return 0;
}
+static long
+ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
+ unsigned long user_rbs_start, unsigned long user_rbs_end)
+{
+ unsigned long addr, val;
+ long ret;
+
+ /* now copy word for word from user rbs to kernel rbs: */
+ for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
+ if (access_process_vm(child, addr, &val, sizeof(val), 0)
+ != sizeof(val))
+ return -EIO;
+
+ ret = ia64_poke(child, sw, user_rbs_end, addr, val);
+ if (ret < 0)
+ return ret;
+ }
+ return 0;
+}
+
+typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *,
+ unsigned long, unsigned long);
+
+static void do_sync_rbs(struct unw_frame_info *info, void *arg)
+{
+ struct pt_regs *pt;
+ unsigned long urbs_end;
+ syncfunc_t fn = arg;
+
+ if (unw_unwind_to_user(info) < 0)
+ return;
+ pt = task_pt_regs(info->task);
+ urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL);
+
+ fn(info->task, info->sw, pt->ar_bspstore, urbs_end);
+}
+
+/*
+ * when a thread is stopped (ptraced), debugger might change thread's user
+ * stack (change memory directly), and we must avoid the RSE stored in kernel
+ * to override user stack (user space's RSE is newer than kernel's in the
+ * case). To workaround the issue, we copy kernel RSE to user RSE before the
+ * task is stopped, so user RSE has updated data. we then copy user RSE to
+ * kernel after the task is resummed from traced stop and kernel will use the
+ * newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need
+ * synchronize user RSE to kernel.
+ */
+void ia64_ptrace_stop(void)
+{
+ if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE))
+ return;
+ tsk_set_notify_resume(current);
+ unw_init_running(do_sync_rbs, ia64_sync_user_rbs);
+}
+
+/*
+ * This is called to read back the register backing store.
+ */
+void ia64_sync_krbs(void)
+{
+ clear_tsk_thread_flag(current, TIF_RESTORE_RSE);
+ tsk_clear_notify_resume(current);
+
+ unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
+}
+
+/*
+ * After PTRACE_ATTACH, a thread's register backing store area in user
+ * space is assumed to contain correct data whenever the thread is
+ * stopped. arch_ptrace_stop takes care of this on tracing stops.
+ * But if the child was already stopped for job control when we attach
+ * to it, then it might not ever get into ptrace_stop by the time we
+ * want to examine the user memory containing the RBS.
+ */
+void
+ptrace_attach_sync_user_rbs (struct task_struct *child)
+{
+ int stopped = 0;
+ struct unw_frame_info info;
+
+ /*
+ * If the child is in TASK_STOPPED, we need to change that to
+ * TASK_TRACED momentarily while we operate on it. This ensures
+ * that the child won't be woken up and return to user mode while
+ * we are doing the sync. (It can only be woken up for SIGKILL.)
+ */
+
+ read_lock(&tasklist_lock);
+ if (child->signal) {
+ spin_lock_irq(&child->sighand->siglock);
+ if (child->state == TASK_STOPPED &&
+ !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
+ tsk_set_notify_resume(child);
+
+ child->state = TASK_TRACED;
+ stopped = 1;
+ }
+ spin_unlock_irq(&child->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
+
+ if (!stopped)
+ return;
+
+ unw_init_from_blocked_task(&info, child);
+ do_sync_rbs(&info, ia64_sync_user_rbs);
+
+ /*
+ * Now move the child back into TASK_STOPPED if it should be in a
+ * job control stop, so that SIGCONT can be used to wake it up.
+ */
+ read_lock(&tasklist_lock);
+ if (child->signal) {
+ spin_lock_irq(&child->sighand->siglock);
+ if (child->state == TASK_TRACED &&
+ (child->signal->flags & SIGNAL_STOP_STOPPED)) {
+ child->state = TASK_STOPPED;
+ }
+ spin_unlock_irq(&child->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
+}
+
static inline int
thread_matches (struct task_struct *thread, unsigned long addr)
{
return 1; /* looks like we've got a winner */
}
-/*
- * GDB apparently wants to be able to read the register-backing store
- * of any thread when attached to a given process. If we are peeking
- * or poking an address that happens to reside in the kernel-backing
- * store of another thread, we need to attach to that thread, because
- * otherwise we end up accessing stale data.
