[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Bug-readline] [readline patch, gdb-7.3?] Avoid free from a signal h

From: Jan Kratochvil
Subject: Re: [Bug-readline] [readline patch, gdb-7.3?] Avoid free from a signal handler [Re: [PATCH] Make interrupting tab-completion safe.]
Date: Wed, 6 Jul 2011 17:46:21 +0200
User-agent: Mutt/1.5.21 (2010-09-15)

On Thu, 30 Jun 2011 16:38:21 +0200, Chet Ramey wrote:
> I have seen cases where the user hits ^C while readline or a filename
> completion function is attempting to traverse a file system on a dead
> NFS server, the signal handler gets hit, but the system call doesn't
> get interrupted.  I haven't seen those cases in a while, though.

I have tried to reproduce it but I think it is outside of the scope of
readline and/or gdb.

        ip6tables -I INPUT 1 -i lo -p tcp --dport 2049 -j DROP
before rl_filename_completion_function's readdir() call will cause (in strace):

rt_sigaction(SIGINT, {0x6518cb=handle_sigint, [INT], SA_RESTORER|SA_RESTART, 
0x7f79cf0bd490}, NULL, 8) = 0
rt_sigaction(SIGQUIT, {0x65196e=handle_sigquit, [QUIT], SA_RESTORER|SA_RESTART, 
0x7f79cf0bd490}, NULL, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
getdents(5, <hang>

and no CTRL-C makes any change.  It was mounted
on kernel- with options:
        localhost:/... /... nfs 
 0 0

where I used "intr" but "intr" / "nointr" is not listed at all and man says:
        The intr / nointr mount option is deprecated after kernel 2.6.25.
        Only SIGKILL can interrupt a pending NFS operation on these kernels,
        and if specified, this mount option is ignored to provide backwards
        compatibility with older kernels.

> remove the references to _rl_interrupt_immediately

I think _rl_interrupt_immediately should never exist as you cannot do anything
much from the signal handler anyway.
man 7 signak "Async-signal-safe functions"


reply via email to

[Prev in Thread] Current Thread [Next in Thread]