This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: SafeStack proposal in GCC




On 5/9/2016 3:41 PM, Ian Lance Taylor wrote:
On Mon, May 9, 2016 at 1:07 PM, Joel Sherrill <joel.sherrill@oarcorp.com> wrote:

One complication on RTEMS which is a single process, multi-threaded RTOS
is that we can no longer check the stack bounds. For threads, we know
where the stack memory is and the range for each thread. For ucontext_t,
it seems this knowledge is unknown to the RTOS.

Thus it would become the responsibility of the run-time using ucontext_t
to put in fence patterns and check those.

On RTEMS and similar systems, you could write makecontext to register
the stack (whose start and length are known to the function) with the
RTOS.

Ahh... slow today. swapcontext() would have to work with the stack
checker.
Interesting.. the stack usage reporting would have to be taught
about the ucontext_t's in the system and report those as well.

Am I missing something or is there no way to know when a context
goes out of existence in the API?


Ian


--joel


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]