diff options
| -rw-r--r-- | arch/ia64/kernel/ptrace.c | 57 | ||||
| -rw-r--r-- | include/asm-ia64/ptrace.h | 4 |
2 files changed, 61 insertions, 0 deletions
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 2de5a524a0ee..331d6768b5d5 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -613,6 +613,63 @@ void ia64_sync_krbs(void) 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) { diff --git a/include/asm-ia64/ptrace.h b/include/asm-ia64/ptrace.h index 13435f778b0c..0bdce7dde1b0 100644 --- a/include/asm-ia64/ptrace.h +++ b/include/asm-ia64/ptrace.h @@ -310,6 +310,10 @@ struct switch_stack { #define arch_ptrace_stop_needed(code, info) \ (!test_thread_flag(TIF_RESTORE_RSE)) + extern void ptrace_attach_sync_user_rbs (struct task_struct *); + #define arch_ptrace_attach(child) \ + ptrace_attach_sync_user_rbs(child) + #endif /* !__KERNEL__ */ /* pt_all_user_regs is used for PTRACE_GETREGS PTRACE_SETREGS */ |