Add documentation for remaining syscalls (fixes #197, #186)

Adds support level documentation for all syscalls. Removes the Undocumented
utility function to discourage usage while leaving SupportUndocumented as the
default support level for Syscall structs.

PiperOrigin-RevId: 256281927

2 files changed, 262 insertions, 271 deletions

diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index 94816b038..99af33cfd 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -50,244 +50,244 @@ var AMD64 = &kernel.SyscallTable{
 	Table: map[uintptr]kernel.Syscall{
 		0:   syscalls.Supported("read", Read),
 		1:   syscalls.Supported("write", Write),
-		2:   syscalls.Supported("open", Open),
+		2:   syscalls.PartiallySupported("open", Open, "Options O_DIRECT, O_NOATIME, O_PATH, O_TMPFILE, O_SYNC are not supported.", nil),
 		3:   syscalls.Supported("close", Close),
-		4:   syscalls.Undocumented("stat", Stat),
-		5:   syscalls.Undocumented("fstat", Fstat),
-		6:   syscalls.Undocumented("lstat", Lstat),
-		7:   syscalls.Undocumented("poll", Poll),
-		8:   syscalls.Undocumented("lseek", Lseek),
-		9:   syscalls.Undocumented("mmap", Mmap),
-		10:  syscalls.Undocumented("mprotect", Mprotect),
-		11:  syscalls.Undocumented("munmap", Munmap),
-		12:  syscalls.Undocumented("brk", Brk),
-		13:  syscalls.Undocumented("rt_sigaction", RtSigaction),
-		14:  syscalls.Undocumented("rt_sigprocmask", RtSigprocmask),
-		15:  syscalls.Undocumented("rt_sigreturn", RtSigreturn),
-		16:  syscalls.Undocumented("ioctl", Ioctl),
-		17:  syscalls.Undocumented("pread64", Pread64),
-		18:  syscalls.Undocumented("pwrite64", Pwrite64),
-		19:  syscalls.Undocumented("readv", Readv),
-		20:  syscalls.Undocumented("writev", Writev),
-		21:  syscalls.Undocumented("access", Access),
-		22:  syscalls.Undocumented("pipe", Pipe),
-		23:  syscalls.Undocumented("select", Select),
-		24:  syscalls.Undocumented("sched_yield", SchedYield),
-		25:  syscalls.Undocumented("mremap", Mremap),
-		26:  syscalls.Undocumented("msync", Msync),
-		27:  syscalls.Undocumented("mincore", Mincore),
-		28:  syscalls.Undocumented("madvise", Madvise),
-		29:  syscalls.Undocumented("shmget", Shmget),
-		30:  syscalls.Undocumented("shmat", Shmat),
-		31:  syscalls.Undocumented("shmctl", Shmctl),
-		32:  syscalls.Undocumented("dup", Dup),
-		33:  syscalls.Undocumented("dup2", Dup2),
-		34:  syscalls.Undocumented("pause", Pause),
-		35:  syscalls.Undocumented("nanosleep", Nanosleep),
-		36:  syscalls.Undocumented("getitimer", Getitimer),
-		37:  syscalls.Undocumented("alarm", Alarm),
-		38:  syscalls.Undocumented("setitimer", Setitimer),
-		39:  syscalls.Undocumented("getpid", Getpid),
-		40:  syscalls.Undocumented("sendfile", Sendfile),
-		41:  syscalls.Undocumented("socket", Socket),
-		42:  syscalls.Undocumented("connect", Connect),
-		43:  syscalls.Undocumented("accept", Accept),
-		44:  syscalls.Undocumented("sendto", SendTo),
-		45:  syscalls.Undocumented("recvfrom", RecvFrom),
-		46:  syscalls.Undocumented("sendmsg", SendMsg),
-		47:  syscalls.Undocumented("recvmsg", RecvMsg),
-		48:  syscalls.Undocumented("shutdown", Shutdown),
-		49:  syscalls.Undocumented("bind", Bind),
-		50:  syscalls.Undocumented("listen", Listen),
-		51:  syscalls.Undocumented("getsockname", GetSockName),
-		52:  syscalls.Undocumented("getpeername", GetPeerName),
-		53:  syscalls.Undocumented("socketpair", SocketPair),
-		54:  syscalls.Undocumented("setsockopt", SetSockOpt),
-		55:  syscalls.Undocumented("getsockopt", GetSockOpt),
-		56:  syscalls.Undocumented("clone", Clone),
-		57:  syscalls.Undocumented("fork", Fork),
-		58:  syscalls.Undocumented("vfork", Vfork),
-		59:  syscalls.Undocumented("execve", Execve),
-		60:  syscalls.Undocumented("exit", Exit),
-		61:  syscalls.Undocumented("wait4", Wait4),
-		62:  syscalls.Undocumented("kill", Kill),
-		63:  syscalls.Undocumented("uname", Uname),
-		64:  syscalls.Undocumented("semget", Semget),
-		65:  syscalls.Undocumented("semop", Semop),
-		66:  syscalls.Undocumented("semctl", Semctl),
-		67:  syscalls.Undocumented("shmdt", Shmdt),
+		4:   syscalls.Supported("stat", Stat),
+		5:   syscalls.Supported("fstat", Fstat),
+		6:   syscalls.Supported("lstat", Lstat),
+		7:   syscalls.Supported("poll", Poll),
+		8:   syscalls.Supported("lseek", Lseek),
+		9:   syscalls.PartiallySupported("mmap", Mmap, "Generally supported with exceptions. Options MAP_FIXED_NOREPLACE, MAP_SHARED_VALIDATE, MAP_SYNC MAP_GROWSDOWN, MAP_HUGETLB are not supported.", nil),
+		10:  syscalls.Supported("mprotect", Mprotect),
+		11:  syscalls.Supported("munmap", Munmap),
+		12:  syscalls.Supported("brk", Brk),
+		13:  syscalls.Supported("rt_sigaction", RtSigaction),
+		14:  syscalls.Supported("rt_sigprocmask", RtSigprocmask),
+		15:  syscalls.Supported("rt_sigreturn", RtSigreturn),
+		16:  syscalls.PartiallySupported("ioctl", Ioctl, "Only a few ioctls are implemented for backing devices and file systems.", nil),
+		17:  syscalls.Supported("pread64", Pread64),
+		18:  syscalls.Supported("pwrite64", Pwrite64),
+		19:  syscalls.Supported("readv", Readv),
+		20:  syscalls.Supported("writev", Writev),
+		21:  syscalls.Supported("access", Access),
+		22:  syscalls.Supported("pipe", Pipe),
+		23:  syscalls.Supported("select", Select),
+		24:  syscalls.Supported("sched_yield", SchedYield),
+		25:  syscalls.Supported("mremap", Mremap),
+		26:  syscalls.PartiallySupported("msync", Msync, "Full data flush is not guaranteed at this time.", nil),
