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111589a558
ladybird/Kernel/Process.cpp
Andreas Kling 111589a558 Kernel: Make sure processes always start out with fds 0, 1 and 2 open. 
If we don't have a TTY for the process, fall back to /dev/null.
2019-02-12 11:25:25 +01:00

2225 lines
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#include "types.h"
#include "Process.h"
#include "kmalloc.h"
#include "StdLib.h"
#include "i386.h"
#include "system.h"
#include <Kernel/FileDescriptor.h>
#include <Kernel/VirtualFileSystem.h>
#include <Kernel/NullDevice.h>
#include "ELFLoader.h"
#include "MemoryManager.h"
#include "i8253.h"
#include "RTC.h"
#include <AK/StdLibExtras.h>
#include <LibC/signal_numbers.h>
#include <LibC/errno_numbers.h>
#include "Syscall.h"
#include "Scheduler.h"
#include "FIFO.h"
#include "KSyms.h"
#include <WindowServer/WSWindow.h>
#include "MasterPTY.h"
#include "elf.h"
//#define DEBUG_IO
//#define TASK_DEBUG
//#define FORK_DEBUG
#define SIGNAL_DEBUG
#define MAX_PROCESS_GIDS 32
static const dword default_kernel_stack_size = 16384;
static const dword default_userspace_stack_size = 65536;
static pid_t next_pid;
InlineLinkedList<Process>* g_processes;
static String* s_hostname;
static Lock* s_hostname_lock;
CoolGlobals* g_cool_globals;
void Process::initialize()
{
#ifdef COOL_GLOBALS
g_cool_globals = reinterpret_cast<CoolGlobals*>(0x1000);
#endif
next_pid = 0;
g_processes = new InlineLinkedList<Process>;
s_hostname = new String("courage");
s_hostname_lock = new Lock;
Scheduler::initialize();
initialize_gui_statics();
}
Vector<pid_t> Process::all_pids()
{
Vector<pid_t> pids;
pids.ensure_capacity(system.nprocess);
InterruptDisabler disabler;
for (auto* process = g_processes->head(); process; process = process->next())
pids.append(process->pid());
return pids;
}
Vector<Process*> Process::all_processes()
{
Vector<Process*> processes;
processes.ensure_capacity(system.nprocess);
InterruptDisabler disabler;
for (auto* process = g_processes->head(); process; process = process->next())
processes.append(process);
return processes;
}
Region* Process::allocate_region(LinearAddress laddr, size_t size, String&& name, bool is_readable, bool is_writable, bool commit)
{
size = PAGE_ROUND_UP(size);
// FIXME: This needs sanity checks. What if this overlaps existing regions?
if (laddr.is_null()) {
laddr = m_next_region;
m_next_region = m_next_region.offset(size).offset(PAGE_SIZE);
}
laddr.mask(0xfffff000);
m_regions.append(adopt(*new Region(laddr, size, move(name), is_readable, is_writable)));
MM.map_region(*this, *m_regions.last());
if (commit)
m_regions.last()->commit();
return m_regions.last().ptr();
}
Region* Process::allocate_file_backed_region(LinearAddress laddr, size_t size, RetainPtr<Inode>&& inode, String&& name, bool is_readable, bool is_writable)
{
size = PAGE_ROUND_UP(size);
// FIXME: This needs sanity checks. What if this overlaps existing regions?
if (laddr.is_null()) {
laddr = m_next_region;
m_next_region = m_next_region.offset(size).offset(PAGE_SIZE);
}
laddr.mask(0xfffff000);
m_regions.append(adopt(*new Region(laddr, size, move(inode), move(name), is_readable, is_writable)));
MM.map_region(*this, *m_regions.last());
return m_regions.last().ptr();
}
Region* Process::allocate_region_with_vmo(LinearAddress laddr, size_t size, RetainPtr<VMObject>&& vmo, size_t offset_in_vmo, String&& name, bool is_readable, bool is_writable)
{
ASSERT(vmo);
size = PAGE_ROUND_UP(size);
// FIXME: This needs sanity checks. What if this overlaps existing regions?
if (laddr.is_null()) {
laddr = m_next_region;
m_next_region = m_next_region.offset(size).offset(PAGE_SIZE);
}
laddr.mask(0xfffff000);
offset_in_vmo &= PAGE_MASK;
size = ceil_div(size, PAGE_SIZE) * PAGE_SIZE;
m_regions.append(adopt(*new Region(laddr, size, move(vmo), offset_in_vmo, move(name), is_readable, is_writable)));
MM.map_region(*this, *m_regions.last());
return m_regions.last().ptr();
}
bool Process::deallocate_region(Region& region)
{
InterruptDisabler disabler;
for (size_t i = 0; i < m_regions.size(); ++i) {
if (m_regions[i].ptr() == &region) {
MM.unmap_region(region);
m_regions.remove(i);
return true;
}
}
return false;
}
Region* Process::region_from_range(LinearAddress laddr, size_t size)
{
for (auto& region : m_regions) {
if (region->laddr() == laddr && region->size() == size)
return region.ptr();
}
return nullptr;
}
int Process::sys$set_mmap_name(void* addr, size_t size, const char* name)
{
if (!validate_read_str(name))
return -EFAULT;
auto* region = region_from_range(LinearAddress((dword)addr), size);
if (!region)
return -EINVAL;
region->set_name(String(name));
return 0;
}
void* Process::sys$mmap(const Syscall::SC_mmap_params* params)
{
if (!validate_read(params, sizeof(Syscall::SC_mmap_params)))
return (void*)-EFAULT;
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;
if (size == 0)
return (void*)-EINVAL;
if ((dword)addr & ~PAGE_MASK)
return (void*)-EINVAL;
if (flags & MAP_ANONYMOUS) {
// FIXME: Implement mapping at a client-specified address. Most of the support is already in plcae.
ASSERT(addr == nullptr);
auto* region = allocate_region(LinearAddress(), size, "mmap", prot & PROT_READ, prot & PROT_WRITE, false);
if (!region)
return (void*)-ENOMEM;
return region->laddr().as_ptr();
}
if (offset & ~PAGE_MASK)
return (void*)-EINVAL;
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return (void*)-EBADF;
if (!descriptor->supports_mmap())
return (void*)-ENODEV;
// FIXME: If PROT_EXEC, check that the underlying file system isn't mounted noexec.
auto region_name = descriptor->absolute_path();
InterruptDisabler disabler;
// FIXME: Implement mapping at a client-specified address. Most of the support is already in plcae.
