Tracepoint: add exec tracepoint

RFC PATCH Superseded David Smith 1 participant 1 message Nov 7, 2011

Subsystems (3)

VFS Tracing exec and binfmt

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David Smith

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2011-11-07 19:49 UTC #0 lore raw

RFC PATCH v3 1/1 Tracepoint: add exec tracepoint

New version adds 'old_pid' parameter and improves ChangeLog description.
---
From: David Smith <[email protected]>

Added general purpose exec tracepoint. Exec is an important major event in the life of a task (like fork or exit). If you want to watch a task start up, when it gets exec'ed is a good place to start. With the addition of this tracepoint, exec's can be monitored and better picture of general system activity can be obtained. This tracepoint will also enable better process life tracking, allowing you to answer questions like "what process keeps starting up process X?".

This tracepoint can also be useful in ftrace filtering (i.e. starting or stopping filtering when exec is called)

Signed-off-by David Smith <[email protected]>

---
 fs/exec.c                    |    8 +++++++-
 include/trace/events/sched.h |   27 +++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletions(-)

fs/exec.c +7 -1

index 3625464..0059e82 100644
@@ -61,6 +61,8 @@
 #include <asm/tlb.h>
 #include "internal.h"
 
+#include <trace/events/sched.h>
+
 int core_uses_pid;
 char core_pattern[CORENAME_MAX_SIZE] = "core";
 unsigned int core_pipe_limit;

@@ -1397,9 +1399,13 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
                         */
                        bprm->recursion_depth = depth;
                        if (retval >= 0) {
-                               if (depth == 0)
+                               if (depth == 0) {
+                                       trace_sched_process_exec(current,
+                                                                old_pid,
+                                                                bprm);
                                        ptrace_event(PTRACE_EVENT_EXEC,
                                                        old_pid);
+                               }
                                put_binfmt(fmt);
                                allow_write_access(bprm->file);
                                if (bprm->file)

include/trace/events/sched.h +27 -0

index 959ff18..731d0bf 100644
@@ -6,6 +6,7 @@
 
 #include <linux/sched.h>
 #include <linux/tracepoint.h>
+#include <linux/binfmts.h>
 
 /*
  * Tracepoint for calling kthread_stop, performed to end a kthread:

@@ -276,6 +277,32 @@ TRACE_EVENT(sched_process_fork,
 );
 
 /*
+ * Tracepoint for exec:
+ */
+TRACE_EVENT(sched_process_exec,
+
+       TP_PROTO(struct task_struct *p, pid_t old_pid,
+                struct linux_binprm *bprm),
+
+       TP_ARGS(p, old_pid, bprm),
+
+       TP_STRUCT__entry(
+               __string(       filename,       bprm->filename  )
+               __field(        pid_t,          pid             )
+               __field(        pid_t,          old_pid         )
+       ),
+
+       TP_fast_assign(
+               __assign_str(filename, bprm->filename);
+               __entry->pid            = p->pid;
+               __entry->old_pid        = p->pid;
+       ),
+
+       TP_printk("filename=%s pid=%d old_pid=%d", __get_str(filename),
+                 __entry->pid, __entry->old_pid)
+);
+
+/*
  * XXX the below sched_stat tracepoints only apply to SCHED_OTHER/BATCH/IDLE
  *     adding sched_stat support to SCHED_FIFO/RR would be welcome.
  */