diff options
10 files changed, 37 insertions, 19 deletions
diff --git a/arch/x86_64/include/arch/context_switching/syscall/main.hpp b/arch/x86_64/include/arch/context_switching/syscall/main.hpp index 48fa195..3af5a5a 100644 --- a/arch/x86_64/include/arch/context_switching/syscall/main.hpp +++ b/arch/x86_64/include/arch/context_switching/syscall/main.hpp @@ -60,6 +60,7 @@ namespace teachos::arch::context_switching::syscall * not function correctly. * @return Bool-convertable error code converting to true if the syscall failed or false if it didn't. */ + [[gnu::section(".user_text")]] auto syscall(type syscall_number, arguments args = {}) -> error; } // namespace teachos::arch::context_switching::syscall diff --git a/arch/x86_64/include/arch/memory/paging/active_page_table.hpp b/arch/x86_64/include/arch/memory/paging/active_page_table.hpp index a4a5b64..d77b76c 100644 --- a/arch/x86_64/include/arch/memory/paging/active_page_table.hpp +++ b/arch/x86_64/include/arch/memory/paging/active_page_table.hpp @@ -82,14 +82,17 @@ namespace teachos::arch::memory::paging for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; --level) { - current_handle = current_handle.next_table_or_create(allocator, page.get_level_index(level)); + // Ignore all bits passed besides the entry::USER_ACCESSIBLE bit, because for the entry into the Level 4 up to + // Level 2 page, we always have to set the entry::PRESENT and entry::WRITABLE bit anyway. + current_handle = current_handle.next_table_or_create(allocator, page.get_level_index(level), + flags.to_ulong() & entry::USER_ACCESSIBLE); } auto & level1_entry = current_handle[page.get_level_index(page_table_handle::LEVEL1)]; arch::exception_handling::assert(!level1_entry.contains_flags(entry::HUGE_PAGE), "[Page Mapper] Unable to map huge pages"); arch::exception_handling::assert(level1_entry.is_unused(), "[Page Mapper] Page table entry is already used"); - level1_entry.set_entry(frame, flags.to_ulong() | entry::PRESENT | entry::USER_ACCESSIBLE); + level1_entry.set_entry(frame, flags.to_ulong() | entry::PRESENT); } /** diff --git a/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp b/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp index 09e9bf4..ce74b98 100644 --- a/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp +++ b/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp @@ -81,12 +81,11 @@ namespace teachos::arch::memory::paging kernel::cpu::read_control_register(kernel::cpu::control_register::CR3)); auto page_table_level4 = temporary_page.map_table_frame(backup, active_table); - active_table[511].set_entry(inactive_table.page_table_level_4_frame, - entry::PRESENT | entry::WRITABLE | entry::USER_ACCESSIBLE); + active_table[511].set_entry(inactive_table.page_table_level_4_frame, entry::PRESENT | entry::WRITABLE); kernel::cpu::tlb_flush_all(); map_elf_kernel_sections(active_table); - page_table_level4[511].set_entry(backup, entry::PRESENT | entry::WRITABLE | entry::USER_ACCESSIBLE); + page_table_level4[511].set_entry(backup, entry::PRESENT | entry::WRITABLE); kernel::cpu::tlb_flush_all(); temporary_page.unmap_page(active_table); } @@ -139,12 +138,15 @@ namespace teachos::arch::memory::paging allocator::frame_container const frames{begin, end}; entry entry{section.flags}; - // TODO: Only set this if we are in the .user_text section. - // address: 0000000000216000, offset: 013000, size: varies depending on code not a a good idea - // Alternatively index Nr. 8 could be used to detect section, can also change if we add more section - entry.set_user_accesible(); - - // TODO: Entering User Mode still works, but then attempting to execute an instruction immedatiately fails. + // TODO: Why exactly are this section required or not required? + // Required to be accesible in User Mode: .user_text (Contains the actuall code executed), .boot_bss (Contains + // statically allocated variables), .boot_rodata (Contains constant data stored in ROM) + // Not required: .text, .rodata, .ctors, .dtors, .bss, .data, .boot_data, .boot_text, .init + if (section.physical_address == 0x100000 || section.physical_address == 0x102000 || + section.physical_address == 0x216000) + { + entry.set_user_accesible(); + } for (auto const & frame : frames) { @@ -154,7 +156,7 @@ namespace teachos::arch::memory::paging auto const vga_buffer_frame = allocator::physical_frame::containing_address(video::vga::text::DEFAULT_VGA_TEXT_BUFFER_ADDRESS); - active_table.identity_map(allocator, vga_buffer_frame, entry::WRITABLE | entry::USER_ACCESSIBLE); + active_table.identity_map(allocator, vga_buffer_frame, entry::WRITABLE); } T & allocator; diff --git a/arch/x86_64/include/arch/memory/paging/page_table.hpp b/arch/x86_64/include/arch/memory/paging/page_table.hpp index db7ba6c..7b7e29e 100644 --- a/arch/x86_64/include/arch/memory/paging/page_table.hpp +++ b/arch/x86_64/include/arch/memory/paging/page_table.hpp @@ -81,9 +81,10 @@ namespace teachos::arch::memory::paging * @param allocator Reference to an allocator following the FrameAllocator concept, which is used to allocate * entries when a new page table is required. * @param table_index Index of this page table in the page table one level lower. + * @param flags A bitset of flags