+		27:  syscalls.PartiallySupported("mincore", Mincore, "Stub implementation. The sandbox does not have access to this information. Reports all mapped pages are resident.", nil),
+		28:  syscalls.PartiallySupported("madvise", Madvise, "Options MADV_DONTNEED, MADV_DONTFORK are supported. Other advice is ignored.", nil),
+		29:  syscalls.PartiallySupported("shmget", Shmget, "Option SHM_HUGETLB is not supported.", nil),
+		30:  syscalls.PartiallySupported("shmat", Shmat, "Option SHM_RND is not supported.", nil),
+		31:  syscalls.PartiallySupported("shmctl", Shmctl, "Options SHM_LOCK, SHM_UNLOCK are not supported.", nil),
+		32:  syscalls.Supported("dup", Dup),
+		33:  syscalls.Supported("dup2", Dup2),
+		34:  syscalls.Supported("pause", Pause),
+		35:  syscalls.Supported("nanosleep", Nanosleep),
+		36:  syscalls.Supported("getitimer", Getitimer),
+		37:  syscalls.Supported("alarm", Alarm),
+		38:  syscalls.Supported("setitimer", Setitimer),
+		39:  syscalls.Supported("getpid", Getpid),
+		40:  syscalls.Supported("sendfile", Sendfile),
+		41:  syscalls.PartiallySupported("socket", Socket, "Limited support for AF_NETLINK, NETLINK_ROUTE sockets. Limited support for SOCK_RAW.", nil),
+		42:  syscalls.Supported("connect", Connect),
+		43:  syscalls.Supported("accept", Accept),
+		44:  syscalls.Supported("sendto", SendTo),
+		45:  syscalls.Supported("recvfrom", RecvFrom),
+		46:  syscalls.Supported("sendmsg", SendMsg),
+		47:  syscalls.PartiallySupported("recvmsg", RecvMsg, "Not all flags and control messages are supported.", nil),
+		48:  syscalls.PartiallySupported("shutdown", Shutdown, "Not all flags and control messages are supported.", nil),
+		49:  syscalls.PartiallySupported("bind", Bind, "Autobind for abstract Unix sockets is not supported.", nil),
+		50:  syscalls.Supported("listen", Listen),
+		51:  syscalls.Supported("getsockname", GetSockName),
+		52:  syscalls.Supported("getpeername", GetPeerName),
+		53:  syscalls.Supported("socketpair", SocketPair),
+		54:  syscalls.PartiallySupported("setsockopt", SetSockOpt, "Not all socket options are supported.", nil),
+		55:  syscalls.PartiallySupported("getsockopt", GetSockOpt, "Not all socket options are supported.", nil),
+		56:  syscalls.PartiallySupported("clone", Clone, "Mount namespace (CLONE_NEWNS) not supported. Options CLONE_PARENT, CLONE_SYSVSEM not supported.", nil),
+		57:  syscalls.Supported("fork", Fork),
+		58:  syscalls.Supported("vfork", Vfork),
+		59:  syscalls.Supported("execve", Execve),
+		60:  syscalls.Supported("exit", Exit),
+		61:  syscalls.Supported("wait4", Wait4),
+		62:  syscalls.Supported("kill", Kill),
+		63:  syscalls.Supported("uname", Uname),
+		64:  syscalls.Supported("semget", Semget),
+		65:  syscalls.PartiallySupported("semop", Semop, "Option SEM_UNDO not supported.", nil),
+		66:  syscalls.PartiallySupported("semctl", Semctl, "Options IPC_INFO, SEM_INFO, IPC_STAT, SEM_STAT, SEM_STAT_ANY, GETNCNT, GETZCNT not supported.", nil),
+		67:  syscalls.Supported("shmdt", Shmdt),
 		68:  syscalls.ErrorWithEvent("msgget", syscall.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
 		69:  syscalls.ErrorWithEvent("msgsnd", syscall.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
 		70:  syscalls.ErrorWithEvent("msgrcv", syscall.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
 		71:  syscalls.ErrorWithEvent("msgctl", syscall.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
-		72:  syscalls.Undocumented("fcntl", Fcntl),
-		73:  syscalls.Undocumented("flock", Flock),
-		74:  syscalls.Undocumented("fsync", Fsync),
-		75:  syscalls.Undocumented("fdatasync", Fdatasync),
-		76:  syscalls.Undocumented("truncate", Truncate),
-		77:  syscalls.Undocumented("ftruncate", Ftruncate),
-		78:  syscalls.Undocumented("getdents", Getdents),
-		79:  syscalls.Undocumented("getcwd", Getcwd),
-		80:  syscalls.Undocumented("chdir", Chdir),
-		81:  syscalls.Undocumented("fchdir", Fchdir),
-		82:  syscalls.Undocumented("rename", Rename),
-		83:  syscalls.Undocumented("mkdir", Mkdir),
-		84:  syscalls.Undocumented("rmdir", Rmdir),
-		85:  syscalls.Undocumented("creat", Creat),
-		86:  syscalls.Undocumented("link", Link),
-		87:  syscalls.Undocumented("link", Unlink),
-		88:  syscalls.Undocumented("symlink", Symlink),
-		89:  syscalls.Undocumented("readlink", Readlink),
-		90:  syscalls.Undocumented("chmod", Chmod),
-		91:  syscalls.Undocumented("fchmod", Fchmod),
-		92:  syscalls.Undocumented("chown", Chown),
-		93:  syscalls.Undocumented("fchown", Fchown),
-		94:  syscalls.Undocumented("lchown", Lchown),
-		95:  syscalls.Undocumented("umask", Umask),
-		96:  syscalls.Undocumented("gettimeofday", Gettimeofday),
-		97:  syscalls.Undocumented("getrlimit", Getrlimit),
-		98:  syscalls.Undocumented("getrusage", Getrusage),
-		99:  syscalls.Undocumented("sysinfo", Sysinfo),
-		100: syscalls.Undocumented("times", Times),
-		101: syscalls.Undocumented("ptrace", Ptrace),
-		102: syscalls.Undocumented("getuid", Getuid),
-		103: syscalls.Undocumented("syslog", Syslog),
-		104: syscalls.Undocumented("getgid", Getgid),
-		105: syscalls.Undocumented("setuid", Setuid),
-		106: syscalls.Undocumented("setgid", Setgid),
-		107: syscalls.Undocumented("geteuid", Geteuid),
-		108: syscalls.Undocumented("getegid", Getegid),
-		109: syscalls.Undocumented("setpgid", Setpgid),
-		110: syscalls.Undocumented("getppid", Getppid),
