[PATCH] net/tls: fix const assignment warning

[PATCH] net/tls: fix const assignment warning

[Arnd Bergmann]

Building with some experimental patches, I came across a warning
in the tls code:

include/linux/compiler.h:215:30: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
  215 |  *(volatile typeof(x) *)&(x) = (val);  \
      |                              ^
net/tls/tls_main.c:650:4: note: in expansion of macro 'smp_store_release'
  650 |    smp_store_release(&saved_tcpv4_prot, prot);

This appears to be a legitimate warning about assigning a const pointer
into the non-const 'saved_tcpv4_prot' global. Annotate both the ipv4 and
ipv6 pointers 'const' to make the code internally consistent.

Fixes: 5bb4c45d466c ("net/tls: Read sk_prot once when building tls proto ops")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 net/tls/tls_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 156efce50dbd..0e989005bdc2 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -56,9 +56,9 @@ enum {
 	TLS_NUM_PROTS,
 };
 
-static struct proto *saved_tcpv6_prot;
+static const struct proto *saved_tcpv6_prot;
 static DEFINE_MUTEX(tcpv6_prot_mutex);
-static struct proto *saved_tcpv4_prot;
+static const struct proto *saved_tcpv4_prot;
 static DEFINE_MUTEX(tcpv4_prot_mutex);
 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
 static struct proto_ops tls_sw_proto_ops;
-- 
2.26.0

Re: [PATCH] net/tls: fix const assignment warning

[Boris Pismenny]

On 08/04/2020 21:54, Arnd Bergmann wrote:
> Building with some experimental patches, I came across a warning
> in the tls code:
> 
> include/linux/compiler.h:215:30: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
>   215 |  *(volatile typeof(x) *)&(x) = (val);  \
>       |                              ^
> net/tls/tls_main.c:650:4: note: in expansion of macro 'smp_store_release'
>   650 |    smp_store_release(&saved_tcpv4_prot, prot);
> 
> This appears to be a legitimate warning about assigning a const pointer
> into the non-const 'saved_tcpv4_prot' global. Annotate both the ipv4 and
> ipv6 pointers 'const' to make the code internally consistent.
> 
> Fixes: 5bb4c45d466c ("net/tls: Read sk_prot once when building tls proto ops")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  net/tls/tls_main.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
> index 156efce50dbd..0e989005bdc2 100644
> --- a/net/tls/tls_main.c
> +++ b/net/tls/tls_main.c
> @@ -56,9 +56,9 @@ enum {
>  	TLS_NUM_PROTS,
>  };
>  
> -static struct proto *saved_tcpv6_prot;
> +static const struct proto *saved_tcpv6_prot;
>  static DEFINE_MUTEX(tcpv6_prot_mutex);
> -static struct proto *saved_tcpv4_prot;
> +static const struct proto *saved_tcpv4_prot;
>  static DEFINE_MUTEX(tcpv4_prot_mutex);
>  static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
>  static struct proto_ops tls_sw_proto_ops;
> 

LGTM

Re: [PATCH] net/tls: fix const assignment warning

[David Miller]

From: Arnd Bergmann <arnd@arndb.de>
Date: Wed,  8 Apr 2020 20:54:43 +0200

> Building with some experimental patches, I came across a warning
> in the tls code:
> 
> include/linux/compiler.h:215:30: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
>   215 |  *(volatile typeof(x) *)&(x) = (val);  \
>       |                              ^
> net/tls/tls_main.c:650:4: note: in expansion of macro 'smp_store_release'
>   650 |    smp_store_release(&saved_tcpv4_prot, prot);
> 
> This appears to be a legitimate warning about assigning a const pointer
> into the non-const 'saved_tcpv4_prot' global. Annotate both the ipv4 and
> ipv6 pointers 'const' to make the code internally consistent.
> 
> Fixes: 5bb4c45d466c ("net/tls: Read sk_prot once when building tls proto ops")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied, thanks.