- *
- * task_list_lock must be read-locked before calling this routine!
- */
-static struct task_struct *
-find_thread_for_addr (struct task_struct *child, unsigned long addr)
-{
- struct task_struct *p;
- struct mm_struct *mm;
- struct list_head *this, *next;
- int mm_users;
-
- if (!(mm = get_task_mm(child)))
- return child;
-
- /* -1 because of our get_task_mm(): */
- mm_users = atomic_read(&mm->mm_users) - 1;
- if (mm_users <= 1)
- goto out; /* not multi-threaded */
-
- /*
- * Traverse the current process' children list. Every task that
- * one attaches to becomes a child. And it is only attached children
- * of the debugger that are of interest (ptrace_check_attach checks
- * for this).
- */
- list_for_each_safe(this, next, ¤t->children) {
- p = list_entry(this, struct task_struct, sibling);
- if (p->tgid != child->tgid)
- continue;
- if (thread_matches(p, addr)) {
- child = p;
- goto out;
- }
- }
-
- out:
- mmput(mm);
- return child;
-}
-
/*
* Write f32-f127 back to task->thread.fph if it has been modified.
*/
if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
< IA64_PT_REGS_SIZE) {
dprintk("ptrace.%s: ran off the top of the kernel "
- "stack\n", __FUNCTION__);
+ "stack\n", __func__);
return;
}
if (unw_get_pr (&prev_info, &pr) < 0) {
unw_get_rp(&prev_info, &ip);
dprintk("ptrace.%s: failed to read "
"predicate register (ip=0x%lx)\n",
- __FUNCTION__, ip);
+ __func__, ip);
return;
}
if (unw_is_intr_frame(&info)
access_uarea (struct task_struct *child, unsigned long addr,
unsigned long *data, int write_access)
{
- unsigned long *ptr, regnum, urbs_end, rnat_addr, cfm;
+ unsigned long *ptr, regnum, urbs_end, cfm;
struct switch_stack *sw;
struct pt_regs *pt;
# define pt_reg_addr(pt, reg) ((void *) \
* the kernel was entered.
*
* Furthermore, when changing the contents of
- * PT_AR_BSP (or PT_CFM) we MUST copy any
- * users-level stacked registers that are
- * stored on the kernel stack back to
- * user-space because otherwise, we might end
- * up clobbering kernel stacked registers.
- * Also, if this happens while the task is
- * blocked in a system call, which convert the
- * state such that the non-system-call exit
+ * PT_AR_BSP (or PT_CFM) while the task is
+ * blocked in a system call, convert the state
+ * so that the non-system-call exit
* path is used. This ensures that the proper
* state will be picked up when resuming
* execution. However, it *also* means that
urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
if (write_access) {
if (*data != urbs_end) {
- if (ia64_sync_user_rbs(child, sw,
- pt->ar_bspstore,
- urbs_end) < 0)
- return -1;
if (in_syscall(pt))
convert_to_non_syscall(child,
pt,
urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
if (write_access) {
if (((cfm ^ *data) & PFM_MASK) != 0) {
- if (ia64_sync_user_rbs(child, sw,
- pt->ar_bspstore,
- urbs_end) < 0)
- return -1;
if (in_syscall(pt))
convert_to_non_syscall(child,
pt,
return 0;
case PT_CR_IPSR:
- if (write_access)
- pt->cr_ipsr = ((*data & IPSR_MASK)
+ if (write_access) {
+ unsigned long tmp = *data;
+ /* psr.ri==3 is a reserved value: SDM 2:25 */
+ if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
+ tmp &= ~IA64_PSR_RI;
+ pt->cr_ipsr = ((tmp & IPSR_MASK)
| (pt->cr_ipsr & ~IPSR_MASK));
- else
+ } else
*data = (pt->cr_ipsr & IPSR_MASK);
return 0;
return 0;
case PT_AR_RNAT:
- urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
- rnat_addr = (long) ia64_rse_rnat_addr((long *)
- urbs_end);
- if (write_access)
- return ia64_poke(child, sw, urbs_end,
- rnat_addr, *data);
- else
- return ia64_peek(child, sw, urbs_end,
- rnat_addr, data);
-
+ ptr = pt_reg_addr(pt, ar_rnat);
+ break;
case PT_R1:
ptr = pt_reg_addr(pt, r1);
break;
return ret;
}
-/*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure the single step bit is not set.
