lkml.org 
[lkml]   [2004]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [LTP] Re: Recent changes in LTP test results
Daniel McNeil <daniel@osdl.org> wrote:
>
> The /proc/pid/maps looked like this:
>
> without nx-update patch:
> 40017000-40018000 ---p 40017000 00:00 0
> =====
> with -mm1:
> 40017000-40018000 --xp 40017000 00:00 0

Here's mine, with current -linus bk:

40000000-40001000 ---p 40000000 00:00 0

> So it looks like the page being executable allows read
> access.
>
> Not sure why you do not see this on your machine. This
> fails on my 2-proc xeon box (and all the STP machines).
>


#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>


main()
{
char *p0 = 0;
char *p1 = (char *)-1;
char *p2;
int err;

p2 = mmap(0, 4096, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);

printf("p2=%p\n", p2);
printf("pid=%d\n", getpid());

getchar();

errno = 0;
err = access(p0, R_OK);
printf("access 0 ptr %p return code %d errno %d\n", p0, err, errno);
perror("access result:");
errno = 0;
err = access(p1, R_OK);
printf("access 1 ptr %p return code %d errno %d\n", p1, err, errno);
perror("access result:");
errno = 0;
err = access(p2, R_OK);
printf("access 2 ptr %p return code %d errno %d\n", p2, err, errno);
perror("access result:");
}

vmm:/home/akpm> ./x
p2=0x40000000
pid=2038

access 0 ptr (nil) return code -1 errno 14
access result:: Bad address
access 1 ptr 0xffffffff return code -1 errno 14
access result:: Bad address
access 2 ptr 0x40000000 return code -1 errno 14
access result:: Bad address

I get this result on both p4 xeon and p3 xeon.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:04    [W:0.078 / U:0.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site