ladybird/Kernel/Syscalls/get_stack_bounds.cpp
2021-08-01 08:10:16 +02:00

32 lines
973 B
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Process.h>
#include <Kernel/VM/Region.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$get_stack_bounds(Userspace<FlatPtr*> user_stack_base, Userspace<size_t*> user_stack_size)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
auto& regs = Thread::current()->get_register_dump_from_stack();
FlatPtr stack_pointer = regs.userspace_sp();
auto* stack_region = space().find_region_containing(Range { VirtualAddress(stack_pointer), 1 });
// The syscall handler should have killed us if we had an invalid stack pointer.
VERIFY(stack_region);
FlatPtr stack_base = stack_region->range().base().get();
size_t stack_size = stack_region->size();
if (!copy_to_user(user_stack_base, &stack_base))
return EFAULT;
if (!copy_to_user(user_stack_size, &stack_size))
return EFAULT;
return 0;
}
}