- */
void
-ptrace_disable (struct task_struct *child)
+user_enable_single_step (struct task_struct *child)
{
struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
- /* make sure the single step/taken-branch trap bits are not set: */
- clear_tsk_thread_flag(child, TIF_SINGLESTEP);
- child_psr->ss = 0;
- child_psr->tb = 0;
+ set_tsk_thread_flag(child, TIF_SINGLESTEP);
+ child_psr->ss = 1;
}
-asmlinkage long
-sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
+void
+user_enable_block_step (struct task_struct *child)
{
- struct pt_regs *pt;
- unsigned long urbs_end, peek_or_poke;
- struct task_struct *child;
- struct switch_stack *sw;
- long ret;
+ struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
- lock_kernel();
- ret = -EPERM;
- if (request == PTRACE_TRACEME) {
- ret = ptrace_traceme();
- goto out;
- }
+ set_tsk_thread_flag(child, TIF_SINGLESTEP);
+ child_psr->tb = 1;
+}
- peek_or_poke = (request == PTRACE_PEEKTEXT
- || request == PTRACE_PEEKDATA
- || request == PTRACE_POKETEXT
- || request == PTRACE_POKEDATA);
- ret = -ESRCH;
- read_lock(&tasklist_lock);
- {
- child = find_task_by_pid(pid);
- if (child) {
- if (peek_or_poke)
- child = find_thread_for_addr(child, addr);
- get_task_struct(child);
- }
- }
- read_unlock(&tasklist_lock);
- if (!child)
- goto out;
- ret = -EPERM;
- if (pid == 1) /* no messing around with init! */
- goto out_tsk;
-
- if (request == PTRACE_ATTACH) {
- ret = ptrace_attach(child);
- goto out_tsk;
- }
+void
+user_disable_single_step (struct task_struct *child)
+{
+ struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
- ret = ptrace_check_attach(child, request == PTRACE_KILL);
- if (ret < 0)
- goto out_tsk;
+ /* make sure the single step/taken-branch trap bits are not set: */
+ clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+ child_psr->ss = 0;
+ child_psr->tb = 0;
+}
- pt = task_pt_regs(child);
- sw = (struct switch_stack *) (child->thread.ksp + 16);
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void
+ptrace_disable (struct task_struct *child)
+{
+ user_disable_single_step(child);
+}
+long
+arch_ptrace (struct task_struct *child, long request, long addr, long data)
+{
switch (request) {
- case PTRACE_PEEKTEXT:
- case PTRACE_PEEKDATA:
+ case PTRACE_PEEKTEXT:
+ case PTRACE_PEEKDATA:
/* read word at location addr */
- urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
- ret = ia64_peek(child, sw, urbs_end, addr, &data);
- if (ret == 0) {
- ret = data;
- /* ensure "ret" is not mistaken as an error code: */
- force_successful_syscall_return();
- }
- goto out_tsk;
+ if (access_process_vm(child, addr, &data, sizeof(data), 0)
+ != sizeof(data))
+ return -EIO;
+ /* ensure return value is not mistaken for error code */
+ force_successful_syscall_return();
+ return data;
- case PTRACE_POKETEXT:
- case PTRACE_POKEDATA:
- /* write the word at location addr */
- urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
- ret = ia64_poke(child, sw, urbs_end, addr, data);
- goto out_tsk;
+ /* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
+ * by the generic ptrace_request().
