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ea4e02ed86
ladybird/Kernel/Process.cpp
Andreas Kling 4bf1a72d21 Kernel: Teach Region how to remap itself 
Now remapping (i.e flushing kernel metadata to the CPU page tables)
is done by simply calling Region::remap().
2019-11-03 21:11:08 +01:00

3219 lines
95 KiB
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#include <AK/ELF/ELFLoader.h>
#include <AK/ELF/exec_elf.h>
#include <AK/FileSystemPath.h>
#include <AK/StdLibExtras.h>
#include <AK/StringBuilder.h>
#include <AK/Time.h>
#include <AK/Types.h>
#include <Kernel/Arch/i386/CPU.h>
#include <Kernel/Arch/i386/PIT.h>
#include <Kernel/Devices/NullDevice.h>
#include <Kernel/Devices/RandomDevice.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/DevPtsFS.h>
#include <Kernel/FileSystem/Ext2FileSystem.h>
#include <Kernel/FileSystem/FIFO.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/FileSystem/InodeWatcher.h>
#include <Kernel/FileSystem/ProcFS.h>
#include <Kernel/FileSystem/SharedMemory.h>
#include <Kernel/FileSystem/TmpFS.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Heap/kmalloc.h>
#include <Kernel/IO.h>
#include <Kernel/KBufferBuilder.h>
#include <Kernel/KSyms.h>
#include <Kernel/Multiboot.h>
#include <Kernel/Net/Socket.h>
#include <Kernel/Process.h>
#include <Kernel/ProcessTracer.h>
#include <Kernel/RTC.h>
#include <Kernel/Scheduler.h>
#include <Kernel/SharedBuffer.h>
#include <Kernel/StdLib.h>
#include <Kernel/Syscall.h>
#include <Kernel/TTY/MasterPTY.h>
#include <Kernel/Thread.h>
#include <Kernel/VM/InodeVMObject.h>
#include <LibC/errno_numbers.h>
#include <LibC/signal_numbers.h>
//#define DEBUG_POLL_SELECT
//#define DEBUG_IO
//#define TASK_DEBUG
//#define FORK_DEBUG
//#define SIGNAL_DEBUG
//#define SHARED_BUFFER_DEBUG
static void create_signal_trampolines();
static pid_t next_pid;
InlineLinkedList<Process>* g_processes;
static String* s_hostname;
static Lock* s_hostname_lock;
VirtualAddress g_return_to_ring3_from_signal_trampoline;
VirtualAddress g_return_to_ring0_from_signal_trampoline;
void Process::initialize()
{
next_pid = 0;
g_processes = new InlineLinkedList<Process>;
s_hostname = new String("courage");
s_hostname_lock = new Lock;
create_signal_trampolines();
}
Vector<pid_t> Process::all_pids()
{
Vector<pid_t> pids;
InterruptDisabler disabler;
pids.ensure_capacity(g_processes->size_slow());
for (auto& process : *g_processes)
pids.append(process.pid());
return pids;
}
Vector<Process*> Process::all_processes()
{
Vector<Process*> processes;
InterruptDisabler disabler;
processes.ensure_capacity(g_processes->size_slow());
for (auto& process : *g_processes)
processes.append(&process);
return processes;
}
bool Process::in_group(gid_t gid) const
{
return m_gids.contains(gid);
}
Range Process::allocate_range(VirtualAddress vaddr, size_t size)
{
vaddr.mask(PAGE_MASK);
size = PAGE_ROUND_UP(size);
if (vaddr.is_null())
return page_directory().range_allocator().allocate_anywhere(size);
return page_directory().range_allocator().allocate_specific(vaddr, size);
}
static unsigned prot_to_region_access_flags(int prot)
{
unsigned access = 0;
if (prot & PROT_READ)
access |= Region::Access::Read;
if (prot & PROT_WRITE)
access |= Region::Access::Write;
if (prot & PROT_EXEC)
access |= Region::Access::Execute;
return access;
}
Region& Process::allocate_split_region(const Region& source_region, const Range& range, size_t offset_in_vmo)
{
m_regions.append(Region::create_user_accessible(range, source_region.vmobject(), offset_in_vmo, source_region.name(), source_region.access()));
return m_regions.last();
}
Region* Process::allocate_region(VirtualAddress vaddr, size_t size, const String& name, int prot, bool commit)
{
auto range = allocate_range(vaddr, size);
if (!range.is_valid())
return nullptr;
m_regions.append(Region::create_user_accessible(range, name, prot_to_region_access_flags(prot)));
m_regions.last().map(page_directory());
if (commit)
m_regions.last().commit();
return &m_regions.last();
}
Region* Process::allocate_file_backed_region(VirtualAddress vaddr, size_t size, NonnullRefPtr<Inode> inode, const String& name, int prot)
{
auto range = allocate_range(vaddr, size);
if (!range.is_valid())
return nullptr;
m_regions.append(Region::create_user_accessible(range, inode, name, prot_to_region_access_flags(prot)));
m_regions.last().map(page_directory());
return &m_regions.last();
}
Region* Process::allocate_region_with_vmo(VirtualAddress vaddr, size_t size, NonnullRefPtr<VMObject> vmo, size_t offset_in_vmo, const String& name, int prot)
{
auto range = allocate_range(vaddr, size);
if (!range.is_valid())
return nullptr;
offset_in_vmo &= PAGE_MASK;
m_regions.append(Region::create_user_accessible(range, move(vmo), offset_in_vmo, name, prot_to_region_access_flags(prot)));
m_regions.last().map(page_directory());
return &m_regions.last();
}
bool Process::deallocate_region(Region& region)
{
InterruptDisabler disabler;
for (int i = 0; i < m_regions.size(); ++i) {
if (&m_regions[i] == &region) {
m_regions.remove(i);
return true;
}
}
return false;
}
Region* Process::region_from_range(const Range& range)
{
size_t size = PAGE_ROUND_UP(range.size());
for (auto& region : m_regions) {
if (region.vaddr() == range.base() && region.size() == size)
return &region;
}
return nullptr;
}
Region* Process::region_containing(const Range& range)
{
for (auto& region : m_regions) {
if (region.contains(range))
return &region;
}
return nullptr;
}
int Process::sys$set_mmap_name(void* addr, size_t size, const char* name)
{
if (!validate_read_str(name))
return -EFAULT;
auto* region = region_from_range({ VirtualAddress((u32)addr), size });
if (!region)
return -EINVAL;
region->set_name(String(name));
return 0;
}
void* Process::sys$mmap(const Syscall::SC_mmap_params* params)
{
if (!validate_read(params, sizeof(Syscall::SC_mmap_params)))
return (void*)-EFAULT;
if (params->name && !validate_read_str(params->name))
return (void*)-EFAULT;
void* addr = (void*)params->addr;
size_t size = params->size;
int prot = params->prot;
int flags = params->flags;
int fd = params->fd;
off_t offset = params->offset;
const char* name = params->name;
if (size == 0)
return (void*)-EINVAL;
if ((u32)addr & ~PAGE_MASK)
return (void*)-EINVAL;
if ((flags & MAP_SHARED) && (flags & MAP_PRIVATE))
return (void*)-EINVAL;
if (flags & MAP_ANONYMOUS) {
auto* region = allocate_region(VirtualAddress((u32)addr), size, name ? name : "mmap", prot, false);
if (!region)
return (void*)-ENOMEM;
if (flags & MAP_SHARED)
region->set_shared(true);
return region->vaddr().as_ptr();
}
if (offset & ~PAGE_MASK)
return (void*)-EINVAL;
auto* description = file_description(fd);
if (!description)
return (void*)-EBADF;
auto region_or_error = description->mmap(*this, VirtualAddress((u32)addr), offset, size, prot);
if (region_or_error.is_error())
return (void*)(int)region_or_error.error();
auto region = region_or_error.value();
if (flags & MAP_SHARED)
region->set_shared(true);
if (name)
region->set_name(name);
return region->vaddr().as_ptr();
}
int Process::sys$munmap(void* addr, size_t size)
{
Range range_to_unmap { VirtualAddress((u32)addr), size };
if (auto* whole_region = region_from_range(range_to_unmap)) {
bool success = deallocate_region(*whole_region);
ASSERT(success);
return 0;
}
if (auto* old_region = region_containing(range_to_unmap)) {
Range old_region_range = old_region->range();
auto remaining_ranges_after_unmap = old_region_range.carve(range_to_unmap);
ASSERT(!remaining_ranges_after_unmap.is_empty());
auto make_replacement_region = [&](const Range& new_range) -> Region& {
ASSERT(new_range.base() >= old_region_range.base());
ASSERT(new_range.end() <= old_region_range.end());
size_t new_range_offset_in_vmobject = old_region->offset_in_vmobject() + (new_range.base().get() - old_region_range.base().get());
return allocate_split_region(*old_region, new_range, new_range_offset_in_vmobject);
};
Vector<Region*, 2> new_regions;
for (auto& new_range : remaining_ranges_after_unmap) {
new_regions.unchecked_append(&make_replacement_region(new_range));
}
// We manually unmap the old region here, specifying that we *don't* want the VM deallocated.
old_region->unmap(Region::ShouldDeallocateVirtualMemoryRange::No);
deallocate_region(*old_region);
// Instead we give back the unwanted VM manually.
page_directory().range_allocator().deallocate(range_to_unmap);
// And finally we map the new region(s).
for (auto* new_region : new_regions) {
new_region->map(page_directory());
}
return 0;
}
// FIXME: We should also support munmap() across multiple regions. (#175)
return -EINVAL;
}
int Process::sys$mprotect(void* addr, size_t size, int prot)
{
auto* region = region_from_range({ VirtualAddress((u32)addr), size });
if (!region)
return -EINVAL;
region->set_writable(prot & PROT_WRITE);
region->remap();
return 0;
}
int Process::sys$gethostname(char* buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (!validate_write(buffer, size))
return -EFAULT;
LOCKER(*s_hostname_lock);
if (size < (s_hostname->length() + 1))
return -ENAMETOOLONG;
strcpy(buffer, s_hostname->characters());
return 0;
}
Process* Process::fork(RegisterDump& regs)
{
auto* child = new Process(String(m_name), m_uid, m_gid, m_pid, m_ring, m_cwd, m_executable, m_tty, this);
#ifdef FORK_DEBUG
dbgprintf("fork: child=%p\n", child);
#endif
for (auto& region : m_regions) {
#ifdef FORK_DEBUG
dbg() << "fork: cloning Region{" << &region << "} '" << region.name() << "' @ " << region.vaddr();
#endif
child->m_regions.append(region.clone());
child->m_regions.last().map(child->page_directory());
if (&region == m_master_tls_region)
child->m_master_tls_region = &child->m_regions.last();
}
for (auto gid : m_gids)
child->m_gids.set(gid);
auto& child_tss = child->main_thread().m_tss;
child_tss.eax = 0; // fork() returns 0 in the child :^)
child_tss.ebx = regs.ebx;
child_tss.ecx = regs.ecx;
child_tss.edx = regs.edx;
child_tss.ebp = regs.ebp;
child_tss.esp = regs.esp_if_crossRing;
child_tss.esi = regs.esi;
child_tss.edi = regs.edi;
child_tss.eflags = regs.eflags;
child_tss.eip = regs.eip;
child_tss.cs = regs.cs;
child_tss.ds = regs.ds;
child_tss.es = regs.es;
child_tss.fs = regs.fs;
child_tss.gs = regs.gs;
child_tss.ss = regs.ss_if_crossRing;
#ifdef FORK_DEBUG
dbgprintf("fork: child will begin executing at %w:%x with stack %w:%x, kstack %w:%x\n", child_tss.cs, child_tss.eip, child_tss.ss, child_tss.esp, child_tss.ss0, child_tss.esp0);
#endif
{
InterruptDisabler disabler;
g_processes->prepend(child);
}
#ifdef TASK_DEBUG
kprintf("Process %u (%s) forked from %u @ %p\n", child->pid(), child->name().characters(), m_pid, child_tss.eip);
#endif
child->main_thread().set_state(Thread::State::Skip1SchedulerPass);
return child;
}
pid_t Process::sys$fork(RegisterDump& regs)
{
auto* child = fork(regs);
ASSERT(child);
return child->pid();
}
int Process::do_exec(String path, Vector<String> arguments, Vector<String> environment)
{
ASSERT(is_ring3());
dbgprintf("%s(%d) do_exec(%s): thread_count() = %d\n", m_name.characters(), m_pid, path.characters(), thread_count());
// FIXME(Thread): Kill any threads the moment we commit to the exec().
