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 07:52:33 -0800 |
| commit | 914f02cd94750cfdf70004d9e086ee51abd84c7b (patch) | |
| tree | 9b4675059fd27239697124e668f1c9e049589bac | |
| parent | 42ddd03e8044fdf101ded7a56b73dd5b4b3436a6 (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 bceee6623b00..d1ff46c0559b 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -8,6 +8,7 @@ config UML default y select HAVE_GENERIC_HARDIRQS select HAVE_UID16 + select HAVE_FUTEX_CMPXCHG if FUTEX select GENERIC_IRQ_SHOW select GENERIC_CPU_DEVICES select GENERIC_IO |