ladybird/Kernel/Process.h
Andreas Kling c414e65498 Kernel: Implement a simple virtual address range allocator.
This replaces the previous virtual address allocator which was basically
just "m_next_address += size;"

With this in place, virtual addresses can get reused, which cuts down on
the number of page tables created. When we implement ASLR some day, we'll
probably have to do page table deallocation, but for now page tables are
only deallocated once the process dies.
2019-05-17 03:40:15 +02:00

450 lines
14 KiB
C++

#pragma once
#include <AK/Types.h>
#include <AK/InlineLinkedList.h>
#include <AK/AKString.h>
#include <AK/Vector.h>
#include <AK/WeakPtr.h>
#include <AK/Weakable.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/VM/RangeAllocator.h>
#include <Kernel/TTY/TTY.h>
#include <Kernel/Syscall.h>
#include <Kernel/UnixTypes.h>
#include <Kernel/Thread.h>
#include <Kernel/Lock.h>
class ELFLoader;
class FileDescriptor;
class PageDirectory;
class Region;
class VMObject;
class ProcessTracer;
void kgettimeofday(timeval&);
class Process : public InlineLinkedListNode<Process>, public Weakable<Process> {
friend class InlineLinkedListNode<Process>;
friend class Thread;
public:
static Process* create_kernel_process(String&& name, void (*entry)());
static Process* create_user_process(const String& path, uid_t, gid_t, pid_t ppid, int& error, Vector<String>&& arguments = Vector<String>(), Vector<String>&& environment = Vector<String>(), TTY* = nullptr);
~Process();
static Vector<pid_t> all_pids();
static Vector<Process*> all_processes();
enum Priority {
IdlePriority,
LowPriority,
NormalPriority,
HighPriority,
};
enum RingLevel {
Ring0 = 0,
Ring3 = 3,
};
bool is_dead() const { return m_dead; }
Thread::State state() const { return main_thread().state(); }
Thread& main_thread() { return *m_main_thread; }
const Thread& main_thread() const { return *m_main_thread; }
bool is_ring0() const { return m_ring == Ring0; }
bool is_ring3() const { return m_ring == Ring3; }
PageDirectory& page_directory() { return *m_page_directory; }
const PageDirectory& page_directory() const { return *m_page_directory; }
static Process* from_pid(pid_t);
void set_priority(Priority p) { m_priority = p; }
Priority priority() const { return m_priority; }
const String& name() const { return m_name; }
pid_t pid() const { return m_pid; }
pid_t sid() const { return m_sid; }
pid_t pgid() const { return m_pgid; }
uid_t uid() const { return m_uid; }
gid_t gid() const { return m_gid; }
const HashTable<gid_t>& gids() const { return m_gids; }
uid_t euid() const { return m_euid; }
gid_t egid() const { return m_egid; }
pid_t ppid() const { return m_ppid; }
mode_t umask() const { return m_umask; }
bool in_group(gid_t) const;
FileDescriptor* file_descriptor(int fd);
const FileDescriptor* file_descriptor(int fd) const;
template<typename Callback> static void for_each(Callback);
template<typename Callback> static void for_each_in_pgrp(pid_t, Callback);
template<typename Callback> void for_each_child(Callback);
template<typename Callback> void for_each_thread(Callback) const;
void die();
void finalize();
int sys$gettid();
int sys$donate(int tid);
int sys$shm_open(const char* name, int flags, mode_t);
int sys$shm_unlink(const char* name);
int sys$ftruncate(int fd, off_t);
pid_t sys$setsid();
pid_t sys$getsid(pid_t);
int sys$setpgid(pid_t pid, pid_t pgid);
pid_t sys$getpgrp();
pid_t sys$getpgid(pid_t);
uid_t sys$getuid();
gid_t sys$getgid();
uid_t sys$geteuid();
gid_t sys$getegid();
pid_t sys$getpid();
pid_t sys$getppid();
mode_t sys$umask(mode_t);
int sys$open(const char* path, int options, mode_t mode = 0);
