uapi libc compat: allow non-glibc to opt out of uapi definitions
PATCH 1/1 uapi libc compat: allow non-glibc to opt out of uapi definitions
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'
--- include/uapi/linux/libc-compat.h | 52 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+)
include/uapi/linux/libc-compat.h +52 -0
@@ -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__ */
Signature · 1 line
2.7.3
Quoted 15 lines · Felix Janda
Currently,
libc-compat.hdetects 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
Quoted 8 lines
fixes the following compiler errors when <
linux/in6.h> is included after musl <netinet/in.h>:
../linux/in6.h:32:8: error: redefinition of 'structin6_addr'../linux/in6.h:49:8: error: redefinition of 'structsockaddr_in6'../linux/in6.h:59:8: error: redefinition of 'structipv6_mreq'Signed-off-by Felix Janda <[email protected]>
include/uapi/linux/libc-compat.h line 171
Quoted 10 lines
--- include/uapi/linux/libc-compat.h | 52 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+)include/uapi/linux/libc-compat.h +0
-0@@ -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
Quoted 94 lines
include/uapi/linux/libc-compat.h +52
-0/* 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__ */ Signature · 1 line
2.7.3