Messages in this thread | | | From | liuyacan@corp ... | Subject | Re: [PATCH net] net/smc: fix listen processing for SMC-Rv2 | Date | Mon, 23 May 2022 20:12:45 +0800 |
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> > From: liuyacan <liuyacan@corp.netease.com> > > > > In the process of checking whether RDMAv2 is available, the current > > implementation first sets ini->smcrv2.ib_dev_v2, and then allocates > > smc buf desc, but the latter may fail. Unfortunately, the caller > > will only check the former. In this case, a NULL pointer reference > > will occur in smc_clc_send_confirm_accept() when accessing > > conn->rmb_desc. > > > > This patch does two things: > > 1. Use the return code to determine whether V2 is available. > > 2. If the return code is NODEV, continue to check whether V1 is > > available. > > > > Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2") > > Signed-off-by: liuyacan <liuyacan@corp.netease.com> > > --- > > I am not happy with this patch. You are right that this is a problem, > but the fix should be much simpler: set ini->smcrv2.ib_dev_v2 = NULL in > smc_find_rdma_v2_device_serv() after the not_found label, just like it is > done in a similar way for the ISM device in smc_find_ism_v1_device_serv(). > > Your patch changes many more things, and beside that you eliminated the calls > to smc_find_ism_store_rc() completely, which is not correct. > > Since your patch was already applied (btw. 3:20 hours after you submitted it), > please revert it and resend. Thank you.
I also have considered this way, one question is that do we need to do more roll back work before V1 check?
Specifically, In smc_find_rdma_v2_device_serv(), there are the following steps:
1. smc_listen_rdma_init() 1.1 smc_conn_create() 1.2 smc_buf_create() --> may fail 2. smc_listen_rdma_reg() --> may fail
When later steps fail, Do we need to roll back previous steps? Thank you.
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