r0 = signalfd4(0xffffffffffffffff, &(0x7f0000000000), 0x8, 0x0)
r1 = openat$procfs(0xffffffffffffff9c, &(0x7f00000000c0)='/proc/cgroups\x00', 0x0, 0x0)
sendfile(r0, r1, &(0x7f0000000040)=0x8001, 0x20000000000080)