Initialize local variable trans_support before it is used rather
than after. It is supposed to contain the value of a register on the
controller containing bits that describe which transport modes the
controller supports (e.g. "performant", "ioaccel1", "ioaccel2"). A
NULL pointer dereference will almost certainly occur if trans_support
is not initialized at the right point. If for example the uninitialized
trans_support value does not have the bit set for ioaccel2 support when it
should be, then ioaccel2_alloc_cmds_and_bft() will not get called as it
should be and the h->ioaccel2_blockFetchTable array will remain NULL
instead of being allocated. Too late, trans_support finally gets
initialized with the correct value with ioaccel2 mode bit set,
which later causes calc_bucket_map() to be called to fill in
h->ioaccel2_blockFetchTable[]. However h->ioaccel2_blockFetchTable
is NULL because it didn't get allocated because earlier trans_support
wasn't initialized at the right point.
Signed-off-by: Stephen M. Cameron <scame...@beardog.cce.hp.com>
---
drivers/scsi/hpsa.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 8cf4a0c..9a6e4a2 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -7463,6 +7463,10 @@ static void hpsa_put_ctlr_into_performant_mode(struct
ctlr_info *h)
if (hpsa_simple_mode)
return;
+ trans_support = readl(&(h->cfgtable->TransportSupport));
+ if (!(trans_support & PERFORMANT_MODE))
+ return;
+
/* Check for I/O accelerator mode support */
if (trans_support & CFGTBL_Trans_io_accel1) {
transMethod |= CFGTBL_Trans_io_accel1 |
@@ -7479,10 +7483,6 @@ static void hpsa_put_ctlr_into_performant_mode(struct
ctlr_info *h)
}
/* TODO, check that this next line h->nreply_queues is correct */
- trans_support = readl(&(h->cfgtable->TransportSupport));
- if (!(trans_support & PERFORMANT_MODE))
- return;
-
h->nreply_queues = h->msix_vector > 0 ? h->msix_vector : 1;
hpsa_get_max_perf_mode_cmds(h);
/* Performant mode ring buffer and supporting data structures */
--
1.7.1
--
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