if (thread_count() != 1) {
dbgprintf("Gonna die because I have many threads! These are the threads:\n");
for_each_thread([](Thread& thread) {
dbgprintf("Thread{%p}: TID=%d, PID=%d\n", &thread, thread.tid(), thread.pid());
return IterationDecision::Continue;
});
ASSERT(thread_count() == 1);
ASSERT_NOT_REACHED();
}
size_t total_blob_size = 0;
for (auto& a : arguments)
total_blob_size += a.length() + 1;
for (auto& e : environment)
total_blob_size += e.length() + 1;
size_t total_meta_size = sizeof(char*) * (arguments.size() + 1) + sizeof(char*) * (environment.size() + 1);
// FIXME: How much stack space does process startup need?
if ((total_blob_size + total_meta_size) >= Thread::default_userspace_stack_size)
return -E2BIG;
auto parts = path.split('/');
if (parts.is_empty())
return -ENOENT;
auto result = VFS::the().open(path, 0, 0, current_directory());
if (result.is_error())
return result.error();
auto description = result.value();
auto metadata = description->metadata();
if (!metadata.may_execute(m_euid, m_gids))
return -EACCES;
if (!metadata.size)
return -ENOTIMPL;
u32 entry_eip = 0;
// FIXME: Is there a race here?
auto old_page_directory = move(m_page_directory);
m_page_directory = PageDirectory::create_for_userspace(*this);
#ifdef MM_DEBUG
dbgprintf("Process %u exec: PD=%x created\n", pid(), m_page_directory.ptr());
#endif
ProcessPagingScope paging_scope(*this);
ASSERT(description->inode());
auto vmo = InodeVMObject::create_with_inode(*description->inode());
auto* region = allocate_region_with_vmo(VirtualAddress(), metadata.size, vmo, 0, description->absolute_path(), PROT_READ);
ASSERT(region);
// NOTE: We yank this out of 'm_regions' since we're about to manipulate the vector
// and we don't want it getting lost.
auto executable_region = m_regions.take_last();
Region* master_tls_region { nullptr };
size_t master_tls_size = 0;
size_t master_tls_alignment = 0;
OwnPtr<ELFLoader> loader;
{
// Okay, here comes the sleight of hand, pay close attention..
auto old_regions = move(m_regions);
m_regions.append(move(executable_region));
loader = make<ELFLoader>(region->vaddr().as_ptr());
loader->map_section_hook = [&](VirtualAddress vaddr, size_t size, size_t alignment, size_t offset_in_image, bool is_readable, bool is_writable, bool is_executable, const String& name) -> u8* {
ASSERT(size);
ASSERT(alignment == PAGE_SIZE);
int prot = 0;
if (is_readable)
prot |= PROT_READ;
if (is_writable)
prot |= PROT_WRITE;
if (is_executable)
prot |= PROT_EXEC;
if (!allocate_region_with_vmo(vaddr, size, vmo, offset_in_image, String(name), prot))
return nullptr;
return vaddr.as_ptr();
};
loader->alloc_section_hook = [&](VirtualAddress vaddr, size_t size, size_t alignment, bool is_readable, bool is_writable, const String& name) -> u8* {
ASSERT(size);
ASSERT(alignment == PAGE_SIZE);
int prot = 0;
if (is_readable)
prot |= PROT_READ;
if (is_writable)
prot |= PROT_WRITE;
if (!allocate_region(vaddr, size, String(name), prot))
return nullptr;
return vaddr.as_ptr();
};
loader->tls_section_hook = [&](size_t size, size_t alignment) {
ASSERT(size);
master_tls_region = allocate_region({}, size, String(), PROT_READ | PROT_WRITE);
master_tls_size = size;
master_tls_alignment = alignment;
return master_tls_region->vaddr().as_ptr();
};
bool success = loader->load();
if (!success || !loader->entry().get()) {
m_page_directory = move(old_page_directory);
// FIXME: RAII this somehow instead.
ASSERT(&current->process() == this);
MM.enter_process_paging_scope(*this);
executable_region = m_regions.take_first();
m_regions = move(old_regions);
kprintf("do_exec: Failure loading %s\n", path.characters());
return -ENOEXEC;
}
// NOTE: At this point, we've committed to the new executable.
entry_eip = loader->entry().get();
}
m_elf_loader = move(loader);
m_executable = description->custody();
// Copy of the master TLS region that we will clone for new threads
m_master_tls_region = master_tls_region;
if (metadata.is_setuid())
m_euid = metadata.uid;
if (metadata.is_setgid())
m_egid = metadata.gid;
current->set_default_signal_dispositions();
current->m_signal_mask = 0;
current->m_pending_signals = 0;
for (int i = 0; i < m_fds.size(); ++i) {
auto& daf = m_fds[i];
if (daf.description && daf.flags & FD_CLOEXEC) {
daf.description->close();
daf = {};
}
}
// We cli() manually here because we don't want to get interrupted between do_exec() and Schedule::yield().
// The reason is that the task redirection we've set up above will be clobbered by the timer IRQ.
// If we used an InterruptDisabler that sti()'d on exit, we might timer tick'd too soon in exec().
if (&current->process() == this)
cli();
Scheduler::prepare_to_modify_tss(main_thread());
m_name = parts.take_last();
// ss0 sp!!!!!!!!!
u32 old_esp0 = main_thread().m_tss.esp0;
m_master_tls_size = master_tls_size;
m_master_tls_alignment = master_tls_alignment;
main_thread().make_thread_specific_region({});
memset(&main_thread().m_tss, 0, sizeof(main_thread().m_tss));
main_thread().m_tss.eflags = 0x0202;
main_thread().m_tss.eip = entry_eip;
main_thread().m_tss.cs = 0x1b;
main_thread().m_tss.ds = 0x23;
main_thread().m_tss.es = 0x23;
main_thread().m_tss.fs = 0x23;
main_thread().m_tss.gs = thread_specific_selector() | 3;
main_thread().m_tss.ss = 0x23;
main_thread().m_tss.cr3 = page_directory().cr3();
main_thread().make_userspace_stack_for_main_thread(move(arguments), move(environment));
main_thread().m_tss.ss0 = 0x10;
main_thread().m_tss.esp0 = old_esp0;
main_thread().m_tss.ss2 = m_pid;
#ifdef TASK_DEBUG
kprintf("Process %u (%s) exec'd %s @ %p\n", pid(), name().characters(), path.characters(), main_thread().tss().eip);
#endif
main_thread().set_state(Thread::State::Skip1SchedulerPass);
big_lock().unlock_if_locked();
return 0;
}
KResultOr<Vector<String>> Process::find_shebang_interpreter_for_executable(const String& executable_path)
{
// FIXME: It's a bit sad that we'll open the executable twice (in case there's no shebang)
// Maybe we can find a way to plumb this opened FileDescription to the rest of the
// exec implementation..
auto result = VFS::the().open(executable_path, 0, 0, current_directory());
if (result.is_error())
return result.error();
auto description = result.value();
auto metadata = description->metadata();
if (!metadata.may_execute(m_euid, m_gids))
return KResult(-EACCES);
if (metadata.size < 3)
return KResult(-ENOEXEC);
char first_page[PAGE_SIZE];
int nread = description->read((u8*)&first_page, sizeof(first_page));
int word_start = 2;
int word_length = 0;
if (nread > 2 && first_page[0] == '#' && first_page[1] == '!') {
Vector<String> interpreter_words;
for (int i = 2; i < nread; ++i) {
if (first_page[i] == '\n') {
break;
}
if (first_page[i] != ' ') {
++word_length;
}
if (first_page[i] == ' ') {
if (word_length > 0) {
interpreter_words.append(String(&first_page[word_start], word_length));
}
word_length = 0;
word_start = i + 1;
}
}
if (word_length > 0)
interpreter_words.append(String(&first_page[word_start], word_length));
if (!interpreter_words.is_empty())
return interpreter_words;
}
return KResult(-ENOEXEC);
}
int Process::exec(String path, Vector<String> arguments, Vector<String> environment)
{
auto result = find_shebang_interpreter_for_executable(path);
if (!result.is_error()) {
Vector<String> new_arguments(result.value());
new_arguments.append(path);
arguments.remove(0);
new_arguments.append(move(arguments));
return exec(result.value().first(), move(new_arguments), move(environment));
}
// The bulk of exec() is done by do_exec(), which ensures that all locals
// are cleaned up by the time we yield-teleport below.
int rc = do_exec(move(path), move(arguments), move(environment));
if (rc < 0)
return rc;
if (&current->process() == this) {
Scheduler::yield();
ASSERT_NOT_REACHED();
}
return 0;
}
int Process::sys$execve(const char* filename, const char** argv, const char** envp)
{
// NOTE: Be extremely careful with allocating any kernel memory in exec().
// On success, the kernel stack will be lost.
if (!validate_read_str(filename))
return -EFAULT;
if (!*filename)
return -ENOENT;
if (argv) {
if (!validate_read_typed(argv))
return -EFAULT;
for (size_t i = 0; argv[i]; ++i) {
if (!validate_read_str(argv[i]))
return -EFAULT;
}
}
if (envp) {
if (!validate_read_typed(envp))
return -EFAULT;
for (size_t i = 0; envp[i]; ++i) {
if (!validate_read_str(envp[i]))
return -EFAULT;
}
}
String path(filename);
Vector<String> arguments;
Vector<String> environment;
{
auto parts = path.split('/');
if (argv) {
for (size_t i = 0; argv[i]; ++i) {
arguments.append(argv[i]);
}
} else {
arguments.append(parts.last());
}
if (envp) {
for (size_t i = 0; envp[i]; ++i)
environment.append(envp[i]);
}
}
int rc = exec(move(path), move(arguments), move(environment));
ASSERT(rc < 0); // We should never continue after a successful exec!
return rc;
}
Process* Process::create_user_process(const String& path, uid_t uid, gid_t gid, pid_t parent_pid, int& error, Vector<String>&& arguments, Vector<String>&& environment, TTY* tty)
{
// FIXME: Don't split() the path twice (sys$spawn also does it...)
auto parts = path.split('/');
if (arguments.is_empty()) {
arguments.append(parts.last());
}
RefPtr<Custody> cwd;
{
InterruptDisabler disabler;
if (auto* parent = Process::from_pid(parent_pid))
cwd = parent->m_cwd;
}
if (!cwd)
cwd = VFS::the().root_custody();
auto* process = new Process(parts.take_last(), uid, gid, parent_pid, Ring3, move(cwd), nullptr, tty);
error = process->exec(path, move(arguments), move(environment));
if (error != 0) {
delete process;
return nullptr;
}
{
InterruptDisabler disabler;
g_processes->prepend(process);
}
#ifdef TASK_DEBUG
kprintf("Process %u (%s) spawned @ %p\n", process->pid(), process->name().characters(), process->main_thread().tss().eip);
#endif
error = 0;
return process;
}
Process* Process::create_kernel_process(String&& name, void (*e)())
{
auto* process = new Process(move(name), (uid_t)0, (gid_t)0, (pid_t)0, Ring0);
process->main_thread().tss().eip = (u32)e;
if (process->pid() != 0) {
InterruptDisabler disabler;
g_processes->prepend(process);
#ifdef TASK_DEBUG
kprintf("Kernel process %u (%s) spawned @ %p\n", process->pid(), process->name().characters(), process->main_thread().tss().eip);
#endif
}
process->main_thread().set_state(Thread::State::Runnable);
return process;
}
Process::Process(String&& name, uid_t uid, gid_t gid, pid_t ppid, RingLevel ring, RefPtr<Custody> cwd, RefPtr<Custody> executable, TTY* tty, Process* fork_parent)
: m_name(move(name))
, m_pid(next_pid++) // FIXME: RACE: This variable looks racy!
