This is a note to let you know that I've just added the patch titled

    um: Skip futex_atomic_cmpxchg_inatomic() test

to the 3.18-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     um-skip-futex_atomic_cmpxchg_inatomic-test.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From f911d731054ab3d82ee72a16b889e17ca3a2332a Mon Sep 17 00:00:00 2001
From: Richard Weinberger <[email protected]>
Date: Wed, 10 Dec 2014 13:53:51 +0100
Subject: um: Skip futex_atomic_cmpxchg_inatomic() test

From: Richard Weinberger <[email protected]>

commit f911d731054ab3d82ee72a16b889e17ca3a2332a upstream.

futex_atomic_cmpxchg_inatomic() does not work on UML because
it triggers a copy_from_user() in kernel context.
On UML copy_from_user() can only be used if the kernel was called
by a real user space process such that UML can use ptrace()
to fetch the value.

Reported-by: Miklos Szeredi <[email protected]>
Suggested-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>
Tested-by: Daniel Walter <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/um/Kconfig.common |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/um/Kconfig.common
+++ b/arch/um/Kconfig.common
@@ -3,6 +3,7 @@ config UML
        default y
        select HAVE_ARCH_AUDITSYSCALL
        select HAVE_UID16
+       select HAVE_FUTEX_CMPXCHG if FUTEX
        select GENERIC_IRQ_SHOW
        select GENERIC_CPU_DEVICES
        select GENERIC_IO


Patches currently in stable-queue which might be from [email protected] are

queue-3.18/x86-um-actually-mark-system-call-tables-readonly.patch
queue-3.18/um-skip-futex_atomic_cmpxchg_inatomic-test.patch
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