| Message ID | 20170914061646.10275-1-shuwang@redhat.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Thu, 2017-09-14 at 14:16 +0800, shuwang@redhat.com wrote: > 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; Thank you for having tracked this down and for having shared this patch. But please keep braces balanced to keep checkpatch happy and please also consider adding a comment similar to the following above the kmemleak_alloc() call: /* Allow kmemleak to scan these pages as they contain pointers to additional allocations. */ > @@ -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); > + } > } Please keep braces balanced in the above code too. Thanks, Bart.
On Thu, Sep 14, 2017 at 02:16:46PM +0800, shuwang@redhat.com wrote: > From: Shu Wang <shuwang@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 <shuwang@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); > + } Apart from Bart's comments on braces and comment before kmemleak_alloc(), I'd call kmemleak_free() before free_pages(), otherwise it may not interact nicely with other tools checking for use after free. With that: Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
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); + } } }