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Date:      Tue, 10 Nov 2009 11:46:53 +0000 (UTC)
From:      Konstantin Belousov <kib@FreeBSD.org>
To:        cvs-src-old@freebsd.org
Subject:   cvs commit: src/sys/kern kern_sig.c src/sys/sys signalvar.h
Message-ID:  <200911101147.nAABlGjU060839@repoman.freebsd.org>

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kib         2009-11-10 11:46:53 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             kern_sig.c 
    sys/sys              signalvar.h 
  Log:
  SVN rev 199136 on 2009-11-10 11:46:53Z by kib
  
  In r198506, kern_sigsuspend() started doing cursig/postsig loop to make
  sure that a signal was delivered to the thread before returning from
  syscall. Signal delivery puts new return frame on the user stack, and
  modifies trap frame to enter signal handler. As a consequence, syscall
  return code sets EINTR as error return for signal frame, instead of the
  syscall return.
  
  Also, for ia64, due to different registers layout for those two kind of
  frames, usermode sigsegfaulted when returned from signal handler.
  
  Use newly-introduced cpu_set_syscall_retval(9) to set syscall result,
  and return EJUSTRETURN from kern_sigsuspend() to prevent syscall return
  code from modifying this frame [1].
  
  Another issue is that pending SIGCONT might be cancelled by SIGSTOP,
  causing postsig() not to deliver any catched signal [2]. Modify
  postsig() to return 1 if signal was posted, and 0 otherwise, and use
  this in the kern_sigsuspend loop.
  
  Proposed by:    marcel [1]
  Noted by:       davidxu [2]
  Reviewed by:    marcel, davidxu
  MFC after:      1 month
  
  Revision  Changes    Path
  1.382     +7 -8      src/sys/kern/kern_sig.c
  1.83      +1 -1      src/sys/sys/signalvar.h



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