fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / arch / um / kernel / skas / process.c
index cb91f8c..ae4fa71 100644 (file)
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
 
-#include <stdlib.h>
-#include <errno.h>
-#include <signal.h>
-#include <setjmp.h>
-#include <sched.h>
-#include <sys/wait.h>
-#include <sys/ptrace.h>
-#include <sys/mman.h>
-#include <sys/user.h>
-#include <asm/unistd.h>
-#include "user.h"
-#include "ptrace_user.h"
-#include "time_user.h"
-#include "sysdep/ptrace.h"
-#include "user_util.h"
+#include "linux/sched.h"
+#include "linux/slab.h"
+#include "linux/ptrace.h"
+#include "linux/proc_fs.h"
+#include "linux/file.h"
+#include "linux/errno.h"
+#include "linux/init.h"
+#include "asm/uaccess.h"
+#include "asm/atomic.h"
 #include "kern_util.h"
 #include "skas.h"
-#include "sysdep/sigcontext.h"
 #include "os.h"
-#include "proc_mm.h"
-#include "skas_ptrace.h"
-
-unsigned long exec_regs[FRAME_SIZE];
-unsigned long exec_fp_regs[HOST_FP_SIZE];
-unsigned long exec_fpx_regs[HOST_XFP_SIZE];
-int have_fpx_regs = 1;
+#include "user_util.h"
+#include "tlb.h"
+#include "kern.h"
+#include "mode.h"
+#include "registers.h"
 
-static void handle_segv(int pid)
+void switch_to_skas(void *prev, void *next)
 {
-       struct ptrace_faultinfo fault;
-       int err;
+       struct task_struct *from, *to;
 
-       err = ptrace(PTRACE_FAULTINFO, pid, 0, &fault);
-       if(err)
-               panic("handle_segv - PTRACE_FAULTINFO failed, errno = %d\n",
-                     errno);
+       from = prev;
+       to = next;
 
-       segv(fault.addr, 0, FAULT_WRITE(fault.is_write), 1, NULL);
-}
-
-static void handle_trap(int pid, union uml_pt_regs *regs)
-{
-       int err, syscall_nr, status;
-
-       syscall_nr = PT_SYSCALL_NR(regs->skas.regs);
-       if(syscall_nr < 1){
-               relay_signal(SIGTRAP, regs);
-               return;
-       }
-       UPT_SYSCALL_NR(regs) = syscall_nr;
+       /* XXX need to check runqueues[cpu].idle */
+       if(current->pid == 0)
+               switch_timers(0);
 
-       err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET, __NR_getpid);
-       if(err < 0)
-               panic("handle_trap - nullifying syscall failed errno = %d\n", 
-                     errno);
+       switch_threads(&from->thread.mode.skas.switch_buf,
+                      &to->thread.mode.skas.switch_buf);
 
-       err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
-       if(err < 0)
-               panic("handle_trap - continuing to end of syscall failed, "
-                     "errno = %d\n", errno);
+       arch_switch_to_skas(current->thread.prev_sched, current);
 
-       err = waitpid(pid, &status, WUNTRACED);
-       if((err < 0) || !WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-               panic("handle_trap - failed to wait at end of syscall, "
-                     "errno = %d, status = %d\n", errno, status);
-
-       handle_syscall(regs);
+       if(current->pid == 0)
+               switch_timers(1);
 }
 
-int userspace_pid;
+extern void schedule_tail(struct task_struct *prev);
 
-static int userspace_tramp(void *arg)
-{
-       init_new_thread_signals(0);
-       enable_timer();
-       ptrace(PTRACE_TRACEME, 0, 0, 0);
-       os_stop_process(os_getpid());
-       return(0);
+/* This is called magically, by its address being stuffed in a jmp_buf
+ * and being longjmp-d to.
+ */
+void new_thread_handler(void)
+{
+       int (*fn)(void *), n;
+       void *arg;
+
+       if(current->thread.prev_sched != NULL)
+               schedule_tail(current->thread.prev_sched);
+       current->thread.prev_sched = NULL;
+
+       fn = current->thread.request.u.thread.proc;
+       arg = current->thread.request.u.thread.arg;
+
+       /* The return value is 1 if the kernel thread execs a process,
+        * 0 if it just exits
+        */
+       n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
+       if(n == 1){
+               /* Handle any immediate reschedules or signals */
+               interrupt_end();
+               userspace(&current->thread.regs.regs);
+       }
+       else do_exit(0);
 }
 
