Re: LuaJIT segfault

[Daurnimator <quae@...>]

On 8 November 2011 21:24, Pierre Chapuis <catwell@archlinux.us> wrote:
> LuaJIT segfaults at GC step when running this snippet:
>
>  local ffi = require "ffi"
>
>  local get_str = function()
>    local f = io.popen("dd if=/dev/urandom bs=1 count=10000")
>    local s = f:read("*all")
>    f:close()
>    return s
>  end
>
>  local convert = function(str)
>    local l = #str
>    local s = ffi.new("char[?]",l,str) // <=
>    return ffi.string(s,l)
>  end
>
>  for i=1,200 do
>    print(i)
>    convert(get_str())
>  end
>
> If I replace the line marked "<=" by this:
>
>  local s = ffi.new("char[?]",l+1,str)
>
> the problem goes away.
>
> Is that behavior expected? It looks like a bug to me.
>
> --
> Pierre Chapuis
>
>

You need room for the terminating null byte.