, m_uid(uid)
, m_gid(gid)
, m_euid(uid)
, m_egid(gid)
, m_ring(ring)
, m_executable(move(executable))
, m_cwd(move(cwd))
, m_tty(tty)
, m_ppid(ppid)
{
dbgprintf("Process: New process PID=%u with name=%s\n", m_pid, m_name.characters());
m_page_directory = PageDirectory::create_for_userspace(*this, fork_parent ? &fork_parent->page_directory().range_allocator() : nullptr);
#ifdef MM_DEBUG
dbgprintf("Process %u ctor: PD=%x created\n", pid(), m_page_directory.ptr());
#endif
// NOTE: fork() doesn't clone all threads; the thread that called fork() becomes the main thread in the new process.
if (fork_parent)
m_main_thread = current->clone(*this);
else
m_main_thread = new Thread(*this);
m_gids.set(m_gid);
if (fork_parent) {
m_sid = fork_parent->m_sid;
m_pgid = fork_parent->m_pgid;
} else {
// FIXME: Use a ProcessHandle? Presumably we're executing *IN* the parent right now though..
InterruptDisabler disabler;
if (auto* parent = Process::from_pid(m_ppid)) {
m_sid = parent->m_sid;
m_pgid = parent->m_pgid;
}
}
if (fork_parent) {
m_fds.resize(fork_parent->m_fds.size());
for (int i = 0; i < fork_parent->m_fds.size(); ++i) {
if (!fork_parent->m_fds[i].description)
continue;
#ifdef FORK_DEBUG
dbgprintf("fork: cloning fd %u... (%p) istty? %u\n", i, fork_parent->m_fds[i].description.ptr(), fork_parent->m_fds[i].description->is_tty());
#endif
m_fds[i] = fork_parent->m_fds[i];
}
} else {
m_fds.resize(m_max_open_file_descriptors);
auto& device_to_use_as_tty = tty ? (CharacterDevice&)*tty : NullDevice::the();
m_fds[0].set(*device_to_use_as_tty.open(O_RDONLY).value());
m_fds[1].set(*device_to_use_as_tty.open(O_WRONLY).value());
m_fds[2].set(*device_to_use_as_tty.open(O_WRONLY).value());
}
if (fork_parent) {
m_sid = fork_parent->m_sid;
m_pgid = fork_parent->m_pgid;
m_umask = fork_parent->m_umask;
}
}
Process::~Process()
{
dbgprintf("~Process{%p} name=%s pid=%d, m_fds=%d\n", this, m_name.characters(), pid(), m_fds.size());
delete m_main_thread;
m_main_thread = nullptr;
Vector<Thread*, 16> my_threads;
for_each_thread([&my_threads](auto& thread) {
my_threads.append(&thread);
return IterationDecision::Continue;
});
for (auto* thread : my_threads)
delete thread;
}
void Process::dump_regions()
{
kprintf("Process %s(%u) regions:\n", name().characters(), pid());
kprintf("BEGIN END SIZE ACCESS NAME\n");
for (auto& region : m_regions) {
kprintf("%08x -- %08x %08x %c%c%c %s\n",
region.vaddr().get(),
region.vaddr().offset(region.size() - 1).get(),
region.size(),
region.is_readable() ? 'R' : ' ',
region.is_writable() ? 'W' : ' ',
region.is_executable() ? 'X' : ' ',
region.name().characters());
}
}
void Process::sys$exit(int status)
{
cli();
#ifdef TASK_DEBUG
kprintf("sys$exit: %s(%u) exit with status %d\n", name().characters(), pid(), status);
#endif
dump_backtrace();
m_termination_status = status;
m_termination_signal = 0;
die();
ASSERT_NOT_REACHED();
}
void signal_trampoline_dummy(void)
{
// The trampoline preserves the current eax, pushes the signal code and
// then calls the signal handler. We do this because, when interrupting a
// blocking syscall, that syscall may return some special error code in eax;
// This error code would likely be overwritten by the signal handler, so it's
// neccessary to preserve it here.
asm(
".intel_syntax noprefix\n"
"asm_signal_trampoline:\n"
"push ebp\n"
"mov ebp, esp\n"
"push eax\n" // we have to store eax 'cause it might be the return value from a syscall
"sub esp, 4\n" // align the stack to 16 bytes
"mov eax, [ebp+12]\n" // push the signal code
"push eax\n"
"call [ebp+8]\n" // call the signal handler
"add esp, 8\n"
"mov eax, %P0\n"
"int 0x82\n" // sigreturn syscall
"asm_signal_trampoline_end:\n"
".att_syntax" ::"i"(Syscall::SC_sigreturn));
}
extern "C" void asm_signal_trampoline(void);
extern "C" void asm_signal_trampoline_end(void);
void create_signal_trampolines()
{
InterruptDisabler disabler;
// NOTE: We leak this region.
auto* trampoline_region = MM.allocate_user_accessible_kernel_region(PAGE_SIZE, "Signal trampolines").leak_ptr();
g_return_to_ring3_from_signal_trampoline = trampoline_region->vaddr();
u8* trampoline = (u8*)asm_signal_trampoline;
u8* trampoline_end = (u8*)asm_signal_trampoline_end;
size_t trampoline_size = trampoline_end - trampoline;
u8* code_ptr = (u8*)trampoline_region->vaddr().as_ptr();
memcpy(code_ptr, trampoline, trampoline_size);
trampoline_region->set_writable(false);
trampoline_region->remap();
}
int Process::sys$restore_signal_mask(u32 mask)
{
current->m_signal_mask = mask;
return 0;
}
int Process::sys$sigreturn(RegisterDump& registers)
{
//Here, we restore the state pushed by dispatch signal and asm_signal_trampoline.
u32* stack_ptr = (u32*)registers.esp_if_crossRing;
u32 smuggled_eax = *stack_ptr;
//pop the stored eax, ebp, return address, handler and signal code
stack_ptr += 5;
current->m_signal_mask = *stack_ptr;
stack_ptr++;
//pop edi, esi, ebp, esp, ebx, edx, ecx and eax
memcpy(&registers.edi, stack_ptr, 8 * sizeof(u32));
stack_ptr += 8;
registers.eip = *stack_ptr;
stack_ptr++;
registers.eflags = *stack_ptr;
stack_ptr++;
registers.esp_if_crossRing = registers.esp;
return smuggled_eax;
}
void Process::crash(int signal, u32 eip)
{
ASSERT_INTERRUPTS_DISABLED();
ASSERT(!is_dead());
if (m_elf_loader && ksyms_ready)
dbgprintf("\033[31;1m%p %s\033[0m\n", eip, m_elf_loader->symbolicate(eip).characters());
dump_backtrace();
m_termination_signal = signal;
dump_regions();
ASSERT(is_ring3());
die();
ASSERT_NOT_REACHED();
}
Process* Process::from_pid(pid_t pid)
{
ASSERT_INTERRUPTS_DISABLED();
for (auto& process : *g_processes) {
if (process.pid() == pid)
return &process;
}
return nullptr;
}
FileDescription* Process::file_description(int fd)
{
if (fd < 0)
return nullptr;
if (fd < m_fds.size())
return m_fds[fd].description.ptr();
return nullptr;
}
const FileDescription* Process::file_description(int fd) const
{
if (fd < 0)
return nullptr;
if (fd < m_fds.size())
return m_fds[fd].description.ptr();
return nullptr;
}
int Process::fd_flags(int fd) const
{
if (fd < 0)
return -1;
if (fd < m_fds.size())
return m_fds[fd].flags;
return -1;
}
ssize_t Process::sys$get_dir_entries(int fd, void* buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (!validate_write(buffer, size))
return -EFAULT;
auto* description = file_description(fd);
if (!description)
return -EBADF;
return description->get_dir_entries((u8*)buffer, size);
}
int Process::sys$lseek(int fd, off_t offset, int whence)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
return description->seek(offset, whence);
}
int Process::sys$ttyname_r(int fd, char* buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (!validate_write(buffer, size))
return -EFAULT;
auto* description = file_description(fd);
if (!description)
return -EBADF;
if (!description->is_tty())
return -ENOTTY;
auto tty_name = description->tty()->tty_name();
if (size < tty_name.length() + 1)
return -ERANGE;
memcpy(buffer, tty_name.characters_without_null_termination(), tty_name.length());
buffer[tty_name.length()] = '\0';
return 0;
}
int Process::sys$ptsname_r(int fd, char* buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (!validate_write(buffer, size))
return -EFAULT;
auto* description = file_description(fd);
if (!description)
return -EBADF;
auto* master_pty = description->master_pty();
if (!master_pty)
return -ENOTTY;
auto pts_name = master_pty->pts_name();
if (size < pts_name.length() + 1)
return -ERANGE;
strcpy(buffer, pts_name.characters());
return 0;
}
ssize_t Process::sys$writev(int fd, const struct iovec* iov, int iov_count)
{
if (iov_count < 0)
return -EINVAL;
if (!validate_read_typed(iov, iov_count))
return -EFAULT;
// FIXME: Return EINVAL if sum of iovecs is greater than INT_MAX
auto* description = file_description(fd);
if (!description)
return -EBADF;
int nwritten = 0;
for (int i = 0; i < iov_count; ++i) {
int rc = do_write(*description, (const u8*)iov[i].iov_base, iov[i].iov_len);
if (rc < 0) {
if (nwritten == 0)
return rc;
return nwritten;
}
nwritten += rc;
}
if (current->has_unmasked_pending_signals()) {
if (current->block<Thread::SemiPermanentBlocker>(Thread::SemiPermanentBlocker::Reason::Signal) == Thread::BlockResult::InterruptedBySignal) {
if (nwritten == 0)
return -EINTR;
}
}
return nwritten;
}
ssize_t Process::do_write(FileDescription& description, const u8* data, int data_size)
{
ssize_t nwritten = 0;
if (!description.is_blocking()) {
if (!description.can_write())
return -EAGAIN;
}
if (description.should_append()) {
#ifdef IO_DEBUG
dbgprintf("seeking to end (O_APPEND)\n");
#endif
description.seek(0, SEEK_END);
}
while (nwritten < data_size) {
#ifdef IO_DEBUG
dbgprintf("while %u < %u\n", nwritten, size);
#endif
if (!description.can_write()) {
#ifdef IO_DEBUG
dbgprintf("block write on %d\n", fd);
#endif
if (current->block<Thread::WriteBlocker>(description) == Thread::BlockResult::InterruptedBySignal) {
if (nwritten == 0)
return -EINTR;
}
}
ssize_t rc = description.write(data + nwritten, data_size - nwritten);
#ifdef IO_DEBUG
dbgprintf(" -> write returned %d\n", rc);
#endif
if (rc < 0) {
// FIXME: Support returning partial nwritten with errno.
