c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5

c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5

[George Dunlap]

gcc  -O1 -fno-omit-frame-pointer -m32 -march=i686 -g
-fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes
-Wno-unused-value -Wdeclaration-after-statement  -D__XEN_TOOLS__ -MMD
-MF .libxl_dm.o.d -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -fno-optimize-sibling-calls
-mno-tls-direct-seg-refs -Werror -Wno-format-zero-length
-Wmissing-declarations -I. -fPIC
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/libxc
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/include
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/libxc
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/include
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/xenstore
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/include
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/blktap2/control
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/blktap2/include
-I/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl/../../tools/include
 -c -o libxl_dm.o libxl_dm.c
cc1: warnings being treated as errors
libxl_dm.c: In function ‘libxl__create_device_model’:
libxl_dm.c:776: error: format not a string literal and no format arguments
make[3]: *** [libxl_dm.o] Error 1
make[3]: Leaving directory
`/home/gdunlap/hg/open-source/xen-unstable.hg/tools/libxl'
make[2]: *** [subdir-install-libxl] Error 2
make[2]: Leaving directory `/home/gdunlap/hg/open-source/xen-unstable.hg/tools'
make[1]: *** [subdirs-install] Error 2
make[1]: Leaving directory `/home/gdunlap/hg/open-source/xen-unstable.hg/tools'
make: *** [install-tools] Error 2

$ gcc --version
gcc (Ubuntu 4.4.3-4ubuntu5) 4.4.3

(This is Ubuntu 10.10.)

The line in question is:
    libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/bios", path),
                    libxl__domain_bios(gc, info));

Looks like libxl__xs_write() is expecting the 4th argument to be a
format string...?

 -George

Re: c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5

[Ian Campbell]

On Fri, 2011-05-06 at 12:14 +0100, George Dunlap wrote:

> The line in question is:
>     libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/bios", path),
>                     libxl__domain_bios(gc, info));
> 
> Looks like libxl__xs_write() is expecting the 4th argument to be a
> format string...?

Yes, and hence it needs to be a const char * not a char *, so we should
change both libxl__domain_bios and libxl__xs_write I think.

Does this help? It works for me, but my compiler doesn't appear to
complain in this way...

Ian.

8<-------------------------------------------

# HG changeset patch
# User Ian Campbell <ian.campbell@citrix.com>
# Date 1304685175 -3600
# Node ID 4e5487962178e7affd7d7d0341a90dde8c60915e
# Parent  faca1c90188e536eb0f02992c766d06759be376f
libxl: libxl__xs_write format string should be const.

George Dunlap reports that gcc 4.4.3 complains:
	libxl_dm.c: In function libxl__create_device_mode:
	libxl_dm.c:776: error: format not a string literal and no format arguments
And indeed the format argument here is a char * from libxl__domain_bios().

Make the argument to libxl__xs_write a const char * and change
libxl__domain_bios to return a const char too.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>

diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_dm.c
--- a/tools/libxl/libxl_dm.c	Fri May 06 13:14:24 2011 +0100
+++ b/tools/libxl/libxl_dm.c	Fri May 06 13:32:55 2011 +0100
@@ -68,12 +68,12 @@ const char *libxl__domain_device_model(l
     return dm;
 }
 
-static char *libxl__domain_bios(libxl__gc *gc,
+static const char *libxl__domain_bios(libxl__gc *gc,
                                 libxl_device_model_info *info)
 {
     switch (info->device_model_version) {
-    case 1: return libxl__strdup(gc, "rombios");
-    case 2: return libxl__strdup(gc, "seabios");
+    case 1: return "rombios";
+    case 2: return "seabios";
     default:return NULL;
     }
 }
diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_internal.h
--- a/tools/libxl/libxl_internal.h	Fri May 06 13:14:24 2011 +0100
+++ b/tools/libxl/libxl_internal.h	Fri May 06 13:32:55 2011 +0100
@@ -153,7 +153,7 @@ _hidden char **libxl__xs_kvs_of_flexarra
 _hidden int libxl__xs_writev(libxl__gc *gc, xs_transaction_t t,
                     char *dir, char **kvs);
 _hidden int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
-                   char *path, char *fmt, ...) PRINTF_ATTRIBUTE(4, 5);
+                   char *path, const char *fmt, ...) PRINTF_ATTRIBUTE(4, 5);
    /* Each fn returns 0 on success.
     * On error: returns -1, sets errno (no logging) */
 
diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_xshelp.c
--- a/tools/libxl/libxl_xshelp.c	Fri May 06 13:14:24 2011 +0100
+++ b/tools/libxl/libxl_xshelp.c	Fri May 06 13:32:55 2011 +0100
@@ -69,7 +69,7 @@ int libxl__xs_writev(libxl__gc *gc, xs_t
 }
 
 int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
-                   char *path, char *fmt, ...)
+                   char *path, const char *fmt, ...)
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
     char *s;

Re: Re: c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5

[George Dunlap]

[-- Attachment #1: Type: text/plain, Size: 3855 bytes --]

Unfortunately not.

Looks like we could either make libxl__domain_bios() a #define (not
tested), or make the argument "%s" (which seems to work, patch
attached).

Adding a format string of just a string seems kind of dumb, but I
don't think this is a really hot path...

 -George


On Fri, May 6, 2011 at 1:33 PM, Ian Campbell <Ian.Campbell@eu.citrix.com> wrote:
> On Fri, 2011-05-06 at 12:14 +0100, George Dunlap wrote:
>
>> The line in question is:
>>     libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/bios", path),
>>                     libxl__domain_bios(gc, info));
>>
>> Looks like libxl__xs_write() is expecting the 4th argument to be a
>> format string...?
>
> Yes, and hence it needs to be a const char * not a char *, so we should
> change both libxl__domain_bios and libxl__xs_write I think.
>
> Does this help? It works for me, but my compiler doesn't appear to
> complain in this way...
>
> Ian.
>
> 8<-------------------------------------------
>
> # HG changeset patch
> # User Ian Campbell <ian.campbell@citrix.com>
> # Date 1304685175 -3600
> # Node ID 4e5487962178e7affd7d7d0341a90dde8c60915e
> # Parent  faca1c90188e536eb0f02992c766d06759be376f
> libxl: libxl__xs_write format string should be const.
>
> George Dunlap reports that gcc 4.4.3 complains:
>        libxl_dm.c: In function libxl__create_device_mode:
>        libxl_dm.c:776: error: format not a string literal and no format arguments
> And indeed the format argument here is a char * from libxl__domain_bios().
>
> Make the argument to libxl__xs_write a const char * and change
> libxl__domain_bios to return a const char too.
>
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
>
> diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_dm.c
> --- a/tools/libxl/libxl_dm.c    Fri May 06 13:14:24 2011 +0100
> +++ b/tools/libxl/libxl_dm.c    Fri May 06 13:32:55 2011 +0100
> @@ -68,12 +68,12 @@ const char *libxl__domain_device_model(l
>     return dm;
>  }
>
> -static char *libxl__domain_bios(libxl__gc *gc,
> +static const char *libxl__domain_bios(libxl__gc *gc,
>                                 libxl_device_model_info *info)
>  {
>     switch (info->device_model_version) {
> -    case 1: return libxl__strdup(gc, "rombios");
> -    case 2: return libxl__strdup(gc, "seabios");
> +    case 1: return "rombios";
> +    case 2: return "seabios";
>     default:return NULL;
>     }
>  }
> diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_internal.h
> --- a/tools/libxl/libxl_internal.h      Fri May 06 13:14:24 2011 +0100
> +++ b/tools/libxl/libxl_internal.h      Fri May 06 13:32:55 2011 +0100
> @@ -153,7 +153,7 @@ _hidden char **libxl__xs_kvs_of_flexarra
>  _hidden int libxl__xs_writev(libxl__gc *gc, xs_transaction_t t,
>                     char *dir, char **kvs);
>  _hidden int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
> -                   char *path, char *fmt, ...) PRINTF_ATTRIBUTE(4, 5);
> +                   char *path, const char *fmt, ...) PRINTF_ATTRIBUTE(4, 5);
>    /* Each fn returns 0 on success.
>     * On error: returns -1, sets errno (no logging) */
>
> diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_xshelp.c
> --- a/tools/libxl/libxl_xshelp.c        Fri May 06 13:14:24 2011 +0100
> +++ b/tools/libxl/libxl_xshelp.c        Fri May 06 13:32:55 2011 +0100
> @@ -69,7 +69,7 @@ int libxl__xs_writev(libxl__gc *gc, xs_t
>  }
>
>  int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
> -                   char *path, char *fmt, ...)
> +                   char *path, const char *fmt, ...)
>  {
>     libxl_ctx *ctx = libxl__gc_owner(gc);
>     char *s;
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>