ASSERT(addr == nullptr);
auto* region = allocate_file_backed_region(LinearAddress(), size, descriptor->inode(), move(region_name), prot & PROT_READ, prot & PROT_WRITE);
if (!region)
return (void*)-ENOMEM;
return region->laddr().as_ptr();
}
int Process::sys$munmap(void* addr, size_t size)
{
auto* region = region_from_range(LinearAddress((dword)addr), size);
if (!region)
return -1;
if (!deallocate_region(*region))
return -1;
return 0;
}
int Process::sys$gethostname(char* buffer, size_t size)
{
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.copy_ref(), m_executable.copy_ref(), m_tty, this);
if (!child)
return nullptr;
memcpy(child->m_signal_action_data, m_signal_action_data, sizeof(m_signal_action_data));
child->m_signal_mask = m_signal_mask;
#ifdef FORK_DEBUG
dbgprintf("fork: child=%p\n", child);
#endif
child->m_initial_arguments = m_initial_arguments;
child->m_initial_environment = m_initial_environment;
for (auto& region : m_regions) {
#ifdef FORK_DEBUG
dbgprintf("fork: cloning Region{%p} \"%s\" L%x\n", region.ptr(), region->name.characters(), region->laddr().get());
#endif
auto cloned_region = region->clone();
child->m_regions.append(move(cloned_region));
MM.map_region(*child, *child->m_regions.last());
if (region.ptr() == m_display_framebuffer_region.ptr())
child->m_display_framebuffer_region = child->m_regions.last().copy_ref();
}
for (auto gid : m_gids)
child->m_gids.set(gid);
child->m_tss.eax = 0; // fork() returns 0 in the child :^)
child->m_tss.ebx = regs.ebx;
child->m_tss.ecx = regs.ecx;
child->m_tss.edx = regs.edx;
child->m_tss.ebp = regs.ebp;
child->m_tss.esp = regs.esp_if_crossRing;
child->m_tss.esi = regs.esi;
child->m_tss.edi = regs.edi;
child->m_tss.eflags = regs.eflags;
child->m_tss.eip = regs.eip;
child->m_tss.cs = regs.cs;
child->m_tss.ds = regs.ds;
child->m_tss.es = regs.es;
child->m_tss.fs = regs.fs;
child->m_tss.gs = regs.gs;
child->m_tss.ss = regs.ss_if_crossRing;
child->m_fpu_state = m_fpu_state;
child->m_has_used_fpu = m_has_used_fpu;
#ifdef FORK_DEBUG
dbgprintf("fork: child will begin executing at %w:%x with stack %w:%x\n", child->m_tss.cs, child->m_tss.eip, child->m_tss.ss, child->m_tss.esp);
#endif
{
InterruptDisabler disabler;
g_processes->prepend(child);
system.nprocess++;
}
#ifdef TASK_DEBUG
kprintf("Process %u (%s) forked from %u @ %p\n", child->pid(), child->name().characters(), m_pid, child->m_tss.eip);
#endif
return child;
}
pid_t Process::sys$fork(RegisterDump& regs)
{
auto* child = fork(regs);
ASSERT(child);
return child->pid();
}
int Process::do_exec(const String& path, Vector<String>&& arguments, Vector<String>&& environment)
{
ASSERT(is_ring3());
auto parts = path.split('/');
if (parts.is_empty())
return -ENOENT;
int error;
auto descriptor = VFS::the().open(path, error, 0, 0, *cwd_inode());
if (!descriptor) {
ASSERT(error != 0);
return error;
}
if (!descriptor->metadata().may_execute(m_euid, m_gids))
return -EACCES;
if (!descriptor->metadata().size) {
kprintf("exec() of 0-length binaries not supported\n");
return -ENOTIMPL;
}
dword entry_eip = 0;
// FIXME: Is there a race here?
auto old_page_directory = move(m_page_directory);
m_page_directory = PageDirectory::create();
#ifdef MM_DEBUG
dbgprintf("Process %u exec: PD=%x created\n", pid(), m_page_directory.ptr());
#endif
ProcessPagingScope paging_scope(*this);
auto vmo = VMObject::create_file_backed(descriptor->inode());
vmo->set_name(descriptor->absolute_path());
RetainPtr<Region> region = allocate_region_with_vmo(LinearAddress(), descriptor->metadata().size, vmo.copy_ref(), 0, "executable", true, false);
// FIXME: Should we consider doing on-demand paging here? Is it actually useful?
bool success = region->page_in();
ASSERT(success);
{
// Okay, here comes the sleight of hand, pay close attention..
auto old_regions = move(m_regions);
ELFLoader loader(region->laddr().as_ptr());
loader.map_section_hook = [&] (LinearAddress laddr, size_t size, size_t alignment, size_t offset_in_image, bool is_readable, bool is_writable, const String& name) {
ASSERT(size);
ASSERT(alignment == PAGE_SIZE);
size = ((size / 4096) + 1) * 4096; // FIXME: Use ceil_div?
(void) allocate_region_with_vmo(laddr, size, vmo.copy_ref(), offset_in_image, String(name), is_readable, is_writable);
return laddr.as_ptr();
};
loader.alloc_section_hook = [&] (LinearAddress laddr, size_t size, size_t alignment, bool is_readable, bool is_writable, const String& name) {
ASSERT(size);
ASSERT(alignment == PAGE_SIZE);
size = ((size / 4096) + 1) * 4096; // FIXME: Use ceil_div?
(void) allocate_region(laddr, size, String(name), is_readable, is_writable);
return laddr.as_ptr();
};
bool success = loader.load();
if (!success) {
m_page_directory = move(old_page_directory);
// FIXME: RAII this somehow instead.
ASSERT(current == this);
MM.enter_process_paging_scope(*this);
m_regions = move(old_regions);
kprintf("sys$execve: Failure loading %s\n", path.characters());
return -ENOEXEC;
}
entry_eip = loader.entry().get();
if (!entry_eip) {
m_page_directory = move(old_page_directory);
// FIXME: RAII this somehow instead.
ASSERT(current == this);
MM.enter_process_paging_scope(*this);
m_regions = move(old_regions);
return -ENOEXEC;
}
}
m_signal_stack_kernel_region = nullptr;
m_signal_stack_user_region = nullptr;
m_display_framebuffer_region = nullptr;
set_default_signal_dispositions();
m_signal_mask = 0xffffffff;
m_pending_signals = 0;
for (size_t i = 0; i < m_fds.size(); ++i) {
auto& daf = m_fds[i];
if (daf.descriptor && daf.flags & FD_CLOEXEC) {
daf.descriptor->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 == this)
cli();
Scheduler::prepare_to_modify_tss(*this);
m_name = parts.take_last();
dword old_esp0 = m_tss.esp0;
memset(&m_tss, 0, sizeof(m_tss));
m_tss.eflags = 0x0202;
m_tss.eip = entry_eip;
m_tss.cs = 0x1b;
m_tss.ds = 0x23;
m_tss.es = 0x23;
m_tss.fs = 0x23;
m_tss.gs = 0x23;
m_tss.ss = 0x23;
m_tss.cr3 = page_directory().cr3();
m_stack_region = allocate_region(LinearAddress(), default_userspace_stack_size, "stack");
ASSERT(m_stack_region);
m_stack_top3 = m_stack_region->laddr().offset(default_userspace_stack_size).get();
m_tss.esp = m_stack_top3;
m_tss.ss0 = 0x10;
m_tss.esp0 = old_esp0;
m_tss.ss2 = m_pid;
m_executable = descriptor->inode();
m_initial_arguments = move(arguments);
m_initial_environment = move(environment);
#ifdef TASK_DEBUG
kprintf("Process %u (%s) exec'd %s @ %p\n", pid(), name().characters(), path.characters(), m_tss.eip);
#endif
set_state(Skip1SchedulerPass);
return 0;
}
int Process::exec(const String& path, Vector<String>&& arguments, Vector<String>&& 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(path, move(arguments), move(environment));
if (rc < 0)
return rc;
if (current == this) {
Scheduler::yield();
ASSERT_NOT_REACHED();
}
return 0;
}
int Process::sys$execve(const char* filename, const char** argv, const char** envp)
{
if (!validate_read_str(filename))
return -EFAULT;
if (argv) {
if (!validate_read_typed(argv))
return -EFAULT;
for (size_t i = 0; argv[i]; ++i) {
if (!validate_read_str(argv[i]))
return -EFAULT;
}
}
if (envp) {
if (!validate_read_typed(envp))
return -EFAULT;
for (size_t i = 0; envp[i]; ++i) {
if (!validate_read_str(envp[i]))
return -EFAULT;
}
}
String path(filename);
auto parts = path.split('/');
Vector<String> arguments;
if (argv) {
for (size_t i = 0; argv[i]; ++i) {
arguments.append(argv[i]);
}
} else {
arguments.append(parts.last());
}
Vector<String> environment;
if (envp) {
for (size_t i = 0; envp[i]; ++i)
environment.append(envp[i]);
}
int rc = exec(path, move(arguments), move(environment));
ASSERT(rc < 0); // We should never continue after a successful exec!
