On Tue, 4 Feb 2014 18:28:52 -0500
Steven Rostedt <rost...@goodmis.org> wrote:
> At least this patch keeps the ugliness with the code. I could even
> encapsulate that in a static inline function to remove the ugliness out
> of exec_binprm().
New version that moves all the ugliness into a static inline helper
function.
I'll start testing this and the added helper, and if there's no
problems or arguments from you, I'll post them tomorrow.
-- Steve
diff --git a/fs/exec.c b/fs/exec.c
index e1529b4..06101e9 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1407,6 +1407,36 @@ int search_binary_handler(struct linux_binprm *bprm)
}
EXPORT_SYMBOL(search_binary_handler);
+static __always_inline void
+do_trace_sched_process_exec(pid_t old_pid, struct linux_binprm *bprm)
+{
+ char *pathname;
+ char *tmp;
+
+ /*
+ * We can't use bprm->filename here because it can be freed
+ * within the search_binary_handler() call (by mm_release()
+ * waking up the cgroup call_usermodehelper parent, that
+ * will free what bprm->filename points to). Instead, if
+ * the sched_process_exec tracepoint is enabled, we need
+ * to create the pathname from the file dentry pointer.
+ */
+ if (tracepoint_enabled(sched_process_exec)) {
+ tmp = (char*)__get_free_page(GFP_TEMPORARY);
+ if (tmp)
+ pathname = dentry_path_raw(bprm->file->f_dentry,
+ tmp, PAGE_SIZE);
+ else
+ pathname = ERR_PTR(-ENOMEM);
+ if (IS_ERR(pathname))
+ trace_sched_process_exec(current, old_pid,
+ "//error-no-mem");
+ else
+ trace_sched_process_exec(current, old_pid, pathname);
+ free_page((unsigned long)tmp);
+ }
+}
+
static int exec_binprm(struct linux_binprm *bprm)
{
pid_t old_pid, old_vpid;
@@ -1421,7 +1451,7 @@ static int exec_binprm(struct linux_binprm *bprm)
ret = search_binary_handler(bprm);
if (ret >= 0) {
audit_bprm(bprm);
- trace_sched_process_exec(current, old_pid, bprm);
+ do_trace_sched_process_exec(old_pid, bprm);
ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
proc_exec_connector(current);
}
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 67e1bbf..520ba9a 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -282,18 +282,18 @@ TRACE_EVENT(sched_process_fork,
TRACE_EVENT(sched_process_exec,
TP_PROTO(struct task_struct *p, pid_t old_pid,
- struct linux_binprm *bprm),
+ const char *pathname),
- TP_ARGS(p, old_pid, bprm),
+ TP_ARGS(p, old_pid, pathname),
TP_STRUCT__entry(
- __string( filename, bprm->filename )
+ __string( filename, pathname )
__field( pid_t, pid )
__field( pid_t, old_pid )
),
TP_fast_assign(
- __assign_str(filename, bprm->filename);
+ __assign_str(filename, pathname);
__entry->pid = p->pid;
__entry->old_pid = old_pid;
),
--
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