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Kernel: Make VM allocation atomic for userspace regions

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This patch move AddressSpace (the per-process memory manager) to using
the new atomic "place" APIs in RegionTree as well, just like we did for
MemoryManager in the previous commit.

This required updating quite a few places where VM allocation and
actually committing a Region object to the AddressSpace were separated
by other code.

All you have to do now is call into AddressSpace once and it'll take
care of everything for you.
This commit is contained in:
Andreas Kling 2022-04-03 17:12:39 +02:00
parent e852a69a06
commit 07f3d09c55
13 changed files with 84 additions and 91 deletions
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15
Kernel/Syscalls/execve.cpp
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@ -294,9 +294,8 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
return ENOEXEC;
}
auto range = TRY(new_space->try_allocate_range({}, program_header.size_in_memory()));
auto region_name = TRY(KString::formatted("{} (master-tls)", elf_name));
master_tls_region = TRY(new_space->allocate_region(range, region_name->view(), PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
master_tls_region = TRY(new_space->allocate_region({}, program_header.size_in_memory(), PAGE_SIZE, region_name->view(), PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
master_tls_size = program_header.size_in_memory();
master_tls_alignment = program_header.alignment();
@ -324,8 +323,7 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
size_t rounded_range_end = TRY(Memory::page_round_up(program_header.vaddr().offset(load_offset).offset(program_header.size_in_memory()).get()));
auto range_end = VirtualAddress { rounded_range_end };
auto range = TRY(new_space->try_allocate_range(range_base, range_end.get() - range_base.get(), program_header.alignment()));
auto region = TRY(new_space->allocate_region(range, region_name->view(), prot, AllocationStrategy::Reserve));
auto region = TRY(new_space->allocate_region(range_base, range_end.get() - range_base.get(), PAGE_SIZE, region_name->view(), prot, AllocationStrategy::Reserve));
// It's not always the case with PIE executables (and very well shouldn't be) that the
// virtual address in the program header matches the one we end up giving the process.
@ -360,8 +358,7 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
auto range_base = VirtualAddress { Memory::page_round_down(program_header.vaddr().offset(load_offset).get()) };
size_t rounded_range_end = TRY(Memory::page_round_up(program_header.vaddr().offset(load_offset).offset(program_header.size_in_memory()).get()));
auto range_end = VirtualAddress { rounded_range_end };
auto range = TRY(new_space->try_allocate_range(range_base, range_end.get() - range_base.get(), program_header.alignment()));
auto region = TRY(new_space->allocate_region_with_vmobject(range, *vmobject, program_header.offset(), elf_name->view(), prot, true));
auto region = TRY(new_space->allocate_region_with_vmobject(range_base, range_end.get() - range_base.get(), program_header.alignment(), *vmobject, program_header.offset(), elf_name->view(), prot, true));
if (should_allow_syscalls == ShouldAllowSyscalls::Yes)
region->set_syscall_region(true);
@ -395,8 +392,7 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
return ENOEXEC;
}
auto stack_range = TRY(new_space->try_allocate_range({}, Thread::default_userspace_stack_size));
auto* stack_region = TRY(new_space->allocate_region(stack_range, "Stack (Main thread)", PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
auto* stack_region = TRY(new_space->allocate_region({}, Thread::default_userspace_stack_size, PAGE_SIZE, "Stack (Main thread)", PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
stack_region->set_stack(true);
return LoadResult {
@ -473,8 +469,7 @@ ErrorOr<void> Process::do_exec(NonnullRefPtr<OpenFileDescription> main_program_d
bool has_interpreter = interpreter_description;
interpreter_description = nullptr;
auto signal_trampoline_range = TRY(load_result.space->try_allocate_range({}, PAGE_SIZE));
auto* signal_trampoline_region = TRY(load_result.space->allocate_region_with_vmobject(signal_trampoline_range, g_signal_trampoline_region->vmobject(), 0, "Signal trampoline", PROT_READ | PROT_EXEC, true));
auto* signal_trampoline_region = TRY(load_result.space->allocate_region_with_vmobject({}, PAGE_SIZE, PAGE_SIZE, g_signal_trampoline_region->vmobject(), 0, "Signal trampoline", PROT_READ | PROT_EXEC, true));
signal_trampoline_region->set_syscall_region(true);
// (For dynamically linked executable) Allocate an FD for passing the main executable to the dynamic loader.