diff options
| author | Dave Airlie <airlied@redhat.com> | 2019-01-24 18:54:15 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-26 09:38:36 +0100 |
| commit | 4b527f25a4ac64c0d17c882cdf8322be66f31611 (patch) | |
| tree | 580fdaae32189aab0cdebe88442c777496f0cf45 | |
| parent | cac2590d2582c04f995c2b1cd2c30d8a0c11b36e (diff) | |
locking/qspinlock: Pull in asm/byteorder.h to ensure correct endianness
This commit is not required upstream, but is required for the 4.9.y
stable series.
Upstream commit 101110f6271c ("Kbuild: always define endianess in
kconfig.h") ensures that either __LITTLE_ENDIAN or __BIG_ENDIAN is
defined to reflect the endianness of the target CPU architecture
regardless of whether or not <asm/byteorder.h> has been #included. The
upstream definition of 'struct qspinlock' relies on this property.
Unfortunately, the 4.9.y stable series does not provide this guarantee,
so the 'spin_unlock()' routine can erroneously treat the underlying
lockword as big-endian on little-endian architectures using native
qspinlock (i.e. x86_64 without PV) if the caller has not included
<asm/byteorder.h>. This can lead to hangs such as the one in
'i915_gem_request()' reported via bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=202063
Fix the issue by ensuring that <asm/byteorder.h> is #included in
<asm/qspinlock_types.h>, where 'struct qspinlock' is defined.
Cc: <stable@vger.kernel.org> # 4.9
Signed-off-by: Dave Airlie <airlied@redhat.com>
[will: wrote commit message]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/asm-generic/qspinlock_types.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/asm-generic/qspinlock_types.h b/include/asm-generic/qspinlock_types.h index d10f1e7d6ba8..6503e96710fa 100644 --- a/include/asm-generic/qspinlock_types.h +++ b/include/asm-generic/qspinlock_types.h @@ -18,6 +18,8 @@ #ifndef __ASM_GENERIC_QSPINLOCK_TYPES_H #define __ASM_GENERIC_QSPINLOCK_TYPES_H +#include <asm/byteorder.h> + /* * Including atomic.h with PARAVIRT on will cause compilation errors because * of recursive header file incluson via paravirt_types.h. So don't include |