ladybird/Kernel/Syscall.cpp
Drew Stratford 81d0f96f20 Kernel: Use user stack for signal handlers.
This commit drastically changes how signals are handled.

In the case that an unblocked thread is signaled it works much
in the same way as previously. However, when a blocking syscall
is interrupted, we set up the signal trampoline on the user
stack, complete the blocking syscall, return down the kernel
stack and then jump to the handler. This means that from the
kernel stack's perspective, we only ever get one system call deep.

The signal trampoline has also been changed in order to properly
store the return value from system calls. This is necessary due
to the new way we exit from signaled system calls.
2019-09-05 16:37:09 +02:00

332 lines
14 KiB
C++

#include <Kernel/Arch/i386/CPU.h>
#include <Kernel/Console.h>
#include <Kernel/IO.h>
#include <Kernel/Process.h>
#include <Kernel/ProcessTracer.h>
#include <Kernel/Scheduler.h>
#include <Kernel/Syscall.h>
extern "C" void syscall_trap_entry(RegisterDump&);
extern "C" void syscall_trap_handler();
extern volatile RegisterDump* syscallRegDump;
asm(
".globl syscall_trap_handler \n"
"syscall_trap_handler:\n"
" pusha\n"
" pushw %ds\n"
" pushw %es\n"
" pushw %fs\n"
" pushw %gs\n"
" pushw %ss\n"
" pushw %ss\n"
" pushw %ss\n"
" pushw %ss\n"
" pushw %ss\n"
" popw %ds\n"
" popw %es\n"
" popw %fs\n"
" popw %gs\n"
" mov %esp, %eax\n"
" call syscall_trap_entry\n"
" popw %gs\n"
" popw %gs\n"
" popw %fs\n"
" popw %es\n"
" popw %ds\n"
" popa\n"
" iret\n");
namespace Syscall {
void initialize()
{
register_user_callable_interrupt_handler(0x82, syscall_trap_handler);
kprintf("Syscall: int 0x82 handler installed\n");
}
int sync()
{
VFS::the().sync();
return 0;
}
static u32 handle(RegisterDump& regs, u32 function, u32 arg1, u32 arg2, u32 arg3)
{
current->process().did_syscall();
ASSERT_INTERRUPTS_ENABLED();
switch (function) {
case Syscall::SC_yield:
Scheduler::yield();
break;
case Syscall::SC_beep:
Scheduler::beep();
break;
case Syscall::SC_donate:
return current->process().sys$donate((int)arg1);
case Syscall::SC_gettid:
return current->process().sys$gettid();
case Syscall::SC_putch:
Console::the().put_char(arg1 & 0xff);
break;
case Syscall::SC_dbgputch:
return current->process().sys$dbgputch((u8)arg1);
case Syscall::SC_dbgputstr:
return current->process().sys$dbgputstr((const u8*)arg1, (int)arg2);
case Syscall::SC_sleep:
return current->process().sys$sleep((unsigned)arg1);
case Syscall::SC_usleep:
return current->process().sys$usleep((unsigned)arg1);
case Syscall::SC_gettimeofday:
return current->process().sys$gettimeofday((timeval*)arg1);
case Syscall::SC_get_dir_entries:
return current->process().sys$get_dir_entries((int)arg1, (void*)arg2, (size_t)arg3);
case Syscall::SC_lstat:
return current->process().sys$lstat((const char*)arg1, (stat*)arg2);
case Syscall::SC_stat:
return current->process().sys$stat((const char*)arg1, (stat*)arg2);
case Syscall::SC_getcwd:
return current->process().sys$getcwd((char*)arg1, (size_t)arg2);
case Syscall::SC_open:
return current->process().sys$open((const SC_open_params*)arg1);
case Syscall::SC_write:
return current->process().sys$write((int)arg1, (const u8*)arg2, (ssize_t)arg3);
case Syscall::SC_close:
return current->process().sys$close((int)arg1);
case Syscall::SC_read:
return current->process().sys$read((int)arg1, (u8*)arg2, (ssize_t)arg3);