[-- Attachment #2: build-fix.diff --]
[-- Type: text/plain, Size: 621 bytes --]

diff -r 4b0692880dfa -r 420b40cb3997 tools/libxl/libxl_dm.c
--- a/tools/libxl/libxl_dm.c	Thu May 05 17:40:34 2011 +0100
+++ b/tools/libxl/libxl_dm.c	Fri May 06 13:55:00 2011 +0100
@@ -773,7 +773,7 @@
     path = libxl__sprintf(gc, "/local/domain/%d/hvmloader", info->domid);
     xs_mkdir(ctx->xsh, XBT_NULL, path);
     libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/bios", path),
-                    libxl__domain_bios(gc, info));
+                    "%s", libxl__domain_bios(gc, info));
 
     path = libxl__sprintf(gc, "/local/domain/0/device-model/%d", info->domid);
     xs_mkdir(ctx->xsh, XBT_NULL, path);

[-- Attachment #3: Type: text/plain, Size: 138 bytes --]

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Re: Re: c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5

[Ian Campbell]

On Fri, 2011-05-06 at 13:50 +0100, George Dunlap wrote:
> Unfortunately not.
> 
> Looks like we could either make libxl__domain_bios() a #define (not
> tested), or make the argument "%s" (which seems to work, patch
> attached).
> 
> Adding a format string of just a string seems kind of dumb, but I
> don't think this is a really hot path...

It's actually sensible to use "%s" when the string might be untrusted
but in this case it's really just a string literal, I guess the
laundering through a function is enough to hide that from gcc. Using %s
is the best fix, I think.

Ian. 

