svn commit: r197031 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Wed Sep  9 10:52:36 2009
New Revision: 197031
URL: http://svn.freebsd.org/changeset/base/197031

Log:
  Unlock the image vnode around the call of pmc PMC_FN_PROCESS_EXEC hook.
  The hook calls vn_fullpath(9), that should not be executed with a vnode
  lock held.
  
  Reported by:	Bruce Cran <bruce cran org uk>
  Tested by:	pho
  MFC after:	3 days

Modified:
  head/sys/kern/kern_exec.c

Modified: head/sys/kern/kern_exec.c
==============================================================================
--- head/sys/kern/kern_exec.c	Wed Sep  9 10:51:50 2009	(r197030)
+++ head/sys/kern/kern_exec.c	Wed Sep  9 10:52:36 2009	(r197031)
@@ -786,10 +786,12 @@ interpret:
 	 */
 	if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
 		PROC_UNLOCK(p);
+		VOP_UNLOCK(imgp->vp, 0);
 		pe.pm_credentialschanged = credential_changing;
 		pe.pm_entryaddr = imgp->entry_addr;
 
 		PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
+		vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
 	} else
 		PROC_UNLOCK(p);
 #else  /* !HWPMC_HOOKS */