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    x86: i386-show-unhandled-signals-v3 · abd4f750
    Masoud Asgharifard Sharbiani 提交于
    This patch makes the i386 behave the same way that x86_64 does when a
    segfault happens.  A line gets printed to the kernel log so that tools
    that need to check for failures can behave more uniformly between
    debug.show_unhandled_signals sysctl variable to 0 (or by doing echo 0 >
    /proc/sys/debug/exception-trace)
    
    Also, all of the lines being printed are now using printk_ratelimit() to
    deny the ability of DoS from a local user with a program like the
    following:
    
    main()
    {
           while (1)
                   if (!fork()) *(int *)0 = 0;
    }
    
    This new revision also includes the fix that Andrew did which got rid of
    new sysctl that was added to the system in earlier versions of this.
    Also, 'show-unhandled-signals' sysctl has been renamed back to the old
    'exception-trace' to avoid breakage of people's scripts.
    
    AK: Enabling by default for i386 will be likely controversal, but let's see what happens
    AK: Really folks, before complaining just fix your segfaults
    AK: I bet this will find a lot of silent issues
    Signed-off-by: NMasoud Sharbiani <masouds@google.com>
    Signed-off-by: NAndi Kleen <ak@suse.de>
    [ Personally, I've found the complaints useful on x86-64, so I'm all for
      this. That said, I wonder if we could do it more prettily..   -Linus ]
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    abd4f750
signal.c 64.7 KB