Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Ard Biesheuvel <ardb+git@google.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, will@kernel.org,
	catalin.marinas@arm.com,  mark.rutland@arm.com,
	Ard Biesheuvel <ardb@kernel.org>,
	Ryan Roberts <ryan.roberts@arm.com>,
	 Anshuman Khandual <anshuman.khandual@arm.com>,
	Liz Prucka <lizprucka@google.com>,
	 Seth Jenkins <sethjenkins@google.com>,
	Kees Cook <kees@kernel.org>,  Mike Rapoport <rppt@kernel.org>,
	David Hildenbrand <david@kernel.org>,
	 Andrew Morton <akpm@linux-foundation.org>,
	Jann Horn <jannh@google.com>,
	linux-mm@kvack.org,  linux-hardening@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org,  linux-sh@vger.kernel.org,
	Kevin Brodsky <kevin.brodsky@arm.com>
Subject: [PATCH v6 01/15] arm64: mm: Remove bogus stop condition from map_mem() loop
Date: Tue, 26 May 2026 19:58:48 +0200	[thread overview]
Message-ID: <20260526175846.2694125-18-ardb+git@google.com> (raw)
In-Reply-To: <20260526175846.2694125-17-ardb+git@google.com>

From: Ard Biesheuvel <ardb@kernel.org>

The memblock API guarantees that start is not greater than or equal to
end, so there is no need to test it. And if it were, it is doubtful that
breaking out of the loop would be a reasonable course of action here
(rather than attempting to map the remaining regions)

So let's drop this check.

Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/mm/mmu.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index dd85e093ffdb..112fa4a3b0eb 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1173,8 +1173,6 @@ static void __init map_mem(pgd_t *pgdp)
 
 	/* map all the memory banks */
 	for_each_mem_range(i, &start, &end) {
-		if (start >= end)
-			break;
 		/*
 		 * The linear map must allow allocation tags reading/writing
 		 * if MTE is present. Otherwise, it has the same attributes as
-- 
2.54.0.794.g4f17f83d09-goog



  reply	other threads:[~2026-05-26 18:24 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-26 17:58 [PATCH v6 00/15] arm64: Unmap linear alias of kernel data/bss Ard Biesheuvel
2026-05-26 17:58 ` Ard Biesheuvel [this message]
2026-05-26 17:58 ` [PATCH v6 02/15] arm64: mm: Drop redundant pgd_t* argument from map_mem() Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 03/15] arm64: mm: Check for pud_/pmd_set_huge() failures on kernel mappings Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 04/15] arm64: mm: Preserve existing table mappings when mapping DRAM Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 05/15] arm64: mm: Preserve non-contiguous descriptors " Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 06/15] arm64: mm: Permit contiguous descriptors to be manipulated Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 07/15] arm64: kfence: Avoid NOMAP tricks when mapping the early pool Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 08/15] arm64: mm: Permit contiguous attribute for preliminary mappings Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 09/15] arm64: Move fixmap and kasan page tables to end of kernel image Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 10/15] arm64: mm: Don't abuse memblock NOMAP to check for overlaps Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 11/15] arm64: mm: Map the kernel data/bss read-only in the linear map Ard Biesheuvel
2026-05-26 17:58 ` [PATCH v6 12/15] powerpc/code-patching: Avoid r/w mapping of the zero page Ard Biesheuvel
2026-05-26 17:59 ` [PATCH v6 13/15] sh: cast away constness from the zero page when flushing it from the cache Ard Biesheuvel
2026-05-26 17:59 ` [PATCH v6 14/15] mm: Make empty_zero_page[] const Ard Biesheuvel
2026-05-26 17:59 ` [PATCH v6 15/15] arm64: mm: Unmap kernel data/bss entirely from the linear map Ard Biesheuvel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260526175846.2694125-18-ardb+git@google.com \
    --to=ardb+git@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=anshuman.khandual@arm.com \
    --cc=ardb@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=david@kernel.org \
    --cc=jannh@google.com \
    --cc=kees@kernel.org \
    --cc=kevin.brodsky@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=lizprucka@google.com \
    --cc=mark.rutland@arm.com \
    --cc=rppt@kernel.org \
    --cc=ryan.roberts@arm.com \
    --cc=sethjenkins@google.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox