[#88] Draft of foundations for clone3() syscall & friends
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| Original file line number | Diff line number | Diff line change | ||||||
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| use crate::prelude::*; | ||||||||
| use crate::syscalls::SyscallHandler; | ||||||||
| use crate::{ | ||||||||
| ctypes::* | ||||||||
| }; | ||||||||
| use kerla_runtime::address::UserVAddr; | ||||||||
| use bitflags::bitflags; | ||||||||
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| bitflags! { | ||||||||
| /// Flags used by [`clone()`] system call | ||||||||
| /// Source: `/usr/include/linux/sched.h` | ||||||||
| /// | ||||||||
| /// [`clone()`]: https://linux.die.net/man/2/clone | ||||||||
| pub struct CloneFlags : c_uint { | ||||||||
| const CLONE_VM = 0x00000100; // set if VM shared between processes | ||||||||
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| const CLONE_FS = 0x00000200; // set if fs info shared between processes | ||||||||
| const CLONE_FILES = 0x00000400; // set if open files shared between processes | ||||||||
| const CLONE_SIGHAND = 0x00000800; // set if signal handlers and blocked signals shared | ||||||||
| const CLONE_PIDFD = 0x00001000; // set if a pidfd should be placed in parent | ||||||||
| const CLONE_PTRACE = 0x00002000; // set if we want to let tracing continue on the child too | ||||||||
| const CLONE_VFORK = 0x00004000; // set if the parent wants the child to wake it up on mm_release | ||||||||
| const CLONE_PARENT = 0x00008000; // set if we want to have the same parent as the cloner | ||||||||
| const CLONE_THREAD = 0x00010000; // Same thread group? | ||||||||
| const CLONE_NEWNS = 0x00020000; // New mount namespace group | ||||||||
| const CLONE_SYSVSEM = 0x00040000; // share system V SEM_UNDO semantics | ||||||||
| const CLONE_SETTLS = 0x00080000; // create a new TLS for the child | ||||||||
| const CLONE_PARENT_SETTID = 0x00100000; // set the TID in the parent | ||||||||
| const CLONE_CHILD_CLEARTID = 0x00200000; // clear the TID in the child | ||||||||
| const CLONE_DETACHED = 0x00400000; // Unused, ignored | ||||||||
| const CLONE_UNTRACED = 0x00800000; // set if the tracing process can't force CLONE_PTRACE on this clone | ||||||||
| const CLONE_CHILD_SETTID = 0x01000000; // set the TID in the child | ||||||||
| const CLONE_NEWCGROUP = 0x02000000; // New cgroup namespace | ||||||||
| const CLONE_NEWUTS = 0x04000000; // New utsname namespace | ||||||||
| const CLONE_NEWIPC = 0x08000000; // New ipc namespace | ||||||||
| const CLONE_NEWUSER = 0x10000000; // New user namespace | ||||||||
| const CLONE_NEWPID = 0x20000000; // New pid namespace | ||||||||
| const CLONE_NEWNET = 0x40000000; // New network namespace | ||||||||
| const CLONE_IO = 0x80000000; // Clone io context | ||||||||
| } | ||||||||
| } | ||||||||
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| #[repr(C, align(8))] | ||||||||
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| pub struct CloneArgs { | ||||||||
| flags: u64, | ||||||||
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| pidfd: u64, | ||||||||
| child_tid: u64, | ||||||||
| parent_tid: u64, | ||||||||
| exit_signal: u64, | ||||||||
| stack: u64, | ||||||||
| stack_size: u64, | ||||||||
| tls: u64, | ||||||||
| set_tid: u64, | ||||||||
| set_tid_size: u64, | ||||||||
| cgroup: u64, | ||||||||
| } | ||||||||
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| /// Internal structure for `clone3()` system call | ||||||||
| /// Modeled on `kernel_clone_args` from `include/linux/sched/task.h` | ||||||||
| pub(crate) struct KernelCloneArgs { | ||||||||
| flags: CloneFlags, | ||||||||
| pidfd: Option<UserVAddr>, /// Address to store pidfd into | ||||||||
| child_tid: Option<UserVAddr>, /// Address to store child TID into or read futex address | ||||||||
| parent_tid: Option<UserVAddr>, /// Address to store parent TID into... | ||||||||
| exit_signal: c_int, /// Exit signal; TODO: I'd suggest enum for signal IDs for type safety | ||||||||
| stack: UserVAddr, | ||||||||
| stack_size: usize, | ||||||||
| tls: UserVAddr, | ||||||||
| set_tid: Option<UserVAddr>, /// Handles TID array, requires namespace support | ||||||||
| set_tid_size: usize, /// Number of elements in set_tid | ||||||||
| cgroup: c_int, | ||||||||
| io_thread: c_int, | ||||||||
| //struct cgroup *cgrp; // TODO: Kerla don't have support for cgroups yet | ||||||||
| //struct css_set *cset; // cgroup sets TODO: Kerla don't have support for cgroups yet | ||||||||
| } | ||||||||
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| impl From<CloneArgs> for KernelCloneArgs { | ||||||||
| fn from(item: CloneArgs) -> Self { | ||||||||
| KernelCloneArgs { | ||||||||
| flags: CloneFlags::from_bits_truncate(item.flags as u32), | ||||||||
| pidfd: UserVAddr::new_nonnull(item.pidfd as usize).map_or(None, |v| Some(v)), | ||||||||
| child_tid: UserVAddr::new_nonnull(item.child_tid as usize).map_or(None, |v| Some(v)), | ||||||||
| parent_tid: UserVAddr::new_nonnull(item.parent_tid as usize).map_or(None, |v| Some(v)), | ||||||||
| exit_signal: item.exit_signal as c_int, // TODO: we need nicer signal type internally | ||||||||
| stack: unsafe { UserVAddr::new_unchecked(item.stack as usize) }, // TODO: this might be a problem - I struggle with distinction which type is output and which is input, damn C ABI | ||||||||
| stack_size: item.stack_size as usize, | ||||||||
| tls: unsafe { UserVAddr::new_unchecked(item.tls as usize) }, | ||||||||
| set_tid: UserVAddr::new_nonnull(item.set_tid as usize).map_or(None, |v| Some(v)), | ||||||||
| set_tid_size: item.set_tid_size as usize, | ||||||||
| cgroup: item.cgroup as i32, | ||||||||
| io_thread: 0, // TODO: find out what's that! | ||||||||
| } | ||||||||
| } | ||||||||
| } | ||||||||
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| impl<'a> SyscallHandler<'a> { | ||||||||
| // TODO: place `fork()` here either! | ||||||||
| pub fn _sys_fork(&mut self) -> Result<isize> { | ||||||||
| // struct kernel_clone_args args = { | ||||||||
| // .exit_signal = SIGCHLD, | ||||||||
| // }; | ||||||||
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| // return kernel_clone(&args); | ||||||||
| Err(Error::new(Errno::ENOSYS)) | ||||||||
| } | ||||||||
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| pub fn sys_vfork(&mut self) -> Result<isize> { | ||||||||
| // struct kernel_clone_args args = { | ||||||||
| // .flags = CLONE_VFORK | CLONE_VM, | ||||||||
| // .exit_signal = SIGCHLD, | ||||||||
| // }; | ||||||||
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| // return kernel_clone(&args); | ||||||||
| Err(Error::new(Errno::ENOSYS)) | ||||||||
| } | ||||||||
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| pub fn sys_clone(&mut self, flags: CloneFlags, child_stack: Option<UserVAddr>, | ||||||||
| parent_tid: Option<UserVAddr>, child_tid: Option<UserVAddr>, | ||||||||
| tls: Option<UserVAddr>, | ||||||||
| ) -> Result<isize> { | ||||||||
| // TODO: implement | ||||||||
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| if let Some(ptid_vaddr) = parent_tid { | ||||||||
| let ptid = 0i32; | ||||||||
| ptid_vaddr.write(&ptid); | ||||||||
| }; | ||||||||
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| if let Some(ctid_vaddr) = child_tid { | ||||||||
| let ctid = 0i32; | ||||||||
| ctid_vaddr.write(&ctid); | ||||||||
| }; | ||||||||
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| Err(Error::new(Errno::ENOSYS)) | ||||||||
| } | ||||||||
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| pub fn sys_clone3(&mut self, uargs: &CloneArgs, size: usize) -> Result<isize> { | ||||||||
| Err(Error::new(Errno::ENOSYS)) | ||||||||
| } | ||||||||
| } | ||||||||
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Please avoid copying from the Linux source code even for a definition like this. Please refer musl instead.