From f2fed21c1139c8d5c030bc5caee5c612dfe7979f Mon Sep 17 00:00:00 2001 From: Liam Date: Sun, 7 Jan 2024 13:59:48 -0500 Subject: kernel: fix page leak on process termination --- src/common/page_table.cpp | 34 ++++++++++------------------------ 1 file changed, 10 insertions(+), 24 deletions(-) (limited to 'src/common/page_table.cpp') diff --git a/src/common/page_table.cpp b/src/common/page_table.cpp index 166dc3dce..85dc18c11 100644 --- a/src/common/page_table.cpp +++ b/src/common/page_table.cpp @@ -2,6 +2,7 @@ // SPDX-License-Identifier: GPL-2.0-or-later #include "common/page_table.h" +#include "common/scope_exit.h" namespace Common { @@ -11,29 +12,10 @@ PageTable::~PageTable() noexcept = default; bool PageTable::BeginTraversal(TraversalEntry* out_entry, TraversalContext* out_context, Common::ProcessAddress address) const { - // Setup invalid defaults. - out_entry->phys_addr = 0; - out_entry->block_size = page_size; - out_context->next_page = 0; - - // Validate that we can read the actual entry. - const auto page = address / page_size; - if (page >= backing_addr.size()) { - return false; - } - - // Validate that the entry is mapped. - const auto phys_addr = backing_addr[page]; - if (phys_addr == 0) { - return false; - } + out_context->next_offset = GetInteger(address); + out_context->next_page = address / page_size; - // Populate the results. - out_entry->phys_addr = phys_addr + GetInteger(address); - out_context->next_page = page + 1; - out_context->next_offset = GetInteger(address) + page_size; - - return true; + return this->ContinueTraversal(out_entry, out_context); } bool PageTable::ContinueTraversal(TraversalEntry* out_entry, TraversalContext* context) const { @@ -41,6 +23,12 @@ bool PageTable::ContinueTraversal(TraversalEntry* out_entry, TraversalContext* c out_entry->phys_addr = 0; out_entry->block_size = page_size; + // Regardless of whether the page was mapped, advance on exit. + SCOPE_EXIT({ + context->next_page += 1; + context->next_offset += page_size; + }); + // Validate that we can read the actual entry. const auto page = context->next_page; if (page >= backing_addr.size()) { @@ -55,8 +43,6 @@ bool PageTable::ContinueTraversal(TraversalEntry* out_entry, TraversalContext* c // Populate the results. out_entry->phys_addr = phys_addr + context->next_offset; - context->next_page = page + 1; - context->next_offset += page_size; return true; } -- cgit v1.2.3