+ */
- case PTRACE_PEEKUSR:
+ case PTRACE_PEEKUSR:
/* read the word at addr in the USER area */
- if (access_uarea(child, addr, &data, 0) < 0) {
- ret = -EIO;
- goto out_tsk;
- }
- ret = data;
- /* ensure "ret" is not mistaken as an error code */
+ if (access_uarea(child, addr, &data, 0) < 0)
+ return -EIO;
+ /* ensure return value is not mistaken for error code */
force_successful_syscall_return();
- goto out_tsk;
+ return data;
- case PTRACE_POKEUSR:
+ case PTRACE_POKEUSR:
/* write the word at addr in the USER area */
- if (access_uarea(child, addr, &data, 1) < 0) {
- ret = -EIO;
- goto out_tsk;
- }
- ret = 0;
- goto out_tsk;
+ if (access_uarea(child, addr, &data, 1) < 0)
+ return -EIO;
+ return 0;
- case PTRACE_OLD_GETSIGINFO:
+ case PTRACE_OLD_GETSIGINFO:
/* for backwards-compatibility */
- ret = ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
- goto out_tsk;
+ return ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
- case PTRACE_OLD_SETSIGINFO:
+ case PTRACE_OLD_SETSIGINFO:
/* for backwards-compatibility */
- ret = ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
- goto out_tsk;
-
- case PTRACE_SYSCALL:
- /* continue and stop at next (return from) syscall */
- case PTRACE_CONT:
- /* restart after signal. */
- ret = -EIO;
- if (!valid_signal(data))
- goto out_tsk;
- if (request == PTRACE_SYSCALL)
- set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- else
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->exit_code = data;
+ return ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
- /*
- * Make sure the single step/taken-branch trap bits
- * are not set:
- */
- clear_tsk_thread_flag(child, TIF_SINGLESTEP);
- ia64_psr(pt)->ss = 0;
- ia64_psr(pt)->tb = 0;
+ case PTRACE_GETREGS:
+ return ptrace_getregs(child,
+ (struct pt_all_user_regs __user *) data);
- wake_up_process(child);
- ret = 0;
- goto out_tsk;
+ case PTRACE_SETREGS:
+ return ptrace_setregs(child,
+ (struct pt_all_user_regs __user *) data);
- case PTRACE_KILL:
- /*
- * Make the child exit. Best I can do is send it a
- * sigkill. Perhaps it should be put in the status
- * that it wants to exit.
- */
- if (child->exit_state == EXIT_ZOMBIE)
- /* already dead */
- goto out_tsk;
- child->exit_code = SIGKILL;
-
- ptrace_disable(child);
- wake_up_process(child);
- ret = 0;
- goto out_tsk;
-
- case PTRACE_SINGLESTEP:
- /* let child execute for one instruction */
- case PTRACE_SINGLEBLOCK:
- ret = -EIO;
- if (!valid_signal(data))
- goto out_tsk;
-
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- set_tsk_thread_flag(child, TIF_SINGLESTEP);
- if (request == PTRACE_SINGLESTEP) {
- ia64_psr(pt)->ss = 1;
- } else {
- ia64_psr(pt)->tb = 1;
- }
- child->exit_code = data;
-
- /* give it a chance to run. */
- wake_up_process(child);
- ret = 0;
- goto out_tsk;
-
- case PTRACE_DETACH:
- /* detach a process that was attached. */
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- ret = ptrace_detach(child, data);
- goto out_tsk;
-
- case PTRACE_GETREGS:
- ret = ptrace_getregs(child,
- (struct pt_all_user_regs __user *) data);
- goto out_tsk;
-
- case PTRACE_SETREGS:
- ret = ptrace_setregs(child,
- (struct pt_all_user_regs __user *) data);
- goto out_tsk;
-
- default:
- ret = ptrace_request(child, request, addr, data);
- goto out_tsk;
+ default:
+ return ptrace_request(child, request, addr, data);
}
- out_tsk:
- put_task_struct(child);
- out:
- unlock_kernel();
- return ret;
}
&& (current->ptrace & PT_PTRACED))
syscall_trace();
+ /* copy user rbs to kernel rbs */
+ if (test_thread_flag(TIF_RESTORE_RSE))
+ ia64_sync_krbs();
+
if (unlikely(current->audit_context)) {
long syscall;
int arch;
|| test_thread_flag(TIF_SINGLESTEP))
&& (current->ptrace & PT_PTRACED))
syscall_trace();
+
+ /* copy user rbs to kernel rbs */
+ if (test_thread_flag(TIF_RESTORE_RSE))
+ ia64_sync_krbs();
}
projects / linux-2.6 / blobdiff