that configure the page table entry for this mapping. */ template<allocator::FrameAllocator T> - auto next_table_or_create(T & allocator, std::size_t table_index) -> page_table_handle + auto next_table_or_create(T & allocator, std::size_t table_index, std::bitset<64U> flags) -> page_table_handle { auto next_handle = next_table(table_index); // If the next table method failed then it means that the page level of the frame we want allocate has not yet @@ -95,7 +96,7 @@ namespace teachos::arch::memory::paging auto const allocated_frame = allocator.allocate_frame(); exception_handling::assert(allocated_frame.has_value(), "[Page mapper] Unable to allocate frame"); this->operator[](table_index) - .set_entry(allocated_frame.value(), entry::PRESENT | entry::WRITABLE | entry::USER_ACCESSIBLE); + .set_entry(allocated_frame.value(), flags.to_ulong() | entry::PRESENT | entry::WRITABLE); // There should now be an entry at the previously not existent index, therefore we can simply access it again. next_handle = next_table(table_index); exception_handling::assert(next_handle.has_value(), "[Page mapper] Unable to create new entry into page table"); diff --git a/arch/x86_64/include/arch/user/main.hpp b/arch/x86_64/include/arch/user/main.hpp index ba30864..c168a1f 100644 --- a/arch/x86_64/include/arch/user/main.hpp +++ b/arch/x86_64/include/arch/user/main.hpp @@ -8,6 +8,7 @@ namespace teachos::arch::user * Additionally this main method is executed at Ring 3 and accessing CPU Registers or Kernel level functionality can * only be done over syscalls and not directly anymore. */ + [[gnu::section(".user_text")]] auto main() -> void; } // namespace teachos::arch::user diff --git a/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp b/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp index 8e2c62d..9d061a8 100644 --- a/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp +++ b/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp @@ -8,5 +8,6 @@ namespace teachos::arch::interrupt_handling { (void)frame; video::vga::text::write("An Interrupt occurred.", video::vga::text::common_attributes::green_on_black); + video::vga::text::newline(); } } // namespace teachos::arch::interrupt_handling diff --git a/arch/x86_64/src/memory/main.cpp b/arch/x86_64/src/memory/main.cpp index 4cccabb..bd094e0 100644 --- a/arch/x86_64/src/memory/main.cpp +++ b/arch/x86_64/src/memory/main.cpp @@ -31,8 +31,7 @@ namespace teachos::arch::memory for (auto const & page : pages) { - active_table.map_page_to_next_free_frame(allocator, page, - paging::entry::WRITABLE | paging::entry::USER_ACCESSIBLE); + active_table.map_page_to_next_free_frame(allocator, page, paging::entry::WRITABLE); } } } // namespace diff --git a/arch/x86_64/src/memory/paging/inactive_page_table.cpp b/arch/x86_64/src/memory/paging/inactive_page_table.cpp index 780f12c..4e0610e 100644 --- a/arch/x86_64/src/memory/paging/inactive_page_table.cpp +++ b/arch/x86_64/src/memory/paging/inactive_page_table.cpp @@ -14,7 +14,7 @@ namespace teachos::arch::memory::paging { auto table = temporary_page.map_table_frame(page_table_level_4_frame, active_page_table); table.zero_entries(); - table[511].set_entry(page_table_level_4_frame, entry::PRESENT | entry::WRITABLE | entry::USER_ACCESSIBLE); + table[511].set_entry(page_table_level_4_frame, entry::PRESENT | entry::WRITABLE); temporary_page.unmap_page(active_page_table); } } // namespace teachos::arch::memory::paging diff --git a/arch/x86_64/src/memory/paging/temporary_page.cpp b/arch/x86_64/src/memory/paging/temporary_page.cpp index 9946f36..8e73523 100644 --- a/arch/x86_64/src/memory/paging/temporary_page.cpp +++ b/arch/x86_64/src/memory/paging/temporary_page.cpp @@ -18,7 +18,7 @@ namespace teachos::arch::memory::paging exception_handling::assert(!active_table.translate_page(page).has_value(), "[Temporary page] Page is already mapped"); - active_table.map_page_to_frame(allocator, page, frame, entry::WRITABLE | entry::USER_ACCESSIBLE); + active_table.map_page_to_frame(allocator, page, frame, entry::WRITABLE); return page.start_address(); } diff --git a/arch/x86_64/src/user/main.cpp b/arch/x86_64/src/user/main.cpp index 3ddcb32..3e7b0ec 100644 --- a/arch/x86_64/src/user/main.cpp +++ b/arch/x86_64/src/user/main.cpp @@ -3,21 +3,31 @@ #include "arch/context_switching/syscall/main.hpp" // TODO: Disallow this import +#include "arch/kernel/cpu/if.hpp" #include "arch/video/vga/text.hpp" namespace teachos::arch::user { - [[gnu::section(".user_text")]] auto main() -> void { char constexpr syscall_message[] = "Successfully entered user mode and wrote to VGA buffer via syscall!"; auto const error = context_switching::syscall::syscall(context_switching::syscall::type::WRITE, {reinterpret_cast<uint64_t>(&syscall_message)}); + kernel::cpu::clear_interrupt_flag(); // Causes crash Kernel Code (.text) is not mapped in User mMde + + auto test = new int{20}; // Causes crash Heap is not mapped in User Mode + (void)test; + if (!error) { + // Causes crash vga is not mapped in User Mode video::vga::text::write("Successfully made a SYSCALL and returned with SYSRETQ!", video::vga::text::common_attributes::green_on_black); } + + for (;;) + { + } } } // namespace teachos::arch::user |