From mboxrd@z Thu Jan 1 00:00:00 1970 From: shuwang@redhat.com Subject: [PATCH V2] megaraid: kmemleak: Track page allocation for fusion Date: Fri, 15 Sep 2017 13:21:52 +0800 Message-ID: <20170915052152.5032-1-shuwang@redhat.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: kashyap.desai@broadcom.com, sumit.saxena@broadcom.com, shivasharan.srikanteshwara@broadcom.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: megaraidlinux.pdl@broadcom.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, chuhu@redhat.com, yizhan@redhat.com, catalin.marinas@arm.com, Shu Wang List-Id: linux-scsi@vger.kernel.org From: Shu Wang 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. V2: Add comment, balance braces, move kmemleak_free before free_pages. checkpatch passed. 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 --- drivers/scsi/megaraid/megaraid_sas_fusion.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c index 11bd2e698b84..161b8e5518c0 100644 --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c @@ -48,6 +48,7 @@ #include #include #include +#include #include #include @@ -4512,6 +4513,13 @@ megasas_alloc_fusion_context(struct megasas_instance *instance) dev_err(&instance->pdev->dev, "Failed from %s %d\n", __func__, __LINE__); return -ENOMEM; } + } else { + /* + * Allow kmemleak to scan these pages as they contain pointers + * to additional allocations. fusion->cmd_list[]. + */ + kmemleak_alloc(instance->ctrl_context, + sizeof(struct fusion_context), 1, GFP_KERNEL); } fusion = instance->ctrl_context; @@ -4548,9 +4556,11 @@ megasas_free_fusion_context(struct megasas_instance *instance) if (is_vmalloc_addr(fusion)) vfree(fusion); - else + else { + kmemleak_free(fusion); free_pages((ulong)fusion, instance->ctrl_context_pages); + } } } -- 2.13.5