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Kernel: Remove double RedBlackTree lookup in VM/Space region removal

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We should never request a regions removal that we don't currently
own. We currently assert this everywhere else by all callers.

Instead lets just push the assert down into the RedBlackTree removal
and assume that we will always successfully remove the region.
This commit is contained in:
Brian Gianforcaro 2021-07-17 06:07:02 -07:00 • committed by Andreas Kling
parent d879709ec7
commit c0987453e6
4 changed files with 13 additions and 26 deletions
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5
Kernel/Syscalls/mmap.cpp
View file

@ -334,7 +334,6 @@ KResultOr<FlatPtr> Process::sys$mprotect(Userspace<void*> addr, size_t size, int
// Remove the old region from our regions tree, since were going to add another region
// with the exact same start address, but dont deallocate it yet
auto region = space().take_region(*old_region);
VERIFY(region);
// Unmap the old region here, specifying that we *don't* want the VM deallocated.
region->unmap(Region::ShouldDeallocateVirtualMemoryRange::No);
@ -398,7 +397,6 @@ KResultOr<FlatPtr> Process::sys$mprotect(Userspace<void*> addr, size_t size, int
// Remove the old region from our regions tree, since were going to add another region
// with the exact same start address, but dont deallocate it yet
auto region = space().take_region(*old_region);
VERIFY(region);
// Unmap the old region here, specifying that we *don't* want the VM deallocated.
region->unmap(Region::ShouldDeallocateVirtualMemoryRange::No);
@ -564,8 +562,7 @@ KResultOr<FlatPtr> Process::sys$mremap(Userspace<const Syscall::SC_mremap_params
// Unmap without deallocating the VM range since we're going to reuse it.
old_region->unmap(Region::ShouldDeallocateVirtualMemoryRange::No);
bool success = space().deallocate_region(*old_region);
VERIFY(success);
space().deallocate_region(*old_region);
auto new_region_or_error = space().allocate_region_with_vmobject(range, new_vmobject.release_nonnull(), old_offset, old_name->view(), old_prot, false);
if (new_region_or_error.is_error())