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| author | Josh Stone <jistone@redhat.com> | 2009-09-17 18:35:12 -0700 |
|---|---|---|
| committer | Josh Stone <jistone@redhat.com> | 2009-09-17 18:35:12 -0700 |
| commit | a9b593471a5d22c820333938d4c4210efd63bd3a (patch) | |
| tree | cd8b863d70edc5f47bdd6a2e439a4238b014553f /tapsets.cxx | |
| parent | 5c34cc891d6929ff9cd52b6fe725873c181b094e (diff) | |
| download | systemtap-steved-a9b593471a5d22c820333938d4c4210efd63bd3a.tar.gz systemtap-steved-a9b593471a5d22c820333938d4c4210efd63bd3a.tar.xz systemtap-steved-a9b593471a5d22c820333938d4c4210efd63bd3a.zip | |
Simplify the sdt semaphore decrement in utrace
The decrement can happen at the same time that the utrace detach is
called. However, I'm concerned that this code isn't correctly handling
the case where multiple tasks may register the same probe, so for now
I've noted those places. I think task finder may have to help in fixing
this...
* tapset-utrace.cxx (utrace_derived_probe_group::emit_module_init): As
noted in uprobes-land, there's no need to tear down anything.
(utrace_derived_probe_group::emit_module_exit): Unify the detach and
semaphore decrement, and note a concern about multiple tasks.
(utrace_derived_probe_group::emit_module_decls): Note same concern.
* tapsets.cxx (uprobe_derived_probe_group::emit_module_decls): Ditto.
(uprobe_derived_probe_group::emit_module_exit): Ditto.
Diffstat (limited to 'tapsets.cxx')
| -rw-r--r-- | tapsets.cxx | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tapsets.cxx b/tapsets.cxx index ed9e1d56..03239ad6 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -4623,6 +4623,7 @@ uprobe_derived_probe_group::emit_module_decls (systemtap_session& s) //---------- s.op->newline() << "if (sups->sdt_sem_address != 0) {"; s.op->newline(1) << "size_t sdt_semaphore;"; + // XXX sups could get registered to more than one task! s.op->newline() << "sups->tsk = tsk;"; s.op->newline() << "__access_process_vm (tsk, relocation + sups->sdt_sem_address, &sdt_semaphore, sizeof (sdt_semaphore), 0);"; s.op->newline() << "sdt_semaphore += 1;"; @@ -4717,6 +4718,7 @@ uprobe_derived_probe_group::emit_module_decls (systemtap_session& s) //---------- s.op->newline() << "if (sups->sdt_sem_address != 0) {"; s.op->newline(1) << "size_t sdt_semaphore;"; + // XXX sups could get registered to more than one task! s.op->newline() << "sups->tsk = tsk;"; s.op->newline() << "__access_process_vm (tsk, sups->sdt_sem_address, &sdt_semaphore, sizeof (sdt_semaphore), 0);"; s.op->newline() << "sdt_semaphore += 1;"; @@ -4850,6 +4852,7 @@ uprobe_derived_probe_group::emit_module_exit (systemtap_session& s) //---------- s.op->newline() << "if (sups->sdt_sem_address != 0) {"; s.op->newline(1) << "size_t sdt_semaphore;"; + // XXX sups could get registered to more than one task! s.op->newline() << "__access_process_vm (sups->tsk, sups->sdt_sem_address, &sdt_semaphore, sizeof (sdt_semaphore), 0);"; s.op->newline() << "sdt_semaphore -= 1;"; s.op->newline() << "__access_process_vm (sups->tsk, sups->sdt_sem_address, &sdt_semaphore, sizeof (sdt_semaphore), 1);"; |