All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] uapi libc compat: allow non-glibc to opt out of uapi definitions
@ 2016-11-11  1:40 Felix Janda
  2016-11-11  4:54 ` [musl] " Rich Felker
  0 siblings, 1 reply; 2+ messages in thread
From: Felix Janda @ 2016-11-11  1:40 UTC (permalink / raw)
  To: linux-devel-u79uwXL29TY76Z2rM5mHXA
  Cc: David S. Miller, linux-api-u79uwXL29TY76Z2rM5mHXA,
	musl-ZwoEplunGu1jrUoiu81ncdBPR1lH4CV8

Currently, libc-compat.h detects inclusion of specific glibc headers,
and defines corresponding _UAPI_DEF_* macros, which in turn are used in
uapi headers to prevent definition of conflicting structures/constants.
There is no such detection for other c libraries, for them the
_UAPI_DEF_* macros are always defined as 1, and so none of the possibly
conflicting definitions are suppressed.

This patch enables non-glibc c libraries to request the suppression of
any specific interface by defining the corresponding _UAPI_DEF_* macro
as 0.

This patch together with the recent musl libc commit

http://git.musl-libc.org/cgit/musl/commit/?id=04983f2272382af92eb8f8838964ff944fbb8258

fixes the following compiler errors when <linux/in6.h> is included
after musl <netinet/in.h>:

./linux/in6.h:32:8: error: redefinition of 'struct in6_addr'
./linux/in6.h:49:8: error: redefinition of 'struct sockaddr_in6'
./linux/in6.h:59:8: error: redefinition of 'struct ipv6_mreq'

Signed-off-by: Felix Janda <felix.janda-1KBjaw7Xf1+zQB+pC5nmwQ@public.gmane.org>
---
 include/uapi/linux/libc-compat.h | 52 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/include/uapi/linux/libc-compat.h b/include/uapi/linux/libc-compat.h
index 44b8a6b..c316725 100644
--- a/include/uapi/linux/libc-compat.h
+++ b/include/uapi/linux/libc-compat.h
@@ -171,42 +171,94 @@
 #else /* !defined(__GLIBC__) */
 
 /* Definitions for if.h */
+#if !defined(__UAPI_DEF_IF_IFCONF)
 #define __UAPI_DEF_IF_IFCONF 1
+#endif
+#if !defined(__UAPI_DEF_IF_IFMAP)
 #define __UAPI_DEF_IF_IFMAP 1
+#endif
+#if !defined(__UAPI_DEF_IFNAMSIZ)
 #define __UAPI_DEF_IF_IFNAMSIZ 1
+#endif
+#if !defined(__UAPI_DEF_IFREQ)
 #define __UAPI_DEF_IF_IFREQ 1
+#endif
 /* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
+#if !defined(__UAPI_DEF_IF_NET_DEVICE_FLAGS)
 #define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1
+#endif
 /* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
+#if !defined(__UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO)
 #define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
+#endif
 
 /* Definitions for in.h */
+#if !defined(__UAPI_DEF_IN_ADDR)
 #define __UAPI_DEF_IN_ADDR		1
+#endif
+#if !defined(__UAPI_DEF_IN_IPPROTO)
 #define __UAPI_DEF_IN_IPPROTO		1
+#endif
+#if !defined(__UAPI_DEF_IN_PKTINFO)
 #define __UAPI_DEF_IN_PKTINFO		1
+#endif
+#if !defined(__UAPI_DEF_IP_MREQ)
 #define __UAPI_DEF_IP_MREQ		1
+#endif
+#if !defined(__UAPI_DEF_SOCKADDR_IN)
 #define __UAPI_DEF_SOCKADDR_IN		1
+#endif
+#if !defined(__UAPI_DEF_IN_CLASS)
 #define __UAPI_DEF_IN_CLASS		1
+#endif
 
 /* Definitions for in6.h */
+#if !defined(__UAPI_DEF_IN6_ADDR)
 #define __UAPI_DEF_IN6_ADDR		1
+#endif
+#if !defined(__UAPI_DEF_IN6_ADDR_ALT)
 #define __UAPI_DEF_IN6_ADDR_ALT		1
+#endif
+#if !defined(__UAPI_DEF_SOCKADDR_IN6)
 #define __UAPI_DEF_SOCKADDR_IN6		1
+#endif
+#if !defined(__UAPI_DEF_IPV6_MREQ)
 #define __UAPI_DEF_IPV6_MREQ		1
+#endif
+#if !defined(__UAPI_DEF_IPPROTO_V6)
 #define __UAPI_DEF_IPPROTO_V6		1
+#endif
+#if !defined(__UAPI_DEF_IPV6_OPTIONS)
 #define __UAPI_DEF_IPV6_OPTIONS		1
+#endif
+#if !defined(__UAPI_DEF_IN6_PKTINFO)
 #define __UAPI_DEF_IN6_PKTINFO		1
+#endif
+#if !defined(__UAPI_DEF_IP6_MTUINFO)
 #define __UAPI_DEF_IP6_MTUINFO		1
+#endif
 
