strace ubuntu

strace -tt ./a.out
17:59:24.176652 execve("./a.out", ["./a.out"], 0x7fff100cfe78 /* 24 vars */) = 0
17:59:24.177070 brk(NULL)               = 0x560de05df000
17:59:24.177119 arch_prctl(0x3001 /* ARCH_??? */, 0x7ffd4b1f97c0) = -1 EINVAL (Invalid argument)
17:59:24.177174 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fd2a80b3000
17:59:24.177202 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
17:59:24.177246 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.177275 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.181884 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.181912 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.181930 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls/x86_64/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.181947 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls/x86_64/x86_64", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.181965 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.181983 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls/x86_64", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.181998 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.182020 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls/x86_64", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.182042 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.182061 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/tls", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.182081 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/x86_64/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.182101 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/x86_64/x86_64", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.182121 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.182140 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/x86_64", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.182159 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
17:59:24.182178 newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/x86_64", 0x7ffd4b1f89f0, 0) = -1 ENOENT (No such file or directory)
17:59:24.182197 openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
17:59:24.182220 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\240\206\2\0\0\0\0\0"..., 832) = 832
17:59:24.182241 pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
17:59:24.182258 pread64(3, "\4\0\0\0 \0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0"..., 48, 848) = 48
17:59:24.182277 pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0+H)\227\201T\214\233\304R\352\306\3379\220%"..., 68, 896) = 68
17:59:24.182293 newfstatat(3, "", {st_mode=S_IFREG|0755, st_size=1983576, ...}, AT_EMPTY_PATH) = 0
17:59:24.182314 pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
17:59:24.182331 mmap(NULL, 2012056, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fd2a7ec7000
17:59:24.182349 mmap(0x7fd2a7eed000, 1486848, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x26000) = 0x7fd2a7eed000
17:59:24.182373 mmap(0x7fd2a8058000, 311296, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x191000) = 0x7fd2a8058000
17:59:24.182391 mmap(0x7fd2a80a4000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1dc000) = 0x7fd2a80a4000
17:59:24.182410 mmap(0x7fd2a80aa000, 33688, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fd2a80aa000
17:59:24.182434 close(3)                = 0
17:59:24.182454 mmap(NULL, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fd2a7ec4000
17:59:24.182471 arch_prctl(ARCH_SET_FS, 0x7fd2a7ec4740) = 0
17:59:24.182538 mprotect(0x7fd2a80a4000, 12288, PROT_READ) = 0
17:59:24.182558 mprotect(0x560ddf463000, 4096, PROT_READ) = 0
17:59:24.182580 mprotect(0x7fd2a80e7000, 8192, PROT_READ) = 0
17:59:24.182621 exit_group(0)           = ?
17:59:24.182669 +++ exited with 0 +++