ASSERT(nwritten == 0);
return rc;
}
if (rc == 0)
break;
if (current->has_unmasked_pending_signals()) {
if (current->block<Thread::SemiPermanentBlocker>(Thread::SemiPermanentBlocker::Reason::Signal) == Thread::BlockResult::InterruptedBySignal) {
if (nwritten == 0)
return -EINTR;
}
}
nwritten += rc;
}
return nwritten;
}
ssize_t Process::sys$write(int fd, const u8* data, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (size == 0)
return 0;
if (!validate_read(data, size))
return -EFAULT;
#ifdef DEBUG_IO
dbgprintf("%s(%u): sys$write(%d, %p, %u)\n", name().characters(), pid(), fd, data, size);
#endif
auto* description = file_description(fd);
if (!description)
return -EBADF;
auto nwritten = do_write(*description, data, size);
if (current->has_unmasked_pending_signals()) {
if (current->block<Thread::SemiPermanentBlocker>(Thread::SemiPermanentBlocker::Reason::Signal) == Thread::BlockResult::InterruptedBySignal) {
if (nwritten == 0)
return -EINTR;
}
}
return nwritten;
}
ssize_t Process::sys$read(int fd, u8* buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (size == 0)
return 0;
if (!validate_write(buffer, size))
return -EFAULT;
#ifdef DEBUG_IO
dbgprintf("%s(%u) sys$read(%d, %p, %u)\n", name().characters(), pid(), fd, buffer, size);
#endif
auto* description = file_description(fd);
if (!description)
return -EBADF;
if (description->is_directory())
return -EISDIR;
if (description->is_blocking()) {
if (!description->can_read()) {
if (current->block<Thread::ReadBlocker>(*description) == Thread::BlockResult::InterruptedBySignal)
return -EINTR;
}
}
return description->read(buffer, size);
}
int Process::sys$close(int fd)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
int rc = description->close();
m_fds[fd] = {};
return rc;
}
int Process::sys$utime(const char* pathname, const utimbuf* buf)
{
if (!validate_read_str(pathname))
return -EFAULT;
if (buf && !validate_read_typed(buf))
return -EFAULT;
time_t atime;
time_t mtime;
if (buf) {
atime = buf->actime;
mtime = buf->modtime;
} else {
struct timeval now;
kgettimeofday(now);
mtime = now.tv_sec;
atime = now.tv_sec;
}
return VFS::the().utime(StringView(pathname), current_directory(), atime, mtime);
}
int Process::sys$access(const char* pathname, int mode)
{
if (!validate_read_str(pathname))
return -EFAULT;
return VFS::the().access(StringView(pathname), mode, current_directory());
}
int Process::sys$fcntl(int fd, int cmd, u32 arg)
{
(void)cmd;
(void)arg;
dbgprintf("sys$fcntl: fd=%d, cmd=%d, arg=%u\n", fd, cmd, arg);
auto* description = file_description(fd);
if (!description)
return -EBADF;
// NOTE: The FD flags are not shared between FileDescription objects.
// This means that dup() doesn't copy the FD_CLOEXEC flag!
switch (cmd) {
case F_DUPFD: {
int arg_fd = (int)arg;
if (arg_fd < 0)
return -EINVAL;
int new_fd = alloc_fd(arg_fd);
if (new_fd < 0)
return new_fd;
m_fds[new_fd].set(*description);
break;
}
case F_GETFD:
return m_fds[fd].flags;
case F_SETFD:
m_fds[fd].flags = arg;
break;
case F_GETFL:
return description->file_flags();
case F_SETFL:
description->set_file_flags(arg);
break;
default:
ASSERT_NOT_REACHED();
}
return 0;
}
int Process::sys$fstat(int fd, stat* statbuf)
{
if (!validate_write_typed(statbuf))
return -EFAULT;
auto* description = file_description(fd);
if (!description)
return -EBADF;
return description->fstat(*statbuf);
}
int Process::sys$lstat(const char* path, stat* statbuf)
{
if (!validate_write_typed(statbuf))
return -EFAULT;
auto metadata_or_error = VFS::the().lookup_metadata(StringView(path), current_directory(), O_NOFOLLOW_NOERROR);
if (metadata_or_error.is_error())
return metadata_or_error.error();
return metadata_or_error.value().stat(*statbuf);
}
int Process::sys$stat(const char* path, stat* statbuf)
{
if (!validate_write_typed(statbuf))
return -EFAULT;
auto metadata_or_error = VFS::the().lookup_metadata(StringView(path), current_directory());
if (metadata_or_error.is_error())
return metadata_or_error.error();
return metadata_or_error.value().stat(*statbuf);
}
int Process::sys$readlink(const char* path, char* buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (!validate_read_str(path))
return -EFAULT;
if (!validate_write(buffer, size))
return -EFAULT;
auto result = VFS::the().open(path, O_RDONLY | O_NOFOLLOW_NOERROR, 0, current_directory());
if (result.is_error())
return result.error();
auto description = result.value();
if (!description->metadata().is_symlink())
return -EINVAL;
auto contents = description->read_entire_file();
if (!contents)
return -EIO; // FIXME: Get a more detailed error from VFS.
memcpy(buffer, contents.data(), min(size, (ssize_t)contents.size()));
if (contents.size() + 1 < size)
buffer[contents.size()] = '\0';
return 0;
}
int Process::sys$chdir(const char* path)
{
if (!validate_read_str(path))
return -EFAULT;
auto directory_or_error = VFS::the().open_directory(StringView(path), current_directory());
if (directory_or_error.is_error())
return directory_or_error.error();
m_cwd = *directory_or_error.value();
return 0;
}
int Process::sys$fchdir(int fd)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
if (!description->is_directory())
return -ENOTDIR;
if (!description->metadata().may_execute(*this))
return -EACCES;
m_cwd = description->custody();
return 0;
}
int Process::sys$getcwd(char* buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
if (!validate_write(buffer, size))
return -EFAULT;
auto path = current_directory().absolute_path();
if (size < path.length() + 1)
return -ERANGE;
strcpy(buffer, path.characters());
return 0;
}
int Process::number_of_open_file_descriptors() const
{
int count = 0;
for (auto& description : m_fds) {
if (description)
++count;
}
return count;
}
int Process::sys$open(const Syscall::SC_open_params* params)
{
if (!validate_read_typed(params))
return -EFAULT;
auto* path = params->path;
auto path_length = params->path_length;
auto options = params->options;
auto mode = params->mode;
#ifdef DEBUG_IO
dbgprintf("%s(%u) sys$open(\"%s\")\n", name().characters(), pid(), path);
#endif
if (!validate_read(path, path_length))
return -EFAULT;
int fd = alloc_fd();
if (fd < 0)
return fd;
auto result = VFS::the().open(path, options, mode & ~umask(), current_directory());
if (result.is_error())
return result.error();
auto description = result.value();
if (options & O_DIRECTORY && !description->is_directory())
return -ENOTDIR; // FIXME: This should be handled by VFS::open.
description->set_file_flags(options);
u32 fd_flags = (options & O_CLOEXEC) ? FD_CLOEXEC : 0;
m_fds[fd].set(move(description), fd_flags);
return fd;
}
int Process::alloc_fd(int first_candidate_fd)
{
int fd = -EMFILE;
for (int i = first_candidate_fd; i < (int)m_max_open_file_descriptors; ++i) {
if (!m_fds[i]) {
fd = i;
break;
}
}
return fd;
}
int Process::sys$pipe(int pipefd[2], int flags)
{
if (!validate_write_typed(pipefd))
return -EFAULT;
if (number_of_open_file_descriptors() + 2 > max_open_file_descriptors())
return -EMFILE;
// Reject flags other than O_CLOEXEC.
if ((flags & O_CLOEXEC) != flags)
return -EINVAL;
u32 fd_flags = (flags & O_CLOEXEC) ? FD_CLOEXEC : 0;
auto fifo = FIFO::create(m_uid);
int reader_fd = alloc_fd();
m_fds[reader_fd].set(fifo->open_direction(FIFO::Direction::Reader), fd_flags);
pipefd[0] = reader_fd;
int writer_fd = alloc_fd();
m_fds[writer_fd].set(fifo->open_direction(FIFO::Direction::Writer), fd_flags);
pipefd[1] = writer_fd;
return 0;
}
int Process::sys$killpg(int pgrp, int signum)
{
if (signum < 1 || signum >= 32)
return -EINVAL;
(void)pgrp;
ASSERT_NOT_REACHED();
}
int Process::sys$setuid(uid_t uid)
{
if (uid != m_uid && !is_superuser())
return -EPERM;
m_uid = uid;
m_euid = uid;
return 0;
}
int Process::sys$setgid(gid_t gid)
{
if (gid != m_gid && !is_superuser())
return -EPERM;
m_gid = gid;
m_egid = gid;
return 0;
}
unsigned Process::sys$alarm(unsigned seconds)
{
unsigned previous_alarm_remaining = 0;
if (m_alarm_deadline && m_alarm_deadline > g_uptime) {
previous_alarm_remaining = (m_alarm_deadline - g_uptime) / TICKS_PER_SECOND;
}
if (!seconds) {
m_alarm_deadline = 0;
return previous_alarm_remaining;
}
m_alarm_deadline = g_uptime + seconds * TICKS_PER_SECOND;
return previous_alarm_remaining;
}
int Process::sys$uname(utsname* buf)
{
if (!validate_write_typed(buf))
return -EFAULT;
strcpy(buf->sysname, "Serenity");
strcpy(buf->release, "1.0-dev");
strcpy(buf->version, "FIXME");
strcpy(buf->machine, "i386");
LOCKER(*s_hostname_lock);
strncpy(buf->nodename, s_hostname->characters(), sizeof(utsname::nodename));
return 0;
}
int Process::sys$isatty(int fd)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
if (!description->is_tty())
return -ENOTTY;
return 1;
}
int Process::sys$kill(pid_t pid, int signal)
{
if (signal < 0 || signal >= 32)
return -EINVAL;
if (pid == 0) {
Process::for_each_in_pgrp(pgid(), [&](auto& process) {
process.send_signal(signal, this);
return IterationDecision::Continue;
});
return 0;
}
if (pid == -1) {
// FIXME: Send to all processes.
ASSERT(pid != -1);
}
if (pid == m_pid) {
// FIXME: If we ignore this signal anyway, we don't need to block here, right?
current->send_signal(signal, this);
(void)current->block<Thread::SemiPermanentBlocker>(Thread::SemiPermanentBlocker::Reason::Signal);
return 0;
}
InterruptDisabler disabler;
auto* peer = Process::from_pid(pid);
if (!peer)
return -ESRCH;
// FIXME: Allow sending SIGCONT to everyone in the process group.