-void start_userspace(void)
+void release_thread_skas(struct task_struct *task)
 {
-       void *stack;
-       unsigned long sp;
-       int pid, status, n;
-
-       stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
-                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-       if(stack == MAP_FAILED)
-               panic("start_userspace : mmap failed, errno = %d", errno);
-       sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
-
-       pid = clone(userspace_tramp, (void *) sp, 
-                   CLONE_FILES | CLONE_VM | SIGCHLD, NULL);
-       if(pid < 0)
-               panic("start_userspace : clone failed, errno = %d", errno);
-
-       do {
-               n = waitpid(pid, &status, WUNTRACED);
-               if(n < 0)
-                       panic("start_userspace : wait failed, errno = %d", 
-                             errno);
-       } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
-
-       if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-               panic("start_userspace : expected SIGSTOP, got status = %d",
-                     status);
-
-       if(munmap(stack, PAGE_SIZE) < 0)
-               panic("start_userspace : munmap failed, errno = %d\n", errno);
-
-       userspace_pid = pid;
 }
 
-void userspace(union uml_pt_regs *regs)
+/* Called magically, see new_thread_handler above */
+void fork_handler(void)
 {
-       int err, status, op;
-
-       restore_registers(regs);
-               
-       err = ptrace(PTRACE_SYSCALL, userspace_pid, 0, 0);
-       if(err)
-               panic("userspace - PTRACE_SYSCALL failed, errno = %d\n", 
-                      errno);
-       while(1){
-               err = waitpid(userspace_pid, &status, WUNTRACED);
-               if(err < 0)
-                       panic("userspace - waitpid failed, errno = %d\n", 
-                             errno);
-
-               regs->skas.is_user = 1;
-               save_registers(regs);
-
-               if(WIFSTOPPED(status)){
-                       switch(WSTOPSIG(status)){
-                       case SIGSEGV:
-                               handle_segv(userspace_pid);
-                               break;
-                       case SIGTRAP:
-                               handle_trap(userspace_pid, regs);
-                               break;
-                       case SIGIO:
-                       case SIGVTALRM:
-                       case SIGILL:
-                       case SIGBUS:
-                       case SIGFPE:
-                               user_signal(WSTOPSIG(status), regs);
-                               break;
-                       default:
-                               printk("userspace - child stopped with signal "
-                                      "%d\n", WSTOPSIG(status));
-                       }
-                       interrupt_end();
-               }
+       force_flush_all();
+       if(current->thread.prev_sched == NULL)
+               panic("blech");
 
-               restore_registers(regs);
+       schedule_tail(current->thread.prev_sched);
 
-               op = singlestepping_skas() ? PTRACE_SINGLESTEP : 
-                       PTRACE_SYSCALL;
-               err = ptrace(op, userspace_pid, 0, 0);
-               if(err)
-                       panic("userspace - PTRACE_SYSCALL failed, "
-                             "errno = %d\n", errno);
-       }
-}
+       /* XXX: if interrupt_end() calls schedule, this call to
+        * arch_switch_to_skas isn't needed. We could want to apply this to
+        * improve performance. -bb */
+       arch_switch_to_skas(current->thread.prev_sched, current);
 
-void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
-               void (*handler)(int))
-{
-       jmp_buf switch_buf, fork_buf;
-
-       *switch_buf_ptr = &switch_buf;
-       *fork_buf_ptr = &fork_buf;
+       current->thread.prev_sched = NULL;
 
-       if(setjmp(fork_buf) == 0)
-               new_thread_proc(stack, handler);
+/* Handle any immediate reschedules or signals */
+       interrupt_end();
 
-       remove_sigstack();
+       userspace(&current->thread.regs.regs);
 }
 
-void thread_wait(void *sw, void *fb)
+int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
+                    unsigned long stack_top, struct task_struct * p,
+                    struct pt_regs *regs)
 {
-       jmp_buf buf, **switch_buf = sw, *fork_buf;
-
-       *switch_buf = &buf;
-       fork_buf = fb;
-       if(setjmp(buf) == 0)
-               longjmp(*fork_buf, 1);
-}
+       void (*handler)(void);
 
