| Message ID | 1402940957-6381-1-git-send-email-xerofoify@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 6/16/2014 12:49 PM, Nicholas Krause wrote: > Signed-off-by: Nicholas Krause <xerofoify@gmail.com> > --- > drivers/infiniband/hw/cxgb4/cm.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c > index 5e153f6..867e664 100644 > --- a/drivers/infiniband/hw/cxgb4/cm.c > +++ b/drivers/infiniband/hw/cxgb4/cm.c > @@ -455,8 +455,11 @@ static void send_flowc(struct c4iw_ep *ep, struct sk_buff *skb) > unsigned int flowclen = 80; > struct fw_flowc_wr *flowc; > int i; > - Please add back the above blank line. > skb = get_skb(skb, flowclen, GFP_KERNEL); > + if (!skb) { > + kfree_skb(skb); Let's do a pr_warn() here; pr_warn(MOD "%s failed to allocate skb.\n", __func__); > + return; > + } > flowc = (struct fw_flowc_wr *)__skb_put(skb, flowclen); > > flowc->op_to_nparams = cpu_to_be32(FW_WR_OP(FW_FLOWC_WR) | -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 16 Jun 2014, Steve Wise wrote: > On 6/16/2014 12:49 PM, Nicholas Krause wrote: > > Signed-off-by: Nicholas Krause <xerofoify@gmail.com> > > --- > > drivers/infiniband/hw/cxgb4/cm.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/infiniband/hw/cxgb4/cm.c > > b/drivers/infiniband/hw/cxgb4/cm.c > > index 5e153f6..867e664 100644 > > --- a/drivers/infiniband/hw/cxgb4/cm.c > > +++ b/drivers/infiniband/hw/cxgb4/cm.c > > @@ -455,8 +455,11 @@ static void send_flowc(struct c4iw_ep *ep, struct > > sk_buff *skb) > > unsigned int flowclen = 80; > > struct fw_flowc_wr *flowc; > > int i; > > - > > Please add back the above blank line. > > > skb = get_skb(skb, flowclen, GFP_KERNEL); > > + if (!skb) { > > + kfree_skb(skb); > > Let's do a pr_warn() here; > > pr_warn(MOD "%s failed to allocate skb.\n", __func__); > No need, if the allocation from skbuff_head_cache fails in the slab allocator, the page allocator will loop forever for orders less than PAGE_ALLOC_COSTLY_ORDER or spew a page allocation failure warning with a stack trace that indicated the high order page allocation failed in this path. > > > + return; > > + } > > flowc = (struct fw_flowc_wr *)__skb_put(skb, flowclen); > > flowc->op_to_nparams = cpu_to_be32(FW_WR_OP(FW_FLOWC_WR) | -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 16 Jun 2014, Nick Krause wrote: > If that is the case ,David I would mark bug id 44631 as closed due to no > need for my if statement. You don't want to depend on the implementation of the page allocator to never return NULL for orders < PAGE_ALLOC_COSTLY_ORDER with GFP_KERNEL, it could possibly change in the future and we wouldn't catch your dependency in send_flowc(). The size object size of the skbuff_head_cache slab cache could also change. You don't need the suggested pr_warn(), though, since the page allocation failure warning would also be noisy enough. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 16 Jun 2014, Nick Krause wrote: > That's true David, > I will resend this parch without the use of the pr_warn. There's no patch to resend if you don't use pr_warn(). kfree_skb(skb) is unnecessary if !skb, look at the first thing it checks: void kfree_skb(struct sk_buff *skb) { if (unlikely(!skb)) return; ... } Thus, I don't see the memory leak you're referring to. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message----- > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-owner@vger.kernel.org] On > Behalf Of David Rientjes > Sent: Monday, June 16, 2014 7:37 PM > To: Nick Krause > Cc: Steve Wise; swise@chelsio.com; roland@kernel.org; sean.hefty@intel.com; > hal.rosenstock@gmail.com; linux-rdma@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] infiniband: Fixes memory leak in send_flowc > > On Mon, 16 Jun 2014, Nick Krause wrote: > > > That's true David, > > I will resend this parch without the use of the pr_warn. > > There's no patch to resend if you don't use pr_warn(). kfree_skb(skb) is > unnecessary if !skb, look at the first thing it checks: > > void kfree_skb(struct sk_buff *skb) > { > if (unlikely(!skb)) > return; > ... > } > > Thus, I don't see the memory leak you're referring to. send_flowc() still needs to handle a NULL return from get_skb(). That is what the bug report is addressing... Steve. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c index 5e153f6..867e664 100644 --- a/drivers/infiniband/hw/cxgb4/cm.c +++ b/drivers/infiniband/hw/cxgb4/cm.c @@ -455,8 +455,11 @@ static void send_flowc(struct c4iw_ep *ep, struct sk_buff *skb) unsigned int flowclen = 80; struct fw_flowc_wr *flowc; int i; - skb = get_skb(skb, flowclen, GFP_KERNEL); + if (!skb) { + kfree_skb(skb); + return; + } flowc = (struct fw_flowc_wr *)__skb_put(skb, flowclen); flowc->op_to_nparams = cpu_to_be32(FW_WR_OP(FW_FLOWC_WR) |
Signed-off-by: Nicholas Krause <xerofoify@gmail.com> --- drivers/infiniband/hw/cxgb4/cm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)