// FIXME: Should setuid processes have some special treatment here?
if (!is_superuser() && m_euid != peer->m_uid && m_uid != peer->m_uid)
return -EPERM;
if (peer->is_ring0() && signal == SIGKILL) {
kprintf("%s(%u) attempted to send SIGKILL to ring 0 process %s(%u)\n", name().characters(), m_pid, peer->name().characters(), peer->pid());
return -EPERM;
}
peer->send_signal(signal, this);
return 0;
}
int Process::sys$usleep(useconds_t usec)
{
if (!usec)
return 0;
u64 wakeup_time = current->sleep(usec / 1000);
if (wakeup_time > g_uptime) {
u32 ticks_left_until_original_wakeup_time = wakeup_time - g_uptime;
return ticks_left_until_original_wakeup_time / TICKS_PER_SECOND;
}
return 0;
}
int Process::sys$sleep(unsigned seconds)
{
if (!seconds)
return 0;
u64 wakeup_time = current->sleep(seconds * TICKS_PER_SECOND);
if (wakeup_time > g_uptime) {
u32 ticks_left_until_original_wakeup_time = wakeup_time - g_uptime;
return ticks_left_until_original_wakeup_time / TICKS_PER_SECOND;
}
return 0;
}
timeval kgettimeofday()
{
timeval tv;
tv.tv_sec = RTC::boot_time() + PIT::seconds_since_boot();
tv.tv_usec = PIT::ticks_this_second() * 1000;
return tv;
}
void kgettimeofday(timeval& tv)
{
tv = kgettimeofday();
}
int Process::sys$gettimeofday(timeval* tv)
{
if (!validate_write_typed(tv))
return -EFAULT;
kgettimeofday(*tv);
return 0;
}
uid_t Process::sys$getuid()
{
return m_uid;
}
gid_t Process::sys$getgid()
{
return m_gid;
}
uid_t Process::sys$geteuid()
{
return m_euid;
}
gid_t Process::sys$getegid()
{
return m_egid;
}
pid_t Process::sys$getpid()
{
return m_pid;
}
pid_t Process::sys$getppid()
{
return m_ppid;
}
mode_t Process::sys$umask(mode_t mask)
{
auto old_mask = m_umask;
m_umask = mask & 0777;
return old_mask;
}
int Process::reap(Process& process)
{
int exit_status;
{
InterruptDisabler disabler;
exit_status = (process.m_termination_status << 8) | process.m_termination_signal;
if (process.ppid()) {
auto* parent = Process::from_pid(process.ppid());
if (parent) {
parent->m_ticks_in_user_for_dead_children += process.m_ticks_in_user + process.m_ticks_in_user_for_dead_children;
parent->m_ticks_in_kernel_for_dead_children += process.m_ticks_in_kernel + process.m_ticks_in_kernel_for_dead_children;
}
}
dbgprintf("reap: %s(%u) {%s}\n", process.name().characters(), process.pid(), process.main_thread().state_string());
ASSERT(process.is_dead());
g_processes->remove(&process);
}
delete &process;
return exit_status;
}
pid_t Process::sys$waitpid(pid_t waitee, int* wstatus, int options)
{
dbgprintf("sys$waitpid(%d, %p, %d)\n", waitee, wstatus, options);
if (!options) {
// FIXME: This can't be right.. can it? Figure out how this should actually work.
options = WEXITED;
}
if (wstatus)
if (!validate_write_typed(wstatus))
return -EFAULT;
int dummy_wstatus;
int& exit_status = wstatus ? *wstatus : dummy_wstatus;
{
InterruptDisabler disabler;
if (waitee != -1 && !Process::from_pid(waitee))
return -ECHILD;
}
if (options & WNOHANG) {
// FIXME: Figure out what WNOHANG should do with stopped children.
if (waitee == -1) {
pid_t reaped_pid = 0;
InterruptDisabler disabler;
for_each_child([&reaped_pid, &exit_status](Process& process) {
if (process.is_dead()) {
reaped_pid = process.pid();
exit_status = reap(process);
}
return IterationDecision::Continue;
});
return reaped_pid;
} else {
ASSERT(waitee > 0); // FIXME: Implement other PID specs.
InterruptDisabler disabler;
auto* waitee_process = Process::from_pid(waitee);
if (!waitee_process)
return -ECHILD;
if (waitee_process->is_dead()) {
exit_status = reap(*waitee_process);
return waitee;
}
return 0;
}
}
pid_t waitee_pid = waitee;
if (current->block<Thread::WaitBlocker>(options, waitee_pid) == Thread::BlockResult::InterruptedBySignal)
return -EINTR;
InterruptDisabler disabler;
// NOTE: If waitee was -1, m_waitee_pid will have been filled in by the scheduler.
Process* waitee_process = Process::from_pid(waitee_pid);
if (!waitee_process)
return -ECHILD;
ASSERT(waitee_process);
if (waitee_process->is_dead()) {
exit_status = reap(*waitee_process);
} else {
ASSERT(waitee_process->main_thread().state() == Thread::State::Stopped);
exit_status = 0x7f;
}
return waitee_pid;
}
enum class KernelMemoryCheckResult {
NotInsideKernelMemory,
AccessGranted,
AccessDenied
};
static KernelMemoryCheckResult check_kernel_memory_access(VirtualAddress vaddr, bool is_write)
{
auto& sections = multiboot_info_ptr->u.elf_sec;
auto* kernel_program_headers = (Elf32_Phdr*)(sections.addr);
for (unsigned i = 0; i < sections.num; ++i) {
auto& segment = kernel_program_headers[i];
if (segment.p_type != PT_LOAD || !segment.p_vaddr || !segment.p_memsz)
continue;
if (vaddr.get() < segment.p_vaddr || vaddr.get() > (segment.p_vaddr + segment.p_memsz))
continue;
if (is_write && !(kernel_program_headers[i].p_flags & PF_W))
return KernelMemoryCheckResult::AccessDenied;
if (!is_write && !(kernel_program_headers[i].p_flags & PF_R))
return KernelMemoryCheckResult::AccessDenied;
return KernelMemoryCheckResult::AccessGranted;
}
return KernelMemoryCheckResult::NotInsideKernelMemory;
}
bool Process::validate_read_from_kernel(VirtualAddress vaddr) const
{
if (vaddr.is_null())
return false;
// We check extra carefully here since the first 4MB of the address space is identity-mapped.
// This code allows access outside of the known used address ranges to get caught.
auto kmc_result = check_kernel_memory_access(vaddr, false);
if (kmc_result == KernelMemoryCheckResult::AccessGranted)
return true;
if (kmc_result == KernelMemoryCheckResult::AccessDenied)
return false;
if (is_kmalloc_address(vaddr.as_ptr()))
return true;
return validate_read(vaddr.as_ptr(), 1);
}
bool Process::validate_read_str(const char* str)
{
if (!validate_read(str, 1))
return false;
return validate_read(str, strlen(str) + 1);
}
bool Process::validate_read(const void* address, ssize_t size) const
{
ASSERT(size >= 0);
VirtualAddress first_address((u32)address);
VirtualAddress last_address = first_address.offset(size - 1);
if (is_ring0()) {
auto kmc_result = check_kernel_memory_access(first_address, false);
if (kmc_result == KernelMemoryCheckResult::AccessGranted)
return true;
if (kmc_result == KernelMemoryCheckResult::AccessDenied)
return false;
if (is_kmalloc_address(address))
return true;
}
ASSERT(size);
if (!size)
return false;
if (first_address.page_base() != last_address.page_base()) {
if (!MM.validate_user_read(*this, last_address))
return false;
}
return MM.validate_user_read(*this, first_address);
}
bool Process::validate_write(void* address, ssize_t size) const
{
ASSERT(size >= 0);
VirtualAddress first_address((u32)address);
VirtualAddress last_address = first_address.offset(size - 1);
if (is_ring0()) {
if (is_kmalloc_address(address))
return true;
auto kmc_result = check_kernel_memory_access(first_address, true);
if (kmc_result == KernelMemoryCheckResult::AccessGranted)
return true;
if (kmc_result == KernelMemoryCheckResult::AccessDenied)
return false;
}
if (!size)
return false;
if (first_address.page_base() != last_address.page_base()) {
if (!MM.validate_user_write(*this, last_address))
return false;
}
return MM.validate_user_write(*this, last_address);
}
pid_t Process::sys$getsid(pid_t pid)
{
if (pid == 0)
return m_sid;
InterruptDisabler disabler;
auto* process = Process::from_pid(pid);
if (!process)
return -ESRCH;
if (m_sid != process->m_sid)
return -EPERM;
return process->m_sid;
}
pid_t Process::sys$setsid()
{
InterruptDisabler disabler;
bool found_process_with_same_pgid_as_my_pid = false;
Process::for_each_in_pgrp(pid(), [&](auto&) {
found_process_with_same_pgid_as_my_pid = true;
return IterationDecision::Break;
});
if (found_process_with_same_pgid_as_my_pid)
return -EPERM;
m_sid = m_pid;
m_pgid = m_pid;
return m_sid;
}
pid_t Process::sys$getpgid(pid_t pid)
{
if (pid == 0)
return m_pgid;
InterruptDisabler disabler; // FIXME: Use a ProcessHandle
auto* process = Process::from_pid(pid);
if (!process)
return -ESRCH;
return process->m_pgid;
}
pid_t Process::sys$getpgrp()
{
return m_pgid;
}
static pid_t get_sid_from_pgid(pid_t pgid)
{
InterruptDisabler disabler;
auto* group_leader = Process::from_pid(pgid);
if (!group_leader)
return -1;
return group_leader->sid();
}
int Process::sys$setpgid(pid_t specified_pid, pid_t specified_pgid)
{
InterruptDisabler disabler; // FIXME: Use a ProcessHandle
pid_t pid = specified_pid ? specified_pid : m_pid;
if (specified_pgid < 0)
return -EINVAL;
auto* process = Process::from_pid(pid);
if (!process)
return -ESRCH;
pid_t new_pgid = specified_pgid ? specified_pgid : process->m_pid;
pid_t current_sid = get_sid_from_pgid(process->m_pgid);
pid_t new_sid = get_sid_from_pgid(new_pgid);
if (current_sid != new_sid) {
// Can't move a process between sessions.
return -EPERM;
}
// FIXME: There are more EPERM conditions to check for here..
process->m_pgid = new_pgid;
return 0;
}
int Process::sys$ioctl(int fd, unsigned request, unsigned arg)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
return description->file().ioctl(*description, request, arg);
}
int Process::sys$getdtablesize()
{
return m_max_open_file_descriptors;
}
int Process::sys$dup(int old_fd)
{
auto* description = file_description(old_fd);
if (!description)
return -EBADF;
int new_fd = alloc_fd(0);
if (new_fd < 0)
return new_fd;
m_fds[new_fd].set(*description);
return new_fd;
}
int Process::sys$dup2(int old_fd, int new_fd)
{
auto* description = file_description(old_fd);
if (!description)
return -EBADF;
if (new_fd < 0 || new_fd >= m_max_open_file_descriptors)
return -EINVAL;
m_fds[new_fd].set(*description);
return new_fd;
}
int Process::sys$sigprocmask(int how, const sigset_t* set, sigset_t* old_set)
{
if (old_set) {
if (!validate_write_typed(old_set))
return -EFAULT;
*old_set = current->m_signal_mask;
}
if (set) {
if (!validate_read_typed(set))
return -EFAULT;
switch (how) {
case SIG_BLOCK:
current->m_signal_mask &= ~(*set);
break;
case SIG_UNBLOCK:
current->m_signal_mask |= *set;
break;
case SIG_SETMASK:
current->m_signal_mask = *set;
break;
default:
return -EINVAL;
}
}
return 0;
}
int Process::sys$sigpending(sigset_t* set)
{
if (!validate_write_typed(set))
return -EFAULT;
*set = current->m_pending_signals;
return 0;
}
int Process::sys$sigaction(int signum, const sigaction* act, sigaction* old_act)
{
if (signum < 1 || signum >= 32 || signum == SIGKILL || signum == SIGSTOP)
return -EINVAL;
if (!validate_read_typed(act))
return -EFAULT;
InterruptDisabler disabler; // FIXME: This should use a narrower lock. Maybe a way to ignore signals temporarily?
auto& action = current->m_signal_action_data[signum];
if (old_act) {
if (!validate_write_typed(old_act))
return -EFAULT;
old_act->sa_flags = action.flags;
old_act->sa_sigaction = (decltype(old_act->sa_sigaction))action.handler_or_sigaction.get();
}
action.flags = act->sa_flags;
action.handler_or_sigaction = VirtualAddress((u32)act->sa_sigaction);
return 0;
}
int Process::sys$getgroups(ssize_t count, gid_t* gids)
{
if (count < 0)
return -EINVAL;
if (!count)
return m_gids.size();
if (count != (int)m_gids.size())
return -EINVAL;
if (!validate_write_typed(gids, m_gids.size()))
return -EFAULT;
size_t i = 0;
for (auto gid : m_gids)
gids[i++] = gid;
return 0;
}
int Process::sys$setgroups(ssize_t count, const gid_t* gids)
{
if (count < 0)
return -EINVAL;
if (!is_superuser())
return -EPERM;
if (!validate_read(gids, count))
return -EFAULT;
m_gids.clear();
m_gids.set(m_gid);
for (int i = 0; i < count; ++i)
m_gids.set(gids[i]);
return 0;
}
int Process::sys$mkdir(const char* pathname, mode_t mode)
{
if (!validate_read_str(pathname))
return -EFAULT;
size_t pathname_length = strlen(pathname);
if (pathname_length == 0)
return -EINVAL;
if (pathname_length >= 255)
return -ENAMETOOLONG;
return VFS::the().mkdir(StringView(pathname, pathname_length), mode & ~umask(), current_directory());
}
int Process::sys$realpath(const char* pathname, char* buffer, size_t size)
{
if (!validate_read_str(pathname))
return -EFAULT;
size_t pathname_length = strlen(pathname);
if (pathname_length == 0)
return -EINVAL;
if (pathname_length >= size)
return -ENAMETOOLONG;
if (!validate_write(buffer, size))
return -EFAULT;
auto custody_or_error = VFS::the().resolve_path(pathname, current_directory());
if (custody_or_error.is_error())
return custody_or_error.error();
auto& custody = custody_or_error.value();
// FIXME: Once resolve_path is fixed to deal with .. and . , remove the use of FileSystemPath::canonical_path.
