more "unreplaced symbol" warnings

more "unreplaced symbol" warnings

[Randy Dunlap]

I see that there was a short thread in Feb. 2008 about unreplaced symbols.
Here are more warnings from Linux 2.6.39-git18 mainline.
Obviously lots of them are just repeats, but this is what I get from x86_64
allmodconfig.

Any suggestions about how to eliminate them?
Thanks.

include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'val'
include/linux/netfilter_bridge.h:62:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/linux/netfilter_bridge.h:64:14: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:80:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:80:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:83:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:83:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:53:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:53:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:56:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:56:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:80:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:80:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:83:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:83:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:80:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:80:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
net/bridge/br_multicast.c:83:14: warning: unreplaced symbol 'val'
net/bridge/br_multicast.c:83:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/net/inet_ecn.h:126:14: warning: unreplaced symbol 'val'
include/net/inet_ecn.h:126:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/net/inet_ecn.h:131:14: warning: unreplaced symbol 'val'
include/net/inet_ecn.h:131:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/net/inet_ecn.h:126:14: warning: unreplaced symbol 'val'
include/net/inet_ecn.h:126:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/net/inet_ecn.h:131:14: warning: unreplaced symbol 'val'
include/net/inet_ecn.h:131:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/net/inet_ecn.h:126:14: warning: unreplaced symbol 'val'
include/net/inet_ecn.h:126:14: warning: unreplaced symbol 'return'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
include/linux/swab.h:51:9: warning: unreplaced symbol 'return'
include/net/inet_ecn.h:131:14: warning: unreplaced symbol 'val'
include/net/inet_ecn.h:131:14: warning: unreplaced symbol 'return'

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: more "unreplaced symbol" warnings

[Christopher Li]

On Sun, May 29, 2011 at 2:54 PM, Randy Dunlap <rdunlap@xenotime.net> wrote:
> I see that there was a short thread in Feb. 2008 about unreplaced symbols.
> Here are more warnings from Linux 2.6.39-git18 mainline.
> Obviously lots of them are just repeats, but this is what I get from x86_64
> allmodconfig.
>
> Any suggestions about how to eliminate them?
> Thanks.
>
> include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
> include/linux/swab.h:51:16: warning: unreplaced symbol 'val'

I am trying to produce those now. If you know  which C file causing
this warning would be great.

It just hit me that, if there is a script to help reproduce the error
would be great. I just give this error line it emits. The script takes the
C source file and try to eliminate as much lines as possible while
still reproduce the error.

Chris

Re: more "unreplaced symbol" warnings

[Al Viro]

On Tue, May 31, 2011 at 10:39:52AM -0700, Christopher Li wrote:
> On Sun, May 29, 2011 at 2:54 PM, Randy Dunlap <rdunlap@xenotime.net> wrote:
> > I see that there was a short thread in Feb. 2008 about unreplaced symbols.
> > Here are more warnings from Linux 2.6.39-git18 mainline.
> > Obviously lots of them are just repeats, but this is what I get from x86_64
> > allmodconfig.
> >
> > Any suggestions about how to eliminate them?
> > Thanks.
> >
> > include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
> > include/linux/swab.h:51:16: warning: unreplaced symbol 'val'
> 
> I am trying to produce those now. If you know  which C file causing
> this warning would be great.
> 
> It just hit me that, if there is a script to help reproduce the error
> would be great. I just give this error line it emits. The script takes the
> C source file and try to eliminate as much lines as possible while
> still reproduce the error.

Hell knows...  net/bridge/br_netfilter.c will give you just that.  From the
look of other similar instances, I suspect that it's handling of case ...:
somewhere:

static inline unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
{
        switch (skb->protocol) {
        case __cpu_to_be16(ETH_P_8021Q):
                return VLAN_HLEN;
        case __cpu_to_be16(ETH_P_PPP_SES):
                return PPPOE_SES_HLEN;
        default:
                return 0;
        }
}

also warns the same way on both __cpu_to_be16()...

Re: more "unreplaced symbol" warnings

[Al Viro]

Here's what is actually triggering that crap.  Have fun...

#define __u16 unsigned short
static inline __attribute__((__const__)) __u16 f(__u16 val)
{
         return val;
}

static inline void barf(unsigned int len)
{
}

static inline unsigned int bar(__u16 n)
{
        switch (n) {
        case (__builtin_constant_p(1) ? 1 : f(1)):
                return 4;
        default:
                return 0;
        }
}

int foo(__u16 n)
{
        unsigned int x = bar(n);
        barf(bar(n));
        return 0;
}

Re: more "unreplaced symbol" warnings

[Christopher Li]

On Tue, May 31, 2011 at 11:58 AM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> Here's what is actually triggering that crap.  Have fun...

Thanks,

I will take a look.

Chris
--
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: more "unreplaced symbol" warnings

[Christopher Li]

On Tue, May 31, 2011 at 11:58 AM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> Here's what is actually triggering that crap.  Have fun...

Here is a slightly simpler version. However I haven't figure out how this happen
yet. Here is what I know so far:

1) It happens with two nested inline within one function.
    Inline bar() once the bug does not trigger.
2) It seems have some thing to do with dead statement call to inline functions.

I am still scratching my head on that inline/uninline business. My guess is that
there is some where we short circuit the inline copy due to dead
statement but some
other part of the code does not agree.

Chris

#define __u16 unsigned short
int foo(__u16 n);
static inline __u16 f(__u16 val)
{
        return val;
}

static inline unsigned int bar(__u16 n)
{
       switch (n) {
       case (1 ? 1 : f(1)):
               return 4;
       }
}

int foo(__u16 n)
{
	bar(n);
	bar(n);
	return 0;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: more "unreplaced symbol" warnings

[Christopher Li]

On Wed, Jun 1, 2011 at 12:41 AM, Christopher Li <sparse@chrisli.org> wrote:
> #define __u16 unsigned short
> int foo(__u16 n);
> static inline __u16 f(__u16 val)
> {
>        return val;
> }
>
> static inline unsigned int bar(__u16 n)
> {
>       switch (n) {
>       case (1 ? 1 : f(1)):
>               return 4;
>       }
> }
>
> int foo(__u16 n)
> {
>        bar(n);
>        bar(n);
>        return 0;
> }

I just submit a fix for this bug. It took me a few days staring at the
inlining code to figure out what is going on. I am glad this is bug is
resolved now.

The example above is actually the minimal setup to trigger this
bug. The root cause is in one of the member during copying case statement
did not replace to the new statement. e.g. when inlining f(), it actually
change the original copy of function definition in bar().

The warning is triggered during the second time bar() get inlined.

The fix is just one line. Finding it is the hard part.

Chris

@@ -381,6 +381,7 @@ static struct statement *copy_one_statement(struct
statement *stmt)
        case STMT_CASE: {
                stmt = dup_statement(stmt);
                stmt->case_label = copy_symbol(stmt->pos, stmt->case_label);
+               stmt->case_label->stmt = stmt;
                stmt->case_expression = copy_expression(stmt->case_expression);
                stmt->case_to = copy_expression(stmt->case_to);
                stmt->case_statement = copy_one_statement(stmt->case_statement);
--
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html