linux-kernel - [tip: x86/mtrr] x86/mtrr: Allocate mtrr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <168597409531.404.16021958975934147782.tip-bot2@tip-bot2>
Date:   Mon, 05 Jun 2023 14:08:15 -0000
From:   "tip-bot2 for Juergen Gross" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Juergen Gross <jgross@...e.com>,
        "Borislav Petkov (AMD)" <bp@...en8.de>,
        Michael Kelley <mikelley@...rosoft.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/mtrr] x86/mtrr: Allocate mtrr_value array dynamically

The following commit has been merged into the x86/mtrr branch of tip:

Commit-ID:     961c6a4326643e6588352b7f1f5d77364415386f
Gitweb:        https://git.kernel.org/tip/961c6a4326643e6588352b7f1f5d77364415386f
Author:        Juergen Gross <jgross@...e.com>
AuthorDate:    Tue, 02 May 2023 14:09:24 +02:00
Committer:     Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Thu, 01 Jun 2023 15:04:33 +02:00

x86/mtrr: Allocate mtrr_value array dynamically

The mtrr_value[] array is a static variable which is used only in a few
configurations. Consuming 6kB is ridiculous for this case, especially as
the array doesn't need to be that large and it can easily be allocated
dynamically.

Signed-off-by: Juergen Gross <jgross@...e.com>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Tested-by: Michael Kelley <mikelley@...rosoft.com>
Link: https://lore.kernel.org/r/20230502120931.20719-10-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
---
 arch/x86/kernel/cpu/mtrr/legacy.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mtrr/legacy.c b/arch/x86/kernel/cpu/mtrr/legacy.c
index 7d379fb..d25882f 100644
--- a/arch/x86/kernel/cpu/mtrr/legacy.c
+++ b/arch/x86/kernel/cpu/mtrr/legacy.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
 #include <linux/types.h>
+#include <linux/slab.h>
 #include <linux/syscore_ops.h>
 #include <asm/cpufeature.h>
 #include <asm/mtrr.h>
@@ -38,12 +39,15 @@ struct mtrr_value {
 	unsigned long	lsize;
 };
 
-static struct mtrr_value mtrr_value[MTRR_MAX_VAR_RANGES];
+static struct mtrr_value *mtrr_value;
 
 static int mtrr_save(void)
 {
 	int i;
 
+	if (!mtrr_value)
+		return -ENOMEM;
+
 	for (i = 0; i < num_var_ranges; i++) {
 		mtrr_if->get(i, &mtrr_value[i].lbase,
 				&mtrr_value[i].lsize,
@@ -72,6 +76,8 @@ static struct syscore_ops mtrr_syscore_ops = {
 
 void mtrr_register_syscore(void)
 {
+	mtrr_value = kcalloc(num_var_ranges, sizeof(*mtrr_value), GFP_KERNEL);
+
 	/*
 	 * The CPU has no MTRR and seems to not support SMP. They have
 	 * specific drivers, we use a tricky method to support