FileSystemPath canonical_path(custody->absolute_path());
if (!canonical_path.is_valid()) {
dbg() << "FileSystemPath failed to canonicalize " << custody->absolute_path();
ASSERT_NOT_REACHED();
}
strncpy(buffer, canonical_path.string().characters(), size);
return 0;
};
clock_t Process::sys$times(tms* times)
{
if (!validate_write_typed(times))
return -EFAULT;
times->tms_utime = m_ticks_in_user;
times->tms_stime = m_ticks_in_kernel;
times->tms_cutime = m_ticks_in_user_for_dead_children;
times->tms_cstime = m_ticks_in_kernel_for_dead_children;
return g_uptime & 0x7fffffff;
}
int Process::sys$select(const Syscall::SC_select_params* params)
{
// FIXME: Return -EINTR if a signal is caught.
// FIXME: Return -EINVAL if timeout is invalid.
if (!validate_read_typed(params))
return -EFAULT;
if (params->writefds && !validate_write_typed(params->writefds))
return -EFAULT;
if (params->readfds && !validate_write_typed(params->readfds))
return -EFAULT;
if (params->exceptfds && !validate_write_typed(params->exceptfds))
return -EFAULT;
if (params->timeout && !validate_read_typed(params->timeout))
return -EFAULT;
if (params->nfds < 0)
return -EINVAL;
timeval timeout;
bool select_has_timeout = false;
if (params->timeout && (params->timeout->tv_sec || params->timeout->tv_usec)) {
timeval_add(kgettimeofday(), *params->timeout, timeout);
select_has_timeout = true;
}
Thread::SelectBlocker::FDVector rfds;
Thread::SelectBlocker::FDVector wfds;
Thread::SelectBlocker::FDVector efds;
auto transfer_fds = [&](auto* fds, auto& vector) -> int {
vector.clear_with_capacity();
if (!fds)
return 0;
for (int fd = 0; fd < params->nfds; ++fd) {
if (FD_ISSET(fd, fds)) {
if (!file_description(fd))
return -EBADF;
vector.append(fd);
}
}
return 0;
};
if (int error = transfer_fds(params->writefds, wfds))
return error;
if (int error = transfer_fds(params->readfds, rfds))
return error;
if (int error = transfer_fds(params->exceptfds, efds))
return error;
#if defined(DEBUG_IO) || defined(DEBUG_POLL_SELECT)
dbgprintf("%s<%u> selecting on (read:%u, write:%u), timeout=%p\n", name().characters(), pid(), rfds.size(), wfds.size(), params->timeout);
#endif
if (!params->timeout || select_has_timeout) {
if (current->block<Thread::SelectBlocker>(timeout, select_has_timeout, rfds, wfds, efds) == Thread::BlockResult::InterruptedBySignal)
return -EINTR;
}
int marked_fd_count = 0;
auto mark_fds = [&](auto* fds, auto& vector, auto should_mark) {
if (!fds)
return;
FD_ZERO(fds);
for (int fd : vector) {
if (auto* description = file_description(fd); description && should_mark(*description)) {
FD_SET(fd, fds);
++marked_fd_count;
}
}
};
mark_fds(params->readfds, rfds, [](auto& description) { return description.can_read(); });
mark_fds(params->writefds, wfds, [](auto& description) { return description.can_write(); });
// FIXME: We should also mark params->exceptfds as appropriate.
return marked_fd_count;
}
int Process::sys$poll(pollfd* fds, int nfds, int timeout)
{
if (!validate_read_typed(fds))
return -EFAULT;
Thread::SelectBlocker::FDVector rfds;
Thread::SelectBlocker::FDVector wfds;
for (int i = 0; i < nfds; ++i) {
if (fds[i].events & POLLIN)
rfds.append(fds[i].fd);
if (fds[i].events & POLLOUT)
wfds.append(fds[i].fd);
}
timeval actual_timeout;
bool has_timeout = false;
if (timeout >= 0) {
// poll is in ms, we want s/us.
struct timeval tvtimeout;
tvtimeout.tv_sec = 0;
while (timeout >= 1000) {
tvtimeout.tv_sec += 1;
timeout -= 1000;
}
tvtimeout.tv_usec = timeout * 1000;
timeval_add(kgettimeofday(), tvtimeout, actual_timeout);
has_timeout = true;
}
#if defined(DEBUG_IO) || defined(DEBUG_POLL_SELECT)
dbgprintf("%s<%u> polling on (read:%u, write:%u), timeout=%d\n", name().characters(), pid(), rfds.size(), wfds.size(), timeout);
#endif
if (has_timeout || timeout < 0) {
if (current->block<Thread::SelectBlocker>(actual_timeout, has_timeout, rfds, wfds, Thread::SelectBlocker::FDVector()) == Thread::BlockResult::InterruptedBySignal)
return -EINTR;
}
int fds_with_revents = 0;
for (int i = 0; i < nfds; ++i) {
auto* description = file_description(fds[i].fd);
if (!description) {
fds[i].revents = POLLNVAL;
continue;
}
fds[i].revents = 0;
if (fds[i].events & POLLIN && description->can_read())
fds[i].revents |= POLLIN;
if (fds[i].events & POLLOUT && description->can_write())
fds[i].revents |= POLLOUT;
if (fds[i].revents)
++fds_with_revents;
}
return fds_with_revents;
}
Custody& Process::current_directory()
{
if (!m_cwd)
m_cwd = VFS::the().root_custody();
return *m_cwd;
}
int Process::sys$link(const char* old_path, const char* new_path)
{
if (!validate_read_str(old_path))
return -EFAULT;
if (!validate_read_str(new_path))
return -EFAULT;
return VFS::the().link(StringView(old_path), StringView(new_path), current_directory());
}
int Process::sys$unlink(const char* pathname)
{
if (!validate_read_str(pathname))
return -EFAULT;
return VFS::the().unlink(StringView(pathname), current_directory());
}
int Process::sys$symlink(const char* target, const char* linkpath)
{
if (!validate_read_str(target))
return -EFAULT;
if (!validate_read_str(linkpath))
return -EFAULT;
return VFS::the().symlink(StringView(target), StringView(linkpath), current_directory());
}
int Process::sys$rmdir(const char* pathname)
{
if (!validate_read_str(pathname))
return -EFAULT;
return VFS::the().rmdir(StringView(pathname), current_directory());
}
int Process::sys$read_tsc(u32* lsw, u32* msw)
{
if (!validate_write_typed(lsw))
return -EFAULT;
if (!validate_write_typed(msw))
return -EFAULT;
read_tsc(*lsw, *msw);
return 0;
}
int Process::sys$chmod(const char* pathname, mode_t mode)
{
if (!validate_read_str(pathname))
return -EFAULT;
return VFS::the().chmod(StringView(pathname), mode, current_directory());
}
int Process::sys$fchmod(int fd, mode_t mode)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
return description->fchmod(mode);
}
int Process::sys$fchown(int fd, uid_t uid, gid_t gid)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
return description->chown(uid, gid);
}
int Process::sys$chown(const char* pathname, uid_t uid, gid_t gid)
{
if (!validate_read_str(pathname))
return -EFAULT;
return VFS::the().chown(StringView(pathname), uid, gid, current_directory());
}
void Process::finalize()
{
ASSERT(current == g_finalizer);
dbgprintf("Finalizing Process %s(%u)\n", m_name.characters(), m_pid);
m_fds.clear();
m_tty = nullptr;
m_executable = nullptr;
m_cwd = nullptr;
m_elf_loader = nullptr;
disown_all_shared_buffers();
{
InterruptDisabler disabler;
if (auto* parent_process = Process::from_pid(m_ppid)) {
// FIXME(Thread): What should we do here? Should we look at all threads' signal actions?
if (parent_process->main_thread().m_signal_action_data[SIGCHLD].flags & SA_NOCLDWAIT) {
// NOTE: If the parent doesn't care about this process, let it go.
m_ppid = 0;
} else {
parent_process->send_signal(SIGCHLD, this);
}
}
}
m_dead = true;
}
void Process::die()
{
if (m_tracer)
m_tracer->set_dead();
{
InterruptDisabler disabler;
for_each_thread([](Thread& thread) {
if (thread.state() != Thread::State::Dead)
thread.set_state(Thread::State::Dying);
return IterationDecision::Continue;
});
}
if (!Scheduler::is_active())
Scheduler::pick_next_and_switch_now();
}
size_t Process::amount_virtual() const
{
size_t amount = 0;
for (auto& region : m_regions) {
amount += region.size();
}
return amount;
}
size_t Process::amount_resident() const
{
// FIXME: This will double count if multiple regions use the same physical page.
size_t amount = 0;
for (auto& region : m_regions) {
amount += region.amount_resident();
}
return amount;
}
size_t Process::amount_shared() const
{
// FIXME: This will double count if multiple regions use the same physical page.
// FIXME: It doesn't work at the moment, since it relies on PhysicalPage ref counts,
// and each PhysicalPage is only reffed by its VMObject. This needs to be refactored
// so that every Region contributes +1 ref to each of its PhysicalPages.
size_t amount = 0;
for (auto& region : m_regions) {
amount += region.amount_shared();
}
return amount;
}
int Process::sys$socket(int domain, int type, int protocol)
{
int fd = alloc_fd();
if (fd < 0)
return fd;
auto result = Socket::create(domain, type, protocol);
if (result.is_error())
return result.error();
auto description = FileDescription::create(*result.value());
unsigned flags = 0;
if (type & SOCK_CLOEXEC)
flags |= FD_CLOEXEC;
if (type & SOCK_NONBLOCK)
description->set_blocking(false);
m_fds[fd].set(move(description), flags);
return fd;
}
int Process::sys$bind(int sockfd, const sockaddr* address, socklen_t address_length)
{
if (!validate_read(address, address_length))
return -EFAULT;
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
return socket.bind(address, address_length);
}
int Process::sys$listen(int sockfd, int backlog)
{
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
return socket.listen(backlog);
}
int Process::sys$accept(int accepting_socket_fd, sockaddr* address, socklen_t* address_size)
{
if (!validate_write_typed(address_size))
return -EFAULT;
if (!validate_write(address, *address_size))
return -EFAULT;
int accepted_socket_fd = alloc_fd();
if (accepted_socket_fd < 0)
return accepted_socket_fd;
auto* accepting_socket_description = file_description(accepting_socket_fd);
if (!accepting_socket_description)
return -EBADF;
if (!accepting_socket_description->is_socket())
return -ENOTSOCK;
auto& socket = *accepting_socket_description->socket();
if (!socket.can_accept()) {
if (accepting_socket_description->is_blocking()) {
if (current->block<Thread::AcceptBlocker>(*accepting_socket_description) == Thread::BlockResult::InterruptedBySignal)
return -EINTR;
} else {
return -EAGAIN;
}
}
auto accepted_socket = socket.accept();
ASSERT(accepted_socket);
bool success = accepted_socket->get_peer_address(address, address_size);
ASSERT(success);
auto accepted_socket_description = FileDescription::create(*accepted_socket);
// NOTE: The accepted socket inherits fd flags from the accepting socket.
