Decrypted per-CPU data is gated by AMD_MEM_ENCRYPT. With INTEL_TDX_GUEST=y and AMD_MEM_ENCRYPT=n it falls back to ordinary per-CPU storage, so converting a variable to shared memory can expose unrelated data on the same page.
Gate the declarations and linker section on X86_MEM_ENCRYPT, which both AMD_MEM_ENCRYPT and INTEL_TDX_GUEST select. Existing AMD configurations are unchanged. Keep the decrypted subsection page-aligned at both ends. The per-CPU template and each allocated per-CPU unit are also page-aligned, so page conversion cannot expose ordinary per-CPU data. TDX-only configurations may need additional space for this alignment and isolation. Signed-off-by: Zack Rusin <[email protected]> --- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/percpu-defs.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index b2988aa12f66..1448e791773e 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -1013,7 +1013,7 @@ * Note: We use a separate section so that only this section gets * decrypted to avoid exposing more than we wish. */ -#ifdef CONFIG_AMD_MEM_ENCRYPT +#ifdef CONFIG_X86_MEM_ENCRYPT #define PERCPU_DECRYPTED_SECTION \ . = ALIGN(PAGE_SIZE); \ *(.data..percpu..decrypted) \ diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index dbe3267a0a13..54ce1442d918 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -172,7 +172,7 @@ * Declaration/definition used for per-CPU variables that should be accessed * as decrypted when memory encryption is enabled in the guest. */ -#ifdef CONFIG_AMD_MEM_ENCRYPT +#ifdef CONFIG_X86_MEM_ENCRYPT #define DECLARE_PER_CPU_DECRYPTED(type, name) \ DECLARE_PER_CPU_SECTION(type, name, "..decrypted") -- 2.53.0