-		111: syscalls.Undocumented("getpgrp", Getpgrp),
-		112: syscalls.Undocumented("setsid", Setsid),
-		113: syscalls.Undocumented("setreuid", Setreuid),
-		114: syscalls.Undocumented("setregid", Setregid),
-		115: syscalls.Undocumented("getgroups", Getgroups),
-		116: syscalls.Undocumented("setgroups", Setgroups),
-		117: syscalls.Undocumented("setresuid", Setresuid),
-		118: syscalls.Undocumented("getresuid", Getresuid),
-		119: syscalls.Undocumented("setresgid", Setresgid),
-		120: syscalls.Undocumented("setresgid", Getresgid),
-		121: syscalls.Undocumented("getpgid", Getpgid),
+		72:  syscalls.PartiallySupported("fcntl", Fcntl, "Not all options are supported.", nil),
+		73:  syscalls.PartiallySupported("flock", Flock, "Locks are held within the sandbox only.", nil),
+		74:  syscalls.PartiallySupported("fsync", Fsync, "Full data flush is not guaranteed at this time.", nil),
+		75:  syscalls.PartiallySupported("fdatasync", Fdatasync, "Full data flush is not guaranteed at this time.", nil),
+		76:  syscalls.Supported("truncate", Truncate),
+		77:  syscalls.Supported("ftruncate", Ftruncate),
+		78:  syscalls.Supported("getdents", Getdents),
+		79:  syscalls.Supported("getcwd", Getcwd),
+		80:  syscalls.Supported("chdir", Chdir),
+		81:  syscalls.Supported("fchdir", Fchdir),
+		82:  syscalls.Supported("rename", Rename),
+		83:  syscalls.Supported("mkdir", Mkdir),
+		84:  syscalls.Supported("rmdir", Rmdir),
+		85:  syscalls.Supported("creat", Creat),
+		86:  syscalls.Supported("link", Link),
+		87:  syscalls.Supported("unlink", Unlink),
+		88:  syscalls.Supported("symlink", Symlink),
+		89:  syscalls.Supported("readlink", Readlink),
+		90:  syscalls.Supported("chmod", Chmod),
+		91:  syscalls.PartiallySupported("fchmod", Fchmod, "Options S_ISUID and S_ISGID not supported.", nil),
+		92:  syscalls.Supported("chown", Chown),
+		93:  syscalls.Supported("fchown", Fchown),
+		94:  syscalls.Supported("lchown", Lchown),
+		95:  syscalls.Supported("umask", Umask),
+		96:  syscalls.Supported("gettimeofday", Gettimeofday),
+		97:  syscalls.Supported("getrlimit", Getrlimit),
+		98:  syscalls.PartiallySupported("getrusage", Getrusage, "Fields ru_maxrss, ru_minflt, ru_majflt, ru_inblock, ru_oublock are not supported. Fields ru_utime and ru_stime have low precision.", nil),
+		99:  syscalls.PartiallySupported("sysinfo", Sysinfo, "Fields loads, sharedram, bufferram, totalswap, freeswap, totalhigh, freehigh not supported.", nil),
+		100: syscalls.Supported("times", Times),
+		101: syscalls.PartiallySupported("ptrace", Ptrace, "Options PTRACE_PEEKSIGINFO, PTRACE_SECCOMP_GET_FILTER not supported.", nil),
+		102: syscalls.Supported("getuid", Getuid),
+		103: syscalls.PartiallySupported("syslog", Syslog, "Outputs a dummy message for security reasons.", nil),
+		104: syscalls.Supported("getgid", Getgid),
+		105: syscalls.Supported("setuid", Setuid),
+		106: syscalls.Supported("setgid", Setgid),
+		107: syscalls.Supported("geteuid", Geteuid),
+		108: syscalls.Supported("getegid", Getegid),
+		109: syscalls.Supported("setpgid", Setpgid),
+		110: syscalls.Supported("getppid", Getppid),
+		111: syscalls.Supported("getpgrp", Getpgrp),
+		112: syscalls.Supported("setsid", Setsid),
+		113: syscalls.Supported("setreuid", Setreuid),
+		114: syscalls.Supported("setregid", Setregid),
+		115: syscalls.Supported("getgroups", Getgroups),
+		116: syscalls.Supported("setgroups", Setgroups),
+		117: syscalls.Supported("setresuid", Setresuid),
+		118: syscalls.Supported("getresuid", Getresuid),
+		119: syscalls.Supported("setresgid", Setresgid),
+		120: syscalls.Supported("setresgid", Getresgid),
+		121: syscalls.Supported("getpgid", Getpgid),
 		122: syscalls.ErrorWithEvent("setfsuid", syscall.ENOSYS, "", []string{"gvisor.dev/issue/260"}), // TODO(b/112851702)
 		123: syscalls.ErrorWithEvent("setfsgid", syscall.ENOSYS, "", []string{"gvisor.dev/issue/260"}), // TODO(b/112851702)
-		124: syscalls.Undocumented("getsid", Getsid),
-		125: syscalls.Undocumented("capget", Capget),
-		126: syscalls.Undocumented("capset", Capset),
-		127: syscalls.Undocumented("rt_sigpending", RtSigpending),
-		128: syscalls.Undocumented("rt_sigtimedwait", RtSigtimedwait),
-		129: syscalls.Undocumented("rt_sigqueueinfo", RtSigqueueinfo),
-		130: syscalls.Undocumented("rt_sigsuspend", RtSigsuspend),
-		131: syscalls.Undocumented("sigaltstack", Sigaltstack),
-		132: syscalls.Undocumented("utime", Utime),
-		133: syscalls.Undocumented("mknod", Mknod),
+		124: syscalls.Supported("getsid", Getsid),
+		125: syscalls.Supported("capget", Capget),
+		126: syscalls.Supported("capset", Capset),
+		127: syscalls.Supported("rt_sigpending", RtSigpending),
+		128: syscalls.Supported("rt_sigtimedwait", RtSigtimedwait),
+		129: syscalls.Supported("rt_sigqueueinfo", RtSigqueueinfo),
+		130: syscalls.Supported("rt_sigsuspend", RtSigsuspend),
+		131: syscalls.Supported("sigaltstack", Sigaltstack),
+		132: syscalls.Supported("utime", Utime),
+		133: syscalls.PartiallySupported("mknod", Mknod, "Device creation is not generally supported. Only regular file and FIFO creation are supported.", nil),
 		134: syscalls.Error("uselib", syscall.ENOSYS, "Obsolete", nil),
 		135: syscalls.ErrorWithEvent("personality", syscall.EINVAL, "Unable to change personality.", nil),
 		136: syscalls.ErrorWithEvent("ustat", syscall.ENOSYS, "Needs filesystem support.", nil),
-		137: syscalls.Undocumented("statfs", Statfs),
