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Kernel: Make Process::allocate_region*() return KResultOr<Region*>

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This allows region allocation to return specific errors and we don't
have to assume every failure is an ENOMEM.
This commit is contained in:
Andreas Kling 2021-01-15 17:27:52 +01:00
parent 7899e14e72
commit 64b0d89335
10 changed files with 70 additions and 79 deletions
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40
Kernel/Syscalls/execve.cpp
View file

@ -142,13 +142,13 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
size_t executable_size = inode.size();
auto region = MM.allocate_kernel_region_with_vmobject(*vmobject, PAGE_ROUND_UP(executable_size), "ELF loading", Region::Access::Read);
if (!region) {
auto executable_region = MM.allocate_kernel_region_with_vmobject(*vmobject, PAGE_ROUND_UP(executable_size), "ELF loading", Region::Access::Read);
if (!executable_region) {
dbgln("Could not allocate memory for ELF loading");
return KResult(-ENOMEM);
}
auto elf_image = ELF::Image(region->vaddr().as_ptr(), executable_size);
auto elf_image = ELF::Image(executable_region->vaddr().as_ptr(), executable_size);
if (!elf_image.is_valid())
return KResult(-ENOEXEC);
@ -173,11 +173,12 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
return IterationDecision::Break;
}
master_tls_region = allocate_region({}, program_header.size_in_memory(), String::formatted("{} (master-tls)", elf_name), PROT_READ | PROT_WRITE, AllocationStrategy::Reserve);
if (!master_tls_region) {
ph_load_result = KResult(-ENOMEM);
auto region_or_error = allocate_region({}, program_header.size_in_memory(), String::formatted("{} (master-tls)", elf_name), PROT_READ | PROT_WRITE, AllocationStrategy::Reserve);
if (region_or_error.is_error()) {
ph_load_result = region_or_error.error();
return IterationDecision::Break;
}
master_tls_region = region_or_error.value();
master_tls_size = program_header.size_in_memory();
master_tls_alignment = program_header.alignment();
@ -207,9 +208,9 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
if (program_header.is_writable())
prot |= PROT_WRITE;
auto region_name = String::formatted("{} (data-{}{})", elf_name, program_header.is_readable() ? "r" : "", program_header.is_writable() ? "w" : "");
auto* region = allocate_region(program_header.vaddr().offset(load_offset), program_header.size_in_memory(), move(region_name), prot, AllocationStrategy::Reserve);
if (!region) {
ph_load_result = KResult(-ENOMEM);
auto region_or_error = allocate_region(program_header.vaddr().offset(load_offset), program_header.size_in_memory(), move(region_name), prot, AllocationStrategy::Reserve);
if (region_or_error.is_error()) {
ph_load_result = region_or_error.error();
return IterationDecision::Break;
}
@ -222,7 +223,7 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
// Accessing it would definitely be a bug.
auto page_offset = program_header.vaddr();
page_offset.mask(~PAGE_MASK);
if (!copy_to_user((u8*)region->vaddr().as_ptr() + page_offset.get(), program_header.raw_data(), program_header.size_in_image())) {
if (!copy_to_user((u8*)region_or_error.value()->vaddr().as_ptr() + page_offset.get(), program_header.raw_data(), program_header.size_in_image())) {
ph_load_result = KResult(-EFAULT);
return IterationDecision::Break;
}
@ -239,13 +240,13 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
prot |= PROT_WRITE;
if (program_header.is_executable())
prot |= PROT_EXEC;
auto* region = allocate_region_with_vmobject(program_header.vaddr().offset(load_offset), program_header.size_in_memory(), *vmobject, program_header.offset(), elf_name, prot, true);
if (!region) {
ph_load_result = KResult(-ENOMEM);
auto region_or_error = allocate_region_with_vmobject(program_header.vaddr().offset(load_offset), program_header.size_in_memory(), *vmobject, program_header.offset(), elf_name, prot, true);
if (region_or_error.is_error()) {
ph_load_result = region_or_error.error();
return IterationDecision::Break;
}
if (program_header.offset() == 0)
load_base_address = (FlatPtr)region->vaddr().as_ptr();
load_base_address = (FlatPtr)region_or_error.value()->vaddr().as_ptr();
return IterationDecision::Continue;
});
@ -259,10 +260,11 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
return KResult(-ENOEXEC);
}
auto* stack_region = allocate_region(VirtualAddress(), Thread::default_userspace_stack_size, "Stack (Main thread)", PROT_READ | PROT_WRITE, AllocationStrategy::Reserve);
if (!stack_region)
return KResult(-ENOMEM);
stack_region->set_stack(true);
auto stack_region_or_error = allocate_region(VirtualAddress(), Thread::default_userspace_stack_size, "Stack (Main thread)", PROT_READ | PROT_WRITE, AllocationStrategy::Reserve);
if (stack_region_or_error.is_error())
return stack_region_or_error.error();
auto& stack_region = *stack_region_or_error.value();
stack_region.set_stack(true);
return LoadResult {
load_base_address,
@ -273,7 +275,7 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
AK::try_make_weak_ptr(master_tls_region),
master_tls_size,
master_tls_alignment,
stack_region->make_weak_ptr()
stack_region.make_weak_ptr()
};
}

