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 08:18:58 -0800 |
| commit | b388e0d11005381b79a8d296e53a376fbf17a577 (patch) | |
| tree | a98b0439650297dc0ceb78fd1699f20433512e31 | |
| parent | d896e223d601ce7abec4783aec3fb563ec9ad4e3 (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 21ca44c4f6d5..1f0ea5537e8a 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -2,6 +2,7 @@ config UML bool default y select HAVE_UID16 + select HAVE_FUTEX_CMPXCHG if FUTEX select GENERIC_IRQ_SHOW select GENERIC_CPU_DEVICES select GENERIC_IO |