SUNRPC: use cmpxchg64() in gss_seq_send64_fetch_and_inc()

arndb · Trond Myklebust · commit 21924765862a · 2018-10-05T09:32:37.000-04:00
The newly introduced gss_seq_send64_fetch_and_inc() fails to build on 32-bit architectures: net/sunrpc/auth_gss/gss_krb5_seal.c:144:14: note: in expansion of macro 'cmpxchg' seq_send = cmpxchg(&ctx->seq_send64, old, old + 1); ^~~~~~~ arch/x86/include/asm/cmpxchg.h:128:3: error: call to '__cmpxchg_wrong_size' declared with attribute error: Bad argument size for cmpxchg __cmpxchg_wrong_size(); \ As the message tells us, cmpxchg() cannot be used on 64-bit arguments, that's what cmpxchg64() does. Fixes: 571ed1f ("SUNRPC: Replace krb5_seq_lock with a lockless scheme") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c
@@ -141,7 +141,7 @@ gss_seq_send64_fetch_and_inc(struct krb5_ctx *ctx)
 
 	do {
 		old = seq_send;
-		seq_send = cmpxchg(&ctx->seq_send64, old, old + 1);
+		seq_send = cmpxchg64(&ctx->seq_send64, old, old + 1);
 	} while (old != seq_send);
 	return seq_send;
 }

Original file line number	Diff line number	Diff line change
`@@ -141,7 +141,7 @@ gss_seq_send64_fetch_and_inc(struct krb5_ctx *ctx)`
`141`	`141`
`142`	`142`	`do {`
`143`	`143`	`old = seq_send;`
`144`		`- seq_send = cmpxchg(&ctx->seq_send64, old, old + 1);`
	`144`	`+ seq_send = cmpxchg64(&ctx->seq_send64, old, old + 1);`
`145`	`145`	`} while (old != seq_send);`
`146`	`146`	`return seq_send;`
`147`	`147`	`}`