From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 362C34F391F for ; Fri, 18 Sep 2026 13:19:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789737547; cv=none; b=pMaKqOt7YORiEB0OgoLwTvTHeEq+cL5vvsj1hRMGrkJqkKlo380LDPCSMzB+21HMKg9tpJAZ7uHrbuM9UQB/9WXsYH0o3k7wNh8r/UmLPPgmigrX986p11Q6VAhfT9tN+H0BD+QtkJlTDlEYRL+OfpkAMWoIXnQwzheMSGZjepk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789737547; c=relaxed/simple; bh=GrzDV6cczkYxjO5tC/93Uw9vwmtlbRDBmm6zE9MIKJ8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=gylF9n624GNcDJgypQFXjDGcPYht7YAvBI5YnO2mGS8+QrC/VSjCwFtF2SxvcpUZXkrvdK69ICSDTY4UvC7ICDBKATMuAgW3FQ19YVASiQF/R6C1mt3BKfCk1i487xk7hcoPAgCq4LrlbU79uTK3mG4vcz9pTOj4o0ZDOlldKhc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=R/JFIC4z; arc=none smtp.client-ip=209.85.221.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="R/JFIC4z" Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-4870663a5c4so313981f8f.1 for ; Fri, 18 Sep 2026 06:19:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1789737544; x=1790342344; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=9aOX9z3d/XK6ZHrErASZL6mYBZmtA4GVOMC24/C+YOg=; b=R/JFIC4zEEQpEff/oP2df94bgAiDtd+SE/pejnaF/QeIS71LUweyItTE7HpAxCZ2fP xl2bZHyQhulpFc5LSOlYLF5L5Q9fwgKT69h0TUjNwap7yIi2RK0Zr2T5X0BFMdK+zucw 8Y06uQ9jD4KqyUvXg6UWPeLOUcoN8jdtsRZYZo+16sK3sYyDoAPW1k1q/IOfuQpAxVKj 8RMfBoAM5/p1Gf5FP93KmZOUtrfqy90KrHdQ8ld8JGMrVJfvdN7LuYepmpeBnV5CyY5e UQk2vMQxiMHymM0k/0Co7Dy/adOvSO7gwweFfJPbjNe8d3t7NQmMMgixVv6+xNZIDGtp kjpQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789737544; x=1790342344; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=9aOX9z3d/XK6ZHrErASZL6mYBZmtA4GVOMC24/C+YOg=; b=lmFpgfnLUwnR9UKHuSAEMvNGGypqBrCZo9Z3QH3X3iItH/UvR5hi4rWgKfIC4JGiEH gMIz5kqjYhxdQHQpcMb0l3+hIi/dJA+NCZGvAftUPAAWko6CveYBM3RNPn0DLxESecDr Ujlg+uZEWqjdQia/c2/XZe2rNQ3E5x1hmxtmApqY3ffsGqtroSa437bF6aFr+zBcdVj+ 5thA6ZWUbBUgw871ky3tjhaAKc0omBf8pSORdo+3VoXTOwBDwokINWuk+1d483iBitxU mk3sQuB10qgLMu3FbZvzqqjfFIlbXfZkZaLHBOcO9V1ywjO+COOUfj4ScxM2bJ9j7AeL Oziw== X-Forwarded-Encrypted: i=1; AKwUvBwglfWEXJZksB7whJdrheOkkMW6cXr2AbklIp6Q2fY+y2s7X6U8IgUYukADMTPsNpixcNlWzwhyRcg0czA=@vger.kernel.org X-Gm-Message-State: AFuF++m0l/R/XmdwsTuYVNsRpCrhBpx5f7HfzLu5ejAVXI8Zg0ltzrb1 Q9LdhXAE1DkXgcGMhqYCHrglHpo3UbjGP7exeNCPZFuAf/+VnxeoFfamftDxyznImJYQVrNDj45 28veL3H3oqwFMbIfS8cEfbQ== X-Received: from wrdf12.prod.google.com ([2002:a5d:58ec:0:b0:487:11c9:7de9]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:2884:b0:487:360:5be1 with SMTP id ffacd0b85a97d-4871e2112femr3684285f8f.8.1789737544221; Fri, 18 Sep 2026 06:19:04 -0700 (PDT) Date: Fri, 18 Sep 2026 14:16:55 +0100 In-Reply-To: <20260918131656.3710047-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260918131656.3710047-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog Message-ID: <20260918131656.3710047-4-vdonnefort@google.com> Subject: [PATCH v1 3/4] arm64: mm: Introduce linear_map_needs_set() helper From: Vincent Donnefort To: catalin.marinas@arm.com, will@kernel.org, rafael@kernel.org Cc: mark.rutland@arm.com, lenb@kernel.org, pavel@kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, thierry.reding@kernel.org, rppt@kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" can_set_direct_map() is