asterinas/kernel/src/syscall/brk.rs

26 lines
781 B
Rust

// SPDX-License-Identifier: MPL-2.0
use crate::{prelude::*, syscall::SyscallReturn};
/// expand the user heap to new heap end, returns the new heap end if expansion succeeds.
pub fn sys_brk(heap_end: u64, ctx: &Context) -> Result<SyscallReturn> {
let new_heap_end = if heap_end == 0 {
None
} else {
Some(heap_end as usize)
};
debug!("new heap end = {:x?}", heap_end);
let user_space = ctx.user_space();
let user_heap = user_space.vmar().process_vm().heap();
let current_heap_end = match new_heap_end {
Some(addr) => user_heap
.modify_heap_end(addr, ctx)
.unwrap_or_else(|cur_heap_end| cur_heap_end),
None => user_heap.heap_end(),
};
Ok(SyscallReturn::Return(current_heap_end as _))
}