Re: [Qemu-devel] [PATCH] Fix utimensat (aka unbreak cp -a)

[Riku Voipio <riku.voipio@iki.fi>]

On Tue, Apr 21, 2009 at 06:38:17PM +0200, Martin Mohring wrote:
> > results in the invalid argutment error. I ll currently check which
> > syscalls are involved here.
> > the time of 1.1.1970 looks to me like a wrongly passed argument (of ==0).

no, NULL is what is supposed to be passed. try stracing a normal host
/bin/touch.

> 27374 open("/var/log/wtmp",0x20941,0666) = 3
> 27374 dup2(3,0,3,0,0,1109324328) = 0
> 27374 close(3) = 0
> 27374 utimensat(0,"(null)",(nil),0) = 0
> 27374 close(0) = 0
> 27374 open("/var/run/utmp",0x20941,0666) = 0
> 27374 utimensat(0,"(null)",(nil),0) = -1 errno=22 (Invalid argument)

It is unclear what svn revision you are using qemu, and/or if you are using
any of the patches in this thread. The patch I sent earlier, should fix
the invalid arg issue. As for the 1970 issue, try this patch.

commit 7f7e93aabde6b8f0e4a1a05537145efa9ed0156b
Author: Riku Voipio <riku.voipio@iki.fi>
Date:   Tue Apr 21 20:37:01 2009 +0300

    linux-user: fix utimensat with NULL timespec
    
    Don't try to copy timespec from user if it is NULL.

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index e19e289..0049840 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6674,17 +6674,22 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 #if defined(TARGET_NR_utimensat) && defined(__NR_utimensat)
     case TARGET_NR_utimensat:
         {
-            struct timespec ts[2];
-            target_to_host_timespec(ts, arg3);
-            target_to_host_timespec(ts+1, arg3+sizeof(struct target_timespec));
+            struct timespec *tsp, ts[2];
+            if (!arg3) {
+                tsp = NULL;
+            } else {
+                target_to_host_timespec(ts, arg3);
+                target_to_host_timespec(ts+1, arg3+sizeof(struct target_timespec));
+                tsp = ts;
+            }
             if (!arg2)
-                ret = get_errno(sys_utimensat(arg1, NULL, ts, arg4));
+                ret = get_errno(sys_utimensat(arg1, NULL, tsp, arg4));
             else {
                 if (!(p = lock_user_string(arg2))) {
                     ret = -TARGET_EFAULT;
                     goto fail;
                 }
-                ret = get_errno(sys_utimensat(arg1, path(p), ts, arg4));
+                ret = get_errno(sys_utimensat(arg1, path(p), tsp, arg4));
                 unlock_user(p, arg2, 0);
             }
         }