int sys$close(int fd);
ssize_t sys$read(int fd, byte*, ssize_t);
ssize_t sys$write(int fd, const byte*, ssize_t);
ssize_t sys$writev(int fd, const struct iovec* iov, int iov_count);
int sys$fstat(int fd, stat*);
int sys$lstat(const char*, stat*);
int sys$stat(const char*, stat*);
int sys$lseek(int fd, off_t, int whence);
int sys$kill(pid_t pid, int sig);
[[noreturn]] void sys$exit(int status);
[[noreturn]] void sys$sigreturn();
pid_t sys$waitpid(pid_t, int* wstatus, int options);
void* sys$mmap(const Syscall::SC_mmap_params*);
int sys$munmap(void*, size_t size);
int sys$set_mmap_name(void*, size_t, const char*);
int sys$select(const Syscall::SC_select_params*);
int sys$poll(pollfd*, int nfds, int timeout);
ssize_t sys$get_dir_entries(int fd, void*, ssize_t);
int sys$getcwd(char*, ssize_t);
int sys$chdir(const char*);
int sys$sleep(unsigned seconds);
int sys$usleep(useconds_t usec);
int sys$gettimeofday(timeval*);
int sys$gethostname(char*, ssize_t);
int sys$uname(utsname*);
int sys$readlink(const char*, char*, ssize_t);
int sys$ttyname_r(int fd, char*, ssize_t);
int sys$ptsname_r(int fd, char*, ssize_t);
pid_t sys$fork(RegisterDump&);
int sys$execve(const char* filename, const char** argv, const char** envp);
int sys$isatty(int fd);
int sys$getdtablesize();
int sys$dup(int oldfd);
int sys$dup2(int oldfd, int newfd);
int sys$sigaction(int signum, const sigaction* act, sigaction* old_act);
int sys$sigprocmask(int how, const sigset_t* set, sigset_t* old_set);
int sys$sigpending(sigset_t*);
int sys$getgroups(ssize_t, gid_t*);
int sys$setgroups(ssize_t, const gid_t*);
int sys$pipe(int* pipefd);
int sys$killpg(int pgrp, int sig);
int sys$setgid(gid_t);
int sys$setuid(uid_t);
unsigned sys$alarm(unsigned seconds);
int sys$access(const char* pathname, int mode);
int sys$fcntl(int fd, int cmd, dword extra_arg);
int sys$ioctl(int fd, unsigned request, unsigned arg);
int sys$mkdir(const char* pathname, mode_t mode);
clock_t sys$times(tms*);
int sys$utime(const char* pathname, const struct utimbuf*);
int sys$link(const char* old_path, const char* new_path);
int sys$unlink(const char* pathname);
int sys$symlink(const char* target, const char* linkpath);
int sys$rmdir(const char* pathname);
int sys$read_tsc(dword* lsw, dword* msw);
int sys$chmod(const char* pathname, mode_t);
int sys$fchmod(int fd, mode_t);
int sys$chown(const char* pathname, uid_t, gid_t);
int sys$socket(int domain, int type, int protocol);
int sys$bind(int sockfd, const sockaddr* addr, socklen_t);
int sys$listen(int sockfd, int backlog);
int sys$accept(int sockfd, sockaddr*, socklen_t*);
int sys$connect(int sockfd, const sockaddr*, socklen_t);
ssize_t sys$sendto(const Syscall::SC_sendto_params*);
ssize_t sys$recvfrom(const Syscall::SC_recvfrom_params*);
int sys$getsockopt(const Syscall::SC_getsockopt_params*);
int sys$setsockopt(const Syscall::SC_setsockopt_params*);
int sys$restore_signal_mask(dword mask);
int sys$create_thread(int(*)(void*), void*);
void sys$exit_thread(int code);
int sys$rename(const char* oldpath, const char* newpath);
int sys$systrace(pid_t);
int sys$mknod(const char* pathname, mode_t, dev_t);
int sys$create_shared_buffer(pid_t peer_pid, int, void** buffer);
void* sys$get_shared_buffer(int shared_buffer_id);
int sys$release_shared_buffer(int shared_buffer_id);
int sys$seal_shared_buffer(int shared_buffer_id);
int sys$get_shared_buffer_size(int shared_buffer_id);
static void initialize();
[[noreturn]] void crash();
[[nodiscard]] static int reap(Process&);
const TTY* tty() const { return m_tty; }
void set_tty(TTY* tty) { m_tty = tty; }
