system/serenity
system/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity synced 2024-10-01 05:34:29 +00:00
Code Issues Packages Projects Releases Wiki Activity

LibDeviceTree: Fix stale pointers in phandle and parent handling

Browse source 
We need to set them after we've created the full tree, as otherwise the
HashMap containing the nodes may reallocate and invalidate the pointers.
This commit is contained in:
Hendiadyoin1 2024-04-27 13:43:13 +02:00 committed by Andrew Kaster
parent b2377f1f9c
commit ffa9875fa6
2 changed files with 65 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
Userland/Libraries/LibDeviceTree/DeviceTree.cpp
View file

@ -39,14 +39,7 @@ ErrorOr<NonnullOwnPtr<DeviceTree>> DeviceTree::parse(ReadonlyBytes flattened_dev
current_node = current_node->parent();
return IterationDecision::Continue;
},
.on_property = [&device_tree, &current_node](StringView name, ReadonlyBytes value) -> ErrorOr<IterationDecision> {
DeviceTreeProperty property { value };
if (name == "phandle"sv) {
auto phandle = property.as<u32>();
TRY(device_tree->set_phandle(phandle, current_node));
}
.on_property = [&current_node](StringView name, ReadonlyBytes value) -> ErrorOr<IterationDecision> {
TRY(current_node->properties().try_set(name, DeviceTreeProperty { value }));
return IterationDecision::Continue;
},
@ -58,6 +51,25 @@ ErrorOr<NonnullOwnPtr<DeviceTree>> DeviceTree::parse(ReadonlyBytes flattened_dev
},
}));
// FIXME: While growing the a nodes children map, we might have reallocated it's storage
// breaking the parent pointers of the children, so we need to fix them here
auto fix_parent = [](auto self, DeviceTreeNodeView& node) -> void {
for (auto& [name, child] : node.children()) {
child.m_parent = &node;
self(self, child);
}
};
fix_parent(fix_parent, *device_tree);
// Note: For the same reason as above, we need to postpone setting the phandles until the tree is fully built
TRY(device_tree->for_each_node([&device_tree]([[maybe_unused]] StringView name, DeviceTreeNodeView& node) -> ErrorOr<RecursionDecision> {
if (auto phandle = node.get_property("phandle"sv); phandle.has_value()) {
auto phandle_value = phandle.value().as<u32>();
TRY(device_tree->set_phandle(phandle_value, &node));
}
return RecursionDecision::Recurse;
}));
return device_tree;
}

45
Userland/Libraries/LibDeviceTree/DeviceTree.h
View file

@ -13,6 +13,7 @@
#include <AK/IterationDecision.h>
#include <AK/MemoryStream.h>
#include <AK/Optional.h>
#include <AK/RecursionDecision.h>
#include <AK/Span.h>
namespace DeviceTree {
@ -168,6 +169,28 @@ public:
// bonus points if it could automatically recurse in the tree under some conditions,
// like "simple-bus" or "pci-bridge" nodes
auto for_each_node(CallableAs<ErrorOr<RecursionDecision>, StringView, DeviceTreeNodeView const&> auto callback) const
{
auto iterate = [&](auto self, StringView name, DeviceTreeNodeView const& node) -> ErrorOr<RecursionDecision> {
auto result = TRY(callback(name, node));
if (result == RecursionDecision::Recurse) {
for (auto const& [name, child] : node.children()) {
auto child_result = TRY(self(self, name, child));
if (child_result == RecursionDecision::Break)
return RecursionDecision::Break;
}
return RecursionDecision::Continue;
}
return result;
};
return iterate(iterate, "/"sv, *this);
}
DeviceTreeNodeView const* phandle(u32 phandle) const
{
if (phandle >= m_phandles.size())
@ -184,6 +207,28 @@ private:
{
}
auto for_each_node(CallableAs<ErrorOr<RecursionDecision>, StringView, DeviceTreeNodeView&> auto callback)
{
auto iterate = [&](auto self, StringView name, DeviceTreeNodeView& node) -> ErrorOr<RecursionDecision> {
auto result = TRY(callback(name, node));
if (result == RecursionDecision::Recurse) {
for (auto& [name, child] : node.children()) {
auto child_result = TRY(self(self, name, child));
if (child_result == RecursionDecision::Break)
return RecursionDecision::Break;
}
return RecursionDecision::Continue;
}
return result;
};
return iterate(iterate, "/"sv, *this);
}
ErrorOr<void> set_phandle(u32 phandle, DeviceTreeNodeView* node)
{
if (m_phandles.size() > phandle && m_phandles[phandle] != nullptr)