return rc;
}
Process* Process::create_user_process(const String& path, uid_t uid, gid_t gid, pid_t parent_pid, int& error, Vector<String>&& arguments, Vector<String>&& environment, TTY* tty)
{
// FIXME: Don't split() the path twice (sys$spawn also does it...)
auto parts = path.split('/');
if (arguments.is_empty()) {
arguments.append(parts.last());
}
RetainPtr<Inode> cwd;
{
InterruptDisabler disabler;
if (auto* parent = Process::from_pid(parent_pid))
cwd = parent->m_cwd.copy_ref();
}
if (!cwd)
cwd = VFS::the().root_inode();
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);
system.nprocess++;
}
#ifdef TASK_DEBUG
kprintf("Process %u (%s) spawned @ %p\n", process->pid(), process->name().characters(), process->m_tss.eip);
#endif
error = 0;
return process;
}
int Process::sys$get_environment(char*** environ)
{
auto* region = allocate_region(LinearAddress(), PAGE_SIZE, "environ");
if (!region)
return -ENOMEM;
MM.map_region(*this, *region);
char* envpage = (char*)region->laddr().get();
*environ = (char**)envpage;
char* bufptr = envpage + (sizeof(char*) * (m_initial_environment.size() + 1));
for (size_t i = 0; i < m_initial_environment.size(); ++i) {
(*environ)[i] = bufptr;
memcpy(bufptr, m_initial_environment[i].characters(), m_initial_environment[i].length());
bufptr += m_initial_environment[i].length();
*(bufptr++) = '\0';
}
(*environ)[m_initial_environment.size()] = nullptr;
return 0;
}
int Process::sys$get_arguments(int* argc, char*** argv)
{
auto* region = allocate_region(LinearAddress(), PAGE_SIZE, "argv");
if (!region)
return -ENOMEM;
MM.map_region(*this, *region);
char* argpage = (char*)region->laddr().get();
*argc = m_initial_arguments.size();
*argv = (char**)argpage;
char* bufptr = argpage + (sizeof(char*) * (m_initial_arguments.size() + 1));
for (size_t i = 0; i < m_initial_arguments.size(); ++i) {
(*argv)[i] = bufptr;
memcpy(bufptr, m_initial_arguments[i].characters(), m_initial_arguments[i].length());
bufptr += m_initial_arguments[i].length();
*(bufptr++) = '\0';
}
(*argv)[m_initial_arguments.size()] = nullptr;
return 0;
}
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->m_tss.eip = (dword)e;
if (process->pid() != 0) {
{
InterruptDisabler disabler;
g_processes->prepend(process);
system.nprocess++;
}
#ifdef TASK_DEBUG
kprintf("Kernel process %u (%s) spawned @ %p\n", process->pid(), process->name().characters(), process->m_tss.eip);
#endif
}
return process;
}
Process::Process(String&& name, uid_t uid, gid_t gid, pid_t ppid, RingLevel ring, RetainPtr<Inode>&& cwd, RetainPtr<Inode>&& 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_state(Runnable)
, m_ring(ring)
, m_cwd(move(cwd))
, m_executable(move(executable))
, m_tty(tty)
, m_ppid(ppid)
{
set_default_signal_dispositions();
memset(&m_fpu_state, 0, sizeof(FPUState));
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;
}
}
m_page_directory = PageDirectory::create();
#ifdef MM_DEBUG
dbgprintf("Process %u ctor: PD=%x created\n", pid(), m_page_directory.ptr());
#endif
if (fork_parent) {
m_fds.resize(fork_parent->m_fds.size());
for (size_t i = 0; i < fork_parent->m_fds.size(); ++i) {
if (!fork_parent->m_fds[i].descriptor)
continue;
#ifdef FORK_DEBUG
dbgprintf("fork: cloning fd %u... (%p) istty? %u\n", i, fork_parent->m_fds[i].descriptor.ptr(), fork_parent->m_fds[i].descriptor->is_tty());
#endif
m_fds[i].descriptor = fork_parent->m_fds[i].descriptor->clone();
m_fds[i].flags = fork_parent->m_fds[i].flags;
}
} else {
m_fds.resize(m_max_open_file_descriptors);
auto& device_to_use_as_tty = tty ? (CharacterDevice&)*tty : NullDevice::the();
int error;
m_fds[0].set(device_to_use_as_tty.open(error, O_RDONLY));
m_fds[1].set(device_to_use_as_tty.open(error, O_WRONLY));
m_fds[2].set(device_to_use_as_tty.open(error, O_WRONLY));
}
if (fork_parent)
m_next_region = fork_parent->m_next_region;
else
m_next_region = LinearAddress(0x10000000);
if (fork_parent) {
memcpy(&m_tss, &fork_parent->m_tss, sizeof(m_tss));
} else {
memset(&m_tss, 0, sizeof(m_tss));
// Only IF is set when a process boots.
m_tss.eflags = 0x0202;
word cs, ds, ss;
if (is_ring0()) {
cs = 0x08;
ds = 0x10;
ss = 0x10;
} else {
cs = 0x1b;
ds = 0x23;
ss = 0x23;
}
m_tss.ds = ds;
m_tss.es = ds;
m_tss.fs = ds;
m_tss.gs = ds;
m_tss.ss = ss;
m_tss.cs = cs;
}
m_tss.cr3 = page_directory().cr3();
if (is_ring0()) {
// FIXME: This memory is leaked.
