On Tue, Nov 11, 2014 at 1:33 PM, Joseph Myers <jos...@codesourcery.com> wrote: > On Tue, 11 Nov 2014, Andi Kleen wrote: > >> On Tue, Nov 11, 2014 at 01:04:42PM -0800, H.J. Lu wrote: >> > On Tue, Nov 11, 2014 at 1:01 PM, Andi Kleen <a...@firstfloor.org> wrote: >> > >> It is similar to libsanitizer. Put it in glibc isn't going to work well >> > >> for MPX. >> > > >> > > Can you explain it more please? >> > > >> > >> > Are you suggesting putting MPX run-time in glibc? Will we have >> > 2 glibc, one with MPX run-time and one without MPX run-time? >> >> No, I just think signal chaining should be in glibc.
Currently mpx-runtime uses dlsym(RTLD_NEXT, "sigaction"); to get the original sigaction in liibc.so. Glibc does provides __sigaction for the original sigaction. But dlsym(RTLD_NEXT, is more portable. > I do wonder whether the signal handler needs to be enabled by default or > whether there should simply be a function __mpx_handle_sigsegv provided > with instructions to the user on how it can be used to get extra > MPX-related information when SIGSEGV occurs (in which case it's entirely > the user's responsibility to write a handler calling their own handler and > the MPX one, if desired). Or an LD_PRELOAD library like libSegFault. > It is certainly an option. -- H.J.