size_t region_count() const { return m_regions.size(); }
const Vector<Retained<Region>>& regions() const { return m_regions; }
void dump_regions();
ProcessTracer* tracer() { return m_tracer.ptr(); }
ProcessTracer& ensure_tracer();
dword m_ticks_in_user { 0 };
dword m_ticks_in_kernel { 0 };
dword m_ticks_in_user_for_dead_children { 0 };
dword m_ticks_in_kernel_for_dead_children { 0 };
bool validate_read_from_kernel(LinearAddress) const;
bool validate_read(const void*, ssize_t) const;
bool validate_write(void*, ssize_t) const;
bool validate_read_str(const char* str);
template<typename T> bool validate_read_typed(T* value, size_t count = 1) { return validate_read(value, sizeof(T) * count); }
template<typename T> bool validate_write_typed(T* value, size_t count = 1) { return validate_write(value, sizeof(T) * count); }
Inode& cwd_inode();
Inode* executable_inode() { return m_executable.ptr(); }
int number_of_open_file_descriptors() const;
int max_open_file_descriptors() const { return m_max_open_file_descriptors; }
size_t amount_virtual() const;
size_t amount_resident() const;
size_t amount_shared() const;
Process* fork(RegisterDump&);
int exec(String path, Vector<String> arguments, Vector<String> environment);
bool is_superuser() const { return m_euid == 0; }
Region* allocate_region_with_vmo(LinearAddress, size_t, Retained<VMObject>&&, size_t offset_in_vmo, String&& name, bool is_readable, bool is_writable);
Region* allocate_file_backed_region(LinearAddress, size_t, RetainPtr<Inode>&&, String&& name, bool is_readable, bool is_writable);
Region* allocate_region(LinearAddress, size_t, String&& name, bool is_readable = true, bool is_writable = true, bool commit = true);
bool deallocate_region(Region& region);
void set_being_inspected(bool b) { m_being_inspected = b; }
bool is_being_inspected() const { return m_being_inspected; }
void terminate_due_to_signal(byte signal);
void send_signal(byte, Process* sender);
int thread_count() const;
Lock& big_lock() { return m_big_lock; }
unsigned syscall_count() const { return m_syscall_count; }
void did_syscall() { ++m_syscall_count; }
const ELFLoader* elf_loader() const { return m_elf_loader.ptr(); }
private:
friend class MemoryManager;
friend class Scheduler;
friend class Region;
Process(String&& name, uid_t, gid_t, pid_t ppid, RingLevel, RetainPtr<Inode>&& cwd = nullptr, RetainPtr<Inode>&& executable = nullptr, TTY* = nullptr, Process* fork_parent = nullptr);
int do_exec(String path, Vector<String> arguments, Vector<String> environment);
ssize_t do_write(FileDescriptor&, const byte*, int data_size);
int alloc_fd(int first_candidate_fd = 0);
void disown_all_shared_buffers();
void create_signal_trampolines_if_needed();
Thread* m_main_thread { nullptr };
RetainPtr<PageDirectory> m_page_directory;
Process* m_prev { nullptr };
Process* m_next { nullptr };
String m_name;
pid_t m_pid { 0 };
uid_t m_uid { 0 };
gid_t m_gid { 0 };
uid_t m_euid { 0 };
gid_t m_egid { 0 };
pid_t m_sid { 0 };
pid_t m_pgid { 0 };
Priority m_priority { NormalPriority };
struct FileDescriptorAndFlags {
operator bool() const { return !!descriptor; }
void clear();
void set(Retained<FileDescriptor>&& d, dword f = 0);
RetainPtr<FileDescriptor> descriptor;
dword flags { 0 };
};
Vector<FileDescriptorAndFlags> m_fds;
RingLevel m_ring { Ring0 };
int m_max_open_file_descriptors { 128 };
byte m_termination_status { 0 };
byte m_termination_signal { 0 };
RetainPtr<Inode> m_cwd;
RetainPtr<Inode> m_executable;
TTY* m_tty { nullptr };
Region* region_from_range(LinearAddress, size_t);
Vector<Retained<Region>> m_regions;
// FIXME: Implement some kind of ASLR?