-static int move_registers(int int_op, int fp_op, union uml_pt_regs *regs,
-                         unsigned long *fp_regs)
-{
-       if(ptrace(int_op, userspace_pid, 0, regs->skas.regs) < 0)
-               return(-errno);
-       if(ptrace(fp_op, userspace_pid, 0, fp_regs) < 0)
-               return(-errno);
-       return(0);
-}
+       if(current->thread.forking){
+               memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
+                      sizeof(p->thread.regs.regs.skas));
+               REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
+               if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
 
-void save_registers(union uml_pt_regs *regs)
-{
-       unsigned long *fp_regs;
-       int err, fp_op;
+               handler = fork_handler;
 
-       if(have_fpx_regs){
-               fp_op = PTRACE_GETFPXREGS;
-               fp_regs = regs->skas.xfp;
+               arch_copy_thread(&current->thread.arch, &p->thread.arch);
        }
        else {
-               fp_op = PTRACE_GETFPREGS;
-               fp_regs = regs->skas.fp;
+               init_thread_registers(&p->thread.regs.regs);
+               p->thread.request.u.thread = current->thread.request.u.thread;
+               handler = new_thread_handler;
        }
 
-       err = move_registers(PTRACE_GETREGS, fp_op, regs, fp_regs);
-       if(err)
-               panic("save_registers - saving registers failed, errno = %d\n",
-                     err);
+       new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
+                  handler);
+       return(0);
 }
 
-void restore_registers(union uml_pt_regs *regs)
+int new_mm(unsigned long stack)
 {
-       unsigned long *fp_regs;
-       int err, fp_op;
+       int fd;
 
-       if(have_fpx_regs){
-               fp_op = PTRACE_SETFPXREGS;
-               fp_regs = regs->skas.xfp;
-       }
-       else {
-               fp_op = PTRACE_SETFPREGS;
-               fp_regs = regs->skas.fp;
-       }
+       fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
+       if(fd < 0)
+               return(fd);
 
-       err = move_registers(PTRACE_SETREGS, fp_op, regs, fp_regs);
-       if(err)
-               panic("restore_registers - saving registers failed, "
-                     "errno = %d\n", err);
-}
+       if(skas_needs_stub)
+               map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 
-void switch_threads(void *me, void *next)
-{
-       jmp_buf my_buf, **me_ptr = me, *next_buf = next;
-       
-       *me_ptr = &my_buf;
-       if(setjmp(my_buf) == 0)
-               longjmp(*next_buf, 1);
+       return(fd);
 }
 
-static jmp_buf initial_jmpbuf;
-
-/* XXX Make these percpu */
-static void (*cb_proc)(void *arg);
-static void *cb_arg;
-static jmp_buf *cb_back;
-
-int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
+void init_idle_skas(void)
 {
-       jmp_buf **switch_buf = switch_buf_ptr;
-       int n;
-
-       *fork_buf_ptr = &initial_jmpbuf;
-       n = setjmp(initial_jmpbuf);
-       if(n == 0)
-               new_thread_proc((void *) stack, new_thread_handler);
-       else if(n == 1)
-               remove_sigstack();
-       else if(n == 2){
-               (*cb_proc)(cb_arg);
-               longjmp(*cb_back, 1);
-       }
-       else if(n == 3){
-               kmalloc_ok = 0;
-               return(0);
-       }
-       else if(n == 4){
-               kmalloc_ok = 0;
-               return(1);
-       }
-       longjmp(**switch_buf, 1);
+       cpu_tasks[current_thread->cpu].pid = os_getpid();
+       default_idle();
 }
 
-void remove_sigstack(void)
-{
-       stack_t stack = ((stack_t) { .ss_flags  = SS_DISABLE,
-                                    .ss_sp     = NULL,
-                                    .ss_size   = 0 });
-
-       if(sigaltstack(&stack, NULL) != 0)
-               panic("disabling signal stack failed, errno = %d\n", errno);
-}
+extern void start_kernel(void);
 
