Linux: Restore commetions in <kernel-features.h>
2017-04-20 Florian Weimer <fweimer@redhat.com>
* sysdeps/unix/sysv/linux/kernel-features.h: Restore the full
*ACCEPT4* macro documentation and apply it to the *RECVMMSG*
macros.
@@ -88,8 +88,17 @@
#define __ASSUME_PREADV 1
#define __ASSUME_PWRITEV 1
-/* Support for recvmmsg functionality was added in 2.6.33. The macros
- defined correspond to those for accept4. */
+/* Support for recvmmsg functionality was added in 2.6.33, but for
+ some architectures using a separate syscall rather than socketcall
+ that syscall was only added later, and some architectures first had
+ socketcall support then a separate syscall. Define
+ __ASSUME_RECVMMSG_SOCKETCALL if glibc uses socketcall on this
+ architecture and recvmmsg is available through socketcall,
+ __ASSUME_RECVMMSG_SYSCALL if it is available through a separate
+ syscall, __ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL if it became
+ available through a separate syscall at the same time as through
+ socketcall, and __ASSUME_RECVMMSG if the recvmmsg function is known
+ to work. */
#if __LINUX_KERNEL_VERSION >= 0x020621
# ifdef __ASSUME_SOCKETCALL
# define __ASSUME_RECVMMSG_SOCKETCALL 1
@@ -115,7 +124,7 @@
#endif
/* Support for sendmmsg functionality was added in 3.0. The macros
- defined correspond to those for accept4 and recvmmsg. */
+ defined correspond to those for recvmmsg. */
#if __LINUX_KERNEL_VERSION >= 0x030000
# ifdef __ASSUME_SOCKETCALL
# define __ASSUME_SENDMMSG_SOCKETCALL 1