LinearAddress m_next_region;
LinearAddress m_return_to_ring3_from_signal_trampoline;
LinearAddress m_return_to_ring0_from_signal_trampoline;
pid_t m_ppid { 0 };
mode_t m_umask { 022 };
static void notify_waiters(pid_t waitee, int exit_status, int signal);
HashTable<gid_t> m_gids;
bool m_being_inspected { false };
bool m_dead { false };
int m_next_tid { 0 };
unsigned m_syscall_count { 0 };
RetainPtr<ProcessTracer> m_tracer;
OwnPtr<ELFLoader> m_elf_loader;
RangeAllocator m_range_allocator;
Lock m_big_lock { "Process" };
};
class ProcessInspectionHandle {
public:
ProcessInspectionHandle(Process& process)
: m_process(process)
{
if (&process != &current->process()) {
ASSERT(!m_process.is_being_inspected());
m_process.set_being_inspected(true);
}
}
~ProcessInspectionHandle()
{
m_process.set_being_inspected(false);
}
Process& process() { return m_process; }
static OwnPtr<ProcessInspectionHandle> from_pid(pid_t pid)
{
InterruptDisabler disabler;
auto* process = Process::from_pid(pid);
if (process)
return make<ProcessInspectionHandle>(*process);
return nullptr;
}
Process* operator->() { return &m_process; }
Process& operator*() { return m_process; }
private:
Process& m_process;
};
extern const char* to_string(Process::Priority);
extern InlineLinkedList<Process>* g_processes;
template<typename Callback>
inline void Process::for_each(Callback callback)
{
ASSERT_INTERRUPTS_DISABLED();
for (auto* process = g_processes->head(); process;) {
auto* next_process = process->next();
if (!callback(*process))
break;
process = next_process;
}
}
template<typename Callback>
inline void Process::for_each_child(Callback callback)
{
ASSERT_INTERRUPTS_DISABLED();
pid_t my_pid = pid();
for (auto* process = g_processes->head(); process;) {
auto* next_process = process->next();
if (process->ppid() == my_pid) {
if (!callback(*process))
break;
}
process = next_process;
}
}
template<typename Callback>
inline void Process::for_each_thread(Callback callback) const
{
InterruptDisabler disabler;
pid_t my_pid = pid();
for (auto* thread = g_threads->head(); thread;) {
auto* next_thread = thread->next();
if (thread->pid() == my_pid) {
if (callback(*thread) == IterationDecision::Abort)
break;
}
thread = next_thread;
}
}
template<typename Callback>
inline void Process::for_each_in_pgrp(pid_t pgid, Callback callback)
{
ASSERT_INTERRUPTS_DISABLED();
for (auto* process = g_processes->head(); process;) {
auto* next_process = process->next();
if (process->pgid() == pgid) {
if (!callback(*process))
break;
}
process = next_process;
}
}
inline bool InodeMetadata::may_read(Process& process) const
{
return may_read(process.euid(), process.gids());
}
inline bool InodeMetadata::may_write(Process& process) const
{
return may_write(process.euid(), process.gids());
}
inline bool InodeMetadata::may_execute(Process& process) const
{
return may_execute(process.euid(), process.gids());
}
inline int Thread::pid() const
{
return m_process.pid();
}