- When disabling ktracing on a process, free any pending requests that

  may be left.  This fixes a memory leak that can occur when tracing is
  disabled on a process via disabling tracing of a specific file (or if
  an I/O error occurs with the tracefile) if the process's next system
  call is exit().  The trace disabling code clears p_traceflag, so exit1()
  doesn't do any KTRACE-related cleanup leading to the leak.  I chose to
  make the free'ing of pending records synchronous rather than patching
  exit1().
- Move KTRACE-specific logic out of kern_(exec|exit|fork).c and into
  kern_ktrace.c instead.  Make ktrace_mtx private to kern_ktrace.c as a
  result.

MFC after:	1 month

1 files changed, 2 insertions, 10 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 3c05530..1e4d690 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -655,16 +655,8 @@ interpret:
 		setsugid(p);
 
 #ifdef KTRACE
-		if (p->p_tracevp != NULL &&
-		    priv_check_cred(oldcred, PRIV_DEBUG_DIFFCRED, 0)) {
-			mtx_lock(&ktrace_mtx);
-			p->p_traceflag = 0;
-			tracevp = p->p_tracevp;
-			p->p_tracevp = NULL;
-			tracecred = p->p_tracecred;
-			p->p_tracecred = NULL;
-			mtx_unlock(&ktrace_mtx);
-		}
+		if (priv_check_cred(oldcred, PRIV_DEBUG_DIFFCRED, 0))
+			ktrprocexec(p, &tracecred, &tracevp);
 #endif
 		/*
 		 * Close any file descriptors 0..2 that reference procfs,