Albert Cahalan writes: > VM_STACK_DEFAULT_FLAGS32 is wrong. A fail-safe > default is important for security. If gcc on PowerPC ever > does generate code which puts trampolines on the stack, > then that can be fixed by converting to legal C code or > by adding the fragile marking to the defective executables. > Did gcc ever generate such code on PowerPC? If not, > then there is no reason to ever allow an executable stack.
I believe it did for nested procedures in C. Now that we have the VDSO and use it for signal trampolines, we probably could change the default stack protections. > No. Look in the segment registers. The granularity > isn't great, but the stack can be protected at least. No, ld.so tends to go just below the stack: f7fe6000-f7fff000 r-xp 00000000 08:05 17069 /lib/ld-2.3.6.so f800e000-f800f000 r--p 00018000 08:05 17069 /lib/ld-2.3.6.so f800f000-f8010000 rwxp 00019000 08:05 17069 /lib/ld-2.3.6.so ffe67000-ffe7c000 rw-p ffe67000 00:00 0 [stack] Paul. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
