No subject

[Cy Schubert]

Hi,

The following little test case segfaults when aslr is enabled:

#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>

int
main(int argc, char *argv[])
{
	struct rlimit   rl;
	int rc;

	rl.rlim_cur = 50 * 4096;
	rl.rlim_max = 50 * 4096;
	rc = setrlimit(RLIMIT_STACK, &rl);

	return(rc);
}


slippy# sysctl kern.elf64.aslr.enable=1
kern.elf64.aslr.enable: 0 -> 1
slippy# ./test 
Segmentation fault (core dumped)
slippy# gdb test
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Reading symbols from test...
(gdb) run
Starting program: /export/home/cy/freebsd/tests/setrlimit/test 

Program received signal SIGSEGV, Segmentation fault.
setrlimit () at setrlimit.S:4
4	setrlimit.S: No such file or directory.
(gdb) bt
#0  setrlimit () at setrlimit.S:4
Backtrace stopped: Cannot access memory at address 0x7fffffe372e8
(gdb) 


It only occurs with aslr enabled and stack gap != 0. This isn't right.


-- 
Cheers,
Cy Schubert <Cy.Schubert at cschubert.com>
FreeBSD UNIX:  <cy at FreeBSD.org>   Web:  http://www.FreeBSD.org

	The need of the many outweighs the greed of the few.