From nobody Wed Sep 30 03:45:54 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 819AC39DBCC; Thu, 13 Aug 2026 11:04:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786619089; cv=none; b=bRN6e3LS7zic6vqEFer7Yw4iam8Q1ZgZq1JPUsfpVWfg/S+cFDAqTdvHG8NMQ5QNiqsFpCppqQGd+m1En+rbwkkAZI2O4uRb8rRmQlVEjQ9yIcv9PT7jcdZviNzPitjTuuHmVxM06DgcHWtwPPtNWSI8bABa7L9BrRmsCDVrI8Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786619089; c=relaxed/simple; bh=PcKCi1LRbWnZy64nxiug7UjKJeLsZzyf1j+yiyWTKZc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FFzm7YA1oS1udBMV4Xz7VWo4GhBXe1octEuzYNG2AekPQBz0NcwixEMdWSeAn9XojD51dHWM506V2LS14THTSNJnIkqGd7VMJWO1dvWnp6wWXC4K8WxQDrERB0+lAj0SnfDteVgtWY1Higmia+sk6VZVAksgmfMDxVkQCbgUj2c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=J+CKo+Qx; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=kIsHvHi4; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="J+CKo+Qx"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="kIsHvHi4" From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1786619081; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=drylERYSkymMGuM71Lww0ecHEIF1JsaXC010vxJDEHc=; b=J+CKo+QxLt7W1XYe43zmJsjrxTH+4WlOCGl6qKbASeGtp3X1ov5SFJ0YJwFY824OVi/SWt vUT3OBv7r6fHJsXCr+LmzLB3nAgF/mrW552nVkH/W5vwTw8z2MipZajES4muihtK3XfKi5 JMB/4akdk2AsnrjJwLdFk2o8XwV638+8b9d/plyNCYrdkJRbgu/DFaLHaXZK+vSP1LRSn1 SuF/SPSBjFRVE+GkhmskqHZKIadewsjC62reM2TdSSMZCgK6kTWgWjeUBkbLsc1RxkLwcS /Ch13ueab1EwJt2DCryG1MLST86a1CNrneddIEfAQeUd474MULOfMAktgwTOXQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1786619081; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=drylERYSkymMGuM71Lww0ecHEIF1JsaXC010vxJDEHc=; b=kIsHvHi4IH0CZs929YaJR3EeJF1DDjgSIiJymDq5HJKQBKe3OwvYQJrz0+H7aNjmXpr4C4 HdTsXAESosnJLCAw== To: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Sebastian Andrzej Siewior , "H. Peter Anvin" , "Maciej W. Rozycki" , Bill Wendling , Borislav Petkov , Dave Hansen , Ingo Molnar , John Paul Adrian Glaubitz , Jonathan Corbet , Justin Stitt , Nathan Chancellor , Neal Gompa , Nick Desaulniers , Richard Purdie , Sam James , Shuah Khan , Thomas Gleixner , =?utf-8?q?Thomas_Wei=C3=9Fschuh?= , Tomas Glozar , Willy Tarreau , x86@kernel.org Subject: [PATCH v3 1/2] selftests/nolibc: remove the x32 testcase Date: Thu, 13 Aug 2026 13:04:32 +0200 Message-ID: <20260813-x32_removal-v3-1-e8f96cd15478@linutronix.de> In-Reply-To: <20260813-x32_removal-v3-0-e8f96cd15478@linutronix.de> References: <20260813-x32_removal-v3-0-e8f96cd15478@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Thomas Wei=C3=9Fschuh Support for the x32 ABI is about to be removed from the kernel itself. This will break the nolibc x32 testcase. Remove the testcase to avoid breaking the testsuite in general. This also ends official support from nolibc proper for x32. But as there is no clear x32-specific code in the nolibc codebase, there won't be a removal patch for that. Signed-off-by: Thomas Wei=C3=9Fschuh Signed-off-by: Sebastian Andrzej Siewior --- tools/testing/selftests/nolibc/Makefile.nolibc | 6 ------ tools/testing/selftests/nolibc/run-tests.sh | 7 +------ 2 files changed, 1 insertion(+), 12 deletions(-) diff --git a/tools/testing/selftests/nolibc/Makefile.nolibc b/tools/testing= /selftests/nolibc/Makefile.nolibc index 06f881e2e90c3..dadde26b9d3bf 100644 --- a/tools/testing/selftests/nolibc/Makefile.nolibc +++ b/tools/testing/selftests/nolibc/Makefile.nolibc @@ -47,7 +47,6 @@ XARCH_riscv =3D riscv64 XARCH =3D $(or $(XARCH_$(ARCH)),$(ARCH)) =20 # map from user input variants to their kernel supported architectures -ARCH_x32 =3D x86 ARCH_armthumb =3D arm ARCH_ppc =3D powerpc ARCH_ppc64 =3D powerpc @@ -70,7 +69,6 @@ ARCH :=3D $(or $(ARCH_$(XARCH)),$(XARCH)) # kernel image names by architecture IMAGE_i386 =3D arch/x86/boot/bzImage IMAGE_x86_64 =3D arch/x86/boot/bzImage -IMAGE_x32 =3D arch/x86/boot/bzImage IMAGE_x86 =3D arch/x86/boot/bzImage IMAGE_arm64 =3D arch/arm64/boot/Image IMAGE_arm =3D arch/arm/boot/zImage @@ -106,7 +104,6 @@ DEFCONFIG_sh4 =3D rts7751r2dplus_defconfig DEFCONFIG_openrisc =3D virt_defconfig DEFCONFIG =3D $(or $(DEFCONFIG_$(XARCH)),defconfig) =20 -EXTRACONFIG_x32 =3D -e CONFIG_X86_X32_ABI EXTRACONFIG_arm =3D -e CONFIG_NAMESPACES EXTRACONFIG_armthumb =3D -e CONFIG_NAMESPACES EXTRACONFIG_sparc32 =3D -e CONFIG_TMPFS @@ -118,7 +115,6 @@ EXTRACONFIG =3D $(EXTRACONFIG_$(XARCH)) TEST =3D =20 # QEMU_ARCH: arch names used by qemu -QEMU_ARCH_x32 =3D x86_64 QEMU_ARCH_x86 =3D x86_64 QEMU_ARCH_arm64 =3D aarch64 QEMU_ARCH_armthumb =3D arm @@ -150,7 +146,6 @@ endif # QEMU_ARGS : some arch-specific args to pass to qemu QEMU_ARGS_i386 =3D -M pc -append "console=3DttyS0,9600 i8042.noaux p= anic=3D-1 $(TEST:%=3DNOLIBC_TEST=3D%)" QEMU_ARGS_x86_64 =3D -M pc -append "console=3DttyS0,9600 i8042.noaux p= anic=3D-1 $(TEST:%=3DNOLIBC_TEST=3D%)" -QEMU_ARGS_x32 =3D -M pc -append "console=3DttyS0,9600 i8042.noaux p= anic=3D-1 $(TEST:%=3DNOLIBC_TEST=3D%)" QEMU_ARGS_x86 =3D -M pc -append "console=3DttyS0,9600 i8042.noaux p= anic=3D-1 $(TEST:%=3DNOLIBC_TEST=3D%)" QEMU_ARGS_arm64 =3D -M virt -cpu cortex-a53 -append "panic=3D-1 $(TES= T:%=3DNOLIBC_TEST=3D%)" QEMU_ARGS_arm =3D -M virt -append "panic=3D-1 $(TEST:%=3DNOLIBC_TES= T=3D%)" @@ -187,7 +182,6 @@ Q=3D@ endif =20 CFLAGS_i386 =3D $(call cc-option,-m32) -CFLAGS_x32 =3D -mx32 CFLAGS_arm =3D -marm CFLAGS_armthumb =3D -mthumb -march=3Darmv6t2 CFLAGS_parisc32 =3D -mfast-indirect-calls diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/se= lftests/nolibc/run-tests.sh index 6460e25001de8..78d59d9e4a8aa 100755 --- a/tools/testing/selftests/nolibc/run-tests.sh +++ b/tools/testing/selftests/nolibc/run-tests.sh @@ -18,7 +18,7 @@ test_mode=3Dsystem werror=3D1 llvm=3D all_archs=3D( - i386 x86_64 x32 + i386 x86_64 arm64 arm armthumb mips32le mips32be mipsn32le mipsn32be mips64le mips64be openrisc @@ -118,7 +118,6 @@ crosstool_arch() { mips*) echo mips;; s390*) echo s390;; sparc*) echo sparc64;; - x32*) echo x86_64;; parisc32) echo hppa;; *) echo "$1";; esac @@ -197,10 +196,6 @@ test_arch() { echo "Unsupported configuration" return fi - if [ "$arch" =3D "x32" ] && [ "$test_mode" =3D "user" ]; then - echo "Unsupported configuration" - return - fi =20 mkdir -p "$build_dir" swallow_output "${MAKE[@]}" defconfig --=20 2.55.0 From nobody Wed Sep 30 03:45:54 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 457FB45D1A8; Thu, 13 Aug 2026 11:04:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786619087; cv=none; b=KFM+VVy3Ks/PpWuJOL6gfxu5FXbgWrk97kiwz6qFEqS7jKcI75vGOucgVjsQa0o+x9Fzh3nu0lxNZYgnAjNUhMt2Pyi/jhcvwQaNdQE64spxiouuoZINIOFIbxm9fS5aOuBEIBTUbdtG84t4OZOfaRLKSzjI8Br4LKie8eWGEpo= ARC-Message-Signature: i=1; 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dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="a58TA44o"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="zNfvu/uZ" From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1786619081; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jjpObbj2WfW43hEykvD0YZhHijZQsYldhHSw+YX23Bk=; b=a58TA44oQ1b0NKdp2U3O+r+I1etNZXeNnZ5xwjEvCiaxuYsktzTd8+Xnd6/JPJnjseCWIP oexHKKnAbdFl5D1c/5+RVbBEu/X9dIuzcC9KvmH6GuUf/5rO7iTUvLhiWvsLY2t5yY1qsU