// I'm not sure if this matches other systems but it makes sense to me.
accepted_socket_description->set_blocking(accepting_socket_description->is_blocking());
m_fds[accepted_socket_fd].set(move(accepted_socket_description), m_fds[accepting_socket_fd].flags);
// NOTE: Moving this state to Completed is what causes connect() to unblock on the client side.
accepted_socket->set_setup_state(Socket::SetupState::Completed);
return accepted_socket_fd;
}
int Process::sys$connect(int sockfd, const sockaddr* address, socklen_t address_size)
{
if (!validate_read(address, address_size))
return -EFAULT;
int fd = alloc_fd();
if (fd < 0)
return fd;
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
return socket.connect(*description, address, address_size, description->is_blocking() ? ShouldBlock::Yes : ShouldBlock::No);
}
ssize_t Process::sys$sendto(const Syscall::SC_sendto_params* params)
{
if (!validate_read_typed(params))
return -EFAULT;
int sockfd = params->sockfd;
const void* data = params->data;
size_t data_length = params->data_length;
int flags = params->flags;
auto* addr = (const sockaddr*)params->addr;
auto addr_length = (socklen_t)params->addr_length;
if (!validate_read(data, data_length))
return -EFAULT;
if (addr && !validate_read(addr, addr_length))
return -EFAULT;
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
kprintf("sendto %p (%u), flags=%u, addr: %p (%u)\n", data, data_length, flags, addr, addr_length);
return socket.sendto(*description, data, data_length, flags, addr, addr_length);
}
ssize_t Process::sys$recvfrom(const Syscall::SC_recvfrom_params* params)
{
if (!validate_read_typed(params))
return -EFAULT;
int sockfd = params->sockfd;
void* buffer = params->buffer;
size_t buffer_length = params->buffer_length;
int flags = params->flags;
auto* addr = (sockaddr*)params->addr;
auto* addr_length = (socklen_t*)params->addr_length;
if (!validate_write(buffer, buffer_length))
return -EFAULT;
if (addr_length) {
if (!validate_write_typed(addr_length))
return -EFAULT;
if (!validate_write(addr, *addr_length))
return -EFAULT;
} else if (addr) {
return -EINVAL;
}
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
bool original_blocking = description->is_blocking();
if (flags & MSG_DONTWAIT)
description->set_blocking(false);
auto nrecv = socket.recvfrom(*description, buffer, buffer_length, flags, addr, addr_length);
if (flags & MSG_DONTWAIT)
description->set_blocking(original_blocking);
return nrecv;
}
int Process::sys$getsockname(int sockfd, sockaddr* addr, socklen_t* addrlen)
{
if (!validate_read_typed(addrlen))
return -EFAULT;
if (*addrlen <= 0)
return -EINVAL;
if (!validate_write(addr, *addrlen))
return -EFAULT;
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
if (!socket.get_local_address(addr, addrlen))
return -EINVAL; // FIXME: Should this be another error? I'm not sure.
return 0;
}
int Process::sys$getpeername(int sockfd, sockaddr* addr, socklen_t* addrlen)
{
if (!validate_read_typed(addrlen))
return -EFAULT;
if (*addrlen <= 0)
return -EINVAL;
if (!validate_write(addr, *addrlen))
return -EFAULT;
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
if (socket.setup_state() != Socket::SetupState::Completed)
return -ENOTCONN;
if (!socket.get_peer_address(addr, addrlen))
return -EINVAL; // FIXME: Should this be another error? I'm not sure.
return 0;
}
int Process::sys$sched_setparam(pid_t pid, const struct sched_param* param)
{
if (!validate_read_typed(param))
return -EFAULT;
InterruptDisabler disabler;
auto* peer = this;
if (pid != 0)
peer = Process::from_pid(pid);
if (!peer)
return -ESRCH;
if (!is_superuser() && m_euid != peer->m_uid && m_uid != peer->m_uid)
return -EPERM;
if (param->sched_priority < Process::FirstPriority || param->sched_priority > Process::LastPriority)
return -EINVAL;
peer->set_priority(Priority(param->sched_priority));
return 0;
}
int Process::sys$sched_getparam(pid_t pid, struct sched_param* param)
{
if (!validate_read_typed(param))
return -EFAULT;
InterruptDisabler disabler;
auto* peer = this;
if (pid != 0)
peer = Process::from_pid(pid);
if (!peer)
return -ESRCH;
if (!is_superuser() && m_euid != peer->m_uid && m_uid != peer->m_uid)
return -EPERM;
param->sched_priority = peer->priority();
return 0;
}
int Process::sys$getsockopt(const Syscall::SC_getsockopt_params* params)
{
if (!validate_read_typed(params))
return -EFAULT;
int sockfd = params->sockfd;
int level = params->level;
int option = params->option;
auto* value = params->value;
auto* value_size = (socklen_t*)params->value_size;
if (!validate_write_typed(value_size))
return -EFAULT;
if (!validate_write(value, *value_size))
return -EFAULT;
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
return socket.getsockopt(level, option, value, value_size);
}
int Process::sys$setsockopt(const Syscall::SC_setsockopt_params* params)
{
if (!validate_read_typed(params))
return -EFAULT;
int sockfd = params->sockfd;
int level = params->level;
int option = params->option;
auto* value = params->value;
auto value_size = (socklen_t)params->value_size;
if (!validate_read(value, value_size))
return -EFAULT;
auto* description = file_description(sockfd);
if (!description)
return -EBADF;
if (!description->is_socket())
return -ENOTSOCK;
auto& socket = *description->socket();
return socket.setsockopt(level, option, value, value_size);
}
void Process::disown_all_shared_buffers()
{
LOCKER(shared_buffers().lock());
Vector<SharedBuffer*, 32> buffers_to_disown;
for (auto& it : shared_buffers().resource())
buffers_to_disown.append(it.value.ptr());
for (auto* shared_buffer : buffers_to_disown)
shared_buffer->disown(m_pid);
}
int Process::sys$create_shared_buffer(int size, void** buffer)
{
if (!size || size < 0)
return -EINVAL;
size = PAGE_ROUND_UP(size);
if (!validate_write_typed(buffer))
return -EFAULT;
LOCKER(shared_buffers().lock());
static int s_next_shared_buffer_id;
int shared_buffer_id = ++s_next_shared_buffer_id;
auto shared_buffer = make<SharedBuffer>(shared_buffer_id, size);
shared_buffer->share_with(m_pid);
*buffer = shared_buffer->ref_for_process_and_get_address(*this);
ASSERT((int)shared_buffer->size() >= size);
#ifdef SHARED_BUFFER_DEBUG
kprintf("%s(%u): Created shared buffer %d @ %p (%u bytes, vmo is %u)\n", name().characters(), pid(), shared_buffer_id, *buffer, size, shared_buffer->size());
#endif
shared_buffers().resource().set(shared_buffer_id, move(shared_buffer));
return shared_buffer_id;
}
int Process::sys$share_buffer_with(int shared_buffer_id, pid_t peer_pid)
{
if (!peer_pid || peer_pid < 0 || peer_pid == m_pid)
return -EINVAL;
LOCKER(shared_buffers().lock());
auto it = shared_buffers().resource().find(shared_buffer_id);
if (it == shared_buffers().resource().end())
return -EINVAL;
auto& shared_buffer = *(*it).value;
if (!shared_buffer.is_shared_with(m_pid))
return -EPERM;
{
InterruptDisabler disabler;
auto* peer = Process::from_pid(peer_pid);
if (!peer)
return -ESRCH;
}
shared_buffer.share_with(peer_pid);
return 0;
}
int Process::sys$share_buffer_globally(int shared_buffer_id)
{
LOCKER(shared_buffers().lock());
auto it = shared_buffers().resource().find(shared_buffer_id);
if (it == shared_buffers().resource().end())
return -EINVAL;
auto& shared_buffer = *(*it).value;
if (!shared_buffer.is_shared_with(m_pid))
return -EPERM;
shared_buffer.share_globally();
return 0;
}
int Process::sys$release_shared_buffer(int shared_buffer_id)
{
LOCKER(shared_buffers().lock());
auto it = shared_buffers().resource().find(shared_buffer_id);
if (it == shared_buffers().resource().end())
return -EINVAL;
auto& shared_buffer = *(*it).value;
if (!shared_buffer.is_shared_with(m_pid))
return -EPERM;
#ifdef SHARED_BUFFER_DEBUG
kprintf("%s(%u): Releasing shared buffer %d, buffer count: %u\n", name().characters(), pid(), shared_buffer_id, shared_buffers().resource().size());
#endif
shared_buffer.deref_for_process(*this);
return 0;
}
void* Process::sys$get_shared_buffer(int shared_buffer_id)
{
LOCKER(shared_buffers().lock());
auto it = shared_buffers().resource().find(shared_buffer_id);
if (it == shared_buffers().resource().end())
return (void*)-EINVAL;
auto& shared_buffer = *(*it).value;
if (!shared_buffer.is_shared_with(m_pid))
return (void*)-EPERM;
#ifdef SHARED_BUFFER_DEBUG
kprintf("%s(%u): Retaining shared buffer %d, buffer count: %u\n", name().characters(), pid(), shared_buffer_id, shared_buffers().resource().size());
#endif
return shared_buffer.ref_for_process_and_get_address(*this);
}
int Process::sys$seal_shared_buffer(int shared_buffer_id)
{
LOCKER(shared_buffers().lock());
auto it = shared_buffers().resource().find(shared_buffer_id);
if (it == shared_buffers().resource().end())
return -EINVAL;
auto& shared_buffer = *(*it).value;
if (!shared_buffer.is_shared_with(m_pid))
return -EPERM;
#ifdef SHARED_BUFFER_DEBUG
kprintf("%s(%u): Sealing shared buffer %d\n", name().characters(), pid(), shared_buffer_id);
#endif
shared_buffer.seal();
return 0;
}
int Process::sys$get_shared_buffer_size(int shared_buffer_id)
{
LOCKER(shared_buffers().lock());
auto it = shared_buffers().resource().find(shared_buffer_id);
if (it == shared_buffers().resource().end())
return -EINVAL;
auto& shared_buffer = *(*it).value;
if (!shared_buffer.is_shared_with(m_pid))
return -EPERM;
#ifdef SHARED_BUFFER_DEBUG
kprintf("%s(%u): Get shared buffer %d size: %u\n", name().characters(), pid(), shared_buffer_id, shared_buffers().resource().size());
#endif
return shared_buffer.size();
}
const char* to_string(Process::Priority priority)
{
switch (priority) {
case Process::IdlePriority:
return "Idle";
case Process::LowPriority:
return "Low";
case Process::NormalPriority:
return "Normal";
case Process::HighPriority:
return "High";
}
kprintf("to_string(Process::Priority): Invalid priority: %u\n", priority);
ASSERT_NOT_REACHED();
return nullptr;
}
void Process::terminate_due_to_signal(u8 signal)
{
ASSERT_INTERRUPTS_DISABLED();
ASSERT(signal < 32);
dbgprintf("terminate_due_to_signal %s(%u) <- %u\n", name().characters(), pid(), signal);
m_termination_status = 0;
m_termination_signal = signal;
die();
}
void Process::send_signal(u8 signal, Process* sender)
{
// FIXME(Thread): Find the appropriate thread to deliver the signal to.
