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| author | Richard Weinberger <richard@nod.at> | 2014-12-10 13:53:51 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-01-29 15:44:47 +0100 |
| commit | ad63ddb0b121132417f91578791e88306396a41b (patch) | |
| tree | 0354ad01d32489260fc595ceb4cd34cbb34b4af0 | |
| parent | 0a5c9ec92cef9186f352f665931053236c1f25ac (diff) | |
| download | lwn-ad63ddb0b121132417f91578791e88306396a41b.tar.gz lwn-ad63ddb0b121132417f91578791e88306396a41b.zip | |
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: Jiri Slaby <jslaby@suse.cz>
| -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 8ddea1f8006a..0228a6ab9b18 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -7,6 +7,7 @@ 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 |