> 
>  -George
> 
> 
> On Fri, May 6, 2011 at 1:33 PM, Ian Campbell <Ian.Campbell@eu.citrix.com> wrote:
> > On Fri, 2011-05-06 at 12:14 +0100, George Dunlap wrote:
> >
> >> The line in question is:
> >>     libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/bios", path),
> >>                     libxl__domain_bios(gc, info));
> >>
> >> Looks like libxl__xs_write() is expecting the 4th argument to be a
> >> format string...?
> >
> > Yes, and hence it needs to be a const char * not a char *, so we should
> > change both libxl__domain_bios and libxl__xs_write I think.
> >
> > Does this help? It works for me, but my compiler doesn't appear to
> > complain in this way...
> >
> > Ian.
> >
> > 8<-------------------------------------------
> >
> > # HG changeset patch
> > # User Ian Campbell <ian.campbell@citrix.com>
> > # Date 1304685175 -3600
> > # Node ID 4e5487962178e7affd7d7d0341a90dde8c60915e
> > # Parent  faca1c90188e536eb0f02992c766d06759be376f
> > libxl: libxl__xs_write format string should be const.
> >
> > George Dunlap reports that gcc 4.4.3 complains:
> >        libxl_dm.c: In function libxl__create_device_mode:
> >        libxl_dm.c:776: error: format not a string literal and no format arguments
> > And indeed the format argument here is a char * from libxl__domain_bios().
> >
> > Make the argument to libxl__xs_write a const char * and change
> > libxl__domain_bios to return a const char too.
> >
> > Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> >
> > diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_dm.c
> > --- a/tools/libxl/libxl_dm.c    Fri May 06 13:14:24 2011 +0100
> > +++ b/tools/libxl/libxl_dm.c    Fri May 06 13:32:55 2011 +0100
> > @@ -68,12 +68,12 @@ const char *libxl__domain_device_model(l
> >     return dm;
> >  }
> >
> > -static char *libxl__domain_bios(libxl__gc *gc,
> > +static const char *libxl__domain_bios(libxl__gc *gc,
> >                                 libxl_device_model_info *info)
> >  {
> >     switch (info->device_model_version) {
> > -    case 1: return libxl__strdup(gc, "rombios");
> > -    case 2: return libxl__strdup(gc, "seabios");
> > +    case 1: return "rombios";
> > +    case 2: return "seabios";
> >     default:return NULL;
> >     }
> >  }
> > diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_internal.h
> > --- a/tools/libxl/libxl_internal.h      Fri May 06 13:14:24 2011 +0100
> > +++ b/tools/libxl/libxl_internal.h      Fri May 06 13:32:55 2011 +0100
> > @@ -153,7 +153,7 @@ _hidden char **libxl__xs_kvs_of_flexarra
> >  _hidden int libxl__xs_writev(libxl__gc *gc, xs_transaction_t t,
> >                     char *dir, char **kvs);
> >  _hidden int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
> > -                   char *path, char *fmt, ...) PRINTF_ATTRIBUTE(4, 5);
> > +                   char *path, const char *fmt, ...) PRINTF_ATTRIBUTE(4, 5);
> >    /* Each fn returns 0 on success.
> >     * On error: returns -1, sets errno (no logging) */
> >
> > diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_xshelp.c
> > --- a/tools/libxl/libxl_xshelp.c        Fri May 06 13:14:24 2011 +0100
> > +++ b/tools/libxl/libxl_xshelp.c        Fri May 06 13:32:55 2011 +0100
> > @@ -69,7 +69,7 @@ int libxl__xs_writev(libxl__gc *gc, xs_t
> >  }
> >
> >  int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
> > -                   char *path, char *fmt, ...)
> > +                   char *path, const char *fmt, ...)
> >  {
> >     libxl_ctx *ctx = libxl__gc_owner(gc);
> >     char *s;
> >
> >
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xensource.com
> > http://lists.xensource.com/xen-devel
> >

Re: Re: c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5

[Shriram Rajagopalan]

[-- Attachment #1.1: Type: text/plain, Size: 4802 bytes --]

On Fri, May 6, 2011 at 7:58 AM, Ian Campbell <Ian.Campbell@eu.citrix.com>wrote:

> On Fri, 2011-05-06 at 13:50 +0100, George Dunlap wrote:
> > Unfortunately not.
> >
> > Looks like we could either make libxl__domain_bios() a #define (not
> > tested), or make the argument "%s" (which seems to work, patch
> > attached).
> >
> > Adding a format string of just a string seems kind of dumb, but I
> > don't think this is a really hot path...
>
> It's actually sensible to use "%s" when the string might be untrusted
> but in this case it's really just a string literal, I guess the
> laundering through a function is enough to hide that from gcc. Using %s
> is the best fix, I think.
>
> Is this going to go in as a patch? I havent seen any so far (or probably
missed it).

