From mboxrd@z Thu Jan 1 00:00:00 1970 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 8D5536027A; Mon, 26 Feb 2024 12:12:45 +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=1708949568; cv=none; b=BSGvDF3lh+2GaFhroouGCZqeNJTNVQdacWp6HtBXR8knGqbXqBUfpAW2Qq9zd+jcmcH/O1oXJydZzMxzdlXWObry/4VRcxHZPwkgDUw83L58BneZ208gCp8EIyyjs/w21Sh3zHK/V8E3KvCeSGy7p1SPqKg+WZRHye0Cb493WTo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708949568; c=relaxed/simple; bh=4ZKMwYphcWz971VinC9q87Wl7cds6VXuBagZvOlWPLA=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=sNyCcRq7a0LSgKjsNz6pULEfXKwIwT8PXqZ6Vy1xrodTqOOb/nxXe1HPITBZ1W+pmsRQ83TuFzB3r3K81M5eWAEBjvS+cYOU2Iw8cOnYPDqXxA3Dy5chUSoiALq3JBpcIcaLbhXQRlpG7p00z7c2JK3Pxjxd30XhLuQYZ4jx5Ps= 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=a4tGqcC2; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=UlGKnC9D; 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="a4tGqcC2"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="UlGKnC9D" Date: Mon, 26 Feb 2024 12:12:43 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1708949564; h=from:from:sender:sender:reply-to: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=Iq+ogLh8TX0YQAgI5lDBWJMTtu+UflACEgVMn43qzrU=; b=a4tGqcC2ge15/pvzlBRUhMYIKHfjbUGx6j98klTqQ9pqJZokOmLTWRNaDpbhy3a7DzaXNX uT6YQUnboFH4H/Y0BSvvM93ESsNUpaXOD0RtbaI6rr1VvT1Aw57P6n8bwpFkX43fUQdW6C XAbcmT7TDEpoXNghO1PEhi8jwewxpsDtdIOv6PpjzTurLVx0bYfjH6YMeO1UwVs36EGB5P DrIwD48xDfepA+bwPiM3gjYrW6Tv6TIb/USUDombmH+0ZoKK098qF/TubgkTthFwKnXCVj 0phIfM4rMk2kAgsvJcV67TgOu5yPsncmjIRvGZ9xEyL/4Pd19K3gcVlM6XsfpQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1708949564; h=from:from:sender:sender:reply-to: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=Iq+ogLh8TX0YQAgI5lDBWJMTtu+UflACEgVMn43qzrU=; b=UlGKnC9DlXbio+4mC+BFPTPvLXIFa9W6l+DX6s/jBxUUczEx3aEXNQZx7s0AisKsTepWZL PmVXszPSZuhPH8CA== From: "tip-bot2 for Ard Biesheuvel" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/boot] x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[] Cc: Ard Biesheuvel , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240221113506.2565718-24-ardb+git@google.com> References: <20240221113506.2565718-24-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <170894956346.398.13084602429251023088.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit The following commit has been merged into the x86/boot branch of tip: Commit-ID: 533568e06b157b175912a960efe5ebce8710b4f9 Gitweb: https://git.kernel.org/tip/533568e06b157b175912a960efe5ebce8710b4f9 Author: Ard Biesheuvel AuthorDate: Wed, 21 Feb 2024 12:35:13 +01:00 Committer: Ingo Molnar CommitterDate: Mon, 26 Feb 2024 12:58:35 +01:00 x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[] early_top_pgt[] is assigned from code that executes from a 1:1 mapping so it cannot use a plain access from C. Replace the use of fixup_pointer() with RIP_REL_REF(), which is better and simpler. For legibility and to align with the code that populates the lower page table levels, statically initialize the root level page table with an entry pointing to level3_kernel_pgt[], and overwrite it when needed to enable 5-level paging. Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240221113506.2565718-24-ardb+git@google.com --- arch/x86/kernel/head64.c | 21 +++++++++------------ arch/x86/kernel/head_64.S | 3 ++- 2 files changed, 11 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 7e2c9b5..72351c3 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -77,6 +77,7 @@ static struct desc_struct startup_gdt[GDT_ENTRIES] __initdata = { [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(DESC_DATA64, 0, 0xfffff), }; +#ifdef CONFIG_X86_5LEVEL static void __head *fixup_pointer(void *ptr, unsigned long physaddr) { return ptr - (void *)_text + (void *)physaddr; @@ -87,7 +88,6 @@ static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr) return fixup_pointer(ptr, physaddr); } -#ifdef CONFIG_X86_5LEVEL static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr) { return fixup_pointer(ptr, physaddr); @@ -165,14 +165,14 @@ static unsigned long __head sme_postprocess_startup(struct boot_params *bp, pmdv * doesn't have to generate PC-relative relocations when accessing globals from * that function. Clang actually does not generate them, which leads to * boot-time crashes. To work around this problem, every global pointer must - * be adjusted using fixup_pointer(). + * be accessed using RIP_REL_REF(). */ unsigned long __head __startup_64(unsigned long physaddr, struct boot_params *bp) { pmd_t (*early_pgts)[PTRS_PER_PMD] = RIP_REL_REF(early_dynamic_pgts); - unsigned long load_delta, *p; unsigned long pgtable_flags; + unsigned long load_delta; pgdval_t *pgd; p4dval_t *p4d; pudval_t *pud; @@ -202,17 +202,14 @@ unsigned long __head __startup_64(unsigned long physaddr, /* Fixup the physical addresses in the page table */ - pgd = fixup_pointer(early_top_pgt, physaddr); - p = pgd + pgd_index(__START_KERNEL_map); - if (la57) - *p = (unsigned long)level4_kernel_pgt; - else - *p = (unsigned long)level3_kernel_pgt; - *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta; + pgd = &RIP_REL_REF(early_top_pgt)->pgd; + pgd[pgd_index(__START_KERNEL_map)] += load_delta; if (la57) { - p4d = fixup_pointer(level4_kernel_pgt, physaddr); - p4d[511] += load_delta; + p4d = (p4dval_t *)&RIP_REL_REF(level4_kernel_pgt); + p4d[MAX_PTRS_PER_P4D - 1] += load_delta; + + pgd[pgd_index(__START_KERNEL_map)] = (pgdval_t)p4d | _PAGE_TABLE_NOENC; } RIP_REL_REF(level3_kernel_pgt)[PTRS_PER_PUD - 2].pud += load_delta; diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index e09cf0b..d295bf6 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -624,7 +624,8 @@ SYM_CODE_END(vc_no_ghcb) .balign 4 SYM_DATA_START_PTI_ALIGNED(early_top_pgt) - .fill 512,8,0 + .fill 511,8,0 + .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC .fill PTI_USER_PGD_FILL,8,0 SYM_DATA_END(early_top_pgt)