// But uh, there's also no kernel process termination, so I guess it's not technically leaked...
dword stack_bottom = (dword)kmalloc_eternal(default_kernel_stack_size);
m_stack_top0 = (stack_bottom + default_kernel_stack_size) & 0xffffff8;
m_tss.esp = m_stack_top0;
} else {
if (fork_parent) {
m_stack_top3 = fork_parent->m_stack_top3;
} else {
auto* region = allocate_region(LinearAddress(), default_userspace_stack_size, "stack");
ASSERT(region);
m_stack_top3 = region->laddr().offset(default_userspace_stack_size).get();
m_tss.esp = m_stack_top3;
}
}
if (is_ring3()) {
// Ring3 processes need a separate stack for Ring0.
m_kernel_stack = kmalloc(default_kernel_stack_size);
m_stack_top0 = ((dword)m_kernel_stack + default_kernel_stack_size) & 0xffffff8;
m_tss.ss0 = 0x10;
m_tss.esp0 = m_stack_top0;
}
// HACK: Ring2 SS in the TSS is the current PID.
m_tss.ss2 = m_pid;
m_far_ptr.offset = 0x98765432;
}
Process::~Process()
{
{
InterruptDisabler disabler;
system.nprocess--;
}
if (g_last_fpu_process == this)
g_last_fpu_process = nullptr;
if (selector())
gdt_free_entry(selector());
if (m_kernel_stack) {
kfree(m_kernel_stack);
m_kernel_stack = nullptr;
}
}
void Process::dump_regions()
{
kprintf("Process %s(%u) regions:\n", name().characters(), pid());
kprintf("BEGIN END SIZE NAME\n");
for (auto& region : m_regions) {
kprintf("%x -- %x %x %s\n",
region->laddr().get(),
region->laddr().offset(region->size() - 1).get(),
region->size(),
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
m_termination_status = status;
m_termination_signal = 0;
die();
ASSERT_NOT_REACHED();
}
void Process::terminate_due_to_signal(byte 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(byte signal, Process* sender)
{
ASSERT_INTERRUPTS_DISABLED();
ASSERT(signal < 32);
if (sender)
dbgprintf("signal: %s(%u) sent %d to %s(%u)\n", sender->name().characters(), sender->pid(), signal, name().characters(), pid());
else
dbgprintf("signal: kernel sent %d to %s(%u)\n", signal, name().characters(), pid());
m_pending_signals |= 1 << signal;
}
bool Process::has_unmasked_pending_signals() const
{
return m_pending_signals & m_signal_mask;
}
ShouldUnblockProcess Process::dispatch_one_pending_signal()
{
ASSERT_INTERRUPTS_DISABLED();
dword signal_candidates = m_pending_signals & m_signal_mask;
ASSERT(signal_candidates);
byte signal = 0;
for (; signal < 32; ++signal) {
if (signal_candidates & (1 << signal)) {
break;
}
}
return dispatch_signal(signal);
}
ShouldUnblockProcess Process::dispatch_signal(byte signal)
{
ASSERT_INTERRUPTS_DISABLED();
ASSERT(signal < 32);
dbgprintf("dispatch_signal %s(%u) <- %u\n", name().characters(), pid(), signal);
auto& action = m_signal_action_data[signal];
// FIXME: Implement SA_SIGINFO signal handlers.
ASSERT(!(action.flags & SA_SIGINFO));
// Mark this signal as handled.
m_pending_signals &= ~(1 << signal);
auto handler_laddr = action.handler_or_sigaction;
if (handler_laddr.is_null()) {
// FIXME: Is termination really always the appropriate action?
terminate_due_to_signal(signal);
return ShouldUnblockProcess::No;
}
if (handler_laddr.as_ptr() == SIG_IGN) {
dbgprintf("%s(%u) ignored signal %u\n", name().characters(), pid(), signal);
return ShouldUnblockProcess::Yes;
}
Scheduler::prepare_to_modify_tss(*this);
word ret_cs = m_tss.cs;
dword ret_eip = m_tss.eip;
dword ret_eflags = m_tss.eflags;
bool interrupting_in_kernel = (ret_cs & 3) == 0;
if (interrupting_in_kernel) {
dbgprintf("dispatch_signal to %s(%u) in state=%s with return to %w:%x\n", name().characters(), pid(), to_string(state()), ret_cs, ret_eip);
ASSERT(is_blocked());
m_tss_to_resume_kernel = m_tss;
#ifdef SIGNAL_DEBUG
dbgprintf("resume tss pc: %w:%x\n", m_tss_to_resume_kernel.cs, m_tss_to_resume_kernel.eip);
#endif
}
ProcessPagingScope paging_scope(*this);
if (interrupting_in_kernel) {
if (!m_signal_stack_user_region) {
m_signal_stack_user_region = allocate_region(LinearAddress(), default_userspace_stack_size, "signal stack (user)");
ASSERT(m_signal_stack_user_region);
m_signal_stack_kernel_region = allocate_region(LinearAddress(), default_userspace_stack_size, "signal stack (kernel)");
ASSERT(m_signal_stack_user_region);
}
m_tss.ss = 0x23;
m_tss.esp = m_signal_stack_user_region->laddr().offset(default_userspace_stack_size).get() & 0xfffffff8;
m_tss.ss0 = 0x10;
m_tss.esp0 = m_signal_stack_kernel_region->laddr().offset(default_userspace_stack_size).get() & 0xfffffff8;
push_value_on_stack(ret_eflags);
push_value_on_stack(ret_cs);
push_value_on_stack(ret_eip);
} else {
push_value_on_stack(ret_cs);
push_value_on_stack(ret_eip);
push_value_on_stack(ret_eflags);
}
// PUSHA
dword old_esp = m_tss.esp;
push_value_on_stack(m_tss.eax);
push_value_on_stack(m_tss.ecx);
push_value_on_stack(m_tss.edx);
push_value_on_stack(m_tss.ebx);
push_value_on_stack(old_esp);
push_value_on_stack(m_tss.ebp);
push_value_on_stack(m_tss.esi);
push_value_on_stack(m_tss.edi);
m_tss.eax = (dword)signal;
m_tss.cs = 0x1b;
m_tss.ds = 0x23;
m_tss.es = 0x23;
m_tss.fs = 0x23;
m_tss.gs = 0x23;
m_tss.eip = handler_laddr.get();
if (m_return_to_ring3_from_signal_trampoline.is_null()) {
// FIXME: This should be a global trampoline shared by all processes, not one created per process!
// FIXME: Remap as read-only after setup.
auto* region = allocate_region(LinearAddress(), PAGE_SIZE, "signal_trampoline", true, true);
m_return_to_ring3_from_signal_trampoline = region->laddr();
byte* code_ptr = m_return_to_ring3_from_signal_trampoline.as_ptr();
*code_ptr++ = 0x61; // popa
*code_ptr++ = 0x9d; // popf
*code_ptr++ = 0xc3; // ret
*code_ptr++ = 0x0f; // ud2
*code_ptr++ = 0x0b;
m_return_to_ring0_from_signal_trampoline = LinearAddress((dword)code_ptr);
*code_ptr++ = 0x61; // popa
*code_ptr++ = 0xb8; // mov eax, <dword>
*(dword*)code_ptr = Syscall::SC_sigreturn;
code_ptr += sizeof(dword);
*code_ptr++ = 0xcd; // int 0x80
*code_ptr++ = 0x80;
*code_ptr++ = 0x0f; // ud2
*code_ptr++ = 0x0b;
// FIXME: For !SA_NODEFER, maybe we could do something like emitting an int 0x80 syscall here that
// unmasks the signal so it can be received again? I guess then I would need one trampoline
// per signal number if it's hard-coded, but it's just a few bytes per each.
