Re: posix/tst-spawn5 failes under make -j

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 09/07/2021 10:41, Florian Weimer wrote:
> * Adhemerval Zanella:
> 
>> On 09/07/2021 06:45, Florian Weimer wrote:
>>> This patch adds some additional diagonstics:
>>>
>>> diff --git a/posix/tst-spawn5.c b/posix/tst-spawn5.c
>>> index 277b848794..5ba7c7fadb 100644
>>> --- a/posix/tst-spawn5.c
>>> +++ b/posix/tst-spawn5.c
>>> @@ -116,7 +116,11 @@ handle_restart (int argc, char *argv[])
>>>  	  fds[i].found = found = true;
>>>  
>>>        if (!found)
>>> -        FAIL_EXIT1 ("unexpected open file descriptor: %ld", fd);
>>> +	{
>>> +	  char *path = xasprintf ("/proc/self/fd/%s", e->d_name);
>>> +	  char *resolved = xreadlink (path);
>>> +	  FAIL_EXIT1 ("unexpected open file descriptor %ld: %s", fd, resolved);
>>> +	}
>>>      }
>>>    closedir (dirp);
>>>  
>>> It's the pipe from the make job server:
>>>
>>> error: tst-spawn5.c:122: unexpected open file descriptor 3: pipe:[9958839]
>>>
>>> I think the test needs to be changed so that lowfd is passed across the
>>> restart, and checking only considers descriptors >= lowfd.
>>
>> The restart process already receive a list of the expected opened files,
>> for instance on my environment it will re-executed with:
>>
>> handle_restart: 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 
>> handle_restart: 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 
>> handle_restart: 3 
>> handle_restart: 
>> handle_restart: 3 4 
>>
>> I am trying to reproduce the issue without much success, even with 
>> make -j or make posix/tests -j.  Maybe we can limit the search to the
>> argument range:
> 
> make -j2 should do it (make -j without argument probably doesn't involve
> the job server), sorry.
> 
> The issue is that the verification should start only at lowfd.
> This will supercede the STDIN_* checks here:
> 
>       if (fd == dirfd (dirp)
>           || fd == STDIN_FILENO
> 	  || fd == STDOUT_FILENO
> 	  || fd == STDERR_FILENO)
>         continue;

I usually ran the check with the current processor number in my system
in fact (in this case 24) and I haven't see any issue so far.  But I 
think the following patch should fine, can you check if it improves the
error you are seeing:

diff --git a/posix/tst-spawn5.c b/posix/tst-spawn5.c
index 277b848794..d586662a8e 100644
--- a/posix/tst-spawn5.c
+++ b/posix/tst-spawn5.c
@@ -68,6 +68,8 @@ handle_restart (int argc, char *argv[])
     int fd;
     _Bool found;
   } *fds = xmalloc (sizeof (struct fd_t) * nfds);
+  int maxfd = 0;
+  int minfd = INT_MAX;
   for (int i = 0; i < nfds; i++)
     {
       char *endptr;
@@ -77,6 +79,11 @@ handle_restart (int argc, char *argv[])
 
       fds[i].fd = fd;
       fds[i].found = false;
+
+      if (fd < minfd)
+       minfd = fd;
+      if (fd > maxfd)
+       maxfd = fd;
     }
 
   DIR *dirp = opendir (FD_TO_FILENAME_PREFIX);
@@ -103,11 +110,8 @@ handle_restart (int argc, char *argv[])
         FAIL_EXIT1 ("readdir: invalid file descriptor name: /proc/self/fd/%s",
                     e->d_name);
 
-      /* Skip the descriptor which is used to enumerate the descriptors.  */
-      if (fd == dirfd (dirp)
-          || fd == STDIN_FILENO
-         || fd == STDOUT_FILENO
-         || fd == STDERR_FILENO)
+      /* Skip the descriptor which are not enumerated in arguments.  */
+      if (fd < minfd || fd > maxfd)
         continue;
 
       bool found = false;