Re: [PATCH v1 3/5] treewide: use get_random_u32() when possible

Joe Perches
2022-10-13T05:59:46Z

On Wed, 2022-10-05 at 23:48 +0200, Jason A. Donenfeld wrote:
> The prandom_u32() function has been a deprecated inline wrapper around
> get_random_u32() for several releases now, and compiles down to the
> exact same code. Replace the deprecated wrapper with a direct call to
> the real function.
[]
> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
[]
> @@ -734,7 +734,7 @@ static int send_connect(struct c4iw_ep *ep)
> &ep->com.remote_addr;
> int ret;
> enum chip_type adapter_type = ep->com.dev->rdev.lldi.adapter_type;
> - u32 isn = (prandom_u32() & ~7UL) - 1;
> + u32 isn = (get_random_u32() & ~7UL) - 1;

trivia:

There are somewhat odd size mismatches here.

I had to think a tiny bit if random() returned a value from 0 to 7
and was promoted to a 64 bit value then truncated to 32 bit.

Perhaps these would be clearer as ~7U and not ~7UL

> struct net_device *netdev;
> u64 params;
>
> @@ -2469,7 +2469,7 @@ static int accept_cr(struct c4iw_ep *ep, struct sk_buff *skb,
> }
>
> if (!is_t4(adapter_type)) {
> - u32 isn = (prandom_u32() & ~7UL) - 1;
> + u32 isn = (get_random_u32() & ~7UL) - 1;

etc...

drivers/infiniband/hw/cxgb4/cm.c: u32 isn = (prandom_u32() & ~7UL) - 1;
drivers/infiniband/hw/cxgb4/cm.c: u32 isn = (prandom_u32() & ~7UL) - 1;
drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c: rpl5->iss = cpu_to_be32((prandom_u32() & ~7UL) - 1);
drivers/scsi/cxgbi/cxgb4i/cxgb4i.c: u32 isn = (prandom_u32() & ~7UL) - 1;
drivers/scsi/cxgbi/cxgb4i/cxgb4i.c: u32 isn = (prandom_u32() & ~7UL) - 1;
drivers/target/iscsi/cxgbit/cxgbit_cm.c: rpl5->iss = cpu_to_be32((prandom_u32() & ~7UL) - 1);