shriram

>  Ian.
>
> >
> >  -George
> >
> >
> > On Fri, May 6, 2011 at 1:33 PM, Ian Campbell <Ian.Campbell@eu.citrix.com>
> wrote:
> > > On Fri, 2011-05-06 at 12:14 +0100, George Dunlap wrote:
> > >
> > >> The line in question is:
> > >>     libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/bios", path),
> > >>                     libxl__domain_bios(gc, info));
> > >>
> > >> Looks like libxl__xs_write() is expecting the 4th argument to be a
> > >> format string...?
> > >
> > > Yes, and hence it needs to be a const char * not a char *, so we should
> > > change both libxl__domain_bios and libxl__xs_write I think.
> > >
> > > Does this help? It works for me, but my compiler doesn't appear to
> > > complain in this way...
> > >
> > > Ian.
> > >
> > > 8<-------------------------------------------
> > >
> > > # HG changeset patch
> > > # User Ian Campbell <ian.campbell@citrix.com>
> > > # Date 1304685175 -3600
> > > # Node ID 4e5487962178e7affd7d7d0341a90dde8c60915e
> > > # Parent  faca1c90188e536eb0f02992c766d06759be376f
> > > libxl: libxl__xs_write format string should be const.
> > >
> > > George Dunlap reports that gcc 4.4.3 complains:
> > >        libxl_dm.c: In function libxl__create_device_mode:
> > >        libxl_dm.c:776: error: format not a string literal and no format
> arguments
> > > And indeed the format argument here is a char * from
> libxl__domain_bios().
> > >
> > > Make the argument to libxl__xs_write a const char * and change
> > > libxl__domain_bios to return a const char too.
> > >
> > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> > >
> > > diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_dm.c
> > > --- a/tools/libxl/libxl_dm.c    Fri May 06 13:14:24 2011 +0100
> > > +++ b/tools/libxl/libxl_dm.c    Fri May 06 13:32:55 2011 +0100
> > > @@ -68,12 +68,12 @@ const char *libxl__domain_device_model(l
> > >     return dm;
> > >  }
> > >
> > > -static char *libxl__domain_bios(libxl__gc *gc,
> > > +static const char *libxl__domain_bios(libxl__gc *gc,
> > >                                 libxl_device_model_info *info)
> > >  {
> > >     switch (info->device_model_version) {
> > > -    case 1: return libxl__strdup(gc, "rombios");
> > > -    case 2: return libxl__strdup(gc, "seabios");
> > > +    case 1: return "rombios";
> > > +    case 2: return "seabios";
> > >     default:return NULL;
> > >     }
> > >  }
> > > diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_internal.h
> > > --- a/tools/libxl/libxl_internal.h      Fri May 06 13:14:24 2011 +0100
> > > +++ b/tools/libxl/libxl_internal.h      Fri May 06 13:32:55 2011 +0100
> > > @@ -153,7 +153,7 @@ _hidden char **libxl__xs_kvs_of_flexarra
> > >  _hidden int libxl__xs_writev(libxl__gc *gc, xs_transaction_t t,
> > >                     char *dir, char **kvs);
> > >  _hidden int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
> > > -                   char *path, char *fmt, ...) PRINTF_ATTRIBUTE(4, 5);
> > > +                   char *path, const char *fmt, ...)
> PRINTF_ATTRIBUTE(4, 5);
> > >    /* Each fn returns 0 on success.
> > >     * On error: returns -1, sets errno (no logging) */
> > >
> > > diff -r faca1c90188e -r 4e5487962178 tools/libxl/libxl_xshelp.c
> > > --- a/tools/libxl/libxl_xshelp.c        Fri May 06 13:14:24 2011 +0100
> > > +++ b/tools/libxl/libxl_xshelp.c        Fri May 06 13:32:55 2011 +0100
> > > @@ -69,7 +69,7 @@ int libxl__xs_writev(libxl__gc *gc, xs_t
> > >  }
> > >
> > >  int libxl__xs_write(libxl__gc *gc, xs_transaction_t t,
> > > -                   char *path, char *fmt, ...)
> > > +                   char *path, const char *fmt, ...)
> > >  {
> > >     libxl_ctx *ctx = libxl__gc_owner(gc);
> > >     char *s;
> > >
> > >
> > >
> > > _______________________________________________
> > > Xen-devel mailing list
> > > Xen-devel@lists.xensource.com
> > > http://lists.xensource.com/xen-devel
> > >
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>

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Re: c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5 [and 1 more messages]

[Ian Jackson]

Ian Campbell writes ("[Xen-devel] Re: c/s 23253:a3db6b91f32d causes build failure with gcc 4.4.3-4ubuntu5"):
> libxl: libxl__xs_write format string should be const.

I have applied this, thanks.

Ian.