 /* Definitions for ipx.h */
+#if !defined(__UAPI_DEF_SOCKADDR_IPX)
 #define __UAPI_DEF_SOCKADDR_IPX			1
+#endif
+#if !defined(__UAPI_DEF_IPX_ROUTE_DEFINITION)
 #define __UAPI_DEF_IPX_ROUTE_DEFINITION		1
+#endif
+#if !defined(__UAPI_DEF_IPX_INTERFACE_DEFINITION)
 #define __UAPI_DEF_IPX_INTERFACE_DEFINITION	1
+#endif
+#if !defined(__UAPI_DEF_IPX_CONFIG_DATA)
 #define __UAPI_DEF_IPX_CONFIG_DATA		1
+#endif
+#if !defined(__UAPI_DEF_IPX_ROUTE_DEF)
 #define __UAPI_DEF_IPX_ROUTE_DEF		1
+#endif
 
 /* Definitions for xattr.h */
+#if !defined(__UAPI_DEF_XATTR)
 #define __UAPI_DEF_XATTR		1
+#endif
 
 #endif /* __GLIBC__ */
 
-- 
2.7.3

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [musl] [PATCH] uapi libc compat: allow non-glibc to opt out of uapi definitions
  2016-11-11  1:40 [PATCH] uapi libc compat: allow non-glibc to opt out of uapi definitions Felix Janda
@ 2016-11-11  4:54 ` Rich Felker
  0 siblings, 0 replies; 2+ messages in thread
From: Rich Felker @ 2016-11-11  4:54 UTC (permalink / raw)
  To: Felix Janda, linux-devel-u79uwXL29TY76Z2rM5mHXA, David S. Miller,
	linux-api-u79uwXL29TY76Z2rM5mHXA,
	musl-ZwoEplunGu1jrUoiu81ncdBPR1lH4CV8

On Thu, Nov 10, 2016 at 08:40:44PM -0500, Felix Janda wrote:
> Currently, libc-compat.h detects inclusion of specific glibc headers,
> and defines corresponding _UAPI_DEF_* macros, which in turn are used in
> uapi headers to prevent definition of conflicting structures/constants.
> There is no such detection for other c libraries, for them the
> _UAPI_DEF_* macros are always defined as 1, and so none of the possibly
> conflicting definitions are suppressed.
> 
> This patch enables non-glibc c libraries to request the suppression of
> any specific interface by defining the corresponding _UAPI_DEF_* macro
> as 0.
> 
> This patch together with the recent musl libc commit
> 
> http://git.musl-libc.org/cgit/musl/commit/?id=04983f2272382af92eb8f8838964ff944fbb8258
> 
> fixes the following compiler errors when <linux/in6.h> is included
> after musl <netinet/in.h>:
> 
> ../linux/in6.h:32:8: error: redefinition of 'struct in6_addr'
> ../linux/in6.h:49:8: error: redefinition of 'struct sockaddr_in6'
> ../linux/in6.h:59:8: error: redefinition of 'struct ipv6_mreq'
> 
> Signed-off-by: Felix Janda <felix.janda-1KBjaw7Xf1+zQB+pC5nmwQ@public.gmane.org>

Acked-by: Rich Felker <dalias-8zAoT0mYgF4@public.gmane.org>

> ---
>  include/uapi/linux/libc-compat.h | 52 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 52 insertions(+)
> 
> diff --git a/include/uapi/linux/libc-compat.h b/include/uapi/linux/libc-compat.h
> index 44b8a6b..c316725 100644
> --- a/include/uapi/linux/libc-compat.h
> +++ b/include/uapi/linux/libc-compat.h
> @@ -171,42 +171,94 @@
>  #else /* !defined(__GLIBC__) */

Note that right now, the content above this line in libc-compat.h
makes assumptions about what glibc does and doesn't define that are
specific to current glibc versions. I think it would be nice to make
the whole remainder of the file unconditional rather than being the
#else path for !defined(__GLIBC__). Then future versions of glibc can
properly define their own __UAPI_DEF_* macros to tell the kernel
headers about anything new the define. But I don't think that has to
be part of the same change you're proposing now.

