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authorPeter Zijlstra <peterz@infradead.org>2022-06-14 23:15:59 +0200
committerBorislav Petkov <bp@suse.de>2022-06-27 10:33:59 +0200
commit9bb2ec608a209018080ca262f771e6a9ff203b6f (patch)
treebe33da1675577b06894f7b15e7617cdd041afc49 /arch
parentintel_idle: Disable IBRS during long idle (diff)
downloadlinux-dev-9bb2ec608a209018080ca262f771e6a9ff203b6f.tar.xz
linux-dev-9bb2ec608a209018080ca262f771e6a9ff203b6f.zip
objtool: Update Retpoline validation
Update retpoline validation with the new CONFIG_RETPOLINE requirement of not having bare naked RET instructions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to '')
-rw-r--r--arch/x86/include/asm/nospec-branch.h6
-rw-r--r--arch/x86/mm/mem_encrypt_boot.S2
-rw-r--r--arch/x86/xen/xen-head.S1
3 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index ce1acb557162..455d79c6c2f3 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -76,6 +76,12 @@
.endm
/*
+ * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
+ * vs RETBleed validation.
+ */
+#define ANNOTATE_UNRET_SAFE ANNOTATE_RETPOLINE_SAFE
+
+/*
* JMP_NOSPEC and CALL_NOSPEC macros can be used instead of a simple
* indirect jmp/call which may be susceptible to the Spectre variant 2
* attack.
diff --git a/arch/x86/mm/mem_encrypt_boot.S b/arch/x86/mm/mem_encrypt_boot.S
index d94dea450fa6..9de3d900bc92 100644
--- a/arch/x86/mm/mem_encrypt_boot.S
+++ b/arch/x86/mm/mem_encrypt_boot.S
@@ -66,6 +66,7 @@ SYM_FUNC_START(sme_encrypt_execute)
pop %rbp
/* Offset to __x86_return_thunk would be wrong here */
+ ANNOTATE_UNRET_SAFE
ret
int3
SYM_FUNC_END(sme_encrypt_execute)
@@ -154,6 +155,7 @@ SYM_FUNC_START(__enc_copy)
pop %r15
/* Offset to __x86_return_thunk would be wrong here */
+ ANNOTATE_UNRET_SAFE
ret
int3
.L__enc_copy_end:
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 3a2cd93bf059..fa884fc73e07 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -26,6 +26,7 @@ SYM_CODE_START(hypercall_page)
.rept (PAGE_SIZE / 32)
UNWIND_HINT_FUNC
ANNOTATE_NOENDBR
+ ANNOTATE_UNRET_SAFE
ret
/*
* Xen will write the hypercall page, and sort out ENDBR.