-		138: syscalls.Undocumented("fstatfs", Fstatfs),
+		137: syscalls.PartiallySupported("statfs", Statfs, "Depends on the backing file system implementation.", nil),
+		138: syscalls.PartiallySupported("fstatfs", Fstatfs, "Depends on the backing file system implementation.", nil),
 		139: syscalls.ErrorWithEvent("sysfs", syscall.ENOSYS, "", []string{"gvisor.dev/issue/165"}),
-		140: syscalls.Undocumented("getpriority", Getpriority),
-		141: syscalls.Undocumented("setpriority", Setpriority),
+		140: syscalls.PartiallySupported("getpriority", Getpriority, "Stub implementation.", nil),
+		141: syscalls.PartiallySupported("setpriority", Setpriority, "Stub implementation.", nil),
 		142: syscalls.CapError("sched_setparam", linux.CAP_SYS_NICE, "", nil),
-		143: syscalls.Undocumented("sched_getparam", SchedGetparam),
-		144: syscalls.Undocumented("sched_setscheduler", SchedSetscheduler),
-		145: syscalls.Undocumented("sched_getscheduler", SchedGetscheduler),
-		146: syscalls.Undocumented("sched_get_priority_max", SchedGetPriorityMax),
-		147: syscalls.Undocumented("sched_get_priority_min", SchedGetPriorityMin),
+		143: syscalls.PartiallySupported("sched_getparam", SchedGetparam, "Stub implementation.", nil),
+		144: syscalls.PartiallySupported("sched_setscheduler", SchedSetscheduler, "Stub implementation.", nil),
+		145: syscalls.PartiallySupported("sched_getscheduler", SchedGetscheduler, "Stub implementation.", nil),
+		146: syscalls.PartiallySupported("sched_get_priority_max", SchedGetPriorityMax, "Stub implementation.", nil),
+		147: syscalls.PartiallySupported("sched_get_priority_min", SchedGetPriorityMin, "Stub implementation.", nil),
 		148: syscalls.ErrorWithEvent("sched_rr_get_interval", syscall.EPERM, "", nil),
-		149: syscalls.Undocumented("mlock", Mlock),
-		150: syscalls.Undocumented("munlock", Munlock),
-		151: syscalls.Undocumented("mlockall", Mlockall),
-		152: syscalls.Undocumented("munlockall", Munlockall),
+		149: syscalls.PartiallySupported("mlock", Mlock, "Stub implementation. The sandbox lacks appropriate permissions.", nil),
+		150: syscalls.PartiallySupported("munlock", Munlock, "Stub implementation. The sandbox lacks appropriate permissions.", nil),
+		151: syscalls.PartiallySupported("mlockall", Mlockall, "Stub implementation. The sandbox lacks appropriate permissions.", nil),
+		152: syscalls.PartiallySupported("munlockall", Munlockall, "Stub implementation. The sandbox lacks appropriate permissions.", nil),
 		153: syscalls.CapError("vhangup", linux.CAP_SYS_TTY_CONFIG, "", nil),
 		154: syscalls.Error("modify_ldt", syscall.EPERM, "", nil),
 		155: syscalls.Error("pivot_root", syscall.EPERM, "", nil),
-		156: syscalls.Error("sysctl", syscall.EPERM, `syscall is "worthless"`, nil),
-		157: syscalls.Undocumented("prctl", Prctl),
-		158: syscalls.Undocumented("arch_prctl", ArchPrctl),
+		156: syscalls.Error("sysctl", syscall.EPERM, "Deprecated. Use /proc/sys instead.", nil),
+		157: syscalls.PartiallySupported("prctl", Prctl, "Not all options are supported.", nil),
+		158: syscalls.PartiallySupported("arch_prctl", ArchPrctl, "Options ARCH_GET_GS, ARCH_SET_GS not supported.", nil),
 		159: syscalls.CapError("adjtimex", linux.CAP_SYS_TIME, "", nil),
-		160: syscalls.Undocumented("setrlimit", Setrlimit),
-		161: syscalls.Undocumented("chroot", Chroot),
-		162: syscalls.Undocumented("sync", Sync),
+		160: syscalls.PartiallySupported("setrlimit", Setrlimit, "Not all rlimits are enforced.", nil),
+		161: syscalls.Supported("chroot", Chroot),
+		162: syscalls.PartiallySupported("sync", Sync, "Full data flush is not guaranteed at this time.", nil),
 		163: syscalls.CapError("acct", linux.CAP_SYS_PACCT, "", nil),
 		164: syscalls.CapError("settimeofday", linux.CAP_SYS_TIME, "", nil),
-		165: syscalls.Undocumented("mount", Mount),
-		166: syscalls.Undocumented("umount2", Umount2),
+		165: syscalls.PartiallySupported("mount", Mount, "Not all options or file systems are supported.", nil),
+		166: syscalls.PartiallySupported("umount2", Umount2, "Not all options or file systems are supported.", nil),
 		167: syscalls.CapError("swapon", linux.CAP_SYS_ADMIN, "", nil),
 		168: syscalls.CapError("swapoff", linux.CAP_SYS_ADMIN, "", nil),
 		169: syscalls.CapError("reboot", linux.CAP_SYS_BOOT, "", nil),
-		170: syscalls.Undocumented("sethostname", Sethostname),
-		171: syscalls.Undocumented("setdomainname", Setdomainname),
+		170: syscalls.Supported("sethostname", Sethostname),
+		171: syscalls.Supported("setdomainname", Setdomainname),
 		172: syscalls.CapError("iopl", linux.CAP_SYS_RAWIO, "", nil),
 		173: syscalls.CapError("ioperm", linux.CAP_SYS_RAWIO, "", nil),
 		174: syscalls.CapError("create_module", linux.CAP_SYS_MODULE, "", nil),
 		175: syscalls.CapError("init_module", linux.CAP_SYS_MODULE, "", nil),
 		176: syscalls.CapError("delete_module", linux.CAP_SYS_MODULE, "", nil),
-		177: syscalls.Error("get_kernel_syms", syscall.ENOSYS, "Not supported in > 2.6", nil),
-		178: syscalls.Error("query_module", syscall.ENOSYS, "Not supported in > 2.6", nil),
+		177: syscalls.Error("get_kernel_syms", syscall.ENOSYS, "Not supported in Linux > 2.6.", nil),
+		178: syscalls.Error("query_module", syscall.ENOSYS, "Not supported in Linux > 2.6.", nil),
 		179: syscalls.CapError("quotactl", linux.CAP_SYS_ADMIN, "", nil), // requires cap_sys_admin for most operations
-		180: syscalls.Error("nfsservctl", syscall.ENOSYS, "Does not exist > 3.1", nil),
