linux-kernel - [PATCH] X86: disable X86

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 for Android: free password hash cracker in your pocket

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

Message-id: <200801182356.14843.yinghai.lu@sun.com>
Date:	Fri, 18 Jan 2008 23:56:14 -0800
From:	Yinghai Lu <Yinghai.Lu@....COM>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Dave Jones <davej@...hat.com>, venkatesh.pallipadi@...el.com,
	LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH] X86: disable X86_PAT really

[PATCH] X86: disable X86_PAT really

when X86_PAT is not selected, we don't need to do anything in reserve_mattr and free_mattr

also need to bail out if cpu not support PAT.

Signed-off-by: Yinghai Lu <yinghai.lu@....com>

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 1036134..b3cdee1 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -57,12 +57,9 @@ static int pat_known_cpu(void)
 
 void pat_init(void)
 {
+#ifdef CONFIG_X86_PAT
 	u64 pat;
 
-#ifndef CONFIG_X86_PAT
-	nopat(NULL);
-#endif
-
 	if (!smp_processor_id() && !pat_known_cpu())
 		return;
 
@@ -90,6 +87,7 @@ void pat_init(void)
 	wrmsrl(MSR_IA32_CR_PAT, pat);
 	printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n",
 		smp_processor_id(), boot_pat_state, pat);
+#endif
 }
 
 #undef PAT
@@ -135,9 +133,13 @@ static DEFINE_SPINLOCK(mattr_lock); 	/* protects memattr list */
 
 int reserve_mattr(u64 start, u64 end, unsigned long attr, unsigned long *fattr)
 {
+#ifdef CONFIG_X86_PAT
 	struct memattr *ma = NULL, *ml;
 	int err = 0;
 
+	if (!pat_wc_enabled)
+		return 0;
+
 	if (fattr)
 		*fattr = attr;
 
@@ -191,13 +193,20 @@ int reserve_mattr(u64 start, u64 end, unsigned long attr, unsigned long *fattr)
 
 	spin_unlock(&mattr_lock);
 	return err;
+#else
+	return 0;
+#endif
 }
 
 int free_mattr(u64 start, u64 end, unsigned long attr)
 {
+#ifdef CONFIG_X86_PAT
 	struct memattr *ml;
 	int err = attr ? -EBUSY : 0;
 
+	if (!pat_wc_enabled)
+		return 0;
+
 	if (is_memory_any_valid(start, end))
 		return 0;
 
@@ -221,6 +230,9 @@ int free_mattr(u64 start, u64 end, unsigned long attr)
 			current->comm, current->pid,
 			start, end, cattr_name(attr));
 	return err;
+#else
+	return 0;
+#endif
 }
 
 /* /dev/mem interface. Use the previous mapping */
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/