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| author | Richard Weinberger <richard@nod.at> | 2014-12-10 13:53:51 +0100 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2015-01-04 14:20:26 +0100 |
| commit | f911d731054ab3d82ee72a16b889e17ca3a2332a (patch) | |
| tree | 57cf2f7ad304459ae6af5fc5aa1788c5d550f7fb /arch/um | |
| parent | d753856c9f9ae33a980192aa7b81d8b97d79dec2 (diff) | |
| download | lwn-f911d731054ab3d82ee72a16b889e17ca3a2332a.tar.gz lwn-f911d731054ab3d82ee72a16b889e17ca3a2332a.zip | |
um: Skip futex_atomic_cmpxchg_inatomic() test
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>
Diffstat (limited to 'arch/um')
| -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 |