diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | runtime/ChangeLog | 6 | ||||
| -rw-r--r-- | runtime/task_finder.c | 4 | ||||
| -rw-r--r-- | tapsets.cxx | 30 |
4 files changed, 42 insertions, 7 deletions
@@ -1,3 +1,12 @@ +2008-08-19 David Smith <dsmith@redhat.com> + + PR 6841 + * tapsets.cxx (utrace_derived_probe_group::emit_probe_decl): + Workaround utrace bug by quiescing threads before attaching a + utrace syscall engine to them. + (utrace_derived_probe_group::emit_module_decls): Emit quiesce + handler. + 2008-08-18 David Smith <dsmith@redhat.com> * tapsets.cxx (register_standard_tapsets): Add missing diff --git a/runtime/ChangeLog b/runtime/ChangeLog index 58678de5..796f812c 100644 --- a/runtime/ChangeLog +++ b/runtime/ChangeLog @@ -1,3 +1,9 @@ +2008-08-19 David Smith <dsmith@redhat.com> + + PR 6841 + * task_finder.c (__stp_utrace_task_finder_target_quiesce): + Quiesces thread before turning on syscall tracing. + 2008-08-14 Frank Ch. Eigler <fche@elastic.org> PR 6842. diff --git a/runtime/task_finder.c b/runtime/task_finder.c index 928b7087..d7450a41 100644 --- a/runtime/task_finder.c +++ b/runtime/task_finder.c @@ -317,7 +317,7 @@ __stp_get_mm_path(struct mm_struct *mm, char *buf, int buflen) | UTRACE_EVENT(SYSCALL_ENTRY) \ | UTRACE_EVENT(SYSCALL_EXIT)) -#define __STP_ATTACHED_TASK_VM_EVENTS (__STP_ATTACHED_TASK_VM_BASE_EVENTS \ +#define __STP_ATTACHED_TASK_VM_EVENTS (__STP_ATTACHED_TASK_BASE_EVENTS \ | UTRACE_ACTION_QUIESCE \ | UTRACE_EVENT(QUIESCE)) @@ -608,7 +608,7 @@ __stp_utrace_task_finder_target_quiesce(struct utrace_attached_engine *engine, { struct stap_task_finder_target *tgt = engine->data; - // Turn off quiesce handling. + // Turn off quiesce handling (and turn on syscall handling). utrace_set_flags(tsk, engine, __STP_ATTACHED_TASK_VM_BASE_EVENTS); if (atomic_read(&__stp_task_finder_state) != __STP_TF_RUNNING) { diff --git a/tapsets.cxx b/tapsets.cxx index 39fc0074..36601b01 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -6096,17 +6096,19 @@ utrace_derived_probe_group::emit_probe_decl (systemtap_session& s, // For UDPF_SYSCALL/UDPF_SYSCALL_RETURN probes, the .report_death // handler isn't strictly necessary. However, it helps to keep - // our attaches/detaches symmetrical. + // our attaches/detaches symmetrical. Notice we're using quiesce + // as a workaround for bug 6841. case UDPF_SYSCALL: s.op->line() << " .flags=(UDPF_SYSCALL),"; - s.op->line() << " .ops={ .report_syscall_entry=stap_utrace_probe_syscall, .report_death=stap_utrace_task_finder_report_death },"; - s.op->line() << " .events=(UTRACE_EVENT(SYSCALL_ENTRY)|UTRACE_EVENT(DEATH)),"; + s.op->line() << " .ops={ .report_syscall_entry=stap_utrace_probe_syscall, .report_death=stap_utrace_task_finder_report_death, .report_quiesce=stap_utrace_probe_syscall_quiesce },"; + s.op->line() << " .events=(UTRACE_ACTION_QUIESCE|UTRACE_EVENT(QUIESCE)|UTRACE_EVENT(DEATH)),"; break; case UDPF_SYSCALL_RETURN: s.op->line() << " .flags=(UDPF_SYSCALL_RETURN),"; - s.op->line() << " .ops={ .report_syscall_exit=stap_utrace_probe_syscall, .report_death=stap_utrace_task_finder_report_death },"; - s.op->line() << " .events=(UTRACE_EVENT(SYSCALL_EXIT)|UTRACE_EVENT(DEATH)),"; + s.op->line() << " .ops={ .report_syscall_exit=stap_utrace_probe_syscall, .report_death=stap_utrace_task_finder_report_death, .report_quiesce=stap_utrace_probe_syscall_quiesce },"; + s.op->line() << " .events=(UTRACE_ACTION_QUIESCE|UTRACE_EVENT(QUIESCE)|UTRACE_EVENT(DEATH)),"; break; + case UDPF_NONE: s.op->line() << " .flags=(UDPF_NONE),"; s.op->line() << " .ops={ },"; @@ -6228,6 +6230,24 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s) // Output handler function for SYSCALL_ENTRY and SYSCALL_EXIT events if (flags_seen[UDPF_SYSCALL] || flags_seen[UDPF_SYSCALL_RETURN]) { + s.op->newline() << "static u32 stap_utrace_probe_syscall_quiesce(struct utrace_attached_engine *engine, struct task_struct *tsk) {"; + s.op->indent(1); + s.op->newline() << "struct stap_utrace_probe *p = (struct stap_utrace_probe *)engine->data;"; + + // Turn off quiesce handling and turn on either syscall entry + // or exit events. + s.op->newline() << "if (p->flags == UDPF_SYSCALL)"; + s.op->indent(1); + s.op->newline() << "utrace_set_flags(tsk, engine, UTRACE_EVENT(SYSCALL_ENTRY)|UTRACE_EVENT(DEATH));"; + s.op->indent(-1); + s.op->newline() << "else if (p->flags == UDPF_SYSCALL_RETURN)"; + s.op->indent(1); + s.op->newline() << "utrace_set_flags(tsk, engine, UTRACE_EVENT(SYSCALL_EXIT)|UTRACE_EVENT(DEATH));"; + s.op->indent(-1); + + s.op->newline() << "return (UTRACE_ACTION_NEWSTATE | UTRACE_ACTION_RESUME);"; + s.op->newline(-1) << "}"; + s.op->newline() << "static u32 stap_utrace_probe_syscall(struct utrace_attached_engine *engine, struct task_struct *tsk, struct pt_regs *regs) {"; s.op->indent(1); s.op->newline() << "struct stap_utrace_probe *p = (struct stap_utrace_probe *)engine->data;"; |