[src/trunk]: src/sys/kern - preserve the error number returned from copyin.

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

details:   https://anonhg.NetBSD.org/src/rev/26800acad082
branches:  trunk
changeset: 810690:26800acad082
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Sep 12 17:04:57 2015 +0000

description:
- preserve the error number returned from copyin.
- preserve the original pathname in ep_kname, because this is what gets passed
  to userland in exec_script.c

diffstat:

 sys/kern/kern_exec.c |  33 +++++++++++++++++++--------------
 1 files changed, 19 insertions(+), 14 deletions(-)

diffs (96 lines):

diff -r 84bf38cd6656 -r 26800acad082 sys/kern/kern_exec.c
--- a/sys/kern/kern_exec.c      Sat Sep 12 15:25:01 2015 +0000
+++ b/sys/kern/kern_exec.c      Sat Sep 12 17:04:57 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_exec.c,v 1.414 2015/09/11 01:23:37 christos Exp $ */
+/*     $NetBSD: kern_exec.c,v 1.415 2015/09/12 17:04:57 christos Exp $ */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -59,7 +59,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.414 2015/09/11 01:23:37 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.415 2015/09/12 17:04:57 christos Exp $");
 
 #include "opt_exec.h"
 #include "opt_execfmt.h"
@@ -593,11 +593,12 @@
 #endif
 }
 
-static struct pathbuf *
-makepathbuf(struct lwp *l, const char *upath)
+static int
+makepathbuf(struct lwp *l, const char *upath, struct pathbuf **pbp,
+    size_t *offs)
 {
        char *path, *bp;
-       size_t len;
+       size_t len, tlen;
        int error;
        struct cwdinfo *cwdi;
 
@@ -606,11 +607,13 @@
        if (error) {
                PNBUF_PUT(path);
                DPRINTF(("%s: copyin path @%p %d\n", __func__, upath, error));
-               return NULL;
+               return error;
        }
 
-       if (path[0] == '/')
+       if (path[0] == '/') {
+               *offs = 0;
                goto out;
+       }
 
        len++;
        if (len + 1 >= MAXPATHLEN)
@@ -630,12 +633,14 @@
                    error));
                goto out;
        }
-       len = path + MAXPATHLEN - bp;
+       tlen = path + MAXPATHLEN - bp;
 
-       memmove(path, bp, len);
-       path[len] = '\0';
+       memmove(path, bp, tlen);
+       path[tlen] = '\0';
+       *offs = tlen - len;
 out:
-       return pathbuf_assimilate(path);
+       *pbp = pathbuf_assimilate(path);
+       return 0;
 }
 
 static int
@@ -648,6 +653,7 @@
        struct proc             *p;
        char                    *dp;
        u_int                   modgen;
+       size_t                  offs;
 
        KASSERT(data != NULL);
 
@@ -697,8 +703,7 @@
         * functions call check_exec() recursively - for example,
         * see exec_script_makecmds().
         */
-       data->ed_pathbuf = makepathbuf(l, path);
-       if (data->ed_pathbuf == NULL)
+       if ((error = makepathbuf(l, path, &data->ed_pathbuf, &offs)) != 0)
                goto clrflg;
        data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf);
        data->ed_resolvedpathbuf = PNBUF_GET();
@@ -706,7 +711,7 @@
        /*
         * initialize the fields of the exec package.
         */
-       epp->ep_kname = data->ed_pathstring;
+       epp->ep_kname = data->ed_pathstring + offs;
        epp->ep_resolvedname = data->ed_resolvedpathbuf;
        epp->ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP);
        epp->ep_hdrlen = exec_maxhdrsz;