bugThe GNU Hurd - Bugs: bug #49278, fprintf(stderr, ...) returns -1...


bug #49278: fprintf(stderr, ...) returns -1 (EINTR)

Submitted by:  Brent Baccala <baccala>
Submitted on:  Thu 06 Oct 2016 04:44:51 AM UTC  
Category: HurdSeverity: 3 - Normal
Priority: 5 - NormalItem Group: None
Status: NonePrivacy: Public
Assigned to: NoneOriginator Name: 
Open/Closed: OpenReproducibility: Every Time
Size (loc): NonePlanned Release: None
Effort: 0.00
Wiki-like text discussion box: 

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Thu 06 Oct 2016 06:58:10 AM UTC, comment #1:

I suspect this is caused by a no-more-senders notification on the receive right of the filesystem root port, to which the client sent the message. If you add sleep(2) after the mach_msg call in the client, so that it doesn't deallocate the send right before mach_msg times out in the server, then the EINTR doesn't happen on the first call. (I didn't test more calls.) The no-more-senders notification would be requested because trivfs_S_fsys_getroot calls ports_get_right. The notification is handled in ports_do_mach_notify_no_senders.

If the EINTR only happens on the first call, that seems wrong.

Kalle Olavi Niemitalo <kon>
Thu 06 Oct 2016 04:44:51 AM UTC, original submission:

Under certain circumstances, fprintf to stderr can return -1 with errno = EINTR.

Test program attached.

Brent Baccala <baccala>


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach File(s):

Attached Files
file #38667:  fprintf-test.c added by baccala (3KiB - text/x-csrc)


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -unavailable- added by kon (Posted a comment)
  • -unavailable- added by baccala (Submitted the item)

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    Follows 1 latest change.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 06 Oct 2016 04:44:51 AM UTCbaccalaAttached File-=>Added fprintf-test.c, #38667

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