Rich

>  /* Definitions for if.h */
> +#if !defined(__UAPI_DEF_IF_IFCONF)
>  #define __UAPI_DEF_IF_IFCONF 1
> +#endif
> +#if !defined(__UAPI_DEF_IF_IFMAP)
>  #define __UAPI_DEF_IF_IFMAP 1
> +#endif
> +#if !defined(__UAPI_DEF_IFNAMSIZ)
>  #define __UAPI_DEF_IF_IFNAMSIZ 1
> +#endif
> +#if !defined(__UAPI_DEF_IFREQ)
>  #define __UAPI_DEF_IF_IFREQ 1
> +#endif
>  /* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */
> +#if !defined(__UAPI_DEF_IF_NET_DEVICE_FLAGS)
>  #define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1
> +#endif
>  /* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
> +#if !defined(__UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO)
>  #define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
> +#endif
>  
>  /* Definitions for in.h */
> +#if !defined(__UAPI_DEF_IN_ADDR)
>  #define __UAPI_DEF_IN_ADDR		1
> +#endif
> +#if !defined(__UAPI_DEF_IN_IPPROTO)
>  #define __UAPI_DEF_IN_IPPROTO		1
> +#endif
> +#if !defined(__UAPI_DEF_IN_PKTINFO)
>  #define __UAPI_DEF_IN_PKTINFO		1
> +#endif
> +#if !defined(__UAPI_DEF_IP_MREQ)
>  #define __UAPI_DEF_IP_MREQ		1
> +#endif
> +#if !defined(__UAPI_DEF_SOCKADDR_IN)
>  #define __UAPI_DEF_SOCKADDR_IN		1
> +#endif
> +#if !defined(__UAPI_DEF_IN_CLASS)
>  #define __UAPI_DEF_IN_CLASS		1
> +#endif
>  
>  /* Definitions for in6.h */
> +#if !defined(__UAPI_DEF_IN6_ADDR)
>  #define __UAPI_DEF_IN6_ADDR		1
> +#endif
> +#if !defined(__UAPI_DEF_IN6_ADDR_ALT)
>  #define __UAPI_DEF_IN6_ADDR_ALT		1
> +#endif
> +#if !defined(__UAPI_DEF_SOCKADDR_IN6)
>  #define __UAPI_DEF_SOCKADDR_IN6		1
> +#endif
> +#if !defined(__UAPI_DEF_IPV6_MREQ)
>  #define __UAPI_DEF_IPV6_MREQ		1
> +#endif
> +#if !defined(__UAPI_DEF_IPPROTO_V6)
>  #define __UAPI_DEF_IPPROTO_V6		1
> +#endif
> +#if !defined(__UAPI_DEF_IPV6_OPTIONS)
>  #define __UAPI_DEF_IPV6_OPTIONS		1
> +#endif
> +#if !defined(__UAPI_DEF_IN6_PKTINFO)
>  #define __UAPI_DEF_IN6_PKTINFO		1
> +#endif
> +#if !defined(__UAPI_DEF_IP6_MTUINFO)
>  #define __UAPI_DEF_IP6_MTUINFO		1
> +#endif
>  
>  /* Definitions for ipx.h */
> +#if !defined(__UAPI_DEF_SOCKADDR_IPX)
>  #define __UAPI_DEF_SOCKADDR_IPX			1
> +#endif
> +#if !defined(__UAPI_DEF_IPX_ROUTE_DEFINITION)
>  #define __UAPI_DEF_IPX_ROUTE_DEFINITION		1
> +#endif
> +#if !defined(__UAPI_DEF_IPX_INTERFACE_DEFINITION)
>  #define __UAPI_DEF_IPX_INTERFACE_DEFINITION	1
> +#endif
> +#if !defined(__UAPI_DEF_IPX_CONFIG_DATA)
>  #define __UAPI_DEF_IPX_CONFIG_DATA		1
> +#endif
> +#if !defined(__UAPI_DEF_IPX_ROUTE_DEF)
>  #define __UAPI_DEF_IPX_ROUTE_DEF		1
> +#endif
>  
>  /* Definitions for xattr.h */
> +#if !defined(__UAPI_DEF_XATTR)
>  #define __UAPI_DEF_XATTR		1
> +#endif
>  
>  #endif /* __GLIBC__ */
>  
> -- 
> 2.7.3

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2016-11-11  4:54 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-11-11  1:40 [PATCH] uapi libc compat: allow non-glibc to opt out of uapi definitions Felix Janda
2016-11-11  4:54 ` [musl] " Rich Felker

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.