[Bug gdb/19998] interrupt test failing due to SIGINT failing to interrupt

["cvs-commit at gcc dot gnu.org" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=19998

--- Comment #2 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Yao Qi <qiyao@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=03d73f1fd9d89d89bdd021cad26693e4f6abc07a

commit 03d73f1fd9d89d89bdd021cad26693e4f6abc07a
Author: Yao Qi <yao.qi@linaro.org>
Date:   Wed Jun 1 09:33:40 2016 +0100

    Wake up interruptible_select in remote_fileio ctrl-c handler

    As reported in PR 19998, after type ctrl-c, GDB hang there and does
    not send interrupt.  It causes a fail in gdb.base/interrupt.exp.
    All targets support remote fileio should be affected.

    When we type ctrc-c, SIGINT is handled by remote_fileio_sig_set,
    as shown below,

     #0  remote_fileio_sig_set (sigint_func=0x4495d0
<remote_fileio_ctrl_c_signal_handler(int)>) at
/home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:325
     #1  0x00000000004495de in remote_fileio_ctrl_c_signal_handler
(signo=<optimised out>) at
/home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:349
     #2  <signal handler called>
     #3  0x00007ffff647ed83 in __select_nocancel () at
../sysdeps/unix/syscall-template.S:81
     #4  0x00000000005530ce in interruptible_select (n=10,
readfds=readfds@entry=0x7fffffffd730, writefds=writefds@entry=0x0,
exceptfds=exceptfds@entry=0x0,
        timeout=timeout@entry=0x0) at
/home/yao/SourceCode/gnu/gdb/git/gdb/event-top.c:1017
     #5  0x000000000061ab20 in stdio_file_read (file=<optimised out>,
buf=0x12d02e0 "\n\022-\001", length_buf=16383)
        at /home/yao/SourceCode/gnu/gdb/git/gdb/ui-file.c:577
     #6  0x000000000044a4dc in remote_fileio_func_read (buf=0x12c0360 "") at
/home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:583
     #7  0x0000000000449598 in do_remote_fileio_request (uiout=<optimised out>,
buf_arg=buf_arg@entry=0x12c0340)
        at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:1179

    we don't set quit_serial_event,

      do
        {
          res = gdb_select (n, readfds, writefds, exceptfds, timeout);
        }
      while (res == -1 && errno == EINTR);

      if (res == 1 && FD_ISSET (fd, readfds))
        {
          errno = EINTR;
          return -1;
        }
      return res;

    we can't go out of the loop above, and that is why GDB can't send
    interrupt.

    Recently, we stop throwing exception from SIGINT handler
    (remote_fileio_ctrl_c_signal_handler)
    https://sourceware.org/ml/gdb-patches/2016-03/msg00372.html, which
    is correct, because gdb_select is interruptible.  However, in the
    same patch series, we add interruptible_select later as a wrapper
    to gdb_select, https://sourceware.org/ml/gdb-patches/2016-03/msg00375.html
    and it is not interruptible (because of the loop in it) unless
    select/poll-able file descriptors are marked.

    This fix in this patch is to call quit_serial_event_set, so that we can
    go out of the loop above, return -1 and set errno to EINTR.

    2016-06-01  Yao Qi  <yao.qi@linaro.org>

        PR remote/19998
        * remote-fileio.c (remote_fileio_ctrl_c_signal_handler): Call
        quit_serial_event_set.

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