From: Zack Rusin <zack.rusin@broadcom.com>
To: Kiryl Shutsemau <kas@kernel.org>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, Dennis Zhou <dennis@kernel.org>,
Tejun Heo <tj@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Ajay Kaher <ajay.kaher@broadcom.com>,
Alexey Makhalov <alexey.makhalov@broadcom.com>,
Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
virtualization@lists.linux.dev,
bcm-kernel-feedback-list@broadcom.com,
linux-kernel@vger.kernel.org, Christoph Lameter <cl@gentwo.org>,
Andrew Morton <akpm@linux-foundation.org>,
Bo Gan <bo.gan@broadcom.com>,
linux-mm@kvack.org, linux-arch@vger.kernel.org,
linux-coco@lists.linux.dev, kvm@vger.kernel.org,
Jonathan Corbet <corbet@lwn.net>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Long Li <longli@microsoft.com>, Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
linux-doc@vger.kernel.org, linux-hyperv@vger.kernel.org,
Nathan Chancellor <nathan@kernel.org>,
Kees Cook <kees@kernel.org>, Ashish Kalra <ashish.kalra@amd.com>
Subject: [PATCH v2 1/6] percpu: Page-align decrypted data in UP kernels
Date: Tue, 29 Sep 2026 00:02:50 -0400 [thread overview]
Message-ID: <20260929040256.543767-2-zack.rusin@broadcom.com> (raw)
In-Reply-To: <20260929040256.543767-1-zack.rusin@broadcom.com>
Without SMP, DEFINE_PER_CPU_DECRYPTED() places variables in
.data..decrypted. Align both ends of that section so that changing a
variable's encryption attribute cannot expose unrelated kernel data.
Keep the section in permanent data, where UP variables are instantiated.
Fixes: 000f8870a47b ("vmlinux.lds.h: Fix placement of '.data..decrypted' section")
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
---
include/asm-generic/vmlinux.lds.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index b2988aa12f66..64bc2bfdd2ec 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -368,10 +368,19 @@
/*
* .data section
*/
+#if defined(CONFIG_AMD_MEM_ENCRYPT) && !defined(CONFIG_SMP)
+#define DATA_DECRYPTED \
+ . = ALIGN(PAGE_SIZE); \
+ *(.data..decrypted) \
+ . = ALIGN(PAGE_SIZE);
+#else
+#define DATA_DECRYPTED *(.data..decrypted)
+#endif
+
#define DATA_DATA \
*(.xiptext) \
*(DATA_MAIN) \
- *(.data..decrypted) \
+ DATA_DECRYPTED \
*(.ref.data) \
*(.data..shared_aligned) /* percpu related */ \
*(.data..unlikely) \
--
2.53.0
next prev parent reply other threads:[~2026-09-29 4:03 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-29 4:02 [PATCH v2 0/6] x86/percpu: Share decrypted storage before guest setup Zack Rusin
2026-09-29 4:02 ` Zack Rusin [this message]
2026-09-29 4:02 ` [PATCH v2 2/6] percpu: Bound decrypted storage for all x86 encrypted guests Zack Rusin
2026-09-29 7:54 ` Peter Zijlstra
2026-09-29 4:02 ` [PATCH v2 3/6] x86/percpu: Require embedded allocation in " Zack Rusin
2026-09-29 4:02 ` [PATCH v2 4/6] x86/mm: Provide common early memory decryption Zack Rusin
2026-09-29 4:02 ` [PATCH v2 5/6] x86/tdx: Support early sharing of kernel data Zack Rusin
2026-09-29 4:02 ` [PATCH v2 6/6] x86/percpu: Share decrypted storage before guest CPU setup Zack Rusin
2026-09-29 5:39 ` [PATCH v2 0/6] x86/percpu: Share decrypted storage before guest setup Borislav Petkov
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