}
if (interrupting_in_kernel)
push_value_on_stack(m_return_to_ring0_from_signal_trampoline.get());
else
push_value_on_stack(m_return_to_ring3_from_signal_trampoline.get());
// FIXME: This state is such a hack. It avoids trouble if 'current' is the process receiving a signal.
set_state(Skip1SchedulerPass);
#ifdef SIGNAL_DEBUG
dbgprintf("signal: Okay, %s(%u) {%s} has been primed with signal handler %w:%x\n", name().characters(), pid(), to_string(state()), m_tss.cs, m_tss.eip);
#endif
return ShouldUnblockProcess::Yes;
}
void Process::sys$sigreturn()
{
InterruptDisabler disabler;
Scheduler::prepare_to_modify_tss(*this);
m_tss = m_tss_to_resume_kernel;
#ifdef SIGNAL_DEBUG
dbgprintf("sys$sigreturn in %s(%u)\n", name().characters(), pid());
dbgprintf(" -> resuming execution at %w:%x\n", m_tss.cs, m_tss.eip);
#endif
set_state(Skip1SchedulerPass);
Scheduler::yield();
kprintf("sys$sigreturn failed in %s(%u)\n", name().characters(), pid());
ASSERT_NOT_REACHED();
}
void Process::push_value_on_stack(dword value)
{
m_tss.esp -= 4;
dword* stack_ptr = (dword*)m_tss.esp;
*stack_ptr = value;
}
void Process::crash()
{
ASSERT_INTERRUPTS_DISABLED();
ASSERT(state() != Dead);
m_termination_signal = SIGSEGV;
dump_regions();
ASSERT(is_ring3());
die();
ASSERT_NOT_REACHED();
}
Process* Process::from_pid(pid_t pid)
{
ASSERT_INTERRUPTS_DISABLED();
for (auto* process = g_processes->head(); process; process = process->next()) {
if (process->pid() == pid)
return process;
}
return nullptr;
}
FileDescriptor* Process::file_descriptor(int fd)
{
if (fd < 0)
return nullptr;
if ((size_t)fd < m_fds.size())
return m_fds[fd].descriptor.ptr();
return nullptr;
}
const FileDescriptor* Process::file_descriptor(int fd) const
{
if (fd < 0)
return nullptr;
if ((size_t)fd < m_fds.size())
return m_fds[fd].descriptor.ptr();
return nullptr;
}
ssize_t Process::sys$get_dir_entries(int fd, void* buffer, size_t size)
{
if (!validate_write(buffer, size))
return -EFAULT;
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
return descriptor->get_dir_entries((byte*)buffer, size);
}
int Process::sys$lseek(int fd, off_t offset, int whence)
{
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
return descriptor->seek(offset, whence);
}
int Process::sys$ttyname_r(int fd, char* buffer, size_t size)
{
if (!validate_write(buffer, size))
return -EFAULT;
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
if (!descriptor->is_tty())
return -ENOTTY;
auto tty_name = descriptor->tty()->tty_name();
if (size < tty_name.length() + 1)
return -ERANGE;
strcpy(buffer, tty_name.characters());
return 0;
}
int Process::sys$ptsname_r(int fd, char* buffer, size_t size)
{
if (!validate_write(buffer, size))
return -EFAULT;
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
auto* master_pty = descriptor->master_pty();
if (!master_pty)
return -ENOTTY;
auto pts_name = master_pty->pts_name();
if (size < pts_name.length() + 1)
return -ERANGE;
strcpy(buffer, pts_name.characters());
return 0;
}
ssize_t Process::sys$write(int fd, const void* data, size_t size)
{
if (!validate_read(data, size))
return -EFAULT;
#ifdef DEBUG_IO
dbgprintf("%s(%u): sys$write(%d, %p, %u)\n", name().characters(), pid(), fd, data, size);
#endif
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
ssize_t nwritten = 0;
if (descriptor->is_blocking()) {
while (nwritten < (ssize_t)size) {
#ifdef IO_DEBUG
dbgprintf("while %u < %u\n", nwritten, size);
#endif
if (!descriptor->can_write(*this)) {
#ifdef IO_DEBUG
dbgprintf("block write on %d\n", fd);
#endif
m_blocked_fd = fd;
block(BlockedWrite);
Scheduler::yield();
}
ssize_t rc = descriptor->write(*this, (const byte*)data + nwritten, size - nwritten);
#ifdef IO_DEBUG
dbgprintf(" -> write returned %d\n", rc);
#endif
if (rc < 0) {
// FIXME: Support returning partial nwritten with errno.
ASSERT(nwritten == 0);
return rc;
}
if (rc == 0)
break;
if (has_unmasked_pending_signals()) {
block(BlockedSignal);
Scheduler::yield();
if (nwritten == 0)
return -EINTR;
}
nwritten += rc;
}
} else {
nwritten = descriptor->write(*this, (const byte*)data, size);
}
if (has_unmasked_pending_signals()) {
block(BlockedSignal);
Scheduler::yield();
if (nwritten == 0)
return -EINTR;
}
#ifdef DEBUG_IO
dbgprintf("%s(%u) sys$write: nwritten=%u\n", name().characters(), pid(), nwritten);
#endif
return nwritten;
}
ssize_t Process::sys$read(int fd, void* outbuf, size_t nread)
{
if (!validate_write(outbuf, nread))
return -EFAULT;
#ifdef DEBUG_IO
dbgprintf("%s(%u) sys$read(%d, %p, %u)\n", name().characters(), pid(), fd, outbuf, nread);
#endif
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
#ifdef DEBUG_IO
dbgprintf(" > descriptor:%p, is_blocking:%u, can_read:%u\n", descriptor, descriptor->is_blocking(), descriptor->can_read(*this));
dbgprintf(" > inode:K%x, device:K%x\n", descriptor->inode(), descriptor->character_device());
#endif
if (descriptor->is_blocking()) {
if (!descriptor->can_read(*this)) {
m_blocked_fd = fd;
block(BlockedRead);
Scheduler::yield();
if (m_was_interrupted_while_blocked)
return -EINTR;
}
}
nread = descriptor->read(*this, (byte*)outbuf, nread);
#ifdef DEBUG_IO
dbgprintf("%s(%u) Process::sys$read: nread=%u\n", name().characters(), pid(), nread);
#endif
return nread;
}
int Process::sys$close(int fd)
{
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
int rc = descriptor->close();
m_fds[fd] = { };
return rc;
}
int Process::sys$utime(const char* pathname, const utimbuf* buf)
{
if (!validate_read_str(pathname))
return -EFAULT;
if (buf && !validate_read_typed(buf))
return -EFAULT;
String path(pathname);
int error;
auto descriptor = VFS::the().open(move(path), error, 0, 0, *cwd_inode());
