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| author | Potyra, Stefan <Stefan.Potyra@elektrobit.com> | 2019-06-13 15:55:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-06-13 17:34:56 -1000 |
| commit | dedca63504a204dc8410d98883fdc16dffa8cb80 (patch) | |
| tree | 9c0cf66ad0333054241acc8bf3c32e32efe25109 | |
| parent | c04e32e911653442fc834be6e92e072aeebe01a1 (diff) | |
| download | linux-stable-dedca63504a204dc8410d98883fdc16dffa8cb80.tar.gz linux-stable-dedca63504a204dc8410d98883fdc16dffa8cb80.tar.bz2 linux-stable-dedca63504a204dc8410d98883fdc16dffa8cb80.zip | |
mm/mlock.c: mlockall error for flag MCL_ONFAULT
If mlockall() is called with only MCL_ONFAULT as flag, it removes any
previously applied lockings and does nothing else.
This behavior is counter-intuitive and doesn't match the Linux man page.
For mlockall():
EINVAL Unknown flags were specified or MCL_ONFAULT was specified
without either MCL_FUTURE or MCL_CURRENT.
Consequently, return the error EINVAL, if only MCL_ONFAULT is passed.
That way, applications will at least detect that they are calling
mlockall() incorrectly.
Link: http://lkml.kernel.org/r/20190527075333.GA6339@er01809n.ebgroup.elektrobit.com
Fixes: b0f205c2a308 ("mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage")
Signed-off-by: Stefan Potyra <Stefan.Potyra@elektrobit.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/mlock.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/mlock.c b/mm/mlock.c index 080f3b36415b..cef65bf3964c 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -797,7 +797,8 @@ SYSCALL_DEFINE1(mlockall, int, flags) unsigned long lock_limit; int ret; - if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT))) + if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT)) || + flags == MCL_ONFAULT) return -EINVAL; if (!can_do_mlock()) |