sunrpc: avoid warning in gss_key_timeout
The gss_key_timeout() function causes a harmless warning in some
configurations, e.g. ARM imx_v6_v7_defconfig with gcc-5.2, if the
compiler cannot figure out the state of the 'expire' variable across
an rcu_read_unlock():
net/sunrpc/auth_gss/auth_gss.c: In function 'gss_key_timeout':
net/sunrpc/auth_gss/auth_gss.c:1422:211: warning: 'expire' may be used uninitialized in this function [-Wmaybe-uninitialized]
To avoid this warning without adding a bogus initialization, this
rewrites the function so the comparison is done inside of the
critical section. As a side-effect, it also becomes slightly
easier to understand because the implementation now more closely
resembles the comment above it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: c5e6aecd034e7 ("sunrpc: fix RCU handling of gc_ctx field")
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index dace13d..799e65b 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1411,17 +1411,16 @@
{
struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
struct gss_cl_ctx *ctx;
- unsigned long now = jiffies;
- unsigned long expire;
+ unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
+ int ret = 0;
rcu_read_lock();
ctx = rcu_dereference(gss_cred->gc_ctx);
- if (ctx)
- expire = ctx->gc_expiry - (gss_key_expire_timeo * HZ);
+ if (!ctx || time_after(timeout, ctx->gc_expiry))
+ ret = -EACCES;
rcu_read_unlock();
- if (!ctx || time_after(now, expire))
- return -EACCES;
- return 0;
+
+ return ret;
}
static int