void destroy_context(struct mm_struct *mm)
{
struct mm_context *mmu = &mm->context;
if (proc_mm)
os_close_file(mmu->id.u.mm_fd);
else {
/*
* If init_new_context wasn't called, this will be
* zero, resulting in a kill(0), which will result in the
* whole UML suddenly dying. Also, cover negative and
* 1 cases, since they shouldn't happen either.
*/
if (mmu->id.u.pid < 2) {
printk(KERN_ERR "corrupt mm_context - pid = %d\n",
mmu->id.u.pid);
return;
}
os_kill_ptraced_process(mmu->id.u.pid, 1);
}
if (skas_needs_stub)
free_page(mmu->id.stack);
free_ldt(mmu);
}
void do_exec(int old_pid, int new_pid)
{
unsigned long regs[FRAME_SIZE];
int err;
if((ptrace(PTRACE_ATTACH, new_pid, 0, 0) < 0) ||
(ptrace(PTRACE_CONT, new_pid, 0, 0) < 0))
tracer_panic("do_exec failed to attach proc - errno = %d",
errno);
CATCH_EINTR(err = waitpid(new_pid, 0, WUNTRACED));
if (err < 0)
tracer_panic("do_exec failed to attach proc in waitpid - errno = %d",
errno);
if(ptrace_getregs(old_pid, regs) < 0)
tracer_panic("do_exec failed to get registers - errno = %d",
errno);
os_kill_ptraced_process(old_pid, 0);
if (ptrace(PTRACE_OLDSETOPTIONS, new_pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
tracer_panic("do_exec: PTRACE_SETOPTIONS failed, errno = %d", errno);
if(ptrace_setregs(new_pid, regs) < 0)
tracer_panic("do_exec failed to start new proc - errno = %d",
errno);
}
static void kill_off_processes(void)
{
if (proc_mm)
os_kill_ptraced_process(userspace_pid[0], 1);
else {
struct task_struct *p;
int pid;
for_each_process(p) {
if (p->mm == NULL)
continue;
pid = p->mm->context.id.u.pid;
os_kill_ptraced_process(pid, 1);
}
}
}
void kill_off_processes_skas(void)
{
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;
me = os_getpid();
for_each_process(p){
if(p->mm == NULL)
continue;
pid = p->mm->context.skas.id.u.pid;
os_kill_ptraced_process(pid, 1);
}
}
}
static void kill_off_processes(void)
{
if (proc_mm)
/*
* FIXME: need to loop over userspace_pids
*/
os_kill_ptraced_process(userspace_pid[0], 1);
else {
struct task_struct *p;
int pid, me;
me = os_getpid();
for_each_process(p) {
if (p->mm == NULL)
continue;
pid = p->mm->context.id.u.pid;
os_kill_ptraced_process(pid, 1);
}
}
}
static void kill_off_processes(void)
{
if (proc_mm)
/*
* FIXME: need to loop over userspace_pids
*/
os_kill_ptraced_process(userspace_pid[0], 1);
else {
struct task_struct *p;
<<<<<<< HEAD
int pid;
=======
<<<<<<< HEAD
static void kill_off_processes(void)
{
struct task_struct *p;
int pid;
read_lock(&tasklist_lock);
for_each_process(p) {
struct task_struct *t;
t = find_lock_task_mm(p);
if (!t)
continue;
pid = t->mm->context.id.u.pid;
task_unlock(t);
os_kill_ptraced_process(pid, 1);
}
read_unlock(&tasklist_lock);
}
void destroy_context_skas(struct mm_struct *mm)
{
struct mmu_context_skas *mmu = &mm->context.skas;
if(proc_mm)
os_close_file(mmu->id.u.mm_fd);
else
os_kill_ptraced_process(mmu->id.u.pid, 1);
if(!proc_mm || !ptrace_faultinfo){
free_page(mmu->id.stack);
pte_lock_deinit(virt_to_page(mmu->last_page_table));
pte_free_kernel((pte_t *) mmu->last_page_table);
dec_zone_page_state(virt_to_page(mmu->last_page_table), NR_PAGETABLE);
#ifdef CONFIG_3_LEVEL_PGTABLES
pmd_free((pmd_t *) mmu->last_pmd);
#endif
}
}
void os_dump_core(void)
{
int pid;
signal(SIGSEGV, SIG_DFL);
/*
* We are about to SIGTERM this entire process group to ensure that
* nothing is around to run after the kernel exits. The
* kernel wants to abort, not die through SIGTERM, so we
* ignore it here.
