diff options
| author | Richard Weinberger <richard@nod.at> | 2014-12-10 13:53:51 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-27 08:29:45 -0800 |
| commit | b9d078ca4432b59f167e9c7824d8248353ede275 (patch) | |
| tree | 4b84a50eb0888267c5d2d5e1555da07aa11465dd | |
| parent | dcd295f7bec22860063b1339162d18b811659c4b (diff) | |
um: Skip futex_atomic_cmpxchg_inatomic() test
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/um/Kconfig.common | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 87bc86821bc9..d195a87ca542 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 |