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Kernel: Take some baby steps towards x86_64

Make more of the kernel compile in 64-bit mode, and make some things
pointer-size-agnostic (by using FlatPtr.)

There's a lot of work to do here before the kernel will even compile.
This commit is contained in:
Andreas Kling 2021-02-25 16:18:36 +01:00
parent eb08a0edd5
commit 8f70528f30
12 changed files with 187 additions and 118 deletions

View file

@ -137,13 +137,13 @@ static bool validate_inode_mmap_prot(const Process& process, int prot, const Ino
return true;
}
void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
FlatPtr Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
{
REQUIRE_PROMISE(stdio);
Syscall::SC_mmap_params params;
if (!copy_from_user(&params, user_params))
return (void*)-EFAULT;
return -EFAULT;
void* addr = (void*)params.addr;
size_t size = params.size;
@ -162,27 +162,27 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
}
if (alignment & ~PAGE_MASK)
return (void*)-EINVAL;
return -EINVAL;
if (page_round_up_would_wrap(size))
return (void*)-EINVAL;
return -EINVAL;
if (!is_user_range(VirtualAddress(addr), page_round_up(size)))
return (void*)-EFAULT;
return -EFAULT;
String name;
if (params.name.characters) {
if (params.name.length > PATH_MAX)
return (void*)-ENAMETOOLONG;
return -ENAMETOOLONG;
name = copy_string_from_user(params.name);
if (name.is_null())
return (void*)-EFAULT;
return -EFAULT;
}
if (size == 0)
return (void*)-EINVAL;
return -EINVAL;
if ((FlatPtr)addr & ~PAGE_MASK)
return (void*)-EINVAL;
return -EINVAL;
bool map_shared = flags & MAP_SHARED;
bool map_anonymous = flags & MAP_ANONYMOUS;
@ -193,19 +193,19 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
bool map_randomized = flags & MAP_RANDOMIZED;
if (map_shared && map_private)
return (void*)-EINVAL;
return -EINVAL;
if (!map_shared && !map_private)
return (void*)-EINVAL;
return -EINVAL;
if (map_fixed && map_randomized)
return (void*)-EINVAL;
return -EINVAL;
if (!validate_mmap_prot(prot, map_stack, map_anonymous))
return (void*)-EINVAL;
return -EINVAL;
if (map_stack && (!map_private || !map_anonymous))
return (void*)-EINVAL;
return -EINVAL;
Region* region = nullptr;
Optional<Range> range;
@ -223,44 +223,44 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
}
if (!range.has_value())
return (void*)-ENOMEM;
return -ENOMEM;
if (map_anonymous) {
auto strategy = map_noreserve ? AllocationStrategy::None : AllocationStrategy::Reserve;
auto region_or_error = space().allocate_region(range.value(), !name.is_null() ? name : "mmap", prot, strategy);
if (region_or_error.is_error())
return (void*)region_or_error.error().error();
return region_or_error.error().error();
region = region_or_error.value();
} else {
if (offset < 0)
return (void*)-EINVAL;
return -EINVAL;
if (static_cast<size_t>(offset) & ~PAGE_MASK)
return (void*)-EINVAL;
return -EINVAL;
auto description = file_description(fd);
if (!description)
return (void*)-EBADF;
return -EBADF;
if (description->is_directory())
return (void*)-ENODEV;
return -ENODEV;
// Require read access even when read protection is not requested.
if (!description->is_readable())
return (void*)-EACCES;
return -EACCES;
if (map_shared) {
if ((prot & PROT_WRITE) && !description->is_writable())
return (void*)-EACCES;
return -EACCES;
}
if (description->inode()) {
if (!validate_inode_mmap_prot(*this, prot, *description->inode(), map_shared))
return (void*)-EACCES;
return -EACCES;
}
auto region_or_error = description->mmap(*this, range.value(), static_cast<size_t>(offset), prot, map_shared);
if (region_or_error.is_error())