if (!descriptor)
return error;
auto& inode = *descriptor->inode();
if (inode.fs().is_readonly())
return -EROFS;
time_t atime;
time_t mtime;
if (buf) {
atime = buf->actime;
mtime = buf->modtime;
} else {
auto now = RTC::now();
mtime = now;
atime = now;
}
inode.set_atime(atime);
inode.set_mtime(mtime);
return 0;
}
int Process::sys$access(const char* pathname, int mode)
{
(void) mode;
if (!validate_read_str(pathname))
return -EFAULT;
ASSERT_NOT_REACHED();
}
int Process::sys$fcntl(int fd, int cmd, dword arg)
{
(void) cmd;
(void) arg;
dbgprintf("sys$fcntl: fd=%d, cmd=%d, arg=%u\n", fd, cmd, arg);
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
// NOTE: The FD flags are not shared between FileDescriptor 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 = -1;
for (int i = arg_fd; i < (int)m_max_open_file_descriptors; ++i) {
if (!m_fds[i]) {
new_fd = i;
break;
}
}
if (new_fd == -1)
return -EMFILE;
m_fds[new_fd].set(descriptor);
break;
}
case F_GETFD:
return m_fds[fd].flags;
case F_SETFD:
m_fds[fd].flags = arg;
break;
case F_GETFL:
return descriptor->file_flags();
case F_SETFL:
// FIXME: Support changing O_NONBLOCK
descriptor->set_file_flags(arg);
break;
default:
ASSERT_NOT_REACHED();
}
return 0;
}
int Process::sys$fstat(int fd, stat* statbuf)
{
if (!validate_write_typed(statbuf))
return -EFAULT;
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
return descriptor->fstat(statbuf);
}
int Process::sys$lstat(const char* path, stat* statbuf)
{
if (!validate_write_typed(statbuf))
return -EFAULT;
int error;
auto descriptor = VFS::the().open(move(path), error, O_NOFOLLOW_NOERROR | O_DONT_OPEN_DEVICE, 0, *cwd_inode());
if (!descriptor)
return error;
return descriptor->fstat(statbuf);
}
int Process::sys$stat(const char* path, stat* statbuf)
{
if (!validate_write_typed(statbuf))
return -EFAULT;
int error;
auto descriptor = VFS::the().open(move(path), error, O_DONT_OPEN_DEVICE, 0, *cwd_inode());
if (!descriptor)
return error;
return descriptor->fstat(statbuf);
}
int Process::sys$readlink(const char* path, char* buffer, size_t size)
{
if (!validate_read_str(path))
return -EFAULT;
if (!validate_write(buffer, size))
return -EFAULT;
int error;
auto descriptor = VFS::the().open(path, error, O_RDONLY | O_NOFOLLOW_NOERROR, 0, *cwd_inode());
if (!descriptor)
return error;
if (!descriptor->metadata().is_symlink())
return -EINVAL;
auto contents = descriptor->read_entire_file(*this);
if (!contents)
return -EIO; // FIXME: Get a more detailed error from VFS.
memcpy(buffer, contents.pointer(), min(size, contents.size()));
if (contents.size() + 1 < size)
buffer[contents.size()] = '\0';
return 0;
}
int Process::sys$chdir(const char* path)
{
if (!validate_read_str(path))
return -EFAULT;
int error;
auto descriptor = VFS::the().open(path, error, 0, 0, *cwd_inode());
if (!descriptor)
return error;
if (!descriptor->is_directory())
return -ENOTDIR;
m_cwd = descriptor->inode();
return 0;
}
int Process::sys$getcwd(char* buffer, size_t size)
{
if (!validate_write(buffer, size))
return -EFAULT;
ASSERT(cwd_inode());
auto path = VFS::the().absolute_path(*cwd_inode());
if (path.is_null())
return -EINVAL;
if (size < path.length() + 1)
return -ERANGE;
strcpy(buffer, path.characters());
return 0;
}
size_t Process::number_of_open_file_descriptors() const
{
size_t count = 0;
for (auto& descriptor : m_fds) {
if (descriptor)
++count;
}
return count;
}
int Process::sys$open(const char* path, int options, mode_t mode)
{
#ifdef DEBUG_IO
dbgprintf("%s(%u) sys$open(\"%s\")\n", name().characters(), pid(), path);
#endif
if (!validate_read_str(path))
return -EFAULT;
if (number_of_open_file_descriptors() >= m_max_open_file_descriptors)
return -EMFILE;
int error = -EWHYTHO;
ASSERT(cwd_inode());
auto descriptor = VFS::the().open(path, error, options, mode, *cwd_inode());
if (!descriptor)
return error;
if (options & O_DIRECTORY && !descriptor->is_directory())
return -ENOTDIR; // FIXME: This should be handled by VFS::open.
if (options & O_NONBLOCK)
descriptor->set_blocking(false);
int fd = 0;
for (; fd < (int)m_max_open_file_descriptors; ++fd) {
if (!m_fds[fd])
break;
}
dword flags = (options & O_CLOEXEC) ? FD_CLOEXEC : 0;
m_fds[fd].set(move(descriptor), flags);
return fd;
}
int Process::alloc_fd()
{
int fd = -1;
for (int i = 0; i < (int)m_max_open_file_descriptors; ++i) {
if (!m_fds[i]) {
fd = i;
break;
}
}
return fd;
}
int Process::sys$pipe(int pipefd[2])
{
if (!validate_write_typed(pipefd))
return -EFAULT;
if (number_of_open_file_descriptors() + 2 > max_open_file_descriptors())
return -EMFILE;
auto fifo = FIFO::create();
int reader_fd = alloc_fd();
m_fds[reader_fd].set(FileDescriptor::create_pipe_reader(*fifo));
pipefd[0] = reader_fd;
int writer_fd = alloc_fd();
m_fds[writer_fd].set(FileDescriptor::create_pipe_writer(*fifo));
pipefd[1] = writer_fd;
return 0;
}
int Process::sys$killpg(int pgrp, int signum)
{
if (signum < 1 || signum >= 32)
return -EINVAL;
(void) pgrp;
ASSERT_NOT_REACHED();
}
int Process::sys$setuid(uid_t)
{
ASSERT_NOT_REACHED();
}
int Process::sys$setgid(gid_t)
{
ASSERT_NOT_REACHED();
}
unsigned Process::sys$alarm(unsigned seconds)
{
(void) seconds;
ASSERT_NOT_REACHED();
}
int Process::sys$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$isatty(int fd)
{
auto* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
if (!descriptor->is_tty())
return -ENOTTY;
return 1;
}
int Process::sys$kill(pid_t pid, int signal)
{
if (pid == 0) {
// FIXME: Send to same-group processes.
ASSERT(pid != 0);
}
if (pid == -1) {
// FIXME: Send to all processes.
ASSERT(pid != -1);
}
ASSERT(pid != current->pid()); // FIXME: Support this scenario.
