linux-kernel - [PATCH 4/5] x86/uapi: Stop leaking kconfig references to userspace

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Message-Id: <20251230-headers_install-config-leak-v1-4-efba5c58073d@linutronix.de>
Date: Tue, 30 Dec 2025 08:10:59 +0100
From: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
To: Vineet Gupta <vgupta@...nel.org>, Russell King <linux@...linux.org.uk>, 
 Dinh Nguyen <dinguyen@...nel.org>, Thomas Gleixner <tglx@...utronix.de>, 
 Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, 
 Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org, 
 "H. Peter Anvin" <hpa@...or.com>
Cc: linux-snps-arc@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, Arnd Bergmann <arnd@...db.de>, 
 Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Subject: [PATCH 4/5] x86/uapi: Stop leaking kconfig references to userspace

UAPI headers are not supposed to leak references to kconfig symbols.
These won't be set when building userspace. Hide the kconfig reference
behind 'if defined(__KERNEL__)', so it will be stripped by
headers_install.sh. The result for userspace will be the same, but the
exceptions in headers_install.sh can also be removed.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
---
 arch/x86/include/uapi/asm/auxvec.h | 2 +-
 scripts/headers_install.sh         | 2 --
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/include/uapi/asm/auxvec.h b/arch/x86/include/uapi/asm/auxvec.h
index 6beb55bbefa4..bdde9e18f94e 100644
--- a/arch/x86/include/uapi/asm/auxvec.h
+++ b/arch/x86/include/uapi/asm/auxvec.h
@@ -11,7 +11,7 @@
 #define AT_SYSINFO_EHDR		33

 /* entries in ARCH_DLINFO: */
-#if defined(CONFIG_IA32_EMULATION) || !defined(CONFIG_X86_64)
+#if defined(__KERNEL__) && (defined(CONFIG_IA32_EMULATION) || !defined(CONFIG_X86_64))
 # define AT_VECTOR_SIZE_ARCH 3
 #else /* else it's non-compat x86-64 */
 # define AT_VECTOR_SIZE_ARCH 2
diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh
index 613f400a67d1..1301ba68d772 100755
--- a/scripts/headers_install.sh
+++ b/scripts/headers_install.sh
@@ -70,8 +70,6 @@ configs=$(sed -e '
 #
 # The format is <file-name>:<CONFIG-option> in each line.
 config_leak_ignores="
-arch/x86/include/uapi/asm/auxvec.h:CONFIG_IA32_EMULATION
-arch/x86/include/uapi/asm/auxvec.h:CONFIG_X86_64
 "

 for c in $configs

-- 
2.52.0