[LTP] [PATCH v3 2/2] pkey: add test for memory protection keys

[Li Wang]

On Tue, Jun 25, 2019 at 5:01 PM Jan Stancek <jstancek@redhat.com> wrote:

>
> ----- Original Message -----
> > +
> > +#ifndef PKEYS_H
> > +#define PKEYS_H
> > +
> > +#include "tst_test.h"
> > +#include "lapi/syscalls.h"
> > +
> > +#ifndef PKEY_DISABLE_ACCESS
> > +# define PKEY_DISABLE_ACCESS 0x1
> > +# define PKEY_DISABLE_WRITE  0x2
> > +#endif
> > +
> > +#ifndef HAVE_PKEY_MPROTECT
> > +static inline int pkey_mprotect(void *addr, size_t len, int prot, int
> pkey)
> > +{
> > +     return tst_syscall(SYS_pkey_mprotect, addr, len, prot, pkey);
>
> Hi,
>
> This should be __NR_*:
>

Exactly. Sorry about that mistake.


>
> In file included from pkey01.c:32:
> pkey.h: In function ‘pkey_mprotect’:
> pkey.h:20: error: ‘SYS_pkey_mprotect’ undeclared (first use in this
> function)
> pkey.h:20: error: (Each undeclared identifier is reported only once
> pkey.h:20: error: for each function it appears in.)
> pkey.h: In function ‘pkey_alloc’:
> pkey.h:25: error: ‘SYS_pkey_alloc’ undeclared (first use in this function)
> pkey.h: In function ‘pkey_free’:
> pkey.h:30: error: ‘SYS_pkey_free’ undeclared (first use in this function)
>
> > +static void setup(void)
> > +{
> > +     int i, fd;
> > +
> > +     if (access("/proc/sys/vm/nr_hugepages", F_OK)) {
> > +             tst_res(TINFO, "Huge page is not supported");
> > +             size = getpagesize();
> > +             no_hugepage = 1;
> > +     } else {
> > +             SAFE_FILE_PRINTF("/proc/sys/vm/nr_hugepages", "%d", 1);
>
> There are 2 problems here, both related to fact that this file exists,
> but may return EOPNOTSUPP on read/write.
>
> 1. save_restore should ignore also read/open errors if path is prefixed
> with '?'
>    I'll send this separately.
>

Thank you for that patch.



>
> 2. SAFE_FILE_PRINTF in pkey01.c shouldn't be safe, because we need to
> somehow
>    detect that write worked
>

Yes, we should verify if that value has been wrote.

>
> # ls -la /proc/sys/vm/nr_hugepages
> -rw-r--r--. 1 root root 0 Jun 25 04:12 /proc/sys/vm/nr_hugepages
>
> # cat /proc/sys/vm/nr_hugepages
> cat: /proc/sys/vm/nr_hugepages: Operation not supported
>
> > +static struct tst_test test = {
> > +     .tcnt = ARRAY_SIZE(tcases),
> > +     .forks_child = 1,
> > +     .test = verify_pkey,
> > +     .setup = setup,
> > +     .cleanup = cleanup,
> > +     .save_restore = save_restore,
>
> .needs_root = 1 as well, since we write to /proc and mount tmpfs
>

Agree.

>
> Rest looks good to me, but I haven't found yet system that could run the
> test.
>
> Regards,
> Jan
>


-- 
Regards,
Li Wang
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