recvmmsg

receive multiple messages on a socket

sys_recvmmsg(int fd, struct mmsghdr *mmsg, unsigned int vlen, unsigned int flags, struct __kernel_timespec *timeout)

register	value
`r1`	357, the syscall number
`r2`	int fd
`r3`	struct mmsghdr *mmsg
`r4`	unsigned int vlen
`r5`	unsigned int flags
`r6`	struct __kernel_timespec *timeout
`r2`	the return value

Then run svc 0 to enter the kernel.

Same syscall on other architectures