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authorJoseph Myers <joseph@codesourcery.com>2017-05-09 20:01:01 +0000
committerJoseph Myers <joseph@codesourcery.com>2017-05-09 20:01:01 +0000
commit9a45f54310573c190fa270e1f80d8307750305e9 (patch)
tree135f79c47c0879424944e74a10192e78eec66201 /sysdeps/unix/sysv/linux/recvmmsg.c
parent4fc12f0eda596b12fb27fb39ea4ac5e68ac4170e (diff)
downloadglibc-9a45f54310573c190fa270e1f80d8307750305e9.tar.gz
Simplify recvmmsg code.
Now we can assume a kernel with recvmmsg support, this patch simplifies the implementation to be similar to that for accept4: either using socketcall or the syscall according to whether the syscall is known to be available, without further fallback implementations. (In fact further simplification is possible, getting rid of the __ASSUME_*_SYSCALL_WITH_SOCKETCALL macros now that the minimum kernel is guaranteed support for all of accept4, recvmmsg, sendmmsg, whether through syscalls or through socketcall. I intend to do that for all of accept4 / recvmmsg / sendmmsg together - so making their implementations just like those for older socket functions - once the basic cleanup for 3.2 minimum kernel is done for sendmmsg as well as recvmmsg.) Tested for x86_64 and x86. * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_RECVMMSG_SYSCALL): Define unconditionally. (__ASSUME_RECVMMSG_SOCKETCALL): Remove macro. (__ASSUME_RECVMMSG): Likewise. * sysdeps/unix/sysv/linux/recvmmsg.c (recvmmsg): Define using recvmmsg syscall if it can be assumed to be present, socketcall otherwise, with no fallback for runtime failure.
Diffstat (limited to 'sysdeps/unix/sysv/linux/recvmmsg.c')
-rw-r--r--sysdeps/unix/sysv/linux/recvmmsg.c70
1 files changed, 9 insertions, 61 deletions
diff --git a/sysdeps/unix/sysv/linux/recvmmsg.c b/sysdeps/unix/sysv/linux/recvmmsg.c
index 28eb678428..de4412972b 100644
--- a/sysdeps/unix/sysv/linux/recvmmsg.c
+++ b/sysdeps/unix/sysv/linux/recvmmsg.c
@@ -21,73 +21,21 @@
#include <sysdep-cancel.h>
#include <sys/syscall.h>
+#include <socketcall.h>
#include <kernel-features.h>
-/* Do not use the recvmmsg syscall on socketcall architectures unless
- it was added at the same time as the socketcall support or can be
- assumed to be present. */
-#if defined __ASSUME_SOCKETCALL \
- && !defined __ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL \
- && !defined __ASSUME_RECVMMSG_SYSCALL
-# undef __NR_recvmmsg
-#endif
-
-#ifdef __NR_recvmmsg
-int
-recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
- struct timespec *tmo)
-{
- return SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo);
-}
-#elif defined __NR_socketcall
-# include <socketcall.h>
-# ifdef __ASSUME_RECVMMSG_SOCKETCALL
int
recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
struct timespec *tmo)
{
+ /* Do not use the recvmmsg syscall on socketcall architectures unless
+ it was added at the same time as the socketcall support or can be
+ assumed to be present. */
+#if defined __ASSUME_SOCKETCALL \
+ && !defined __ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL \
+ && !defined __ASSUME_RECVMMSG_SYSCALL
return SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo);
-}
-# else
-static int have_recvmmsg;
-
-int
-recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
- struct timespec *tmo)
-{
- if (__glibc_likely (have_recvmmsg >= 0))
- {
- int ret = SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags,
- tmo);
- /* The kernel returns -EINVAL for unknown socket operations.
- We need to convert that error to an ENOSYS error. */
- if (__builtin_expect (ret < 0, 0)
- && have_recvmmsg == 0
- && errno == EINVAL)
- {
- /* Try another call, this time with an invalid file
- descriptor and all other parameters cleared. This call
- will not cause any harm and it will return
- immediately. */
- ret = SOCKETCALL_CANCEL (invalid, -1);
- if (errno == EINVAL)
- {
- have_recvmmsg = -1;
- __set_errno (ENOSYS);
- }
- else
- {
- have_recvmmsg = 1;
- __set_errno (EINVAL);
- }
- return -1;
- }
- return ret;
- }
- __set_errno (ENOSYS);
- return -1;
-}
-# endif /* __ASSUME_RECVMMSG_SOCKETCALL */
#else
-# include <socket/recvmmsg.c>
+ return SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo);
#endif
+}