*/
signal(SIGTERM, SIG_IGN);
kill(0, SIGTERM);
/*
* Most of the other processes associated with this UML are
* likely sTopped, so give them a SIGCONT so they see the
* SIGTERM.
*/
kill(0, SIGCONT);
/*
* Now, having sent signals to everyone but us, make sure they
* die by ptrace. Processes can survive what's been done to
* them so far - the mechanism I understand is receiving a
* SIGSEGV and segfaulting immediately upon return. There is
* always a SIGSEGV pending, and (I'm guessing) signals are
* processed in numeric order so the SIGTERM (signal 15 vs
* SIGSEGV being signal 11) is never handled.
*
* Run a waitpid loop until we get some kind of error.
* Hopefully, it's ECHILD, but there's not a lot we can do if
* it's something else. Tell os_kill_ptraced_process not to
* wait for the child to report its death because there's
* nothing reasonable to do if that fails.
*/
while ((pid = waitpid(-1, NULL, WNOHANG)) > 0)
os_kill_ptraced_process(pid, 0);
abort();
}
void *switch_to_tt(void *prev, void *next, void *last)
{
struct task_struct *from, *to, *prev_sched;
unsigned long flags;
int err, vtalrm, alrm, prof, cpu;
char c;
/* jailing and SMP are incompatible, so this doesn't need to be
* made per-cpu
*/
static int reading;
from = prev;
to = next;
to->thread.prev_sched = from;
cpu = from->thread_info->cpu;
if(cpu == 0)
forward_interrupts(to->thread.mode.tt.extern_pid);
#ifdef CONFIG_SMP
forward_ipi(cpu_data[cpu].ipi_pipe[0], to->thread.mode.tt.extern_pid);
#endif
local_irq_save(flags);
vtalrm = change_sig(SIGVTALRM, 0);
alrm = change_sig(SIGALRM, 0);
prof = change_sig(SIGPROF, 0);
forward_pending_sigio(to->thread.mode.tt.extern_pid);
c = 0;
set_current(to);
reading = 0;
err = os_write_file(to->thread.mode.tt.switch_pipe[1], &c, sizeof(c));
if(err != sizeof(c))
panic("write of switch_pipe failed, err = %d", -err);
reading = 1;
if((from->exit_state == EXIT_ZOMBIE) || (from->exit_state == EXIT_DEAD))
os_kill_process(os_getpid(), 0);
err = os_read_file(from->thread.mode.tt.switch_pipe[0], &c, sizeof(c));
if(err != sizeof(c))
panic("read of switch_pipe failed, errno = %d", -err);
/* If the process that we have just scheduled away from has exited,
* then it needs to be killed here. The reason is that, even though
* it will kill itself when it next runs, that may be too late. Its
* stack will be freed, possibly before then, and if that happens,
* we have a use-after-free situation. So, it gets killed here
* in case it has not already killed itself.
*/
prev_sched = current->thread.prev_sched;
if((prev_sched->exit_state == EXIT_ZOMBIE) ||
(prev_sched->exit_state == EXIT_DEAD))
os_kill_ptraced_process(prev_sched->thread.mode.tt.extern_pid, 1);
/* This works around a nasty race with 'jail'. If we are switching
* between two threads of a threaded app and the incoming process
* runs before the outgoing process reaches the read, and it makes
* it all the way out to userspace, then it will have write-protected
* the outgoing process stack. Then, when the outgoing process
* returns from the write, it will segfault because it can no longer
* write its own stack. So, in order to avoid that, the incoming
* thread sits in a loop yielding until 'reading' is set. This
* isn't entirely safe, since there may be a reschedule from a timer
* happening between setting 'reading' and sleeping in read. But,
* it should get a whole quantum in which to reach the read and sleep,
* which should be enough.
*/
if(jail){
while(!reading) sched_yield();
}
change_sig(SIGVTALRM, vtalrm);
change_sig(SIGALRM, alrm);
change_sig(SIGPROF, prof);
arch_switch();
flush_tlb_all();
local_irq_restore(flags);
return(current->thread.prev_sched);
}
