[PATCH v2] io/mmap.c: fix musl build on mips64

[PATCH v2] io/mmap.c: fix musl build on mips64

[Fabrice Fontaine]

musl undefines MAP_SYNC on some architectures such as mips64 since
version 1.1.20 and
https://github.com/ifduyue/musl/commit/9b57db3f958d9adc3b1c7371b5c6723aaee448b7
resulting in the following build failure:

mmap.c: In function 'mmap_f':
mmap.c:196:33: error: 'MAP_SYNC' undeclared (first use in this function); did you mean 'MS_SYNC'?
  196 |                         flags = MAP_SYNC | MAP_SHARED_VALIDATE;
      |                                 ^~~~~~~~
      |                                 MS_SYNC

This build failure is raised because header includes have been tangled
up:

input.h -> libfrog/projects.h -> xfs.h -> linux.h.

As a result, linux.h will be included before sys/mman.h and the
following piece of code from linux.h will be "overriden" on platforms
without MAP_SYNC:

 #ifndef HAVE_MAP_SYNC
 #define MAP_SYNC 0
 #define MAP_SHARED_VALIDATE 0
 #else
 #include <asm-generic/mman.h>
 #include <asm-generic/mman-common.h>
 #endif /* HAVE_MAP_SYNC */

To fix this build failure, include <sys/mman.h> before the other
includes.

A more long-term solution would be to untangle the headers.

Fixes:
 - http://autobuild.buildroot.org/results/3296194907baf7d3fe039f59bcbf595aa8107a28

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
---
Changes v1 -> v2 (after review of Dave Chinner):
 - Update commit message

 io/mmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io/mmap.c b/io/mmap.c
index 8c048a0a..b8609295 100644
--- a/io/mmap.c
+++ b/io/mmap.c
@@ -4,9 +4,9 @@
  * All Rights Reserved.
  */
 
+#include <sys/mman.h>
 #include "command.h"
 #include "input.h"
-#include <sys/mman.h>
 #include <signal.h>
 #include "init.h"
 #include "io.h"
-- 
2.35.1

Re: [PATCH v2] io/mmap.c: fix musl build on mips64

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

(and another example of why the old rule of thumb to always include
system headers before local ones is a good idea)

Re: [PATCH v2] io/mmap.c: fix musl build on mips64

[Darrick J. Wong]

On Sun, May 08, 2022 at 09:30:29PM +0200, Fabrice Fontaine wrote:
> musl undefines MAP_SYNC on some architectures such as mips64 since
> version 1.1.20 and
> https://github.com/ifduyue/musl/commit/9b57db3f958d9adc3b1c7371b5c6723aaee448b7
> resulting in the following build failure:
> 
> mmap.c: In function 'mmap_f':
> mmap.c:196:33: error: 'MAP_SYNC' undeclared (first use in this function); did you mean 'MS_SYNC'?
>   196 |                         flags = MAP_SYNC | MAP_SHARED_VALIDATE;
>       |                                 ^~~~~~~~
>       |                                 MS_SYNC
> 
> This build failure is raised because header includes have been tangled
> up:
> 
> input.h -> libfrog/projects.h -> xfs.h -> linux.h.
> 
> As a result, linux.h will be included before sys/mman.h and the
> following piece of code from linux.h will be "overriden" on platforms
> without MAP_SYNC:
> 
>  #ifndef HAVE_MAP_SYNC
>  #define MAP_SYNC 0
>  #define MAP_SHARED_VALIDATE 0
>  #else
>  #include <asm-generic/mman.h>
>  #include <asm-generic/mman-common.h>
>  #endif /* HAVE_MAP_SYNC */
> 
> To fix this build failure, include <sys/mman.h> before the other
> includes.
> 
> A more long-term solution would be to untangle the headers.
> 
> Fixes:
>  - http://autobuild.buildroot.org/results/3296194907baf7d3fe039f59bcbf595aa8107a28
> 
> Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>

LGTM,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> Changes v1 -> v2 (after review of Dave Chinner):
>  - Update commit message
> 
>  io/mmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/io/mmap.c b/io/mmap.c
> index 8c048a0a..b8609295 100644
> --- a/io/mmap.c
> +++ b/io/mmap.c
> @@ -4,9 +4,9 @@
>   * All Rights Reserved.
>   */
>  
> +#include <sys/mman.h>
>  #include "command.h"
>  #include "input.h"
> -#include <sys/mman.h>
>  #include <signal.h>
>  #include "init.h"
>  #include "io.h"
> -- 
> 2.35.1
>