On Thu, Jul 11, 2013 at 11:52:34AM -0700, Brendan Conoboy wrote:
On 07/11/2013 11:49 AM, Jakub Jelinek wrote:
>Stack guards are present, but using libssp, which is the fallback way,
>second class citizen and most likely slower than the standard way.
>E.g. the libssp stack guard setup always uses /dev/urandom, while I guess
>even on ARM kernel provides AT_RANDOM that can be just used.
>And I'd bet that even on ARM reading the stack guard via TLS (well,
>static only always, i.e. hardcoded offset from TLS register), especially for
>PIC, is faster than doing GOT read and two memory references.
Thanks. Security-wise, is the implementation roughly equivalent in
what is protected against, albeit less efficient?
Not sure how exactly /dev/urandom compares to AT_RANDOM security-wise,
but most probably it is just less efficient. Definitely something to be
benchmarked, analyzed for code size etc.