On Linux (or Solaris) is there a better way than hand parsing /proc/self/maps repeatedly to figure out whether or not you can read, write or execute whatever is stored at one or more addresses in memory? For instance, in Windows you have VirtualQuery. In Linux, I can mprotect to change those values, but I can't read them back. Furthe...
I'm trying to use mprotect API on MacOSX 10.4 (tiger), I tried every possible way i know , it always returns -1, with errno 13, which means "permission denied" while I'm trying to add the write permission to some executable code. The same code exactly works on MacOS X 10.5 (leopard). the code is pretty simple int ret = mprotect((void*...
Hi I'm trying to load raw machine code into memory and run it from within a C program, right now when the program executes it breaks when trying to run mprotect on the memory to make it executable. I'm also not entirely sure that if the memory does get set right it will execute. I am currently running this on Ubuntu Linux x86 (Maybe the ...
Hi all, I want to write a signal handler to catch SIGSEGV. First , I would protect a block of memory for read or writes using char *buffer; char *p; char a; int pagesize = 4096; " mprotect(buffer,pagesize,PROT_NONE) " What this will do is , it will protect the memory starting from buffer till pagesize for any reads or writes. ...
I'm constructing a program which uses mprotect() to restrict a block of memory from accessing. When the memory is requested, a SIGSEGV is thrown which I listen for using a signal() call. Once the SIGSEGV has been detected, I need to somehow access the pointer to the memory that was requested (that threw the fault) and the size of the s...
I am writing a JIT on ARM Linux that executes an instruction set that contains self-modifying code. The instruction set does not have any cache flush instructions (similar to x86 in that respect). If I write out some code to a page and then call mprotect on that page, is that sufficient to invalidate the instruction cache? Or do I also ...
I'm wondering if there's a way to write-protect every page in a Linux process' address space (from inside of the process itself, by way of mprotect()). By "every page", I really mean every page of the process's address space that might be written to by an ordinary program running in user mode -- so, the program text, the constants, the ...