-----Original Message----- From: shuw...@redhat.com [mailto:shuw...@redhat.com] Sent: Thursday, September 14, 2017 11:47 AM To: kashyap.de...@broadcom.com; sumit.sax...@broadcom.com; shivasharan.srikanteshw...@broadcom.com; j...@linux.vnet.ibm.com; martin.peter...@oracle.com Cc: megaraidlinux....@broadcom.com; linux-scsi@vger.kernel.org; linux-ker...@vger.kernel.org; catalin.mari...@arm.com; liw...@redhat.com; ch...@redhat.com; Shu Wang Subject: [PATCH] megaraid: kmemleak: Track page allocation for fusion
From: Shu Wang <shuw...@redhat.com> Kmemleak reports about a thousand false positives for fusion-> cmd_list[]. Root casue is the cmd_list objects are allocated from slab allocator, and stored its pointer in object allocated by page allocator. The fix will tell kmemleak to track and scan fusion object. Before patch: kmemleak: 1004 new suspected memory leaks (see /sys/kernel/debug/kmemleak) unreferenced object 0xffff88042584e000 (size 8192): backtrace: kmemleak_alloc+0x4a/0xa0 __kmalloc+0xec/0x220 megasas_alloc_cmdlist_fusion+0x3e/0x140 [megaraid_sas] megasas_alloc_cmds_fusion+0x44/0x450 [megaraid_sas] megasas_init_adapter_fusion+0x21d/0x6e0 [megaraid_sas] megasas_init_fw+0x357/0xd30 [megaraid_sas] megasas_probe_one.part.34+0x5be/0x1040 [megaraid_sas] megasas_probe_one+0x46/0xc0 [megaraid_sas] local_pci_probe+0x45/0xa0 work_for_cpu_fn+0x14/0x20 process_one_work+0x149/0x360 worker_thread+0x1d8/0x3c0 kthread+0x109/0x140 ret_from_fork+0x25/0x30 Signed-off-by: Shu Wang <shuw...@redhat.com> --- drivers/scsi/megaraid/megaraid_sas_fusion.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c index 11bd2e698b84..621299edd8de 100644 --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c @@ -48,6 +48,7 @@ #include <linux/mutex.h> #include <linux/poll.h> #include <linux/vmalloc.h> +#include <linux/kmemleak.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -4512,7 +4513,9 @@ megasas_alloc_fusion_context(struct megasas_instance *instance) dev_err(&instance->pdev->dev, "Failed from %s %d\n", __func__, __LINE__); return -ENOMEM; } - } + } else + kmemleak_alloc(instance->ctrl_context, + sizeof(struct fusion_context), 1, GFP_KERNEL); fusion = instance->ctrl_context; @@ -4548,9 +4551,11 @@ megasas_free_fusion_context(struct megasas_instance *instance) if (is_vmalloc_addr(fusion)) vfree(fusion); - else + else { free_pages((ulong)fusion, instance->ctrl_context_pages); + kmemleak_free(fusion); + } } } Looks good. Thanks for catching this. Acked-by: Sumit Saxena <sumit.sax...@broadcom.com> -- 2.13.5