Re: [PATCH net] net/smc: fix incorrect SMC-D link group matching logic

Alexandra Winter
2024-01-25T15:26:30Z

On 25.01.24 13:39, Wen Gu wrote:
> The logic to determine if SMC-D link group matches is incorrect. The
> correct logic should be that it only returns true when the GID is the
> same, and the SMC-D device is the same and the extended GID is the same
> (in the case of virtual ISM).
>
> It can be fixed by adding brackets around the conditional (or ternary)
> operator expression. But for better readability and maintainability, it
> has been changed to an if-else statement.
>
> Reported-by: Matthew Rosato <mjrosato@linux.ibm.com>
> Closes: https://lore.kernel.org/r/13579588-eb9d-4626-a063-c0b77ed80f11@linux.ibm.com
> Fixes: b40584d14570 ("net/smc: compatible with 128-bits extended GID of virtual ISM device")
> Link: https://lore.kernel.org/r/13579588-eb9d-4626-a063-c0b77ed80f11@linux.ibm.com
> Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
> ---
> net/smc/smc_core.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
> index 95cc95458e2d..e4c858411207 100644
> --- a/net/smc/smc_core.c
> +++ b/net/smc/smc_core.c
> @@ -1877,9 +1877,15 @@ static bool smcd_lgr_match(struct smc_link_group *lgr,
> struct smcd_dev *smcismdev,
> struct smcd_gid *peer_gid)
> {
> - return lgr->peer_gid.gid == peer_gid->gid && lgr->smcd == smcismdev &&
> - smc_ism_is_virtual(smcismdev) ?
> - (lgr->peer_gid.gid_ext == peer_gid->gid_ext) : 1;
> + if (lgr->peer_gid.gid != peer_gid->gid ||
> + lgr->smcd != smcismdev)
> + return false;
> +
> + if (smc_ism_is_virtual(smcismdev) &&
> + lgr->peer_gid.gid_ext != peer_gid->gid_ext)
> + return false;
> +
> + return true;
> }
>
> /* create a new SMC connection (and a new link group if necessary) */

Thank you Wen Gu

Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>