[src/trunk]: src/sys/dev/filemon staircase flattening police.

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/cd7d7555746a
branches:  trunk
changeset: 809042:cd7d7555746a
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Jun 15 19:45:31 2015 +0000

description:
staircase flattening police.

diffstat:

 sys/dev/filemon/filemon_wrapper.c |  364 +++++++++++++++++++------------------
 1 files changed, 185 insertions(+), 179 deletions(-)

diffs (truncated from 499 to 300 lines):

diff -r 966d980ad2c6 -r cd7d7555746a sys/dev/filemon/filemon_wrapper.c
--- a/sys/dev/filemon/filemon_wrapper.c Mon Jun 15 18:11:36 2015 +0000
+++ b/sys/dev/filemon/filemon_wrapper.c Mon Jun 15 19:45:31 2015 +0000
@@ -1,3 +1,5 @@
+/*     $NetBSD: filemon_wrapper.c,v 1.7 2015/06/15 19:45:31 christos Exp $     */
+
 /*
  * Copyright (c) 2010, Juniper Networks, Inc.
  *
@@ -24,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: filemon_wrapper.c,v 1.6 2015/06/15 18:11:36 sjg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: filemon_wrapper.c,v 1.7 2015/06/15 19:45:31 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -41,27 +43,27 @@
 filemon_wrapper_chdir(struct lwp * l, const struct sys_chdir_args * uap,
     register_t * retval)
 {
-       int ret;
        int error;
        size_t done;
        struct filemon *filemon;
        
-       if ((ret = sys_chdir(l, uap, retval)) == 0) {
-               filemon = filemon_lookup(curproc);
+       if ((error = sys_chdir(l, uap, retval)) != 0)
+               return 0;
 
-               if (filemon) {
+       filemon = filemon_lookup(curproc);
+       if (filemon == NULL)
+               return 0;
 
-                       error = copyinstr(SCARG(uap, path), filemon->fm_fname1,
-                           sizeof(filemon->fm_fname1), &done);
-                       if (error == 0) {
-                               filemon_printf(filemon,
-                                   "C %d %s\n",
-                                   curproc->p_pid, filemon->fm_fname1);
-                       }
-                       rw_exit(&filemon->fm_mtx);
-               }
-       }
-       return (ret);
+       error = copyinstr(SCARG(uap, path), filemon->fm_fname1,
+           sizeof(filemon->fm_fname1), &done);
+       if (error)
+               goto out;
+
+       filemon_printf(filemon, "C %d %s\n",
+           curproc->p_pid, filemon->fm_fname1);
+out:
+       rw_exit(&filemon->fm_mtx);
+       return 0;
 }
 
 static int
@@ -69,232 +71,234 @@
     register_t * retval)
 {
        char fname[MAXPATHLEN];
-       int ret;
        int error;
        size_t done;
        struct filemon *filemon;
        
-       error = copyinstr(SCARG(uap, path), fname, sizeof(fname), &done);
+       if ((error = sys_execve(l, uap, retval)) != EJUSTRETURN)
+               return 0;
 
-       if ((ret = sys_execve(l, uap, retval)) == EJUSTRETURN && error == 0) {
-               filemon = filemon_lookup(curproc);
+       filemon = filemon_lookup(curproc);
+       if (filemon == NULL)
+               return 0;
 
-               if (filemon) {
-                       filemon_printf(filemon, "E %d %s\n",
-                           curproc->p_pid, fname);
-                       rw_exit(&filemon->fm_mtx);
-               }
-       }
-       return (ret);
+       error = copyinstr(SCARG(uap, path), fname, sizeof(fname), &done);
+       if (error)
+               goto out;
+
+       filemon_printf(filemon, "E %d %s\n", curproc->p_pid, fname);
+out:
+       rw_exit(&filemon->fm_mtx);
+       return 0;
 }
 
 
 static int
 filemon_wrapper_fork(struct lwp * l, const void *v, register_t * retval)
 {
-       int ret;
+       int error;
        struct filemon *filemon;
 
-       if ((ret = sys_fork(l, v, retval)) == 0) {
-               filemon = filemon_lookup(curproc);
+       if ((error = sys_fork(l, v, retval)) != 0)
+               return error;
 
-               if (filemon) {
-                       filemon_printf(filemon, "F %d %ld\n",
-                           curproc->p_pid, (long) retval[0]);
-                       rw_exit(&filemon->fm_mtx);
-               }
-       }
-       return (ret);
+       filemon = filemon_lookup(curproc);
+       if (filemon == NULL)
+               return 0;
+
+       filemon_printf(filemon, "F %d %ld\n", curproc->p_pid, (long) retval[0]);
+
+       rw_exit(&filemon->fm_mtx);
+       return 0;
 }
 
 static int
 filemon_wrapper_vfork(struct lwp * l, const void *v, register_t * retval)
 {
-       int ret;
+       int error;
        struct filemon *filemon;
 
-       if ((ret = sys_vfork(l, v, retval)) == 0) {
-               filemon = filemon_lookup(curproc);
+       if ((error = sys_vfork(l, v, retval)) != 0)
+               return error;
+
+       filemon = filemon_lookup(curproc);
+       if (filemon == NULL)
+               return 0;
+
+       filemon_printf(filemon, "F %d %ld\n", curproc->p_pid, (long) retval[0]);
 
