Re: [PATCH] net: make getname() functions return length rather than use int* parameter

[Denys Vlasenko]

On 02/12/2018 06:47 PM, David Miller wrote:
From: Denys Vlasenko <dvlas...@redhat.com>
Date: Mon, 12 Feb 2018 15:15:18 +0100
Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.

"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.

None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.

This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.

Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.

rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.

Userspace API is not changed.

     text    data     bss      dec     hex filename
30108430 2633624  873672 33615726 200ef6e vmlinux.before.o
30108109 2633612  873672 33615393 200ee21 vmlinux.o

Signed-off-by: Denys Vlasenko <dvlas...@redhat.com>

Please do an allmodconfig build, there are still some conversions you
missed:

security/tomoyo/network.c: In function ‘tomoyo_socket_listen_permission’:
security/tomoyo/network.c:658:19: warning: passing argument 3 of 
‘sock->ops->getname’ makes integer from pointer without a cast 
[-Wint-conversion]
             &addr, &addr_len, 0);
                    ^
security/tomoyo/network.c:658:19: note: expected ‘int’ but argument is of type 
‘int *’
security/tomoyo/network.c:657:21: error: too many arguments to function 
‘sock->ops->getname’
    const int error = sock->ops->getname(sock, (struct sockaddr *)
                      ^~~~
fs/dlm/lowcomms.c: In function ‘lowcomms_error_report’:
fs/dlm/lowcomms.c:495:6: error: too many arguments to function 
‘kernel_getpeername’
       kernel_getpeername(con->sock, (struct sockaddr *)&saddr, &buflen)) {
       ^~~~~~~~~~~~~~~~~~
fs/dlm/lowcomms.c: In function ‘tcp_accept_from_sock’:
fs/dlm/lowcomms.c:761:7: warning: passing argument 3 of ‘newsock->ops->getname’ 
makes integer from pointer without a cast [-Wint-conversion]
        &len, 2)) {
        ^
fs/dlm/lowcomms.c:761:7: note: expected ‘int’ but argument is of type ‘int *’
fs/dlm/lowcomms.c:760:6: error: too many arguments to function 
‘newsock->ops->getname’
   if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
       ^~~~~~~

Sorry. Will send updated patch.