34
Kernel/Syscalls/mmap.cpp
View file

@ -142,9 +142,12 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
if (map_anonymous) {
auto strategy = map_noreserve ? AllocationStrategy::None : AllocationStrategy::Reserve;
region = allocate_region(range.value(), !name.is_null() ? name : "mmap", prot, strategy);
if (!region && (!map_fixed && addr != 0))
region = allocate_region(allocate_range({}, size), !name.is_null() ? name : "mmap", prot, strategy);
auto region_or_error = allocate_region(range.value(), !name.is_null() ? name : "mmap", prot, strategy);
if (region_or_error.is_error() && (!map_fixed && addr != 0))
region_or_error = allocate_region(allocate_range({}, size), !name.is_null() ? name : "mmap", prot, strategy);
if (region_or_error.is_error())
return (void*)region_or_error.error().error();
region = region_or_error.value();
} else {
if (offset < 0)
return (void*)-EINVAL;
@ -170,11 +173,11 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
if (region_or_error.is_error()) {
// Fail if MAP_FIXED or address is 0, retry otherwise
if (map_fixed || addr == 0)
return (void*)(int)region_or_error.error();
return (void*)region_or_error.error().error();
region_or_error = description->mmap(*this, {}, static_cast<size_t>(offset), size, prot, map_shared);
}
if (region_or_error.is_error())
return (void*)(int)region_or_error.error();
return (void*)region_or_error.error().error();
region = region_or_error.value();
}
@ -438,13 +441,12 @@ void* Process::sys$mremap(Userspace<const Syscall::SC_mremap_params*> user_param
deallocate_region(*old_region);
auto new_vmobject = PrivateInodeVMObject::create_with_inode(inode);
auto* new_region = allocate_region_with_vmobject(range.base(), range.size(), new_vmobject, 0, old_name, old_prot, false);
new_region->set_mmap(true);
if (!new_region)
return (void*)-ENOMEM;
return new_region->vaddr().as_ptr();
auto new_region_or_error = allocate_region_with_vmobject(range.base(), range.size(), new_vmobject, 0, old_name, old_prot, false);
if (new_region_or_error.is_error())
return (void*)new_region_or_error.error().error();
auto& new_region = *new_region_or_error.value();
new_region.set_mmap(true);
return new_region.vaddr().as_ptr();
}
dbgln("sys$mremap: Unimplemented remap request (flags={})", params.flags);
@ -471,11 +473,11 @@ void* Process::sys$allocate_tls(size_t size)
});
ASSERT(main_thread);
auto tls_region = allocate_region({}, size, String(), PROT_READ | PROT_WRITE);
if (!tls_region)
return (void*)-EFAULT;
auto region_or_error = allocate_region({}, size, String(), PROT_READ | PROT_WRITE);
if (region_or_error.is_error())
return (void*)region_or_error.error().error();
m_master_tls_region = tls_region->make_weak_ptr();
m_master_tls_region = region_or_error.value()->make_weak_ptr();
m_master_tls_size = size;
m_master_tls_alignment = PAGE_SIZE;