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Kernel: Wrap process address spaces in SpinlockProtected

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This forces anyone who wants to look into and/or manipulate an address
space to lock it. And this replaces the previous, more flimsy, manual
spinlock use.

Note that pointers *into* the address space are not safe to use after
you unlock the space. We've got many issues like this, and we'll have
to track those down as wlel.
This commit is contained in:
Andreas Kling 2022-08-23 17:58:05 +02:00
parent d6ef18f587
commit cf16b2c8e6
38 changed files with 708 additions and 627 deletions
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45
Kernel/Syscalls/ptrace.cpp
View file

@ -197,31 +197,34 @@ ErrorOr<void> Process::peek_user_data(Span<u8> destination, Userspace<u8 const*>
ErrorOr<void> Process::poke_user_data(Userspace<FlatPtr*> address, FlatPtr data)
{
Memory::VirtualRange range = { address.vaddr(), sizeof(FlatPtr) };
auto* region = address_space().find_region_containing(range);
if (!region)
return EFAULT;
ScopedAddressSpaceSwitcher switcher(*this);
if (region->is_shared()) {
// If the region is shared, we change its vmobject to a PrivateInodeVMObject
// to prevent the write operation from changing any shared inode data
VERIFY(region->vmobject().is_shared_inode());
auto vmobject = TRY(Memory::PrivateInodeVMObject::try_create_with_inode(static_cast<Memory::SharedInodeVMObject&>(region->vmobject()).inode()));
region->set_vmobject(move(vmobject));
region->set_shared(false);
}
bool const was_writable = region->is_writable();
if (!was_writable) {
region->set_writable(true);
region->remap();
}
ScopeGuard rollback([&]() {
return address_space().with([&](auto& space) -> ErrorOr<void> {
auto* region = space->find_region_containing(range);
if (!region)
return EFAULT;
ScopedAddressSpaceSwitcher switcher(*this);
if (region->is_shared()) {
// If the region is shared, we change its vmobject to a PrivateInodeVMObject
// to prevent the write operation from changing any shared inode data
VERIFY(region->vmobject().is_shared_inode());
auto vmobject = TRY(Memory::PrivateInodeVMObject::try_create_with_inode(static_cast<Memory::SharedInodeVMObject&>(region->vmobject()).inode()));
region->set_vmobject(move(vmobject));
region->set_shared(false);
}
bool const was_writable = region->is_writable();
if (!was_writable) {
region->set_writable(false);
region->set_writable(true);
region->remap();
}
});
ScopeGuard rollback([&]() {
if (!was_writable) {
region->set_writable(false);
region->remap();
}
});
return copy_to_user(address, &data);
return copy_to_user(address, &data);
});
}
ErrorOr<FlatPtr> Thread::peek_debug_register(u32 register_index)