Messages in this thread Patch in this message | | | From | "Potyra, Stefan" <> | Subject | [PATCH] mm: mlockall error for flag MCL_ONFAULT | Date | Wed, 22 May 2019 11:23:37 +0000 |
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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.
Consequently, return the error EINVAL, if only MCL_ONFAULT is passed. That way, applications will at least detect that they are calling mlockall() incorrectly.
Fixes: b0f205c2a308 ("mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage") Signed-off-by: Stefan Potyra <Stefan.Potyra@elektrobit.com> --- Sparse shows a warning for mlock.c, but it is not related to this patch.
mm/mlock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/mlock.c b/mm/mlock.c index e492a155c51a..03f39cbdd4c4 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()) -- 2.20.1
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