Hello Hariprasad S,
The patch c5dfb000b904: "iw_cxgb4: Pass qid range to user space
driver" from Dec 11, 2015, leads to the following static checker
warning:
drivers/infiniband/hw/cxgb4/device.c:857 c4iw_rdev_open()
warn: variable dereferenced before check 'rdev->status_page' (see line 853)
drivers/infiniband/hw/cxgb4/device.c
841 err = c4iw_rqtpool_create(rdev);
842 if (err) {
843 printk(KERN_ERR MOD "error %d initializing rqt pool\n", err);
844 goto err3;
845 }
846 err = c4iw_ocqp_pool_create(rdev);
847 if (err) {
848 printk(KERN_ERR MOD "error %d initializing ocqp pool\n", err);
849 goto err4;
850 }
851 rdev->status_page = (struct t4_dev_status_page *)
852 __get_free_page(GFP_KERNEL);
853 rdev->status_page->qp_start = rdev->lldi.vr->qp.start;
854 rdev->status_page->qp_size = rdev->lldi.vr->qp.size;
855 rdev->status_page->cq_start = rdev->lldi.vr->cq.start;
856 rdev->status_page->cq_size = rdev->lldi.vr->cq.size;
857 if (!rdev->status_page) {
858 pr_err(MOD "error allocating status page\n");
859 goto err4;
Ugh... Obviously move the error handling first. But then fix the
GW-Basic labels to meaningful error names. You wouldn't name functions
one(), two() or variables var1, var2, labels are the same. Pick names
that reflect what the goto does. "goto err_destroy_rqt;" If we
had picked a good name we wouldn't have had to scroll down to see the
second bug. It should be goto err_destroy_ocqp; but we are missing a
call to c4iw_ocqp_pool_destroy().
Normal error handling is formulaic and does not require active thinking.
It is easy to review because you just have to keep track of the most
recent allocation.
https://plus.google.com/106378716002406849458/posts/dnanfhQ4mHQ
860 }
861
862 if (c4iw_wr_log) {
863 rdev->wr_log = kzalloc((1 << c4iw_wr_log_size_order) *
864 sizeof(*rdev->wr_log), GFP_KERNEL);
865 if (rdev->wr_log) {
866 rdev->wr_log_size = 1 << c4iw_wr_log_size_order;
867 atomic_set(&rdev->wr_log_idx, 0);
868 } else {
869 pr_err(MOD "error allocating wr_log. Logging disabled\n");
870 }
871 }
872
873 rdev->status_page->db_off = 0;
874
875 return 0;
876 err4:
877 c4iw_rqtpool_destroy(rdev);
878 err3:
879 c4iw_pblpool_destroy(rdev);
880 err2:
regards,
dan carpenter
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