Messages in this thread Patch in this message | | | From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 068/135] um: Skip futex_atomic_cmpxchg_inatomic() test | Date | Fri, 6 Feb 2015 12:00:46 +0000 |
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3.16.7-ckt6 -stable review patch. If anyone has any objections, please let me know.
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From: Richard Weinberger <richard@nod.at>
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 <miklos@szeredi.hu> Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Richard Weinberger <richard@nod.at> Tested-by: Daniel Walter <d.walter@0x90.at> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/um/Kconfig.common | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 6915d28cf118..85a70c14d70f 100644 --- 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 -- 2.1.4
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