> We are using “is_mem_defined” (in mc_main.) to test for “is it safe to read > this location?” and that does not appear to be quite right. It looks as > though an address in a code segment is defined, but not readable. We get a > SIGSEGV with a bad permissions message when we try. Whether or not that is > the correct analysis is not as important as the primary question: > > > > What is the proper way to check to see if an address is readable? And, > similarly, is writable?
The *only* way to get a definitive answer is to attempt a write() from that address to a temporary file. If and only if you get no error, then the address is readable. You can read and decode /proc/self/maps, but even if a page has PROT_READ you might still get SIGBUS, such as when the page maps a hardware device which does not respond to the particular address. ------------------------------------------------------------------------------ _______________________________________________ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
