 +               goto rcu_unlock_buf_done;
  30
  31         /* Port state is only one of two values for now. */
  32         if (localport->port_id)
  33 @@ -354,7 +354,7 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
  34                   wwn_to_u64(vport->fc_nodename.u.wwn),
  35                   localport->port_id, statep);
  36         if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
  37 -               goto buffer_done;
  38 +               goto rcu_unlock_buf_done;
  39
  40         list_for_each_entry(ndlp, &vport->fc_nodes, nlp_listp) {
  41                 nrport = NULL;
  42 @@ -381,39 +381,39 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
  43
  44                 /* Tab in to show lport ownership. */
  45                 if (strlcat(buf, "NVME RPORT       ", PAGE_SIZE) >= PAGE_SIZE)
  46 -                       goto buffer_done;
  47 +                       goto rcu_unlock_buf_done;
  48                 if (phba->brd_no >= 10) {
  49                         if (strlcat(buf, " ", PAGE_SIZE) >= PAGE_SIZE)
  50 -                               goto buffer_done;
  51 +                               goto rcu_unlock_buf_done;
  52                 }
  53
  54                 scnprintf(tmp, sizeof(tmp), "WWPN x%llx ",
  55                           nrport->port_name);
  56                 if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
  57 -                       goto buffer_done;
  58 +                       goto rcu_unlock_buf_done;
  59
  60                 scnprintf(tmp, sizeof(tmp), "WWNN x%llx ",
  61                           nrport->node_name);
  62                 if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
  63 -                       goto buffer_done;
  64 +                       goto rcu_unlock_buf_done;
  65
  66                 scnprintf(tmp, sizeof(tmp), "DID x%06x ",
  67                           nrport->port_id);
  68                 if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
  69 -                       goto buffer_done;
  70 +                       goto rcu_unlock_buf_done;
  71
  72                 /* An NVME rport can have multiple roles. */
  73                 if (nrport->port_role & FC_PORT_ROLE_NVME_INITIATOR) {
  74                         if (strlcat(buf, "INITIATOR ", PAGE_SIZE) >= PAGE_SIZE)
  75 -                               goto buffer_done;
  76 +                               goto rcu_unlock_buf_done;
  77                 }
  78                 if (nrport->port_role & FC_PORT_ROLE_NVME_TARGET) {
  79                         if (strlcat(buf, "TARGET ", PAGE_SIZE) >= PAGE_SIZE)
  80 -                               goto buffer_done;
  81 +                               goto rcu_unlock_buf_done;
  82                 }
  83                 if (nrport->port_role & FC_PORT_ROLE_NVME_DISCOVERY) {
  84                         if (strlcat(buf, "DISCSRVC ", PAGE_SIZE) >= PAGE_SIZE)
  85 -                               goto buffer_done;
  86 +                               goto rcu_unlock_buf_done;
  87                 }
  88                 if (nrport->port_role & ~(FC_PORT_ROLE_NVME_INITIATOR |
  89                                           FC_PORT_ROLE_NVME_TARGET |
  90 @@ -421,12 +421,12 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
  91                         scnprintf(tmp, sizeof(tmp), "UNKNOWN ROLE x%x",
  92                                   nrport->port_role);
  93                         if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
  94 -                               goto buffer_done;
  95 +                               goto rcu_unlock_buf_done;
  96                 }
  97
  98                 scnprintf(tmp, sizeof(tmp), "%s\n", statep);
  99                 if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
 100 -                       goto buffer_done;
 101 +                       goto rcu_unlock_buf_done;
 102         }
 103         rcu_read_unlock();
 104
 105 @@ -488,7 +488,13 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 106                   atomic_read(&lport->cmpl_fcp_err));
 107         strlcat(buf, tmp, PAGE_SIZE);
 108
 109 -buffer_done:
 110 +       /* RCU is already unlocked. */
 111 +       goto buffer_done;
 112 +
 113 + rcu_unlock_buf_done:
 114 +       rcu_read_unlock();
 115 +
 116 + buffer_done:
 117         len = strnlen(buf, PAGE_SIZE);
 118
 119         if (unlikely(len >= (PAGE_SIZE - 1))) {
 120 --
 121 2.20.1
 122