Hi, Neil, Apparently I was duplicating work. However, using char servername[UNIX_PATH_MAX]; has some advantages when compared to hard-coded integer? Correct me if I'm wrong. Best regards, Mirsad Todorovac On 9/23/24 23:24, NeilBrown wrote: > On Tue, 24 Sep 2024, Mirsad Todorovac wrote: >> GCC 13.2.0 reported with W=1 build option the following warning: > > See > https://lore.kernel.org/all/20240814093853.48657-1-kunwu.chan@xxxxxxxxx/ > > I don't think anyone really cares about this one. > > NeilBrown > > >> >> net/sunrpc/clnt.c: In function ‘rpc_create’: >> net/sunrpc/clnt.c:582:75: warning: ‘%s’ directive output may be truncated writing up to 107 bytes into \ >> a region of size 48 [-Wformat-truncation=] >> 582 | snprintf(servername, sizeof(servername), "%s", >> | ^~ >> net/sunrpc/clnt.c:582:33: note: ‘snprintf’ output between 1 and 108 bytes into a destination of size 48 >> 582 | snprintf(servername, sizeof(servername), "%s", >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> 583 | sun->sun_path); >> | ~~~~~~~~~~~~~~ >> >> 548 }; >> → 549 char servername[48]; >> 550 struct rpc_clnt *clnt; >> 551 int i; >> 552 >> 553 if (args->bc_xprt) { >> 554 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC)); >> 555 xprt = args->bc_xprt->xpt_bc_xprt; >> 556 if (xprt) { >> 557 xprt_get(xprt); >> 558 return rpc_create_xprt(args, xprt); >> 559 } >> 560 } >> 561 >> 562 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS) >> 563 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS; >> 564 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT) >> 565 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT; >> 566 /* >> 567 * If the caller chooses not to specify a hostname, whip >> 568 * up a string representation of the passed-in address. >> 569 */ >> 570 if (xprtargs.servername == NULL) { >> 571 struct sockaddr_un *sun = >> 572 (struct sockaddr_un *)args->address; >> 573 struct sockaddr_in *sin = >> 574 (struct sockaddr_in *)args->address; >> 575 struct sockaddr_in6 *sin6 = >> 576 (struct sockaddr_in6 *)args->address; >> 577 >> 578 servername[0] = '\0'; >> 579 switch (args->address->sa_family) { >> → 580 case AF_LOCAL: >> → 581 if (sun->sun_path[0]) >> → 582 snprintf(servername, sizeof(servername), "%s", >> → 583 sun->sun_path); >> → 584 else >> → 585 snprintf(servername, sizeof(servername), "@%s", >> → 586 sun->sun_path+1); >> → 587 break; >> 588 case AF_INET: >> 589 snprintf(servername, sizeof(servername), "%pI4", >> 590 &sin->sin_addr.s_addr); >> 591 break; >> 592 case AF_INET6: >> 593 snprintf(servername, sizeof(servername), "%pI6", >> 594 &sin6->sin6_addr); >> 595 break; >> 596 default: >> 597 /* caller wants default server name, but >> 598 * address family isn't recognized. */ >> 599 return ERR_PTR(-EINVAL); >> 600 } >> 601 xprtargs.servername = servername; >> 602 } >> 603 >> 604 xprt = xprt_create_transport(&xprtargs); >> 605 if (IS_ERR(xprt)) >> 606 return (struct rpc_clnt *)xprt; >> >> After the address family AF_LOCAL was added in the commit 176e21ee2ec89, the old hard-coded >> size for servername of char servername[48] no longer fits. The maximum AF_UNIX address size >> has now grown to UNIX_PATH_MAX defined as 108 in "include/uapi/linux/un.h" . >> >> The lines 580-587 were added later, addressing the leading zero byte '\0', but did not fix >> the hard-coded servername limit. >> >> The AF_UNIX address was truncated to 47 bytes + terminating null byte. This patch will fix the >> servername in AF_UNIX family to the maximum permitted by the system: >> >> 548 }; >> → 549 char servername[UNIX_PATH_MAX]; >> 550 struct rpc_clnt *clnt; >> >> Fixes: 4388ce05fa38b ("SUNRPC: support abstract unix socket addresses") >> Fixes: 510deb0d7035d ("SUNRPC: rpc_create() default hostname should support AF_INET6 addresses") >> Fixes: 176e21ee2ec89 ("SUNRPC: Support for RPC over AF_LOCAL transports") >> Cc: Neil Brown <neilb@xxxxxxx> >> Cc: Chuck Lever <chuck.lever@xxxxxxxxxx> >> Cc: Trond Myklebust <trondmy@xxxxxxxxxx> >> Cc: Anna Schumaker <anna@xxxxxxxxxx> >> Cc: Jeff Layton <jlayton@xxxxxxxxxx> >> Cc: Olga Kornievskaia <okorniev@xxxxxxxxxx> >> Cc: Dai Ngo <Dai.Ngo@xxxxxxxxxx> >> Cc: Tom Talpey <tom@xxxxxxxxxx> >> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> >> Cc: Eric Dumazet <edumazet@xxxxxxxxxx> >> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> >> Cc: Paolo Abeni <pabeni@xxxxxxxxxx> >> Cc: linux-nfs@xxxxxxxxxxxxxxx >> Cc: netdev@xxxxxxxxxxxxxxx >> Cc: linux-kernel@xxxxxxxxxxxxxxx >> Signed-off-by: Mirsad Todorovac <mtodorovac69@xxxxxxxxx> >> --- >> v1: >> initial version. >> >> net/sunrpc/clnt.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c >> index 09f29a95f2bc..67099719893e 100644 >> --- a/net/sunrpc/clnt.c >> +++ b/net/sunrpc/clnt.c >> @@ -546,7 +546,7 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args) >> .connect_timeout = args->connect_timeout, >> .reconnect_timeout = args->reconnect_timeout, >> }; >> - char servername[48]; >> + char servername[UNIX_PATH_MAX]; >> struct rpc_clnt *clnt; >> int i; >> >> -- >> 2.43.0 >> >> >
