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clone: Make stack manipulation arch specific

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This commit is contained in:
Robin Randhawa
2021-01-17 10:26:49 +00:00
parent ae0aebd036
commit 95bd8f2013
1 changed files with 23 additions and 18 deletions
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41
src/syscall/process.rs
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@@ -94,28 +94,33 @@ pub fn clone(flags: CloneFlags, stack_base: usize) -> Result<ContextId> {
kfx_opt = Some(new_fx);
}
if let Some(ref stack) = context.kstack {
// Get the relative offset to the return address of the function
// obtaining `stack_base`.
//
// (base pointer - start of stack) - one
offset = stack_base - stack.as_ptr() as usize - mem::size_of::<usize>(); // Add clone ret
let mut new_stack = stack.clone();
#[cfg(target_arch = "x86_64")]
{
if let Some(ref stack) = context.kstack {
// Get the relative offset to the return address of the function
// obtaining `stack_base`.
//
// (base pointer - start of stack) - one
offset = stack_base - stack.as_ptr() as usize - mem::size_of::<usize>(); // Add clone ret
let mut new_stack = stack.clone();
unsafe {
// Set clone's return value to zero. This is done because
// the clone won't return like normal, which means the value
// would otherwise never get set.
#[cfg(target_arch = "x86_64")] // TODO
if let Some(regs) = ptrace::rebase_regs_ptr_mut(context.regs, Some(&mut new_stack)) {
(*regs).scratch.rax = 0;
unsafe {
// Set clone's return value to zero. This is done because
// the clone won't return like normal, which means the value
// would otherwise never get set.
if let Some(regs) = ptrace::rebase_regs_ptr_mut(context.regs, Some(&mut new_stack)) {
(*regs).scratch.rax = 0;
}
// Change the return address of the child (previously
// syscall) to the arch-specific clone_ret callback
let func_ptr = new_stack.as_mut_ptr().add(offset);
*(func_ptr as *mut usize) = interrupt::syscall::clone_ret as usize;
}
// Change the return address of the child (previously
// syscall) to the arch-specific clone_ret callback
let func_ptr = new_stack.as_mut_ptr().add(offset);
*(func_ptr as *mut usize) = interrupt::syscall::clone_ret as usize;
kstack_opt = Some(new_stack);
}
}
kstack_opt = Some(new_stack);
}