From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2EAD1218AC7; Wed, 9 Apr 2025 11:07:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744196837; cv=none; b=Gkm4brOtk4rnIMzBjxBozfDwmvI6deIV3nqs1uYkpnANulszs6jN+3Kr8ffdiUmxpLDsqqeqH/ODDDGsfqzDx7zIUteN1tD0/XTyTUBNpfKWY/+FVF9+1YF06iSzao9GtcUXICeuvptCeLEYTjlBX0A1SR9mfwr1KCtlYpoLPTA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744196837; c=relaxed/simple; bh=5WALcSlXLF4jOWGCUwqVjywh8RLohDbgqlLN686J2Co=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LwZcMY3fOyquGo1q1bAhZF1mz63fHUto9sDVqOQfXJP15xJixsPd1P0pwe0QGyKPyEEuyFL3kQhFOPYe890y0nvUzHxmA6lhH8x9s5m14qZ921qD8v5+IYC27z5DRSIiJeNfEyL4zGBkdT32YLY3hBX5J8JlBMSFyUw/kGuxkIY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JMFcv85N; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JMFcv85N" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 282B0C4CEE3; Wed, 9 Apr 2025 11:07:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744196837; bh=5WALcSlXLF4jOWGCUwqVjywh8RLohDbgqlLN686J2Co=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=JMFcv85NoqIbs4DlNh1qTYARvZUZr7qnD6MYTCBnS1G1L2lbk2dErmODU1foLYFGu MOkY1q7D5/QVRHYEdCphs9+N/wYsulyW237bRmUNa42sKemo64gxVxZgfjFE2YQDwo oACNTULyMZXi1mLH3Q/VcGTwZp+URx76kspAgajXRw9G0tLGrqtyjO8gm4Slg9VDFv JnuH0ZRSfSgsB5hyo51dhOaJvObq5ZxGk4JSnhdRIAz2XFkws37ZJAWaTQ2KeePD0t V/7Ge0OCTeuIKR9WBwQ+3KUno9Ems9m5LJVHCUTPX5Ggn4Dc1OfE1sn8uKK7WLAPO2 TQlyHB/vkq4NQ== Message-ID: <66e54eb9-58b3-4559-af32-66a77fe1ea01@kernel.org> Date: Wed, 9 Apr 2025 13:07:11 +0200 Precedence: bulk X-Mailing-List: linux-bcachefs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 6/6] percpu/x86: Enable strict percpu checks via named AS qualifiers To: Uros Bizjak , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-bcachefs@vger.kernel.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org Cc: Nadav Amit , Dennis Zhou , Tejun Heo , Christoph Lameter , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Linus Torvalds , Andy Lutomirski , Brian Gerst , Peter Zijlstra References: <20250127160709.80604-1-ubizjak@gmail.com> <20250127160709.80604-7-ubizjak@gmail.com> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: <20250127160709.80604-7-ubizjak@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 27. 01. 25, 17:05, Uros Bizjak wrote: > This patch declares percpu variables in __seg_gs/__seg_fs named AS > and keeps them named AS qualified until they are dereferenced with > percpu accessor. This approach enables various compiler check > for cross-namespace variable assignments. So this causes modpost to fail to version some symbols: > WARNING: modpost: EXPORT symbol "xen_vcpu_id" [vmlinux] version generation failed, symbol will not be versioned. > Is "xen_vcpu_id" prototyped in ? > WARNING: modpost: EXPORT symbol "irq_stat" [vmlinux] version generation failed, symbol will not be versioned. > Is "irq_stat" prototyped in ? > WARNING: modpost: EXPORT symbol "fred_rsp0" [vmlinux] version generation failed, symbol will not be versioned. > Is "fred_rsp0" prototyped in ? > WARNING: modpost: EXPORT symbol "cpu_dr7" [vmlinux] version generation failed, symbol will not be versioned. > Is "cpu_dr7" prototyped in ? > WARNING: modpost: EXPORT symbol "cpu_tss_rw" [vmlinux] version generation failed, symbol will not be versioned. > Is "cpu_tss_rw" prototyped in ? > WARNING: modpost: EXPORT symbol "__tss_limit_invalid" [vmlinux] version generation failed, symbol will not be versioned. > Is "__tss_limit_invalid" prototyped in ? > WARNING: modpost: EXPORT symbol "irq_fpu_usable" [vmlinux] version generation failed, symbol will not be versioned. > Is "irq_fpu_usable" prototyped in ? > WARNING: modpost: EXPORT symbol "cpu_info" [vmlinux] version generation failed, symbol will not be versioned. > Is "cpu_info" prototyped in ? > WARNING: modpost: EXPORT symbol "gdt_page" [vmlinux] version generation failed, symbol will not be versioned. > Is "gdt_page" prototyped in ? > ... That happens both with 6.15-rc1 and today's -next. Ideas? Config: https://github.com/SUSE/kernel-source/blob/master/config/x86_64/default It is enough to: make CC='ccache gcc-14' O=../our -j160 vmlinux to see the above. > Signed-off-by: Uros Bizjak > Acked-by: Nadav Amit > Cc: Dennis Zhou > Cc: Tejun Heo > Cc: Christoph Lameter > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: Dave Hansen > Cc: "H. Peter Anvin" > Cc: Linus Torvalds > Cc: Andy Lutomirski > Cc: Brian Gerst > Cc: Peter Zijlstra > --- > arch/x86/include/asm/percpu.h | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h > index 27f668660abe..474d648bca9a 100644 > --- a/arch/x86/include/asm/percpu.h > +++ b/arch/x86/include/asm/percpu.h > @@ -95,9 +95,18 @@ > > #endif /* CONFIG_SMP */ > > -#define __my_cpu_type(var) typeof(var) __percpu_seg_override > -#define __my_cpu_ptr(ptr) (__my_cpu_type(*(ptr))*)(__force uintptr_t)(ptr) > -#define __my_cpu_var(var) (*__my_cpu_ptr(&(var))) > +#if defined(CONFIG_USE_X86_SEG_SUPPORT) && defined(USE_TYPEOF_UNQUAL) > +# define __my_cpu_type(var) typeof(var) > +# define __my_cpu_ptr(ptr) (ptr) > +# define __my_cpu_var(var) (var) > + > +# define __percpu_qual __percpu_seg_override > +#else > +# define __my_cpu_type(var) typeof(var) __percpu_seg_override > +# define __my_cpu_ptr(ptr) (__my_cpu_type(*(ptr))*)(__force uintptr_t)(ptr) > +# define __my_cpu_var(var) (*__my_cpu_ptr(&(var))) > +#endif > + > #define __percpu_arg(x) __percpu_prefix "%" #x > #define __force_percpu_arg(x) __force_percpu_prefix "%" #x thanks, -- js suse labs