| Message ID | 6995148.OQIKcAcqHW@wuerfel (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 09, 2015 at 04:13:45PM +0200, Arnd Bergmann wrote: > 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. Looks reasonable, thanks; applying for 4.4--b. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Fixes: c5e6aecd034e7 ("sunrpc: fix RCU handling of gc_ctx field") > > diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c > index dace13d7638e..799e65b944b9 100644 > --- a/net/sunrpc/auth_gss/auth_gss.c > +++ b/net/sunrpc/auth_gss/auth_gss.c > @@ -1411,17 +1411,16 @@ gss_key_timeout(struct rpc_cred *rc) > { > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index dace13d7638e..799e65b944b9 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -1411,17 +1411,16 @@ gss_key_timeout(struct rpc_cred *rc) { 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
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") -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html