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authorMaarten Lankhorst <maarten.lankhorst@linux.intel.com>2024-05-28 22:21:34 +0200
committerMaarten Lankhorst <maarten.lankhorst@linux.intel.com>2024-05-28 22:21:34 +0200
commitf73a058be5d70dd81a43f16b2bbff4b1576a7af8 (patch)
treeb7959c01cf7a5d95c7c4d5b61929ff9123370322 /arch/x86/include/asm/nospec-branch.h
parentdma-buf: handle testing kthreads creation failure (diff)
parentMerge tag 'drm-misc-fixes-2024-05-23' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes (diff)
downloadwireguard-linux-f73a058be5d70dd81a43f16b2bbff4b1576a7af8.tar.xz
wireguard-linux-f73a058be5d70dd81a43f16b2bbff4b1576a7af8.zip
Merge remote-tracking branch 'drm/drm-fixes' into drm-misc-fixes
v6.10-rc1 is released, forward from v6.9 Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Diffstat (limited to 'arch/x86/include/asm/nospec-branch.h')
-rw-r--r--arch/x86/include/asm/nospec-branch.h38
1 files changed, 33 insertions, 5 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index fc3a8a3c7ffe..ff5f1ecc7d1e 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -262,11 +262,20 @@
.Lskip_rsb_\@:
.endm
+/*
+ * The CALL to srso_alias_untrain_ret() must be patched in directly at
+ * the spot where untraining must be done, ie., srso_alias_untrain_ret()
+ * must be the target of a CALL instruction instead of indirectly
+ * jumping to a wrapper which then calls it. Therefore, this macro is
+ * called outside of __UNTRAIN_RET below, for the time being, before the
+ * kernel can support nested alternatives with arbitrary nesting.
+ */
+.macro CALL_UNTRAIN_RET
#if defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO)
-#define CALL_UNTRAIN_RET "call entry_untrain_ret"
-#else
-#define CALL_UNTRAIN_RET ""
+ ALTERNATIVE_2 "", "call entry_untrain_ret", X86_FEATURE_UNRET, \
+ "call srso_alias_untrain_ret", X86_FEATURE_SRSO_ALIAS
#endif
+.endm
/*
* Mitigate RETBleed for AMD/Hygon Zen uarch. Requires KERNEL CR3 because the
@@ -282,8 +291,8 @@
.macro __UNTRAIN_RET ibpb_feature, call_depth_insns
#if defined(CONFIG_MITIGATION_RETHUNK) || defined(CONFIG_MITIGATION_IBPB_ENTRY)
VALIDATE_UNRET_END
- ALTERNATIVE_3 "", \
- CALL_UNTRAIN_RET, X86_FEATURE_UNRET, \
+ CALL_UNTRAIN_RET
+ ALTERNATIVE_2 "", \
"call entry_ibpb", \ibpb_feature, \
__stringify(\call_depth_insns), X86_FEATURE_CALL_DEPTH
#endif
@@ -317,6 +326,19 @@
ALTERNATIVE "", __stringify(verw _ASM_RIP(mds_verw_sel)), X86_FEATURE_CLEAR_CPU_BUF
.endm
+#ifdef CONFIG_X86_64
+.macro CLEAR_BRANCH_HISTORY
+ ALTERNATIVE "", "call clear_bhb_loop", X86_FEATURE_CLEAR_BHB_LOOP
+.endm
+
+.macro CLEAR_BRANCH_HISTORY_VMEXIT
+ ALTERNATIVE "", "call clear_bhb_loop", X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT
+.endm
+#else
+#define CLEAR_BRANCH_HISTORY
+#define CLEAR_BRANCH_HISTORY_VMEXIT
+#endif
+
#else /* __ASSEMBLY__ */
#define ANNOTATE_RETPOLINE_SAFE \
@@ -342,6 +364,8 @@ extern void retbleed_return_thunk(void);
static inline void retbleed_return_thunk(void) {}
#endif
+extern void srso_alias_untrain_ret(void);
+
#ifdef CONFIG_MITIGATION_SRSO
extern void srso_return_thunk(void);
extern void srso_alias_return_thunk(void);
@@ -357,6 +381,10 @@ extern void srso_alias_return_thunk(void);
extern void entry_untrain_ret(void);
extern void entry_ibpb(void);
+#ifdef CONFIG_X86_64
+extern void clear_bhb_loop(void);
+#endif
+
extern void (*x86_return_thunk)(void);
extern void __warn_thunk(void);