main_thread().send_signal(signal, sender);
}
int Process::thread_count() const
{
int count = 0;
for_each_thread([&count](auto&) {
++count;
return IterationDecision::Continue;
});
return count;
}
int Process::sys$create_thread(int (*entry)(void*), void* argument)
{
if (!validate_read((const void*)entry, sizeof(void*)))
return -EFAULT;
auto* thread = new Thread(*this);
auto& tss = thread->tss();
tss.eip = (u32)entry;
tss.eflags = 0x0202;
tss.cr3 = page_directory().cr3();
thread->make_userspace_stack_for_secondary_thread(argument);
thread->make_thread_specific_region({});
thread->set_state(Thread::State::Runnable);
return thread->tid();
}
void Process::sys$exit_thread(int code)
{
cli();
if (&current->process().main_thread() == current) {
sys$exit(code);
return;
}
current->set_state(Thread::State::Dying);
big_lock().unlock_if_locked();
Scheduler::pick_next_and_switch_now();
ASSERT_NOT_REACHED();
}
int Process::sys$gettid()
{
return current->tid();
}
int Process::sys$donate(int tid)
{
if (tid < 0)
return -EINVAL;
InterruptDisabler disabler;
Thread* beneficiary = nullptr;
for_each_thread([&](Thread& thread) {
if (thread.tid() == tid) {
beneficiary = &thread;
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
if (!beneficiary)
return -ENOTHREAD;
Scheduler::donate_to(beneficiary, "sys$donate");
return 0;
}
int Process::sys$rename(const char* oldpath, const char* newpath)
{
if (!validate_read_str(oldpath))
return -EFAULT;
if (!validate_read_str(newpath))
return -EFAULT;
return VFS::the().rename(StringView(oldpath), StringView(newpath), current_directory());
}
int Process::sys$shm_open(const char* name, int flags, mode_t mode)
{
if (!validate_read_str(name))
return -EFAULT;
int fd = alloc_fd();
if (fd < 0)
return fd;
auto shm_or_error = SharedMemory::open(String(name), flags, mode);
if (shm_or_error.is_error())
return shm_or_error.error();
auto description = FileDescription::create(shm_or_error.value());
m_fds[fd].set(move(description), FD_CLOEXEC);
return fd;
}
int Process::sys$shm_unlink(const char* name)
{
if (!validate_read_str(name))
return -EFAULT;
return SharedMemory::unlink(String(name));
}
int Process::sys$ftruncate(int fd, off_t length)
{
auto* description = file_description(fd);
if (!description)
return -EBADF;
// FIXME: Check that fd is writable, otherwise EINVAL.
return description->truncate(length);
}
int Process::sys$watch_file(const char* path, int path_length)
{
if (!validate_read(path, path_length))
return -EFAULT;
auto custody_or_error = VFS::the().resolve_path({ path, path_length }, current_directory());
if (custody_or_error.is_error())
return custody_or_error.error();
auto& custody = custody_or_error.value();
auto& inode = custody->inode();
int fd = alloc_fd();
if (fd < 0)
return fd;
m_fds[fd].set(FileDescription::create(*InodeWatcher::create(inode)));
return fd;
}
int Process::sys$systrace(pid_t pid)
{
InterruptDisabler disabler;
auto* peer = Process::from_pid(pid);
if (!peer)
return -ESRCH;
if (peer->uid() != m_euid)
return -EACCES;
int fd = alloc_fd();
if (fd < 0)
return fd;
auto description = FileDescription::create(peer->ensure_tracer());
m_fds[fd].set(move(description), 0);
return fd;
}
int Process::sys$halt()
{
if (!is_superuser())
return -EPERM;
dbgprintf("acquiring FS locks...\n");
FS::lock_all();
dbgprintf("syncing mounted filesystems...\n");
FS::sync();
dbgprintf("attempting system shutdown...\n");
IO::out16(0x604, 0x2000);
return ESUCCESS;
}
int Process::sys$reboot()
{
if (!is_superuser())
return -EPERM;
dbgprintf("acquiring FS locks...\n");
FS::lock_all();
dbgprintf("syncing mounted filesystems...\n");
FS::sync();
dbgprintf("attempting reboot via KB Controller...\n");
IO::out8(0x64, 0xFE);
return ESUCCESS;
}
int Process::sys$mount(const char* device_path, const char* mountpoint, const char* fstype)
{
if (!is_superuser())
return -EPERM;
if (!validate_read_str(device_path) || !validate_read_str(mountpoint) || !validate_read_str(fstype))
return -EFAULT;
dbg() << "mount " << fstype << ": device " << device_path << " @ " << mountpoint;
auto custody_or_error = VFS::the().resolve_path(mountpoint, current_directory());
if (custody_or_error.is_error())
return custody_or_error.error();
auto& mountpoint_custody = custody_or_error.value();
RefPtr<FS> fs { nullptr };
if (strcmp(fstype, "ext2") == 0 || strcmp(fstype, "Ext2FS") == 0) {
auto metadata_or_error = VFS::the().lookup_metadata(device_path, current_directory());
if (metadata_or_error.is_error())
return metadata_or_error.error();
auto major = metadata_or_error.value().major_device;
auto minor = metadata_or_error.value().minor_device;
auto* device = Device::get_device(major, minor);
if (!device) {
dbg() << "mount: device (" << major << "," << minor << ") not found";
return -ENODEV;
}
if (!device->is_disk_device()) {
dbg() << "mount: device (" << major << "," << minor << ") is not a DiskDevice";
return -ENODEV;
}
auto& disk_device = static_cast<DiskDevice&>(*device);
dbg() << "mount: attempting to mount device (" << major << "," << minor << ") on " << mountpoint;
fs = Ext2FS::create(disk_device);
} else if (strcmp(fstype, "proc") == 0 || strcmp(fstype, "ProcFS") == 0)
fs = ProcFS::create();
else if (strcmp(fstype, "devpts") == 0 || strcmp(fstype, "DevPtsFS") == 0)
fs = DevPtsFS::create();
else if (strcmp(fstype, "tmp") == 0 || strcmp(fstype, "TmpFS") == 0)
fs = TmpFS::create();
else
return -ENODEV;
if (!fs->initialize()) {
dbg() << "mount: failed to initialize " << fstype << " filesystem on " << device_path;
return -ENODEV;
}
auto result = VFS::the().mount(fs.release_nonnull(), mountpoint_custody);
dbg() << "mount: successfully mounted " << device_path << " on " << mountpoint;
return result;
}
int Process::sys$umount(const char* mountpoint)
{
if (!is_superuser())
return -EPERM;
if (!validate_read_str(mountpoint))
return -EFAULT;
auto metadata_or_error = VFS::the().lookup_metadata(mountpoint, current_directory());
if (metadata_or_error.is_error())
return metadata_or_error.error();
auto guest_inode_id = metadata_or_error.value().inode;
return VFS::the().unmount(guest_inode_id);
}
ProcessTracer& Process::ensure_tracer()
{
if (!m_tracer)
m_tracer = ProcessTracer::create(m_pid);
return *m_tracer;
}
void Process::FileDescriptionAndFlags::clear()
{
description = nullptr;
flags = 0;
}
void Process::FileDescriptionAndFlags::set(NonnullRefPtr<FileDescription>&& d, u32 f)
{
description = move(d);
flags = f;
}
int Process::sys$mknod(const char* pathname, mode_t mode, dev_t dev)
{
if (!validate_read_str(pathname))
return -EFAULT;
return VFS::the().mknod(StringView(pathname), mode, dev, current_directory());
}
int Process::sys$dump_backtrace()
{
dump_backtrace();
return 0;
}
int Process::sys$dbgputch(u8 ch)
{
IO::out8(0xe9, ch);
return 0;
}
int Process::sys$dbgputstr(const u8* characters, int length)
{
if (!length)
return 0;
if (!validate_read(characters, length))
return -EFAULT;
for (int i = 0; i < length; ++i)
IO::out8(0xe9, characters[i]);
return 0;
}
KBuffer Process::backtrace(ProcessInspectionHandle& handle) const
{
KBufferBuilder builder;
for_each_thread([&](Thread& thread) {
builder.appendf("Thread %d:\n", thread.tid());
builder.append(thread.backtrace(handle));
return IterationDecision::Continue;
});
return builder.build();
}
int Process::sys$set_process_icon(int icon_id)
{
LOCKER(shared_buffers().lock());
auto it = shared_buffers().resource().find(icon_id);
if (it == shared_buffers().resource().end())
return -EINVAL;
auto& shared_buffer = *(*it).value;
if (!shared_buffer.is_shared_with(m_pid))
return -EPERM;
m_icon_id = icon_id;
return 0;
}
int Process::sys$get_process_name(char* buffer, int buffer_size)
{
if (buffer_size <= 0)
return -EINVAL;
if (!validate_write(buffer, buffer_size))
return -EFAULT;
if (m_name.length() >= buffer_size)
return -ENAMETOOLONG;
strncpy(buffer, m_name.characters(), buffer_size);
return 0;
}
// We don't use the flag yet, but we could use it for distinguishing
// random source like Linux, unlike the OpenBSD equivalent. However, if we
// do, we should be able of the caveats that Linux has dealt with.
int Process::sys$getrandom(void* buffer, size_t buffer_size, unsigned int flags __attribute__((unused)))
{
if (buffer_size <= 0)
return -EINVAL;
if (!validate_write(buffer, buffer_size))
return -EFAULT;
// We prefer to get whole words of entropy.
// If the length is unaligned, we can work with bytes instead.
// Mask out the bottom two bits for words.
size_t words_len = buffer_size & ~3;
if (words_len) {
uint32_t* words = (uint32_t*)buffer;
for (size_t i = 0; i < words_len / 4; i++)
words[i] = RandomDevice::random_value();
}
// The remaining non-whole word bytes we can fill in.
size_t bytes_len = buffer_size & 3;
if (bytes_len) {
uint8_t* bytes = (uint8_t*)buffer + words_len;
// Get a whole word of entropy to use.
uint32_t word = RandomDevice::random_value();
for (size_t i = 0; i < bytes_len; i++)
bytes[i] = ((uint8_t*)&word)[i];
}
return 0;
}
int Process::sys$clock_gettime(clockid_t clock_id, timespec* ts)
{
if (!validate_write_typed(ts))
return -EFAULT;
switch (clock_id) {
case CLOCK_MONOTONIC:
ts->tv_sec = g_uptime / TICKS_PER_SECOND;
ts->tv_nsec = (g_uptime % TICKS_PER_SECOND) * 1000000;
break;
default:
return -EINVAL;
}
return 0;
}
int Process::sys$clock_nanosleep(const Syscall::SC_clock_nanosleep_params* params)
{
if (!validate_read_typed(params))
return -EFAULT;
if (params->requested_sleep && !validate_read_typed(params->requested_sleep))
return -EFAULT;
if (params->remaining_sleep && !validate_write_typed(params->remaining_sleep))
return -EFAULT;
clockid_t clock_id = params->clock_id;
int flags = params->flags;
bool is_absolute = flags & TIMER_ABSTIME;
auto* requested_sleep = params->requested_sleep;
auto* remaining_sleep = params->remaining_sleep;
switch (clock_id) {
case CLOCK_MONOTONIC: {
u64 wakeup_time;
if (is_absolute) {
u64 time_to_wake = (requested_sleep->tv_sec * 1000 + requested_sleep->tv_nsec / 1000000);
wakeup_time = current->sleep_until(time_to_wake);
} else {
u32 ticks_to_sleep = (requested_sleep->tv_sec * 1000 + requested_sleep->tv_nsec / 1000000);
if (!ticks_to_sleep)
return 0;
wakeup_time = current->sleep(ticks_to_sleep);
}
if (wakeup_time > g_uptime) {
u32 ticks_left = wakeup_time - g_uptime;
if (!is_absolute && remaining_sleep) {
remaining_sleep->tv_sec = ticks_left / TICKS_PER_SECOND;
ticks_left -= remaining_sleep->tv_sec * TICKS_PER_SECOND;
remaining_sleep->tv_nsec = ticks_left * 1000000;
}
return -EINTR;
}
return 0;
}
default:
return -EINVAL;
}
}
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