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authorMarcel Ziswiler <marcel.ziswiler@toradex.com>2020-05-21 00:54:36 +0200
committerMarcel Ziswiler <marcel.ziswiler@toradex.com>2020-05-21 00:54:36 +0200
commit135d39dcedcedd1f44ea0bba52f15ac5922c114f (patch)
tree12379fc8ef7489eaca1c7245f8bd6af74c619a8f /arch/x86/entry/calling.h
parent187764bd111b27783b6d68ffb3b3dbb3a9bafd38 (diff)
parent1279cd128bba968ebe0a2df7f7ae38bae90250ef (diff)
Merge remote-tracking branch 'remotes/fslc/4.9-2.3.x-imx' into toradex_4.9-2.3.x-imx-next
Conflicts: sound/soc/codecs/sgtl5000.c sound/soc/fsl/imx-sgtl5000.c
Diffstat (limited to 'arch/x86/entry/calling.h')
-rw-r--r--arch/x86/entry/calling.h18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index 9a9e5884066c..8af8c070f213 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -1,4 +1,5 @@
#include <linux/jump_label.h>
+#include <asm/cpufeatures.h>
/*
@@ -201,6 +202,23 @@ For 32-bit we have the following conventions - kernel is built with
.byte 0xf1
.endm
+/*
+ * Mitigate Spectre v1 for conditional swapgs code paths.
+ *
+ * FENCE_SWAPGS_USER_ENTRY is used in the user entry swapgs code path, to
+ * prevent a speculative swapgs when coming from kernel space.
+ *
+ * FENCE_SWAPGS_KERNEL_ENTRY is used in the kernel entry non-swapgs code path,
+ * to prevent the swapgs from getting speculatively skipped when coming from
+ * user space.
+ */
+.macro FENCE_SWAPGS_USER_ENTRY
+ ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_USER
+.endm
+.macro FENCE_SWAPGS_KERNEL_ENTRY
+ ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_KERNEL
+.endm
+
#endif /* CONFIG_X86_64 */
/*