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From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>, Ard Biesheuvel <ardb@kernel.org>,
	Juergen Gross <jgross@suse.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Brian Gerst <brgerst@gmail.com>
Subject: [PATCH 1/5] x86/sme: Clear decrypted BSS separately
Date: Thu, 23 Jul 2026 23:02:52 -0400	[thread overview]
Message-ID: <20260724030256.232690-2-brgerst@gmail.com> (raw)
In-Reply-To: <20260724030256.232690-1-brgerst@gmail.com>

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@gmail.com>
---
 arch/x86/kernel/vmlinux.lds.S | 2 +-
 arch/x86/mm/mem_encrypt_amd.c | 3 +++
 2 files changed, 4 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..d39e1e29bcb9 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -479,6 +479,9 @@ void __init sme_early_init(void)
 	if (!sme_me_mask)
 		return;
 
+	memset(__start_bss_decrypted, 0,
+	       (unsigned long) __end_bss_decrypted - (unsigned long) __start_bss_decrypted);
+
 	early_pmd_flags = __sme_set(early_pmd_flags);
 
 	__supported_pte_mask = __sme_set(__supported_pte_mask);
-- 
2.55.0


  reply	other threads:[~2026-07-24  3:03 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-24  3:02 [PATCH 0/5] x86/boot: Early boot cleanups Brian Gerst
2026-07-24  3:02 ` Brian Gerst [this message]
2026-07-24 16:41   ` [PATCH 1/5] x86/sme: Clear decrypted BSS separately Tom Lendacky
2026-07-24 18:57     ` Brian Gerst
2026-07-24 19:56       ` Tom Lendacky
2026-07-24 21:06         ` Brian Gerst
2026-07-24  3:02 ` [PATCH 2/5] x86/boot/64: Clear BSS as early as possible Brian Gerst
2026-07-24 11:04   ` Nikolay Borisov
2026-07-24 11:34     ` Brian Gerst
2026-07-27 19:00       ` Brian Gerst
2026-07-24  3:02 ` [PATCH 3/5] x86/boot: Remove hardcoded boot_param constants Brian Gerst
2026-07-24 13:19   ` Nikolay Borisov
2026-07-24 18:22   ` Tom Lendacky
2026-07-24 19:03     ` Brian Gerst
2026-07-24  3:02 ` [PATCH 4/5] x86/boot/64: Remove copy_bootdata() call Brian Gerst
2026-07-24  3:02 ` [PATCH 5/5] x86/boot/64: Copy boot parameters and command line earlier Brian Gerst

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