Re: [PATCH v5 29/32] x86/mm: Add support to encrypt the kernel in-place

From	Borislav Petkov <bp@alien8.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5 29/32] x86/mm: Add support to encrypt the kernel in-place
Date	2017-05-31 12:00 +0200
Message-ID	<tN8A2-34j-11@gated-at.bofh.it> (permalink)
References	(1 earlier) <tIt2p-2Cz-11@gated-at.bofh.it> <tIt2p-2Cz-9@gated-at.bofh.it> <tLqhI-8aW-13@gated-at.bofh.it> <tLqhI-8aW-11@gated-at.bofh.it> <tN8A2-34j-13@gated-at.bofh.it>
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On Tue, May 30, 2017 at 11:39:07AM -0500, Tom Lendacky wrote:
> Yes, it's from objtool:
> 
> arch/x86/mm/mem_encrypt_boot.o: warning: objtool: .text+0xd2: return
> instruction outside of a callable function

Oh, well, let's make it a global symbol then. Who knows, we might have
to live-patch it someday :-)

---
diff --git a/arch/x86/mm/mem_encrypt_boot.S b/arch/x86/mm/mem_encrypt_boot.S
index fb58f9f953e3..7720b0050840 100644
--- a/arch/x86/mm/mem_encrypt_boot.S
+++ b/arch/x86/mm/mem_encrypt_boot.S
@@ -47,9 +47,9 @@ ENTRY(sme_encrypt_execute)
 	movq	%rdx, %r12		/* Kernel length */
 
 	/* Copy encryption routine into the workarea */
-	movq	%rax, %rdi		/* Workarea encryption routine */
-	leaq	.Lenc_start(%rip), %rsi	/* Encryption routine */
-	movq	$(.Lenc_stop - .Lenc_start), %rcx	/* Encryption routine length */
+	movq	%rax, %rdi				/* Workarea encryption routine */
+	leaq	__enc_copy(%rip), %rsi			/* Encryption routine */
+	movq	$(.L__enc_copy_end - __enc_copy), %rcx	/* Encryption routine length */
 	rep	movsb
 
 	/* Setup registers for call */
@@ -70,8 +70,7 @@ ENTRY(sme_encrypt_execute)
 	ret
 ENDPROC(sme_encrypt_execute)
 
-.Lenc_start:
-ENTRY(sme_enc_routine)
+ENTRY(__enc_copy)
 /*
  * Routine used to encrypt kernel.
  *   This routine must be run outside of the kernel proper since
@@ -147,5 +146,5 @@ ENTRY(sme_enc_routine)
 	wrmsr
 
 	ret
-ENDPROC(sme_enc_routine)
-.Lenc_stop:
+.L__enc_copy_end:
+ENDPROC(__enc_copy)

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

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Re: [PATCH v5 29/32] x86/mm: Add support to encrypt the kernel  in-place Borislav Petkov <bp@alien8.de> - 2017-05-26 18:30 +0200
  Re: [PATCH v5 29/32] x86/mm: Add support to encrypt the kernel  in-place Borislav Petkov <bp@alien8.de> - 2017-05-31 12:00 +0200

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