-void initial_thread_cb_skas(void (*proc)(void *), void *arg)
+static int start_kernel_proc(void *unused)
 {
-       jmp_buf here;
-
-       cb_proc = proc;
-       cb_arg = arg;
-       cb_back = &here;
+       int pid;
 
        block_signals();
-       if(setjmp(here) == 0)
-               longjmp(initial_jmpbuf, 2);
-       unblock_signals();
-
-       cb_proc = NULL;
-       cb_arg = NULL;
-       cb_back = NULL;
+       pid = os_getpid();
+
+       cpu_tasks[0].pid = pid;
+       cpu_tasks[0].task = current;
+#ifdef CONFIG_SMP
+       cpu_online_map = cpumask_of_cpu(0);
+#endif
+       start_kernel();
+       return(0);
 }
 
-void halt_skas(void)
-{
-       block_signals();
-       longjmp(initial_jmpbuf, 3);
-}
+extern int userspace_pid[];
 
-void reboot_skas(void)
+int start_uml_skas(void)
 {
-       block_signals();
-       longjmp(initial_jmpbuf, 4);
-}
+       if(proc_mm)
+               userspace_pid[0] = start_userspace(0);
 
-int new_mm(int from)
-{
-       struct proc_mm_op copy;
-       int n, fd = os_open_file("/proc/mm", of_write(OPENFLAGS()), 0);
+       init_new_thread_signals();
 
-       if(fd < 0)
-               return(-errno);
-
-       if(from != -1){
-               copy = ((struct proc_mm_op) { .op       = MM_COPY_SEGMENTS,
-                                             .u        = 
-                                             { .copy_segments  = from } } );
-               n = os_write_file(fd, &copy, sizeof(copy));
-               if(n != sizeof(copy)) 
-                       printk("new_mm : /proc/mm copy_segments failed, "
-                              "errno = %d\n", errno);
-       }
-       return(fd);
+       init_task.thread.request.u.thread.proc = start_kernel_proc;
+       init_task.thread.request.u.thread.arg = NULL;
+       return(start_idle_thread(task_stack_page(&init_task),
+                                &init_task.thread.mode.skas.switch_buf));
 }
 
-void switch_mm_skas(int mm_fd)
+int external_pid_skas(struct task_struct *task)
 {
-       int err;
-
-       err = ptrace(PTRACE_SWITCH_MM, userspace_pid, 0, mm_fd);
-       if(err)
-               panic("switch_mm_skas - PTRACE_SWITCH_MM failed, errno = %d\n",
-                     errno);
+#warning Need to look up userspace_pid by cpu
+       return(userspace_pid[0]);
 }
 
-void kill_off_processes_skas(void)
+int thread_pid_skas(struct task_struct *task)
 {
-       os_kill_process(userspace_pid, 1);
+#warning Need to look up userspace_pid by cpu
+       return(userspace_pid[0]);
 }
 
-void init_registers(int pid)
+void kill_off_processes_skas(void)
 {
-       int err;
+       if(proc_mm)
+#warning need to loop over userspace_pids in kill_off_processes_skas
+               os_kill_ptraced_process(userspace_pid[0], 1);
+       else {
+               struct task_struct *p;
+               int pid, me;
 
-       if(ptrace(PTRACE_GETREGS, pid, 0, exec_regs) < 0)
-               panic("check_ptrace : PTRACE_GETREGS failed, errno = %d", 
-                     errno);
+               me = os_getpid();
+               for_each_process(p){
+                       if(p->mm == NULL)
+                               continue;
 
-       err = ptrace(PTRACE_GETFPXREGS, pid, 0, exec_fpx_regs);
-       if(!err)
-               return;
+                       pid = p->mm->context.skas.id.u.pid;
+                       os_kill_ptraced_process(pid, 1);
+               }
+       }
+}
 
-       have_fpx_regs = 0;
-       if(errno != EIO)
-               panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d", 
-                     errno);
+unsigned long current_stub_stack(void)
+{
+       if(current->mm == NULL)
+               return(0);
 
-       err = ptrace(PTRACE_GETFPREGS, pid, 0, exec_fp_regs);
-       if(err)
-               panic("check_ptrace : PTRACE_GETFPREGS failed, errno = %d", 
-                     errno);
+       return(current->mm->context.skas.id.stack);
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */