r0 = openat$sysfs(0xffffffffffffff9c, &(0x7f0000000040)='/sys/kernel/kexec_crash_size', 0x0, 0x0)
mmap$IORING_OFF_CQ_RING(&(0x7f0000ffc000/0x3000)=nil, 0x3000, 0x0, 0x12, r0, 0x8000000)