case Syscall::SC_lseek:
return current->process().sys$lseek((int)arg1, (off_t)arg2, (int)arg3);
case Syscall::SC_kill:
return current->process().sys$kill((pid_t)arg1, (int)arg2);
case Syscall::SC_getuid:
return current->process().sys$getuid();
case Syscall::SC_getgid:
return current->process().sys$getgid();
case Syscall::SC_getpid:
return current->process().sys$getpid();
case Syscall::SC_getppid:
return current->process().sys$getppid();
case Syscall::SC_waitpid:
return current->process().sys$waitpid((pid_t)arg1, (int*)arg2, (int)arg3);
case Syscall::SC_mmap:
return (u32)current->process().sys$mmap((const SC_mmap_params*)arg1);
case Syscall::SC_select:
return current->process().sys$select((const SC_select_params*)arg1);
case Syscall::SC_poll:
return current->process().sys$poll((pollfd*)arg1, (int)arg2, (int)arg3);
case Syscall::SC_munmap:
return current->process().sys$munmap((void*)arg1, (size_t)arg2);
case Syscall::SC_gethostname:
return current->process().sys$gethostname((char*)arg1, (size_t)arg2);
case Syscall::SC_exit:
cli();
if (auto* tracer = current->process().tracer())
tracer->did_syscall(function, arg1, arg2, arg3, 0);
current->process().sys$exit((int)arg1);
ASSERT_NOT_REACHED();
return 0;
case Syscall::SC_exit_thread:
cli();
if (auto* tracer = current->process().tracer())
tracer->did_syscall(function, arg1, arg2, arg3, 0);
current->process().sys$exit_thread((int)arg1);
ASSERT_NOT_REACHED();
break;
case Syscall::SC_chdir:
return current->process().sys$chdir((const char*)arg1);
case Syscall::SC_uname:
return current->process().sys$uname((utsname*)arg1);
case Syscall::SC_set_mmap_name:
return current->process().sys$set_mmap_name((void*)arg1, (size_t)arg2, (const char*)arg3);
case Syscall::SC_readlink:
return current->process().sys$readlink((const char*)arg1, (char*)arg2, (size_t)arg3);
case Syscall::SC_ttyname_r:
return current->process().sys$ttyname_r((int)arg1, (char*)arg2, (size_t)arg3);
case Syscall::SC_ptsname_r:
return current->process().sys$ptsname_r((int)arg1, (char*)arg2, (size_t)arg3);
case Syscall::SC_setsid:
return current->process().sys$setsid();
case Syscall::SC_getsid:
return current->process().sys$getsid((pid_t)arg1);
case Syscall::SC_setpgid:
return current->process().sys$setpgid((pid_t)arg1, (pid_t)arg2);
case Syscall::SC_getpgid:
return current->process().sys$getpgid((pid_t)arg1);
case Syscall::SC_getpgrp:
return current->process().sys$getpgrp();
case Syscall::SC_fork:
return current->process().sys$fork(regs);
case Syscall::SC_execve:
return current->process().sys$execve((const char*)arg1, (const char**)arg2, (const char**)arg3);
case Syscall::SC_geteuid:
return current->process().sys$geteuid();
case Syscall::SC_getegid:
return current->process().sys$getegid();
case Syscall::SC_isatty:
return current->process().sys$isatty((int)arg1);
case Syscall::SC_getdtablesize:
return current->process().sys$getdtablesize();
case Syscall::SC_dup:
return current->process().sys$dup((int)arg1);
case Syscall::SC_dup2:
return current->process().sys$dup2((int)arg1, (int)arg2);
case Syscall::SC_sigaction:
return current->process().sys$sigaction((int)arg1, (const sigaction*)arg2, (sigaction*)arg3);
case Syscall::SC_umask:
return current->process().sys$umask((mode_t)arg1);
case Syscall::SC_getgroups:
return current->process().sys$getgroups((ssize_t)arg1, (gid_t*)arg2);
case Syscall::SC_setgroups:
return current->process().sys$setgroups((ssize_t)arg1, (const gid_t*)arg2);
case Syscall::SC_sigreturn:
return current->process().sys$sigreturn(regs);
case Syscall::SC_sigprocmask:
return current->process().sys$sigprocmask((int)arg1, (const sigset_t*)arg2, (sigset_t*)arg3);
case Syscall::SC_pipe:
return current->process().sys$pipe((int*)arg1, (int)arg2);
case Syscall::SC_killpg:
return current->process().sys$killpg((int)arg1, (int)arg2);
case Syscall::SC_setuid:
return current->process().sys$setuid((uid_t)arg1);
case Syscall::SC_setgid:
return current->process().sys$setgid((gid_t)arg1);
case Syscall::SC_alarm:
return current->process().sys$alarm((unsigned)arg1);
case Syscall::SC_access:
return current->process().sys$access((const char*)arg1, (int)arg2);
case Syscall::SC_fcntl:
return current->process().sys$fcntl((int)arg1, (int)arg2, (u32)arg3);
case Syscall::SC_ioctl:
return current->process().sys$ioctl((int)arg1, (unsigned)arg2, (unsigned)arg3);
case Syscall::SC_fstat:
return current->process().sys$fstat((int)arg1, (stat*)arg2);
case Syscall::SC_mkdir:
return current->process().sys$mkdir((const char*)arg1, (mode_t)arg2);
case Syscall::SC_times:
return current->process().sys$times((tms*)arg1);
case Syscall::SC_utime:
return current->process().sys$utime((const char*)arg1, (const utimbuf*)arg2);
case Syscall::SC_sync:
return sync();
case Syscall::SC_link:
return current->process().sys$link((const char*)arg1, (const char*)arg2);
case Syscall::SC_unlink:
return current->process().sys$unlink((const char*)arg1);
case Syscall::SC_symlink:
return current->process().sys$symlink((const char*)arg1, (const char*)arg2);
case Syscall::SC_read_tsc:
return current->process().sys$read_tsc((u32*)arg1, (u32*)arg2);
case Syscall::SC_rmdir:
return current->process().sys$rmdir((const char*)arg1);
case Syscall::SC_chmod:
return current->process().sys$chmod((const char*)arg1, (mode_t)arg2);
case Syscall::SC_fchmod:
return current->process().sys$fchmod((int)arg1, (mode_t)arg2);
case Syscall::SC_socket:
return current->process().sys$socket((int)arg1, (int)arg2, (int)arg3);
case Syscall::SC_bind:
return current->process().sys$bind((int)arg1, (const sockaddr*)arg2, (socklen_t)arg3);
case Syscall::SC_listen:
return current->process().sys$listen((int)arg1, (int)arg2);
case Syscall::SC_accept:
return current->process().sys$accept((int)arg1, (sockaddr*)arg2, (socklen_t*)arg3);
case Syscall::SC_connect:
return current->process().sys$connect((int)arg1, (const sockaddr*)arg2, (socklen_t)arg3);
case Syscall::SC_create_shared_buffer:
return current->process().sys$create_shared_buffer((size_t)arg1, (void**)arg2);
case Syscall::SC_share_buffer_with:
return current->process().sys$share_buffer_with((int)arg1, (pid_t)arg2);
case Syscall::SC_get_shared_buffer:
return (u32)current->process().sys$get_shared_buffer((int)arg1);
case Syscall::SC_release_shared_buffer:
return current->process().sys$release_shared_buffer((int)arg1);
case Syscall::SC_chown:
return current->process().sys$chown((const char*)arg1, (uid_t)arg2, (gid_t)arg3);
case Syscall::SC_fchown:
return current->process().sys$fchown((int)arg1, (uid_t)arg2, (gid_t)arg3);
case Syscall::SC_restore_signal_mask:
return current->process().sys$restore_signal_mask((u32)arg1);
case Syscall::SC_seal_shared_buffer:
return current->process().sys$seal_shared_buffer((int)arg1);
case Syscall::SC_get_shared_buffer_size:
return current->process().sys$get_shared_buffer_size((int)arg1);
case Syscall::SC_sendto:
return current->process().sys$sendto((const SC_sendto_params*)arg1);
case Syscall::SC_recvfrom:
return current->process().sys$recvfrom((const SC_recvfrom_params*)arg1);
case Syscall::SC_getsockopt:
return current->process().sys$getsockopt((const SC_getsockopt_params*)arg1);
case Syscall::SC_setsockopt:
return current->process().sys$setsockopt((const SC_setsockopt_params*)arg1);
case Syscall::SC_create_thread:
return current->process().sys$create_thread((int (*)(void*))arg1, (void*)arg2);
case Syscall::SC_rename:
return current->process().sys$rename((const char*)arg1, (const char*)arg2);
case Syscall::SC_shm_open:
return current->process().sys$shm_open((const char*)arg1, (int)arg2, (mode_t)arg3);
case Syscall::SC_shm_close:
return current->process().sys$shm_unlink((const char*)arg1);
case Syscall::SC_ftruncate:
return current->process().sys$ftruncate((int)arg1, (off_t)arg2);
case Syscall::SC_systrace:
return current->process().sys$systrace((pid_t)arg1);
case Syscall::SC_mknod:
return current->process().sys$mknod((const char*)arg1, (mode_t)arg2, (dev_t)arg3);
case Syscall::SC_writev:
return current->process().sys$writev((int)arg1, (const struct iovec*)arg2, (int)arg3);
case Syscall::SC_getsockname:
return current->process().sys$getsockname((int)arg1, (sockaddr*)arg2, (socklen_t*)arg3);
case Syscall::SC_getpeername:
return current->process().sys$getpeername((int)arg1, (sockaddr*)arg2, (socklen_t*)arg3);
case Syscall::SC_sched_setparam:
return current->process().sys$sched_setparam((pid_t)arg1, (struct sched_param*)arg2);
case Syscall::SC_sched_getparam:
return current->process().sys$sched_setparam((pid_t)arg1, (struct sched_param*)arg2);
case Syscall::SC_halt: {
return current->process().sys$halt();
break;
}
case Syscall::SC_mount:
return current->process().sys$mount((const char*)arg1, (const char*)arg2, (const char*)arg3);
case Syscall::SC_reboot: {
return current->process().sys$reboot();
}
case Syscall::SC_umount:
return current->process().sys$umount((const char*)arg1);
case Syscall::SC_dump_backtrace:
return current->process().sys$dump_backtrace();
case Syscall::SC_watch_file:
return current->process().sys$watch_file((const char*)arg1, (int)arg2);
case Syscall::SC_share_buffer_globally:
return current->process().sys$share_buffer_globally((int)arg1);
case Syscall::SC_set_process_icon:
return current->process().sys$set_process_icon((int)arg1);
case Syscall::SC_mprotect:
return current->process().sys$mprotect((void*)arg1, (size_t)arg2, (int)arg3);
case Syscall::SC_get_process_name:
return current->process().sys$get_process_name((char*)arg1, (int)arg2);
case Syscall::SC_realpath:
return current->process().sys$realpath((const char*)arg1, (char*)arg2, (size_t)arg3);
default:
kprintf("<%u> int0x82: Unknown function %u requested {%x, %x, %x}\n", current->process().pid(), function, arg1, arg2, arg3);
return -ENOSYS;
}
return 0;
}
}
void syscall_trap_entry(RegisterDump& regs)
{
current->process().big_lock().lock();
u32 function = regs.eax;
u32 arg1 = regs.edx;
u32 arg2 = regs.ecx;
u32 arg3 = regs.ebx;
regs.eax = Syscall::handle(regs, function, arg1, arg2, arg3);
if (auto* tracer = current->process().tracer())
tracer->did_syscall(function, arg1, arg2, arg3, regs.eax);
current->process().big_lock().unlock();
}