gdIQrr1el71Kd2xGazpVQcxuT4c7e9XYnILLuVPd8D0Y0iE1L/qLRWFdTnrDrgaOq+bRNb aBjQbH8oWSYqGowXBVGyBAIX+JVc2o0yayrbzxgj4E75mJTsLQR00y+f3wcryZXafPUX7q Ba4rWV+S4EFu7Hi+B+YkWCDKAI4HLhJjjeckXX0CHdblmoJce+C0cykEsNtSsA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1786619081; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jjpObbj2WfW43hEykvD0YZhHijZQsYldhHSw+YX23Bk=; b=zNfvu/uZu0EXARvxIQRbX5eYcms6yK8oqDPjfmgpk0muDeWbGDUyZoBIzSFGzxNpc7Nc6Q GXDslDXi3zoDOUBw== To: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Sebastian Andrzej Siewior , "H. Peter Anvin" , "Maciej W. Rozycki" , Bill Wendling , Borislav Petkov , Dave Hansen , Ingo Molnar , John Paul Adrian Glaubitz , Jonathan Corbet , Justin Stitt , Nathan Chancellor , Neal Gompa , Nick Desaulniers , Richard Purdie , Sam James , Shuah Khan , Thomas Gleixner , =?utf-8?q?Thomas_Wei=C3=9Fschuh?= , Tomas Glozar , Willy Tarreau , x86@kernel.org, Arnd Bergmann Subject: [PATCH v3 2/2] x86: Start removing X86_X32_ABI Date: Thu, 13 Aug 2026 13:04:33 +0200 Message-ID: <20260813-x32_removal-v3-2-e8f96cd15478@linutronix.de> In-Reply-To: <20260813-x32_removal-v3-0-e8f96cd15478@linutronix.de> References: <20260813-x32_removal-v3-0-e8f96cd15478@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The x32 ABI was introduced in v3.4 to leverage the additional registers which were available on x86_64 but not on i386 while keeping the smaller 32bit pointers. This did not take off. The memory usage usually knows no limit and the better performance did not reach a point where certain workloads widely move to x32 and use it exclusively. In the meantime Debian introduced a patch to disable x32 by default (so it has to be enabled at boot time on the command line) because they are afraid of the increased attack surface. Fedora as far as I tell has X32 disabled (looking at 7.0-rc5 rpm in rawhide). The syscall range >512 used by x32 can not be reused because on earlier kernels (before v5.4 with x32 enabled, see commit 6365b842aae4 ("x86/syscalls: Split the x32 syscalls into their own table") it is not obvious if the syscall is for x86-64 and not implemented or meant for x32. What can be removed are the special compat cases due to different alignment. Since there is practically no real use for x32, start removing it by removing the symbol first, not allowing to enable it. Should nothing happening by the end of the year, it will removed after the last LTS kernel this year. Acked-by: Arnd Bergmann Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/Kconfig | 14 -------------- 1 file changed, 14 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index bdad90f210e4b..f6fe55fdc928a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -3097,20 +3097,6 @@ config IA32_EMULATION_DEFAULT_DISABLED processes and access to 32-bit syscalls. If unsure, leave it to its default value. =20 -config X86_X32_ABI - bool "x32 ABI for 64-bit mode" - depends on X86_64 - # llvm-objcopy does not convert x86_64 .note.gnu.property or - # compressed debug sections to x86_x32 properly: - # https://github.com/ClangBuiltLinux/linux/issues/514 - # https://github.com/ClangBuiltLinux/linux/issues/1141 - depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) - help - Include code to run binaries for the x32 native 32-bit ABI - for 64-bit processors. An x32 process gets access to the - full 64-bit register file and wide data path while leaving - pointers at 32 bits for smaller memory footprint. - config COMPAT_32 def_bool y depends on IA32_EMULATION || X86_32 --=20 2.55.0