linux-kernel - [PATCH v2 06/10] arm64: mm: Remove bogus stop condition from map

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Message-ID: <20260126092630.1800589-18-ardb+git@google.com>
Date: Mon, 26 Jan 2026 10:26:37 +0100
From: Ard Biesheuvel <ardb+git@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org, will@...nel.org, 
	catalin.marinas@....com, mark.rutland@....com, 
	Ard Biesheuvel <ardb@...nel.org>, Ryan Roberts <ryan.roberts@....com>, 
	Anshuman Khandual <anshuman.khandual@....com>, Liz Prucka <lizprucka@...gle.com>, 
	Seth Jenkins <sethjenkins@...gle.com>, Kees Cook <kees@...nel.org>, 
	linux-hardening@...r.kernel.org
Subject: [PATCH v2 06/10] arm64: mm: Remove bogus stop condition from
 map_mem() loop

From: Ard Biesheuvel <ardb@...nel.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 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.

Signed-off-by: Ard Biesheuvel <ardb@...nel.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 d7faa98f427c..377bdc4d84a1 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1158,8 +1158,6 @@ 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
-- 
2.52.0.457.g6b5491de43-goog