Executing from dynamically allocated memory

In the past, I've malloc'd memory, written machine instructions into it,
and called the function I built there.


All this on a 32-bit intel instruction set, on a Debian system.


This appears no longer too work. My program gives a segmentation fault.
The debugger tells me that the segmentation fault occurs on the first
instruction of the called function, a
push %ebp
residing in malloced memory.


Now it was a year or three ago that this worked. Has Linux changed in
this respect? Is there something new I have to do to allocate executable
writable memory for this purpose?


Or might there be something even weirder going on?


-- hendrik


[ Sounds like the NX bit. See http://en.wikipedia.org/wiki/NX_bit#Linux -John]

Return to the comp.compilers page.
Search the comp.compilers archives again.