Process* peer = nullptr;
{
InterruptDisabler disabler;
peer = Process::from_pid(pid);
}
if (!peer)
return -ESRCH;
peer->send_signal(signal, this);
return 0;
}
int Process::sys$usleep(useconds_t usec)
{
if (!usec)
return 0;
sleep(usec / 1000);
if (m_wakeup_time > system.uptime) {
ASSERT(m_was_interrupted_while_blocked);
dword ticks_left_until_original_wakeup_time = m_wakeup_time - system.uptime;
return ticks_left_until_original_wakeup_time / TICKS_PER_SECOND;
}
return 0;
}
int Process::sys$sleep(unsigned seconds)
{
if (!seconds)
return 0;
sleep(seconds * TICKS_PER_SECOND);
if (m_wakeup_time > system.uptime) {
ASSERT(m_was_interrupted_while_blocked);
dword ticks_left_until_original_wakeup_time = m_wakeup_time - system.uptime;
return ticks_left_until_original_wakeup_time / TICKS_PER_SECOND;
}
return 0;
}
int Process::sys$gettimeofday(timeval* tv)
{
if (!validate_write_typed(tv))
return -EFAULT;
auto now = RTC::now();
tv->tv_sec = now;
tv->tv_usec = PIT::ticks_since_boot() % 1000;
return 0;
}
uid_t Process::sys$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;
return old_mask;
}
int Process::reap(Process& process)
{
InterruptDisabler disabler;
int 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(), to_string(process.state()));
ASSERT(process.state() == 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);
// FIXME: Respect options
(void) options;
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) {
if (waitee == -1) {
pid_t reaped_pid = 0;
InterruptDisabler disabler;
for_each_child([&reaped_pid, &exit_status] (Process& process) {
if (process.state() == Dead) {
reaped_pid = process.pid();
exit_status = reap(process);
}
return true;
});
return reaped_pid;
} else {
ASSERT(waitee > 0); // FIXME: Implement other PID specs.
auto* waitee_process = Process::from_pid(waitee);
if (!waitee_process)
return -ECHILD;
if (waitee_process->state() == Dead) {
exit_status = reap(*waitee_process);
return waitee;
}
return 0;
}
}
m_waitee_pid = waitee;
block(BlockedWait);
Scheduler::yield();
if (m_was_interrupted_while_blocked)
return -EINTR;
Process* waitee_process;
{
InterruptDisabler disabler;
// NOTE: If waitee was -1, m_waitee will have been filled in by the scheduler.
waitee_process = Process::from_pid(m_waitee_pid);
}
ASSERT(waitee_process);
exit_status = reap(*waitee_process);
return m_waitee_pid;
}
void Process::unblock()
{
if (current == this) {
system.nblocked--;
m_state = Process::Running;
return;
}
ASSERT(m_state != Process::Runnable && m_state != Process::Running);
system.nblocked--;
m_state = Process::Runnable;
}
void Process::block(Process::State new_state)
{
if (state() != Process::Running) {
kprintf("Process::block: %s(%u) block(%u/%s) with state=%u/%s\n", name().characters(), pid(), new_state, to_string(new_state), state(), to_string(state()));
}
ASSERT(state() == Process::Running);
system.nblocked++;
m_was_interrupted_while_blocked = false;
set_state(new_state);
}
void block(Process::State state)
{
current->block(state);
Scheduler::yield();
}
void sleep(dword ticks)
{
ASSERT(current->state() == Process::Running);
current->set_wakeup_time(system.uptime + ticks);
current->block(Process::BlockedSleep);
Scheduler::yield();
}
enum class KernelMemoryCheckResult {
NotInsideKernelMemory,
AccessGranted,
AccessDenied
};
static KernelMemoryCheckResult check_kernel_memory_access(LinearAddress laddr, bool is_write)
{
auto* kernel_elf_header = (Elf32_Ehdr*)0xf000;
auto* kernel_program_headers = (Elf32_Phdr*)(0xf000 + kernel_elf_header->e_phoff);
for (unsigned i = 0; i < kernel_elf_header->e_phnum; ++i) {
auto& segment = kernel_program_headers[i];
if (segment.p_type != PT_LOAD || !segment.p_vaddr || !segment.p_memsz)
continue;
if (laddr.get() < segment.p_vaddr || laddr.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(LinearAddress laddr) const
{
// 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(laddr, false);
if (kmc_result == KernelMemoryCheckResult::AccessGranted)
return true;
if (kmc_result == KernelMemoryCheckResult::AccessDenied)
return false;
if (is_kmalloc_address(laddr.as_ptr()))
return true;
return validate_read(laddr.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, size_t size) const
{
LinearAddress first_address((dword)address);
LinearAddress 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, size_t size) const
{
LinearAddress first_address((dword)address);
LinearAddress 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 false;
});
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* descriptor = file_descriptor(fd);
if (!descriptor)
return -EBADF;
if (!descriptor->is_character_device())
return -ENOTTY;
return descriptor->character_device()->ioctl(*this, request, arg);
}
int Process::sys$getdtablesize()
{
return m_max_open_file_descriptors;
}
int Process::sys$dup(int old_fd)
{
auto* descriptor = file_descriptor(old_fd);
if (!descriptor)
return -EBADF;
if (number_of_open_file_descriptors() == m_max_open_file_descriptors)
return -EMFILE;
int new_fd = 0;
for (; new_fd < (int)m_max_open_file_descriptors; ++new_fd) {
if (!m_fds[new_fd])
break;
}
m_fds[new_fd].set(descriptor);
return new_fd;
}
int Process::sys$dup2(int old_fd, int new_fd)
{
auto* descriptor = file_descriptor(old_fd);
if (!descriptor)
return -EBADF;
if (number_of_open_file_descriptors() == m_max_open_file_descriptors)
return -EMFILE;
m_fds[new_fd].set(descriptor);
return new_fd;
}
int Process::sys$sigprocmask(int how, const sigset_t* set, sigset_t* old_set)
{
if (old_set) {
if (!validate_read_typed(old_set))
return -EFAULT;
*old_set = m_signal_mask;
}
if (set) {
if (!validate_read_typed(set))
return -EFAULT;
switch (how) {
case SIG_BLOCK:
m_signal_mask &= ~(*set);
break;
case SIG_UNBLOCK:
m_signal_mask |= *set;
break;
case SIG_SETMASK:
m_signal_mask = *set;
break;
default:
return -EINVAL;
}
}
return 0;
}
int Process::sys$sigpending(sigset_t* set)
{
if (!validate_read_typed(set))
return -EFAULT;
*set = m_pending_signals;
return 0;
}
void Process::set_default_signal_dispositions()
{
// FIXME: Set up all the right default actions. See signal(7).
memset(&m_signal_action_data, 0, sizeof(m_signal_action_data));
m_signal_action_data[SIGCHLD].handler_or_sigaction = LinearAddress((dword)SIG_IGN);
}
int Process::sys$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 = 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_restorer = (decltype(old_act->sa_restorer))action.restorer.get();
old_act->sa_sigaction = (decltype(old_act->sa_sigaction))action.handler_or_sigaction.get();
}
action.restorer = LinearAddress((dword)act->sa_restorer);
action.flags = act->sa_flags;
action.handler_or_sigaction = LinearAddress((dword)act->sa_sigaction);
return 0;
}
int Process::sys$getgroups(int count, gid_t* gids)
{
if (count < 0)
return -EINVAL;
ASSERT(m_gids.size() < MAX_PROCESS_GIDS);
if (!count)
return m_gids.size();
if (count != (int)m_gids.size())
return -EINVAL;
if (!validate_write_typed(gids, m_gids.size()))
return -EFAULT;
size_t i = 0;
for (auto gid : m_gids)
gids[i++] = gid;
return 0;
}
int Process::sys$setgroups(size_t count, const gid_t* gids)
{
if (!is_root())
return -EPERM;
if (count >= MAX_PROCESS_GIDS)
return -EINVAL;
if (!validate_read(gids, count))
return -EFAULT;
m_gids.clear();
m_gids.set(m_gid);
for (size_t i = 0; i < count; ++i)
m_gids.set(gids[i]);
return 0;
}
int Process::sys$mkdir(const char* pathname, mode_t mode)
{
if (!validate_read_str(pathname))
return -EFAULT;
size_t pathname_length = strlen(pathname);
if (pathname_length == 0)
return -EINVAL;
if (pathname_length >= 255)
return -ENAMETOOLONG;
int error;
if (!VFS::the().mkdir(String(pathname, pathname_length), mode, *cwd_inode(), error))
return error;
return 0;
}
clock_t Process::sys$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 0;
}
int Process::sys$select(const Syscall::SC_select_params* params)
{
if (!validate_read_typed(params))
return -EFAULT;
if (params->writefds && !validate_read_typed(params->writefds))
return -EFAULT;
if (params->readfds && !validate_read_typed(params->readfds))
return -EFAULT;
if (params->exceptfds && !validate_read_typed(params->exceptfds))
return -EFAULT;
if (params->timeout && !validate_read_typed(params->timeout))
return -EFAULT;
int nfds = params->nfds;
fd_set* writefds = params->writefds;
fd_set* readfds = params->readfds;
fd_set* exceptfds = params->exceptfds;
auto* timeout = params->timeout;
// FIXME: Implement exceptfds support.
