summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorOleg Nesterov <oleg@redhat.com>2014-06-27 19:01:36 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-09 11:21:31 -0700
commitd197dca0ebbc2a93c8cffcd7ab15f40b69a9eb3a (patch)
treefbc464e172dfc1a729b89726efa7d8b0d66fd186 /kernel
parent4a48e173c310f84103984dce2b7202973db9e6fc (diff)
tracing/uprobes: Revert "Support mix of ftrace and perf"
commit 48212542067a7ff6cbe829dbae279c2ff7557b44 upstream. 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> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 c082a7441345..59f7991c39c2 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)