-               if (filemon) {
-                       filemon_printf(filemon, "F %d %ld\n",
-                           curproc->p_pid, (long) retval[0]);
-                       rw_exit(&filemon->fm_mtx);
-               }
+       rw_exit(&filemon->fm_mtx);
+       return 0;
+}
+
+static void
+filemon_flags(struct filemon * filemon, int f)
+{
+       if (f & O_RDWR) {
+               /* we want a separate R record */
+               filemon_printf(filemon, "R %d %s\n", curproc->p_pid,
+                   filemon->fm_fname1);
        }
-       return (ret);
+
+       filemon_printf(filemon, "%c %d %s\n", (f & O_ACCMODE) ? 'W' : 'R',
+           curproc->p_pid, filemon->fm_fname1);
 }
 
 static int
 filemon_wrapper_open(struct lwp * l, struct sys_open_args * uap,
     register_t * retval)
 {
-       int ret;
        int error;
        size_t done;
        struct filemon *filemon;
 
-       if ((ret = sys_open(l, uap, retval)) == 0) {
-               filemon = filemon_lookup(curproc);
+       if ((error = sys_open(l, uap, retval)) != 0)
+               return error;
+
+       filemon = filemon_lookup(curproc);
+       if (filemon == NULL)
+               return 0;
 
-               if (filemon) {
-                       error = copyinstr(SCARG(uap, path), filemon->fm_fname1,
-                           sizeof(filemon->fm_fname1), &done);
-                       if (error == 0) {
-                               if (SCARG(uap, flags) & O_RDWR) {
-                                       /* we want a separate R record */
-                                       filemon_printf(filemon,
-                                               "R %d %s\n",
-                                               curproc->p_pid,
-                                               filemon->fm_fname1);
-                               }                       
-                               filemon_printf(filemon,
-                                   "%c %d %s\n",
-                                   (SCARG(uap, flags) & O_ACCMODE) ? 'W' : 'R',
-                                   curproc->p_pid, filemon->fm_fname1);
-                       }
-                       rw_exit(&filemon->fm_mtx);
-               }
-       }
-       return (ret);
+       error = copyinstr(SCARG(uap, path), filemon->fm_fname1,
+           sizeof(filemon->fm_fname1), &done);
+       if (error)
+               goto out;
+
+       filemon_flags(filemon, SCARG(uap, flags));
+out:
+       rw_exit(&filemon->fm_mtx);
+       return 0;
 }
 
 static int
 filemon_wrapper_openat(struct lwp * l, struct sys_openat_args * uap,
     register_t * retval)
 {
-       int ret;
        int error;
        size_t done;
        struct filemon *filemon;
 
-       if ((ret = sys_openat(l, uap, retval)) == 0) {
-               filemon = filemon_lookup(curproc);
+       if ((error = sys_openat(l, uap, retval)) != 0)
+               return error;
+
+       filemon = filemon_lookup(curproc);
+       if (filemon == NULL)
+               return 0;
+
+       error = copyinstr(SCARG(uap, path), filemon->fm_fname1,
+           sizeof(filemon->fm_fname1), &done);
+       if (error)
+               goto out;
 
-               if (filemon) {
-                       error = copyinstr(SCARG(uap, path), filemon->fm_fname1,
-                           sizeof(filemon->fm_fname1), &done);
-                       if (error == 0) {
-                               if (filemon->fm_fname1[0] != '/' &&
-                                   SCARG(uap, fd) != AT_FDCWD) {
-                                       /*
-                                        * Rats we cannot just treat like open.
-                                        * Output an 'A' record as a clue.
-                                        */
-                                       filemon_printf(filemon,
-                                               "A %d %s\n",
-                                               curproc->p_pid,
-                                               filemon->fm_fname1);
-                               }
-                               if (SCARG(uap, oflags) & O_RDWR) {
-                                       /* we want a separate R record */
-                                       filemon_printf(filemon,
-                                               "R %d %s\n",
-                                               curproc->p_pid,
-                                               filemon->fm_fname1);
-                               }                       
-                               filemon_printf(filemon,
-                                   "%c %d %s\n",
-                                   (SCARG(uap, oflags) & O_ACCMODE) ? 'W' : 'R',
-                                   curproc->p_pid, filemon->fm_fname1);
-                       }
-                       rw_exit(&filemon->fm_mtx);
-               }
+       if (filemon->fm_fname1[0] != '/' && SCARG(uap, fd) != AT_FDCWD) {
+               /*
+                * Rats we cannot just treat like open.
+                * Output an 'A' record as a clue.
+                */
+               filemon_printf(filemon, "A %d %s\n", curproc->p_pid,
+                   filemon->fm_fname1);
        }
-       return (ret);
+
+       filemon_flags(filemon, SCARG(uap, oflags));
+out:
+       rw_exit(&filemon->fm_mtx);
+       return 0;
 }
 
 static int
 filemon_wrapper_rename(struct lwp * l, struct sys_rename_args * uap,
     register_t * retval)
 {
-       int ret;
        int error;
        size_t done;
        struct filemon *filemon;
 
-       if ((ret = sys_rename(l, uap, retval)) == 0) {
-               filemon = filemon_lookup(curproc);
+       if ((error = sys_rename(l, uap, retval)) != 0)
+               return error;
+
+       filemon = filemon_lookup(curproc);