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authorOleg Nesterov <oleg@redhat.com>2014-06-27 19:01:36 +0200
committerSteven Rostedt <rostedt@goodmis.org>2014-06-30 13:21:58 -0400
commit48212542067a7ff6cbe829dbae279c2ff7557b44 (patch)
treecddf954fff810ca3dd1e03b817e263357d2ee686 /kernel
parent4d4c9cc839a308be3289a361ccba4447ee140552 (diff)
downloadblackbird-op-linux-48212542067a7ff6cbe829dbae279c2ff7557b44.tar.gz
blackbird-op-linux-48212542067a7ff6cbe829dbae279c2ff7557b44.zip
tracing/uprobes: Revert "Support mix of ftrace and perf"
This reverts commit 43fe98913c9f67e3b523615ee3316f9520a623e0. This patch is very wrong. Firstly, this change leads to unbalanced uprobe_unregister(). Just for example, # perf probe -x /lib/libc.so.6 syscall # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable # perf record -e probe_libc:syscall whatever after that uprobe is dead (unregistered) but the user of ftrace/perf can't know this, and it looks as if nobody hits this probe. This would be easy to fix, but there are other reasons why it is not simple to mix ftrace and perf. If nothing else, they can't share the same ->consumer.filter. This is fixable too, but probably we need to fix the poorly designed uprobe_register() interface first. At least "register" and "apply" should be clearly separated. Link: http://lkml.kernel.org/p/20140627170136.GA18319@redhat.com Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com> Cc: stable@vger.kernel.org # v3.14 Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace_uprobe.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 04fdb5de823c..08e7970bf3f9 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -893,6 +893,9 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
int ret;
if (file) {
+ if (tu->tp.flags & TP_FLAG_PROFILE)
+ return -EINTR;
+
link = kmalloc(sizeof(*link), GFP_KERNEL);
if (!link)
return -ENOMEM;
@@ -901,8 +904,12 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
list_add_tail_rcu(&link->list, &tu->tp.files);
tu->tp.flags |= TP_FLAG_TRACE;
- } else
+ } else {
+ if (tu->tp.flags & TP_FLAG_TRACE)
+ return -EINTR;
+
tu->tp.flags |= TP_FLAG_PROFILE;
+ }
ret = uprobe_buffer_enable();
if (ret < 0)
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