intended as an external query function, but is also being called internally by map_mem() to initialise linear_map_requires_bbml3, duplicating the feature checks already present in force_pte_mapping(). Factor the list of features that require modifying linear map attributes into a shared helper linear_map_needs_set(). Signed-off-by: Vincent Donnefort --- arch/arm64/include/asm/mmu.h | 1 + arch/arm64/mm/mmu.c | 22 ++++++++++++++++++++-- arch/arm64/mm/pageattr.c | 12 +----------- 3 files changed, 22 insertions(+), 13 deletions(-) diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index 5e1211c540ab..12ed21e2d0d7 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -70,6 +70,7 @@ extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, pgprot_t prot, bool page_mappings_only); extern void *fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot); extern void mark_linear_text_alias_ro(void); +extern bool linear_map_needs_set(void); extern int split_kernel_leaf_mapping(unsigned long start, unsigned long end); extern void linear_map_maybe_split_to_ptes(void); diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 79d90226fd5d..c18ed601f0a8 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -776,6 +776,24 @@ static int split_kernel_leaf_mapping_locked(unsigned long addr) return ret; } +/* + * True if the linear map needs to be modified for one of the following + * features: + * + * rodata_full and DEBUG_PAGEALLOC need to protect/unprotect pages in + * the linear map. + * + * KFENCE pool needs to protect/unprotect pages in the linear map if + * initialized late. + * + * Realms need to mark pages shared/protected in the linear map. + */ +bool linear_map_needs_set(void) +{ + return rodata_full || debug_pagealloc_enabled() || + arm64_kfence_can_set_direct_map() || is_realm_world(); +} + static inline bool force_pte_mapping(void) { const bool bbml3 = system_capabilities_finalized() ? @@ -785,7 +803,7 @@ static inline bool force_pte_mapping(void) return true; if (bbml3) return false; - return rodata_full || arm64_kfence_can_set_direct_map() || is_realm_world(); + return linear_map_needs_set(); } static DEFINE_MUTEX(pgtable_split_lock); @@ -1203,7 +1221,7 @@ static void __init map_mem(void) arm64_kfence_map_pool(); - linear_map_requires_bbml3 = !force_pte_mapping() && can_set_direct_map(); + linear_map_requires_bbml3 = !force_pte_mapping() && linear_map_needs_set(); if (force_pte_mapping()) flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index bbe98ac9ad8c..c1ba74eb602f 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -89,17 +89,7 @@ bool rodata_full __ro_after_init = true; bool can_set_direct_map(void) { - /* - * rodata_full, DEBUG_PAGEALLOC and a Realm guest all require linear - * map to be mapped at page granularity, so that it is possible to - * protect/unprotect single pages. - * - * KFENCE pool requires page-granular mapping if initialized late. - * - * Realms need to make pages shared/protected at page granularity. - */ - return rodata_full || debug_pagealloc_enabled() || - arm64_kfence_can_set_direct_map() || is_realm_world(); + return linear_map_needs_set(); } static int update_range_prot(unsigned long start, unsigned long size, -- 2.55.0.1082.g2b9226bbc0-goog