From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0D557337B9C; Tue, 27 Jan 2026 10:10:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769508630; cv=none; b=C4dZ3IXb3gsJBWErWiQuDgwVmTj5ahI1IIIz7fmJaH9vzL8XkGTnxvhJDaVT+GyXeQ3rkfLPC118bAEzgpV8DsK2LQsWld2Ihq0zpTsK3TSFBkDZFG7IN4LcU779zHjVadW9GKDbcrcv1Cxh9+i1s2bqqt0158XrFIeu/k9/+AU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769508630; c=relaxed/simple; bh=uvSGBm8LaahpIHTUn+AMYYNzc/DtlcLbnVBXs7pAMEk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=bGWAn22XgYSfhCiOW8ky1l5Am8/UFHToEdT7ajICuJ1j3moP8R6D5BLGzFqvNPGeG19OaJokKQOEHlUo0ATa2Am3++viRP+jpIoboIpdIlhA0D+Vm2Q2tkHFTXYRQ7eKCbv0NARAfWxw95P2XrZRnNdxyIE6riT+VuAMzLOXNNo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A18521595; Tue, 27 Jan 2026 02:10:20 -0800 (PST) Received: from [10.57.94.246] (unknown [10.57.94.246]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4F6283F73F; Tue, 27 Jan 2026 02:10:25 -0800 (PST) Message-ID: <49dfb613-3075-4b55-8873-9b72aa4de85c@arm.com> Date: Tue, 27 Jan 2026 10:10:23 +0000 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 07/10] arm64: mm: Drop redundant pgd_t* argument from map_mem() Content-Language: en-GB To: Ard Biesheuvel , linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, Ard Biesheuvel , Anshuman Khandual , Liz Prucka , Seth Jenkins , Kees Cook , linux-hardening@vger.kernel.org References: <20260126092630.1800589-12-ardb+git@google.com> <20260126092630.1800589-19-ardb+git@google.com> From: Ryan Roberts In-Reply-To: <20260126092630.1800589-19-ardb+git@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 26/01/2026 09:26, Ard Biesheuvel wrote: > From: Ard Biesheuvel > > __map_memblock() and map_mem() always operate on swapper_pg_dir, so > there is no need to pass around a pgd_t pointer between them. > > Signed-off-by: Ard Biesheuvel nice simplification: Reviewed-by: Ryan Roberts > --- > arch/arm64/mm/mmu.c | 25 ++++++++++---------- > 1 file changed, 12 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 377bdc4d84a1..80587cd47ce7 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1020,11 +1020,11 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt, > flush_tlb_kernel_range(virt, virt + size); > } > > -static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start, > - phys_addr_t end, pgprot_t prot, int flags) > +static void __init __map_memblock(phys_addr_t start, phys_addr_t end, > + pgprot_t prot, int flags) > { > - early_create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start, > - prot, early_pgtable_alloc, flags); > + early_create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start), > + end - start, prot, early_pgtable_alloc, flags); > } > > void __init mark_linear_text_alias_ro(void) > @@ -1072,13 +1072,13 @@ static phys_addr_t __init arm64_kfence_alloc_pool(void) > return kfence_pool; > } > > -static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) > +static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool) > { > if (!kfence_pool) > return; > > /* KFENCE pool needs page-level mapping. */ > - __map_memblock(pgdp, kfence_pool, kfence_pool + KFENCE_POOL_SIZE, > + __map_memblock(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, > pgprot_tagged(PAGE_KERNEL), > NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); > memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE); > @@ -1114,11 +1114,11 @@ bool arch_kfence_init_pool(void) > #else /* CONFIG_KFENCE */ > > static inline phys_addr_t arm64_kfence_alloc_pool(void) { return 0; } > -static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) { } > +static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool) { } > > #endif /* CONFIG_KFENCE */ > > -static void __init map_mem(pgd_t *pgdp) > +static void __init map_mem(void) > { > static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); > phys_addr_t kernel_start = __pa_symbol(_text); > @@ -1163,7 +1163,7 @@ static void __init map_mem(pgd_t *pgdp) > * if MTE is present. Otherwise, it has the same attributes as > * PAGE_KERNEL. > */ > - __map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL), > + __map_memblock(start, end, pgprot_tagged(PAGE_KERNEL), > flags); > } > > @@ -1177,10 +1177,9 @@ static void __init map_mem(pgd_t *pgdp) > * Note that contiguous mappings cannot be remapped in this way, > * so we should avoid them here. > */ > - __map_memblock(pgdp, kernel_start, kernel_end, > - PAGE_KERNEL, NO_CONT_MAPPINGS); > + __map_memblock(kernel_start, kernel_end, PAGE_KERNEL, NO_CONT_MAPPINGS); > memblock_clear_nomap(kernel_start, kernel_end - kernel_start); > - arm64_kfence_map_pool(early_kfence_pool, pgdp); > + arm64_kfence_map_pool(early_kfence_pool); > } > > void mark_rodata_ro(void) > @@ -1402,7 +1401,7 @@ static void __init create_idmap(void) > > void __init paging_init(void) > { > - map_mem(swapper_pg_dir); > + map_mem(); > > memblock_allow_resize(); >