[PATCH v2 1/5] x86/sme: Clear decrypted BSS separately

[Brian Gerst]

The decrypted BSS section needs to be cleared after it is remapped as
decrypted memory.  Separate it so that the normal BSS section can be
cleared earlier.

Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
---
 arch/x86/kernel/vmlinux.lds.S | 2 +-
 arch/x86/mm/mem_encrypt_amd.c | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 2438b89a4620..e64c797e06c7 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -365,9 +365,9 @@ SECTIONS
 		*(.bss..page_aligned)
 		. = ALIGN(PAGE_SIZE);
 		*(BSS_MAIN)
-		BSS_DECRYPTED
 		. = ALIGN(PAGE_SIZE);
 		__bss_stop = .;
+		BSS_DECRYPTED
 	}
 
 	/*
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index 2f8c32173972..50a53fa10c96 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -476,6 +476,10 @@ void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, unsigned long s
 
 void __init sme_early_init(void)
 {
+	/* Needs to be cleared even if encryption is not enabled */
+	memset(__start_bss_decrypted, 0,
+	       (unsigned long) __end_bss_decrypted - (unsigned long) __start_bss_decrypted);
+
 	if (!sme_me_mask)
 		return;
 
-- 
2.55.0