On Mon, Nov 14, 2016 at 02:12:16PM -0500, Jeff Layton wrote: > We have been seeing errors like this for a while now in the sparse > Fedora package, when doing kernel builds: > > ./include/linux/err.h:53:25: warning: dereference of noderef expression > ./include/linux/err.h:35:16: warning: dereference of noderef expression > > This spews all over the build because this comes from IS_ERR(), which > is called everywhere. Even odder, it turns out that if we build the > package with -fpic turned off, then it works fine. > > With some brute-force debugging, I think I've finally found the cause. > This array is missing the SForced element. When this is added then the > problem goes away. > > As to why this goes away when -fpic is removed, I can only assume that > we get lucky with the memory layout and have a zeroed out region just > beyond the end of the array. > > Fixes: 3829c4d8b097776e6b3472290a9fae08a705ab7a > Cc: Al Viro <viro@xxxxxxxxxxxxxxxx> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > --- > parse.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/parse.c b/parse.c > index 205e12644a6c..b290ff2636f2 100644 > --- a/parse.c > +++ b/parse.c > @@ -1286,7 +1286,8 @@ static unsigned long storage_modifiers(struct decl_state *ctx) > [SAuto] = MOD_AUTO, > [SExtern] = MOD_EXTERN, > [SStatic] = MOD_STATIC, > - [SRegister] = MOD_REGISTER > + [SRegister] = MOD_REGISTER, > + [SForced] = 0 > }; > return mod[ctx->storage_class] | (ctx->is_inline ? MOD_INLINE : 0) > | (ctx->is_tls ? MOD_TLS : 0); > -- Humm, The array is statically initialized and never modified, your patch shouldn't change anything, and this regardless of the memory layout or compiler options. Luc Van Oostenryck -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
