barrier_nospec() is a speculation barrier with arch dependent
implementation. To be able to use barrier_nospec() in non-architecture
code add a generic version that does nothing. Architectures that don't
have a use case for speculation barrier shouldn't need to define an arch
specific version.
Architectures needing speculation barrier can override the generic
version in their asm/barrier.h.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
---
include/linux/nospec.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/linux/nospec.h b/include/linux/nospec.h
index c1e79f72cd89..60e040a5df27 100644
--- a/include/linux/nospec.h
+++ b/include/linux/nospec.h
@@ -60,6 +60,10 @@ static inline unsigned long array_index_mask_nospec(unsigned long index,
(typeof(_i)) (_i & _mask); \
})
+#ifndef barrier_nospec
+#define barrier_nospec() do { } while (0)
+#endif
+
/* Speculation control prctl */
int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which);
int arch_prctl_spec_ctrl_set(struct task_struct *task, unsigned long which,
--
2.37.3