ASSERT(!exceptfds);
if (timeout) {
m_select_timeout = *timeout;
m_select_has_timeout = true;
} else {
m_select_has_timeout = false;
}
if (nfds < 0)
return -EINVAL;
// FIXME: Return -EINTR if a signal is caught.
// FIXME: Return -EINVAL if timeout is invalid.
auto transfer_fds = [this, nfds] (fd_set* set, auto& vector) -> int {
if (!set)
return 0;
vector.clear_with_capacity();
auto bitmap = Bitmap::wrap((byte*)set, FD_SETSIZE);
for (int i = 0; i < nfds; ++i) {
if (bitmap.get(i)) {
if (!file_descriptor(i))
return -EBADF;
vector.append(i);
}
}
return 0;
};
int error = 0;
error = transfer_fds(writefds, m_select_write_fds);
if (error)
return error;
error = transfer_fds(readfds, m_select_read_fds);
if (error)
return error;
#ifdef DEBUG_IO
dbgprintf("%s<%u> selecting on (read:%u, write:%u), wakeup_req:%u, timeout=%p\n", name().characters(), pid(), m_select_read_fds.size(), m_select_write_fds.size(), m_wakeup_requested, timeout);
#endif
if (!m_wakeup_requested && (!timeout || (timeout->tv_sec || timeout->tv_usec))) {
block(BlockedSelect);
Scheduler::yield();
}
m_wakeup_requested = false;
int markedfds = 0;
if (readfds) {
memset(readfds, 0, sizeof(fd_set));
auto bitmap = Bitmap::wrap((byte*)readfds, FD_SETSIZE);
for (int fd : m_select_read_fds) {
auto* descriptor = file_descriptor(fd);
if (!descriptor)
continue;
if (descriptor->can_read(*this)) {
bitmap.set(fd, true);
++markedfds;
}
}
}
if (writefds) {
memset(writefds, 0, sizeof(fd_set));
auto bitmap = Bitmap::wrap((byte*)writefds, FD_SETSIZE);
for (int fd : m_select_write_fds) {
auto* descriptor = file_descriptor(fd);
if (!descriptor)
continue;
if (descriptor->can_write(*this)) {
bitmap.set(fd, true);
++markedfds;
}
}
}
return markedfds;
}
int Process::sys$poll(pollfd* fds, int nfds, int timeout)
{
if (!validate_read_typed(fds))
return -EFAULT;
m_select_write_fds.clear_with_capacity();
m_select_read_fds.clear_with_capacity();
for (int i = 0; i < nfds; ++i) {
if (fds[i].events & POLLIN)
m_select_read_fds.append(fds[i].fd);
if (fds[i].events & POLLOUT)
m_select_write_fds.append(fds[i].fd);
}
if (!m_wakeup_requested && timeout < 0) {
block(BlockedSelect);
Scheduler::yield();
}
m_wakeup_requested = false;
int fds_with_revents = 0;
for (int i = 0; i < nfds; ++i) {
auto* descriptor = file_descriptor(fds[i].fd);
if (!descriptor) {
fds[i].revents = POLLNVAL;
continue;
}
fds[i].revents = 0;
if (fds[i].events & POLLIN && descriptor->can_read(*this))
fds[i].revents |= POLLIN;
if (fds[i].events & POLLOUT && descriptor->can_write(*this))
fds[i].revents |= POLLOUT;
if (fds[i].revents)
++fds_with_revents;
}
return fds_with_revents;
}
Inode* Process::cwd_inode()
{
// FIXME: This is retarded factoring.
if (!m_cwd)
m_cwd = VFS::the().root_inode();
return m_cwd.ptr();
}
int Process::sys$unlink(const char* pathname)
{
if (!validate_read_str(pathname))
return -EFAULT;
int error;
if (!VFS::the().unlink(String(pathname), *cwd_inode(), error))
return error;
return 0;
}
int Process::sys$rmdir(const char* pathname)
{
if (!validate_read_str(pathname))
return -EFAULT;
int error;
if (!VFS::the().rmdir(String(pathname), *cwd_inode(), error))
return error;
return 0;
}
int Process::sys$read_tsc(dword* lsw, dword* msw)
{
if (!validate_write_typed(lsw))
return -EFAULT;
if (!validate_write_typed(msw))
return -EFAULT;
read_tsc(*lsw, *msw);
return 0;
}
int Process::sys$chmod(const char* pathname, mode_t mode)
{
if (!validate_read_str(pathname))
return -EFAULT;
int error;
if (!VFS::the().chmod(String(pathname), mode, *cwd_inode(), error))
return error;
return 0;
}
void Process::finalize()
{
ASSERT(current == g_finalizer);
destroy_all_menus();
destroy_all_windows();
m_fds.clear();
m_tty = nullptr;
{
InterruptDisabler disabler;
if (auto* parent_process = Process::from_pid(m_ppid)) {
parent_process->send_signal(SIGCHLD, this);
}
}
set_state(Dead);
}
void Process::die()
{
set_state(Dying);
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_in_bitmaps() const
{
size_t amount = 0;
for (auto& region : m_regions) {
if (region->is_bitmap())
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 retain counts,
// and each PhysicalPage is only retained by its VMObject. This needs to be refactored
// so that every Region contributes +1 retain to each of its PhysicalPages.
size_t amount = 0;
for (auto& region : m_regions) {
amount += region->amount_shared();
}
return amount;
}
void Process::finalize_dying_processes()
{
Vector<Process*> dying_processes;
{
InterruptDisabler disabler;
dying_processes.ensure_capacity(system.nprocess);
for (auto* process = g_processes->head(); process; process = process->next()) {
if (process->state() == Process::Dying)
dying_processes.append(process);
}
}
for (auto* process : dying_processes)
process->finalize();
}
bool Process::tick()
{
++m_ticks;
if (tss().cs & 3)
++m_ticks_in_user;
else
++m_ticks_in_kernel;
return --m_ticks_left;
}
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