return (void*)region_or_error.error().error();
return region_or_error.error().error();
region = region_or_error.value();
}
if (!region)
return (void*)-ENOMEM;
return -ENOMEM;
region->set_mmap(true);
if (map_shared)
region->set_shared(true);
@ -268,7 +268,7 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
region->set_stack(true);
if (!name.is_null())
region->set_name(name);
return region->vaddr().as_ptr();
return region->vaddr().get();
}
static KResultOr<Range> expand_range_to_page_boundaries(FlatPtr address, size_t size)
@ -494,26 +494,26 @@ int Process::sys$munmap(void* addr, size_t size)
return -EINVAL;
}
void* Process::sys$mremap(Userspace<const Syscall::SC_mremap_params*> user_params)
FlatPtr Process::sys$mremap(Userspace<const Syscall::SC_mremap_params*> user_params)
{
REQUIRE_PROMISE(stdio);
Syscall::SC_mremap_params params {};
if (!copy_from_user(&params, user_params))
return (void*)-EFAULT;
return -EFAULT;
auto range_or_error = expand_range_to_page_boundaries((FlatPtr)params.old_address, params.old_size);
if (range_or_error.is_error())
return (void*)range_or_error.error().error();
return range_or_error.error().error();
auto old_range = range_or_error.value();
auto* old_region = space().find_region_from_range(old_range);
if (!old_region)
return (void*)-EINVAL;
return -EINVAL;
if (!old_region->is_mmap())
return (void*)-EPERM;
return -EPERM;
if (old_region->vmobject().is_shared_inode() && params.flags & MAP_PRIVATE && !(params.flags & (MAP_ANONYMOUS | MAP_NORESERVE))) {
auto range = old_region->range();
@ -529,28 +529,28 @@ void* Process::sys$mremap(Userspace<const Syscall::SC_mremap_params*> user_param
auto new_region_or_error = space().allocate_region_with_vmobject(range, new_vmobject, 0, old_name, old_prot, false);
if (new_region_or_error.is_error())
return (void*)new_region_or_error.error().error();
return new_region_or_error.error().error();
auto& new_region = *new_region_or_error.value();
new_region.set_mmap(true);
return new_region.vaddr().as_ptr();
return new_region.vaddr().get();
}
dbgln("sys$mremap: Unimplemented remap request (flags={})", params.flags);
return (void*)-ENOTIMPL;
return -ENOTIMPL;
}
void* Process::sys$allocate_tls(size_t size)
FlatPtr Process::sys$allocate_tls(size_t size)
{
REQUIRE_PROMISE(stdio);
if (!size)
return (void*)-EINVAL;
return -EINVAL;
if (!m_master_tls_region.is_null())
return (void*)-EEXIST;
return -EEXIST;
if (thread_count() != 1)
return (void*)-EFAULT;
return -EFAULT;
Thread* main_thread = nullptr;
for_each_thread([&main_thread](auto& thread) {
@ -561,11 +561,11 @@ void* Process::sys$allocate_tls(size_t size)
auto range = space().allocate_range({}, size);
if (!range.has_value())
return (void*)-ENOMEM;
return -ENOMEM;
auto region_or_error = space().allocate_region(range.value(), String(), PROT_READ | PROT_WRITE);
if (region_or_error.is_error())
return (void*)region_or_error.error().error();
return region_or_error.error().error();
m_master_tls_region = region_or_error.value()->make_weak_ptr();
m_master_tls_size = size;
@ -573,13 +573,13 @@ void* Process::sys$allocate_tls(size_t size)
auto tsr_result = main_thread->make_thread_specific_region({});
if (tsr_result.is_error())
return (void*)-EFAULT;
return -EFAULT;
auto& tls_descriptor = Processor::current().get_gdt_entry(GDT_SELECTOR_TLS);
tls_descriptor.set_base(main_thread->thread_specific_data());
tls_descriptor.set_limit(main_thread->thread_specific_region_size());
return m_master_tls_region.unsafe_ptr()->vaddr().as_ptr();
return m_master_tls_region.unsafe_ptr()->vaddr().get();
}
int Process::sys$msyscall(void* address)