/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <setjmp.h>
#include <sched.h>
#include <sys/wait.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 "kern_util.h"
#include "skas.h"
#include "sysdep/sigcontext.h"
#include "os.h"
#include "proc_mm.h"
#include "skas_ptrace.h"
#include "chan_user.h"
#include "signal_user.h"
#include "registers.h"
#include "process.h"
int is_skas_winch(int pid, int fd, void *data)
{
if(pid != os_getpgrp())
return(0);
register_winch_irq(-1, fd, -1, data);
return(1);
}
void get_skas_faultinfo(int pid, struct faultinfo * fi)
{
int err;
err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
if(err)
panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
"errno = %d\n", errno);
/* Special handling for i386, which has different structs */
if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
sizeof(struct faultinfo) -
sizeof(struct ptrace_faultinfo));
}
static void handle_segv(int pid, union uml_pt_regs * regs)
{
get_skas_faultinfo(pid, ®s->skas.faultinfo);
segv(regs->skas.faultinfo, 0, 1, NULL);
}
/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu)
{
int err, status;
/* Mark this as a syscall */
UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs);
if (!local_using_sysemu)
{
err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, __NR_getpid);
if(err < 0)
panic("handle_trap - nullifying syscall failed errno = %d\n",
errno);
err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
if(err < 0)
panic("handle_trap - continuing to end of syscall failed, "
"errno = %d\n", errno);
CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
if((err < 0) || !WIFSTOPPED(status) ||
(WSTOPSIG(status) != SIGTRAP + 0x80))
panic("handle_trap - failed to wait at end of syscall, "
"errno = %d, status = %d\n", errno, status);
}
handle_syscall(regs);
}
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);
}
/* Each element set once, and only accessed by a single processor anyway */
#undef NR_CPUS
#define NR_CPUS 1
int userspace_pid[NR_CPUS];
void start_userspace(int cpu)
{
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 {
CATCH_EINTR(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 (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
panic("start_userspace : PTRACE_SETOPTIONS failed, errno=%d\n",
errno);
if(munmap(stack, PAGE_SIZE) < 0)
panic("start_userspace : munmap failed, errno = %d\n", errno);
userspace_pid[cpu] = pid;
}
void userspace(union uml_pt_regs *regs)
{
int err, status, op, pid = userspace_pid[0];
int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
while(1){
restore_registers(pid, regs);
/* Now we set local_using_sysemu to be used for one loop */
local_using_sysemu = get_using_sysemu();
op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
err = ptrace(op, pid, 0, 0);
if(err)
panic("userspace - could not resume userspace process, "
"pid=%d, ptrace operation = %d, errno = %d\n",
op, errno);
CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
if(err < 0)
panic("userspace - waitpid failed, errno = %d\n",
errno);
regs->skas.is_user = 1;
save_registers(pid, regs);
UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
if(WIFSTOPPED(status)){
switch(WSTOPSIG(status)){
case SIGSEGV:
handle_segv(pid, regs);
break;
case SIGTRAP + 0x80:
handle_trap(pid, regs, local_using_sysemu);
break;
case SIGTRAP:
relay_signal(SIGTRAP, regs);
break;
case SIGIO:
case SIGVTALRM:
case SIGILL:
case SIGBUS:
case SIGFPE:
case SIGWINCH:
user_signal(WSTOPSIG(status), regs, pid);
break;
default:
printk("userspace - child stopped with signal "
"%d\n", WSTOPSIG(status));
}
interrupt_end();
/* Avoid -ERESTARTSYS handling in host */
PT_SYSCALL_NR(regs->skas.regs) = -1;
}
}
}
#define INIT_JMP_NEW_THREAD 0
#define INIT_JMP_REMOVE_SIGSTACK 1
#define INIT_JMP_CALLBACK 2
#define INIT_JMP_HALT 3
#define INIT_JMP_REBOOT 4
void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
void (*handler)(int))
{
unsigned long flags;
sigjmp_buf switch_buf, fork_buf;
*switch_buf_ptr = &switch_buf;
*fork_buf_ptr = &fork_buf;
/* Somewhat subtle - siglongjmp restores the signal mask before doing
* the longjmp. This means that when jumping from one stack to another
* when the target stack has interrupts enabled, an interrupt may occur
* on the source stack. This is bad when starting up a process because
* it's not supposed to get timer ticks until it has been scheduled.
* So, we disable interrupts around the sigsetjmp to ensure that
* they can't happen until we get back here where they are safe.
*/
flags = get_signals();
block_signals();
if(sigsetjmp(fork_buf, 1) == 0)
new_thread_proc(stack, handler);
remove_sigstack();
set_signals(flags);
}
void thread_wait(void *sw, void *fb)
{
sigjmp_buf buf, **switch_buf = sw, *fork_buf;
*switch_buf = &buf;
fork_buf = fb;
if(sigsetjmp(buf, 1) == 0)
siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
}
void switch_threads(void *me, void *next)
{
sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
*me_ptr = &my_buf;
if(sigsetjmp(my_buf, 1) == 0)
siglongjmp(*next_buf, 1);
}
static sigjmp_buf initial_jmpbuf;
/* XXX Make these percpu */
static void (*cb_proc)(void *arg);
static void *cb_arg;
static sigjmp_buf *cb_back;
int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
{
sigjmp_buf **switch_buf = switch_buf_ptr;
int n;
set_handler(SIGWINCH, (__sighandler_t) sig_handler,
SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
SIGVTALRM, -1);
*fork_buf_ptr = &initial_jmpbuf;
n = sigsetjmp(initial_jmpbuf, 1);
switch(n){
case INIT_JMP_NEW_THREAD:
new_thread_proc((void *) stack, new_thread_handler);
break;
case INIT_JMP_REMOVE_SIGSTACK:
remove_sigstack();
break;
case INIT_JMP_CALLBACK:
(*cb_proc)(cb_arg);
siglongjmp(*cb_back, 1);
break;
case INIT_JMP_HALT:
kmalloc_ok = 0;
return(0);
case INIT_JMP_REBOOT:
kmalloc_ok = 0;
return(1);
default:
panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
}
siglongjmp(**switch_buf, 1);
}
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);
}
void initial_thread_cb_skas(void (*proc)(void *), void *arg)
{
sigjmp_buf here;
cb_proc = proc;
cb_arg = arg;
cb_back = &here;
block_signals();
if(sigsetjmp(here, 1) == 0)
siglongjmp(initial_jmpbuf, INIT_JMP_CALLBACK);
unblock_signals();
cb_proc = NULL;
cb_arg = NULL;
cb_back = NULL;
}
void halt_skas(void)
{
block_signals();
siglongjmp(initial_jmpbuf, INIT_JMP_HALT);
}
void reboot_skas(void)
{
block_signals();
siglongjmp(initial_jmpbuf, INIT_JMP_REBOOT);
}
void switch_mm_skas(int mm_fd)
{
int err;
#warning need cpu pid in switch_mm_skas
err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0, mm_fd);
if(err)
panic("switch_mm_skas - PTRACE_SWITCH_MM failed, errno = %d\n",
errno);
}
void kill_off_processes_skas(void)
{
#warning need to loop over userspace_pids in kill_off_processes_skas
os_kill_ptraced_process(userspace_pid[0], 1);
}
/*
* 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:
*/
