Struct UserContext 

pub struct UserContext {
    pub fs_base: u64,
    pub gs_base: u64,
    /* private fields */
}

Available on crate feature uspace only.

Context to enter user space.

Fields

fs_base: u64

User-owned FS segment base.

CR4.FSGSBASE stays disabled, so userspace cannot modify this value without an arch_prctl-style kernel operation updating this image.

gs_base: u64

User-owned GS segment base.

Implementations

impl UserContext

pub fn new(entry: usize, ustack_top: VirtAddr, arg0: usize) -> Self

Creates a new context with the given entry point, user stack pointer, and the argument.

pub fn prepare_clone_child_return_state(&mut self)

Normalizes a cloned user context so it can safely return to ring 3.

pub fn clear_single_step_after_debug(&mut self) -> bool

Clears the single-step trap flag after a debug exception.

Returns whether the flag had been set in the saved user context.

pub const fn syscall_insn_len(&self) -> usize

Returns the syscall instruction length in bytes.

pub const fn tls(&self) -> usize

Gets the TLS area.

pub const fn set_tls(&mut self, tls_area: usize)

Sets the TLS area.

pub fn has_interruptible_user_return_mode(&self) -> bool

Returns whether this register image can be restored as an interruptible ring-3 context.

pub unsafe fn run_unchecked(&mut self) -> ReturnReason

Enters user space without validating the runtime transition.

It restores the user registers and jumps to the user entry point (saved in rip).

This function returns when an exception or syscall occurs.

Safety

The caller must be the runtime’s prepared user-entry boundary for the current scheduler task. Its context-switch tail must be complete, no IRQ/preemption guard or hard interrupt may be active, and local IRQs must remain disabled after the final scheduler-work check. The active logical address space, hardware root and CPU footprint must match this task and keep every user address referenced by self valid. The saved selectors and RFLAGS must describe an interruptible ring-3 return. No code may run between those validations and this call.

Safe code cannot invoke this raw boundary:

fn bypass_runtime(context: &mut ax_cpu::uspace::UserContext) {
    context.run_unchecked();
}

Methods from Deref<Target = TrapFrame>

pub fn origin(&self) -> TrapOrigin

Returns the privilege domain represented by this register image.

pub fn arg0(&self) -> usize

Gets the 0th syscall argument.

pub fn set_arg0(&mut self, rdi: usize)

Sets the 0th syscall argument.

pub fn arg1(&self) -> usize

Gets the 1st syscall argument.

pub fn set_arg1(&mut self, rsi: usize)

Sets the 1st syscall argument.

pub fn arg2(&self) -> usize

Gets the 2nd syscall argument.

pub fn set_arg2(&mut self, rdx: usize)

Sets the 2nd syscall argument.

pub fn arg3(&self) -> usize

Gets the 3rd syscall argument.

pub fn set_arg3(&mut self, r10: usize)

Sets the 3rd syscall argument.

pub fn arg4(&self) -> usize

Gets the 4th syscall argument.

pub fn set_arg4(&mut self, r8: usize)

Sets the 4th syscall argument.

pub fn arg5(&self) -> usize

Gets the 5th syscall argument.

pub fn set_arg5(&mut self, r9: usize)

Sets the 5th syscall argument.

pub fn ip(&self) -> usize

Gets the instruction pointer.

pub fn set_ip(&mut self, rip: usize)

Sets the instruction pointer.

pub fn sp(&self) -> usize

Gets the stack pointer.

pub fn set_sp(&mut self, rsp: usize)

Sets the stack pointer.

pub fn sysno(&self) -> usize

Gets the syscall number.

pub fn set_sysno(&mut self, rax: usize)

Sets the syscall number.

pub fn retval(&self) -> usize

Gets the return value register.

pub fn set_retval(&mut self, rax: usize)

Sets the return value register.

pub fn backtrace(&self) -> Backtrace

Unwind the stack and get the backtrace.

Trait Implementations

impl Clone for UserContext

fn clone(&self) -> UserContext

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for UserContext

impl Debug for UserContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for UserContext

type Target = TrapFrame

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for UserContext

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl NoUninit for UserContext