Re: [PATCH 5.4.y] RDMA/srpt: Support specifying the srpt_service_guid parameter

[Zhu Yanjun <yanjun.zhu@linux.dev>]

On 03.04.25 14:59, Alok Tiwari wrote:
> From: Bart Van Assche <bvanassche@acm.org>
> 
> [ Upstream commit fdfa083549de5d50ebf7f6811f33757781e838c0 ]
> 
> Make loading ib_srpt with this parameter set work. The current behavior is
> that setting that parameter while loading the ib_srpt kernel module
> triggers the following kernel crash:
> 
> BUG: kernel NULL pointer dereference, address: 0000000000000000
> Call Trace:
>   <TASK>
>   parse_one+0x18c/0x1d0
>   parse_args+0xe1/0x230
>   load_module+0x8de/0xa60
>   init_module_from_file+0x8b/0xd0
>   idempotent_init_module+0x181/0x240
>   __x64_sys_finit_module+0x5a/0xb0
>   do_syscall_64+0x5f/0xe0
>   entry_SYSCALL_64_after_hwframe+0x6e/0x76
> 
> Cc: LiHonggang <honggangli@163.com>
> Reported-by: LiHonggang <honggangli@163.com>
> Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> Link: https://lore.kernel.org/r/20240205004207.17031-1-bvanassche@acm.org
> Signed-off-by: Leon Romanovsky <leon@kernel.org>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> [Alok: Backport to 5.4.y since the commit has already been backported to
> 5.15y, 5.10.y, and 4.19.y]
> Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>

Not sure if this "Cc: stable@vger.kernel.org" is needed to notify the 
engineer of stable branch or not.

Zhu Yanjun

> ---
>   drivers/infiniband/ulp/srpt/ib_srpt.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
> index d03a4f2e006f..f5fd8c1058ce 100644
> --- a/drivers/infiniband/ulp/srpt/ib_srpt.c
> +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
> @@ -79,12 +79,16 @@ module_param(srpt_srq_size, int, 0444);
>   MODULE_PARM_DESC(srpt_srq_size,
>   		 "Shared receive queue (SRQ) size.");
>   
> +static int srpt_set_u64_x(const char *buffer, const struct kernel_param *kp)
> +{
> +	return kstrtou64(buffer, 16, (u64 *)kp->arg);
> +}
>   static int srpt_get_u64_x(char *buffer, const struct kernel_param *kp)
>   {
>   	return sprintf(buffer, "0x%016llx", *(u64 *)kp->arg);
>   }
> -module_param_call(srpt_service_guid, NULL, srpt_get_u64_x, &srpt_service_guid,
> -		  0444);
> +module_param_call(srpt_service_guid, srpt_set_u64_x, srpt_get_u64_x,
> +		  &srpt_service_guid, 0444);
>   MODULE_PARM_DESC(srpt_service_guid,
>   		 "Using this value for ioc_guid, id_ext, and cm_listen_id instead of using the node_guid of the first HCA.");
>