linux-kernel - [PATCH 1/1] x86/boot/compressed: Fix avoiding memmap in physical KASLR

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Message-ID: <20250610214140.2775339-1-mclapinski@google.com>
Date: Tue, 10 Jun 2025 23:41:40 +0200
From: Michal Clapinski <mclapinski@...gle.com>
To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, 
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org
Cc: "H. Peter Anvin" <hpa@...or.com>, Ard Biesheuvel <ardb@...nel.org>, 
	Michal Clapinski <mclapinski@...gle.com>, Dan Williams <dan.j.williams@...el.com>, 
	Pasha Tatashin <pasha.tatashin@...een.com>, linux-kernel@...r.kernel.org
Subject: [PATCH 1/1] x86/boot/compressed: Fix avoiding memmap in physical KASLR

The intent of the code was to cancel KASLR if there are more than 4
memmap args. Unfortunately, it was only doing that if the memmap args
were comma delimited, not if they were entirely separate.
This change fixes it.

Signed-off-by: Michal Clapinski <mclapinski@...gle.com>
---
I would like KASLR to support more than 4 memmap args. Do you think
I can just increase the MAX_MEMMAP_REGIONS or should I implement
support for the general case?

 arch/x86/boot/compressed/kaslr.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index f03d59ea6e40..4aa9c9781ca7 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -162,9 +162,6 @@ static void mem_avoid_memmap(char *str)
 {
 	static int i;
 
-	if (i >= MAX_MEMMAP_REGIONS)
-		return;
-
 	while (str && (i < MAX_MEMMAP_REGIONS)) {
 		int rc;
 		u64 start, size;
-- 
2.50.0.rc0.642.g800a2b2222-goog