-		181: syscalls.Error("getpmsg", syscall.ENOSYS, "Not implemented in Linux", nil),
-		182: syscalls.Error("putpmsg", syscall.ENOSYS, "Not implemented in Linux", nil),
-		183: syscalls.Error("afs_syscall", syscall.ENOSYS, "Not implemented in Linux", nil),
-		184: syscalls.Error("tuxcall", syscall.ENOSYS, "Not implemented in Linux", nil),
-		185: syscalls.Error("security", syscall.ENOSYS, "Not implemented in Linux", nil),
-		186: syscalls.Undocumented("gettid", Gettid),
+		180: syscalls.Error("nfsservctl", syscall.ENOSYS, "Removed after Linux 3.1.", nil),
+		181: syscalls.Error("getpmsg", syscall.ENOSYS, "Not implemented in Linux.", nil),
+		182: syscalls.Error("putpmsg", syscall.ENOSYS, "Not implemented in Linux.", nil),
+		183: syscalls.Error("afs_syscall", syscall.ENOSYS, "Not implemented in Linux.", nil),
+		184: syscalls.Error("tuxcall", syscall.ENOSYS, "Not implemented in Linux.", nil),
+		185: syscalls.Error("security", syscall.ENOSYS, "Not implemented in Linux.", nil),
+		186: syscalls.Supported("gettid", Gettid),
 		187: syscalls.ErrorWithEvent("readahead", syscall.ENOSYS, "", []string{"gvisor.dev/issue/261"}), // TODO(b/29351341)
-		188: syscalls.ErrorWithEvent("setxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		189: syscalls.ErrorWithEvent("lsetxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		190: syscalls.ErrorWithEvent("fsetxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		191: syscalls.ErrorWithEvent("getxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		192: syscalls.ErrorWithEvent("lgetxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		193: syscalls.ErrorWithEvent("fgetxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		194: syscalls.ErrorWithEvent("listxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		195: syscalls.ErrorWithEvent("llistxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		196: syscalls.ErrorWithEvent("flistxattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		197: syscalls.ErrorWithEvent("removexattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		198: syscalls.ErrorWithEvent("lremovexattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		199: syscalls.ErrorWithEvent("fremovexattr", syscall.ENOTSUP, "Requires filesystem support", nil),
-		200: syscalls.Undocumented("tkill", Tkill),
-		201: syscalls.Undocumented("time", Time),
-		202: syscalls.Undocumented("futex", Futex),
-		203: syscalls.Undocumented("sched_setaffinity", SchedSetaffinity),
-		204: syscalls.Undocumented("sched_getaffinity", SchedGetaffinity),
+		188: syscalls.ErrorWithEvent("setxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		189: syscalls.ErrorWithEvent("lsetxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		190: syscalls.ErrorWithEvent("fsetxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		191: syscalls.ErrorWithEvent("getxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		192: syscalls.ErrorWithEvent("lgetxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		193: syscalls.ErrorWithEvent("fgetxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		194: syscalls.ErrorWithEvent("listxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		195: syscalls.ErrorWithEvent("llistxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		196: syscalls.ErrorWithEvent("flistxattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		197: syscalls.ErrorWithEvent("removexattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		198: syscalls.ErrorWithEvent("lremovexattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		199: syscalls.ErrorWithEvent("fremovexattr", syscall.ENOTSUP, "Requires filesystem support.", nil),
+		200: syscalls.Supported("tkill", Tkill),
+		201: syscalls.Supported("time", Time),
+		202: syscalls.PartiallySupported("futex", Futex, "Robust futexes not supported.", nil),
+		203: syscalls.PartiallySupported("sched_setaffinity", SchedSetaffinity, "Stub implementation.", nil),
+		204: syscalls.PartiallySupported("sched_getaffinity", SchedGetaffinity, "Stub implementation.", nil),
 		205: syscalls.Error("set_thread_area", syscall.ENOSYS, "Expected to return ENOSYS on 64-bit", nil),
-		206: syscalls.Undocumented("io_setup", IoSetup),
-		207: syscalls.Undocumented("io_destroy", IoDestroy),
-		208: syscalls.Undocumented("io_getevents", IoGetevents),
-		209: syscalls.Undocumented("io_submit", IoSubmit),
-		210: syscalls.Undocumented("io_cancel", IoCancel),
+		206: syscalls.PartiallySupported("io_setup", IoSetup, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
+		207: syscalls.PartiallySupported("io_destroy", IoDestroy, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
+		208: syscalls.PartiallySupported("io_getevents", IoGetevents, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
+		209: syscalls.PartiallySupported("io_submit", IoSubmit, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
+		210: syscalls.PartiallySupported("io_cancel", IoCancel, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
 		211: syscalls.Error("get_thread_area", syscall.ENOSYS, "Expected to return ENOSYS on 64-bit", nil),
 		212: syscalls.CapError("lookup_dcookie", linux.CAP_SYS_ADMIN, "", nil),
-		213: syscalls.Undocumented("epoll_create", EpollCreate),
-		214: syscalls.ErrorWithEvent("epoll_ctl_old", syscall.ENOSYS, "Deprecated", nil),
-		215: syscalls.ErrorWithEvent("epoll_wait_old", syscall.ENOSYS, "Deprecated", nil),
-		216: syscalls.ErrorWithEvent("remap_file_pages", syscall.ENOSYS, "Deprecated since 3.16", nil),
-		217: syscalls.Undocumented("getdents64", Getdents64),
-		218: syscalls.Undocumented("set_tid_address", SetTidAddress),
-		219: syscalls.Undocumented("restart_syscall", RestartSyscall),
+		213: syscalls.Supported("epoll_create", EpollCreate),
+		214: syscalls.ErrorWithEvent("epoll_ctl_old", syscall.ENOSYS, "Deprecated.", nil),
+		215: syscalls.ErrorWithEvent("epoll_wait_old", syscall.ENOSYS, "Deprecated.", nil),
+		216: syscalls.ErrorWithEvent("remap_file_pages", syscall.ENOSYS, "Deprecated since Linux 3.16.", nil),
+		217: syscalls.Supported("getdents64", Getdents64),
+		218: syscalls.Supported("set_tid_address", SetTidAddress),
+		219: syscalls.Supported("restart_syscall", RestartSyscall),
 		220: syscalls.ErrorWithEvent("semtimedop", syscall.ENOSYS, "", []string{"gvisor.dev/issue/137"}), // TODO(b/29354920)
-		221: syscalls.Undocumented("fadvise64", Fadvise64),
-		222: syscalls.Undocumented("timer_create", TimerCreate),
-		223: syscalls.Undocumented("timer_settime", TimerSettime),
-		224: syscalls.Undocumented("timer_gettime", TimerGettime),
-		225: syscalls.Undocumented("timer_getoverrun", TimerGetoverrun),
-		226: syscalls.Undocumented("timer_delete", TimerDelete),
-		227: syscalls.Undocumented("clock_settime", ClockSettime),
-		228: syscalls.Undocumented("clock_gettime", ClockGettime),
-		229: syscalls.Undocumented("clock_getres", ClockGetres),
-		230: syscalls.Undocumented("clock_nanosleep", ClockNanosleep),
-		231: syscalls.Undocumented("exit_group", ExitGroup),
-		232: syscalls.Undocumented("epoll_wait", EpollWait),
-		233: syscalls.Undocumented("epoll_ctl", EpollCtl),
-		234: syscalls.Undocumented("tgkill", Tgkill),
-		235: syscalls.Undocumented("utimes", Utimes),
+		221: syscalls.PartiallySupported("fadvise64", Fadvise64, "Not all options are supported.", nil),
+		222: syscalls.Supported("timer_create", TimerCreate),
+		223: syscalls.Supported("timer_settime", TimerSettime),
+		224: syscalls.Supported("timer_gettime", TimerGettime),
+		225: syscalls.Supported("timer_getoverrun", TimerGetoverrun),
+		226: syscalls.Supported("timer_delete", TimerDelete),
+		227: syscalls.Supported("clock_settime", ClockSettime),
+		228: syscalls.Supported("clock_gettime", ClockGettime),
+		229: syscalls.Supported("clock_getres", ClockGetres),
+		230: syscalls.Supported("clock_nanosleep", ClockNanosleep),
+		231: syscalls.Supported("exit_group", ExitGroup),
+		232: syscalls.Supported("epoll_wait", EpollWait),
+		233: syscalls.Supported("epoll_ctl", EpollCtl),
+		234: syscalls.Supported("tgkill", Tgkill),
+		235: syscalls.Supported("utimes", Utimes),
 		236: syscalls.Error("vserver", syscall.ENOSYS, "Not implemented by Linux", nil),
 		237: syscalls.PartiallySupported("mbind", Mbind, "Stub implementation. Only a single NUMA node is advertised, and mempolicy is ignored accordingly, but mbind() will succeed and has effects reflected by get_mempolicy.", []string{"gvisor.dev/issue/262"}),
-		238: syscalls.Undocumented("set_mempolicy", SetMempolicy),
-		239: syscalls.Undocumented("get_mempolicy", GetMempolicy),
+		238: syscalls.PartiallySupported("set_mempolicy", SetMempolicy, "Stub implementation.", nil),
+		239: syscalls.PartiallySupported("get_mempolicy", GetMempolicy, "Stub implementation.", nil),
 		240: syscalls.ErrorWithEvent("mq_open", syscall.ENOSYS, "", []string{"gvisor.dev/issue/136"}),         // TODO(b/29354921)
 		241: syscalls.ErrorWithEvent("mq_unlink", syscall.ENOSYS, "", []string{"gvisor.dev/issue/136"}),       // TODO(b/29354921)
 		242: syscalls.ErrorWithEvent("mq_timedsend", syscall.ENOSYS, "", []string{"gvisor.dev/issue/136"}),    // TODO(b/29354921)
@@ -295,69 +295,69 @@ var AMD64 = &kernel.SyscallTable{
 		244: syscalls.ErrorWithEvent("mq_notify", syscall.ENOSYS, "", []string{"gvisor.dev/issue/136"}),       // TODO(b/29354921)
 		245: syscalls.ErrorWithEvent("mq_getsetattr", syscall.ENOSYS, "", []string{"gvisor.dev/issue/136"}),   // TODO(b/29354921)
 		246: syscalls.CapError("kexec_load", linux.CAP_SYS_BOOT, "", nil),
-		247: syscalls.Undocumented("waitid", Waitid),
-		248: syscalls.Error("add_key", syscall.EACCES, "Not available to user", nil),
-		249: syscalls.Error("request_key", syscall.EACCES, "Not available to user", nil),
-		250: syscalls.Error("keyctl", syscall.EACCES, "Not available to user", nil),
+		247: syscalls.Supported("waitid", Waitid),
+		248: syscalls.Error("add_key", syscall.EACCES, "Not available to user.", nil),
+		249: syscalls.Error("request_key", syscall.EACCES, "Not available to user.", nil),
+		250: syscalls.Error("keyctl", syscall.EACCES, "Not available to user.", nil),
 		251: syscalls.CapError("ioprio_set", linux.CAP_SYS_ADMIN, "", nil), // requires cap_sys_nice or cap_sys_admin (depending)
 		252: syscalls.CapError("ioprio_get", linux.CAP_SYS_ADMIN, "", nil), // requires cap_sys_nice or cap_sys_admin (depending)
-		253: syscalls.Undocumented("inotify_init", InotifyInit),
-		254: syscalls.Undocumented("inotify_add_watch", InotifyAddWatch),
-		255: syscalls.Undocumented("inotify_rm_watch", InotifyRmWatch),
+		253: syscalls.PartiallySupported("inotify_init", InotifyInit, "inotify events are only available inside the sandbox.", nil),
+		254: syscalls.PartiallySupported("inotify_add_watch", InotifyAddWatch, "inotify events are only available inside the sandbox.", nil),
+		255: syscalls.PartiallySupported("inotify_rm_watch", InotifyRmWatch, "inotify events are only available inside the sandbox.", nil),
 		256: syscalls.CapError("migrate_pages", linux.CAP_SYS_NICE, "", nil),
-		257: syscalls.Undocumented("openat", Openat),
-		258: syscalls.Undocumented("mkdirat", Mkdirat),
-		259: syscalls.Undocumented("mknodat", Mknodat),
-		260: syscalls.Undocumented("fchownat", Fchownat),
-		261: syscalls.Undocumented("futimesat", Futimesat),
-		262: syscalls.Undocumented("fstatat", Fstatat),
-		263: syscalls.Undocumented("unlinkat", Unlinkat),
-		264: syscalls.Undocumented("renameat", Renameat),
-		265: syscalls.Undocumented("linkat", Linkat),
-		266: syscalls.Undocumented("symlinkat", Symlinkat),
-		267: syscalls.Undocumented("readlinkat", Readlinkat),
-		268: syscalls.Undocumented("fchmodat", Fchmodat),
-		269: syscalls.Undocumented("faccessat", Faccessat),
-		270: syscalls.Undocumented("pselect", Pselect),
-		271: syscalls.Undocumented("ppoll", Ppoll),
-		272: syscalls.Undocumented("unshare", Unshare),
-		273: syscalls.Error("set_robust_list", syscall.ENOSYS, "Obsolete", nil),
-		274: syscalls.Error("get_robust_list", syscall.ENOSYS, "Obsolete", nil),
-		275: syscalls.PartiallySupported("splice", Splice, "Stub implementation", []string{"gvisor.dev/issue/138"}), // TODO(b/29354098)
-		276: syscalls.ErrorWithEvent("tee", syscall.ENOSYS, "", []string{"gvisor.dev/issue/138"}),                   // TODO(b/29354098)
-		277: syscalls.Undocumented("sync_file_range", SyncFileRange),
+		257: syscalls.Supported("openat", Openat),
+		258: syscalls.Supported("mkdirat", Mkdirat),
+		259: syscalls.Supported("mknodat", Mknodat),
+		260: syscalls.Supported("fchownat", Fchownat),
+		261: syscalls.Supported("futimesat", Futimesat),
+		262: syscalls.Supported("fstatat", Fstatat),
+		263: syscalls.Supported("unlinkat", Unlinkat),
+		264: syscalls.Supported("renameat", Renameat),
+		265: syscalls.Supported("linkat", Linkat),
+		266: syscalls.Supported("symlinkat", Symlinkat),
+		267: syscalls.Supported("readlinkat", Readlinkat),
+		268: syscalls.Supported("fchmodat", Fchmodat),
+		269: syscalls.Supported("faccessat", Faccessat),
+		270: syscalls.Supported("pselect", Pselect),
+		271: syscalls.Supported("ppoll", Ppoll),
+		272: syscalls.PartiallySupported("unshare", Unshare, "Mount, cgroup namespaces not supported. Network namespaces supported but must be empty.", nil),
+		273: syscalls.Error("set_robust_list", syscall.ENOSYS, "Obsolete.", nil),
+		274: syscalls.Error("get_robust_list", syscall.ENOSYS, "Obsolete.", nil),
+		275: syscalls.PartiallySupported("splice", Splice, "Stub implementation.", []string{"gvisor.dev/issue/138"}), // TODO(b/29354098)
+		276: syscalls.ErrorWithEvent("tee", syscall.ENOSYS, "", []string{"gvisor.dev/issue/138"}),                    // TODO(b/29354098)
+		277: syscalls.PartiallySupported("sync_file_range", SyncFileRange, "Full data flush is not guaranteed at this time.", nil),
 		278: syscalls.ErrorWithEvent("vmsplice", syscall.ENOSYS, "", []string{"gvisor.dev/issue/138"}), // TODO(b/29354098)
 		279: syscalls.CapError("move_pages", linux.CAP_SYS_NICE, "", nil),                              // requires cap_sys_nice (mostly)
-		280: syscalls.Undocumented("utimensat", Utimensat),
-		281: syscalls.Undocumented("epoll_pwait", EpollPwait),
+		280: syscalls.Supported("utimensat", Utimensat),
+		281: syscalls.Supported("epoll_pwait", EpollPwait),
 		282: syscalls.ErrorWithEvent("signalfd", syscall.ENOSYS, "", []string{"gvisor.dev/issue/139"}), // TODO(b/19846426)
-		283: syscalls.Undocumented("timerfd_create", TimerfdCreate),
-		284: syscalls.Undocumented("eventfd", Eventfd),
-		285: syscalls.Undocumented("fallocate", Fallocate),
-		286: syscalls.Undocumented("timerfd_settime", TimerfdSettime),
-		287: syscalls.Undocumented("timerfd_gettime", TimerfdGettime),
-		288: syscalls.Undocumented("accept4", Accept4),
+		283: syscalls.Supported("timerfd_create", TimerfdCreate),
+		284: syscalls.Supported("eventfd", Eventfd),
+		285: syscalls.PartiallySupported("fallocate", Fallocate, "Not all options are supported.", nil),
+		286: syscalls.Supported("timerfd_settime", TimerfdSettime),
+		287: syscalls.Supported("timerfd_gettime", TimerfdGettime),
+		288: syscalls.Supported("accept4", Accept4),
 		289: syscalls.ErrorWithEvent("signalfd4", syscall.ENOSYS, "", []string{"gvisor.dev/issue/139"}), // TODO(b/19846426)
-		290: syscalls.Undocumented("eventfd2", Eventfd2),
-		291: syscalls.Undocumented("epoll_create1", EpollCreate1),
-		292: syscalls.Undocumented("dup3", Dup3),
-		293: syscalls.Undocumented("pipe2", Pipe2),
-		294: syscalls.Undocumented("inotify_init1", InotifyInit1),
-		295: syscalls.Undocumented("preadv", Preadv),
-		296: syscalls.Undocumented("pwritev", Pwritev),
-		297: syscalls.Undocumented("rt_tgsigqueueinfo", RtTgsigqueueinfo),
+		290: syscalls.Supported("eventfd2", Eventfd2),
+		291: syscalls.Supported("epoll_create1", EpollCreate1),
+		292: syscalls.Supported("dup3", Dup3),
+		293: syscalls.Supported("pipe2", Pipe2),
+		294: syscalls.Supported("inotify_init1", InotifyInit1),
+		295: syscalls.Supported("preadv", Preadv),
+		296: syscalls.Supported("pwritev", Pwritev),
+		297: syscalls.Supported("rt_tgsigqueueinfo", RtTgsigqueueinfo),
 		298: syscalls.ErrorWithEvent("perf_event_open", syscall.ENODEV, "No support for perf counters", nil),
-		299: syscalls.Undocumented("recvmmsg", RecvMMsg),
+		299: syscalls.PartiallySupported("recvmmsg", RecvMMsg, "Not all flags and control messages are supported.", nil),
 		300: syscalls.ErrorWithEvent("fanotify_init", syscall.ENOSYS, "Needs CONFIG_FANOTIFY", nil),
 		301: syscalls.ErrorWithEvent("fanotify_mark", syscall.ENOSYS, "Needs CONFIG_FANOTIFY", nil),
-		302: syscalls.Undocumented("prlimit64", Prlimit64),
+		302: syscalls.Supported("prlimit64", Prlimit64),
 		303: syscalls.Error("name_to_handle_at", syscall.EOPNOTSUPP, "Not supported by gVisor filesystems", nil),
 		304: syscalls.Error("open_by_handle_at", syscall.EOPNOTSUPP, "Not supported by gVisor filesystems", nil),
 		305: syscalls.CapError("clock_adjtime", linux.CAP_SYS_TIME, "", nil),
-		306: syscalls.Undocumented("syncfs", Syncfs),
-		307: syscalls.Undocumented("sendmmsg", SendMMsg),
+		306: syscalls.PartiallySupported("syncfs", Syncfs, "Depends on backing file system.", nil),
+		307: syscalls.PartiallySupported("sendmmsg", SendMMsg, "Not all flags and control messages are supported.", nil),
 		308: syscalls.ErrorWithEvent("setns", syscall.EOPNOTSUPP, "Needs filesystem support", []string{"gvisor.dev/issue/140"}), // TODO(b/29354995)
-		309: syscalls.Undocumented("getcpu", Getcpu),
+		309: syscalls.Supported("getcpu", Getcpu),
 		310: syscalls.ErrorWithEvent("process_vm_readv", syscall.ENOSYS, "", []string{"gvisor.dev/issue/158"}),
 		311: syscalls.ErrorWithEvent("process_vm_writev", syscall.ENOSYS, "", []string{"gvisor.dev/issue/158"}),
 		312: syscalls.CapError("kcmp", linux.CAP_SYS_PTRACE, "", nil),
@@ -365,20 +365,20 @@ var AMD64 = &kernel.SyscallTable{
 		314: syscalls.ErrorWithEvent("sched_setattr", syscall.ENOSYS, "gVisor does not implement a scheduler.", []string{"gvisor.dev/issue/264"}), // TODO(b/118902272)
 		315: syscalls.ErrorWithEvent("sched_getattr", syscall.ENOSYS, "gVisor does not implement a scheduler.", []string{"gvisor.dev/issue/264"}), // TODO(b/118902272)
 		316: syscalls.ErrorWithEvent("renameat2", syscall.ENOSYS, "", []string{"gvisor.dev/issue/263"}),                                           // TODO(b/118902772)
-		317: syscalls.Undocumented("seccomp", Seccomp),
-		318: syscalls.Undocumented("getrandom", GetRandom),
-		319: syscalls.Undocumented("memfd_create", MemfdCreate),
+		317: syscalls.Supported("seccomp", Seccomp),
+		318: syscalls.Supported("getrandom", GetRandom),
+		319: syscalls.Supported("memfd_create", MemfdCreate),
 		320: syscalls.CapError("kexec_file_load", linux.CAP_SYS_BOOT, "", nil),
 		321: syscalls.CapError("bpf", linux.CAP_SYS_ADMIN, "", nil),
 		322: syscalls.ErrorWithEvent("execveat", syscall.ENOSYS, "", []string{"gvisor.dev/issue/265"}),    // TODO(b/118901836)
 		323: syscalls.ErrorWithEvent("userfaultfd", syscall.ENOSYS, "", []string{"gvisor.dev/issue/266"}), // TODO(b/118906345)
 		324: syscalls.ErrorWithEvent("membarrier", syscall.ENOSYS, "", []string{"gvisor.dev/issue/267"}),  // TODO(b/118904897)
-		325: syscalls.Undocumented("mlock2", Mlock2),
+		325: syscalls.PartiallySupported("mlock2", Mlock2, "Stub implementation. The sandbox lacks appropriate permissions.", nil),
 
 		// Syscalls after 325 are "backports" from versions of Linux after 4.4.
 		326: syscalls.ErrorWithEvent("copy_file_range", syscall.ENOSYS, "", nil),
-		327: syscalls.Undocumented("preadv2", Preadv2),
-		328: syscalls.Undocumented("pwritev2", Pwritev2),
+		327: syscalls.Supported("preadv2", Preadv2),
+		328: syscalls.PartiallySupported("pwritev2", Pwritev2, "Flag RWF_HIPRI is not supported.", nil),
 		332: syscalls.Supported("statx", Statx),
 	},
 
diff --git a/pkg/sentry/syscalls/syscalls.go b/pkg/sentry/syscalls/syscalls.go
index a5f3d8407..94d52d5d5 100644
--- a/pkg/sentry/syscalls/syscalls.go
+++ b/pkg/sentry/syscalls/syscalls.go
@@ -40,16 +40,7 @@ func Supported(name string, fn kernel.SyscallFn) kernel.Syscall {
 		Name:         name,
 		Fn:           fn,
 		SupportLevel: kernel.SupportFull,
-		Note:         "Full Support",
-	}
-}
-
-// Undocumented returns a syscall that is undocumented.
-func Undocumented(name string, fn kernel.SyscallFn) kernel.Syscall {
-	return kernel.Syscall{
-		Name:         name,
-		Fn:           fn,
-		SupportLevel: kernel.SupportUndocumented,
+		Note:         "Fully Supported.",
 	}
 }
 
@@ -75,7 +66,7 @@ func Error(name string, err syscall.Errno, note string, urls []string) kernel.Sy
 			return 0, nil, err
 		},
 		SupportLevel: kernel.SupportUnimplemented,
-		Note:         fmt.Sprintf("%sReturns %q", note, err.Error()),
+		Note:         fmt.Sprintf("%sReturns %q.", note, err.Error()),
 		URLs:         urls,
 	}
 }
@@ -93,7 +84,7 @@ func ErrorWithEvent(name string, err syscall.Errno, note string, urls []string)
 			return 0, nil, err
 		},
 		SupportLevel: kernel.SupportUnimplemented,
-		Note:         fmt.Sprintf("%sReturns %q", note, err.Error()),
+		Note:         fmt.Sprintf("%sReturns %q.", note, err.Error()),
 		URLs:         urls,
 	}
 }
@@ -115,7 +106,7 @@ func CapError(name string, c linux.Capability, note string, urls []string) kerne
 			return 0, nil, syserror.ENOSYS
 		},
 		SupportLevel: kernel.SupportUnimplemented,
-		Note:         fmt.Sprintf("%sReturns %q if the process does not have %s; %q otherwise", note, syserror.EPERM, c.String(), syserror.ENOSYS),
+		Note:         fmt.Sprintf("%sReturns %q if the process does not have %s; %q otherwise.", note, syserror.EPERM, c.String(), syserror.ENOSYS),
 		URLs:         urls,
 	}
 }