From: Harvey Harrison <harvey.harrison@gmail.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
"Ian Campbell" <ijc@hellion.org.uk>,
"Mika Penttilä" <mika.penttila@kolumbus.fi>,
linux-kernel@vger.kernel.org,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: [PATCH] x86: make nx_enabled conditional on CONFIG_X86_PAE
Date: Tue, 22 Jan 2008 13:00:11 -0800 [thread overview]
Message-ID: <1201035611.16972.61.camel@brick> (raw)
In-Reply-To: <20080122203611.GA12892@elte.hu>
nx_enabled can only be set to non-zero when CONFIG_X86_PAE is
set. The only use not currently inside a CONFIG_X86_PAE block
is the definition, the declaration and a conditional unlikely
test in fault_32.c (is_prefetch).
When !CONFIG_X86_PAE, is_prefetch always returns 0 immediately
as nx_enabled is always 0.
When CONFIG_X86_PAE, the test is preserved, but the test against
the cpu model and stepping is deleted, this may not be correct.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
Ingo, further to your nx vs !nx comment, had this lying around,
needs testing, only affects the CONFIG_X86_PAE case.
arch/x86/mm/fault_32.c | 17 ++++++++---------
arch/x86/mm/fault_64.c | 17 ++++++++---------
arch/x86/mm/init_32.c | 4 +---
include/asm-x86/page_32.h | 2 ++
4 files changed, 19 insertions(+), 21 deletions(-)
diff --git a/arch/x86/mm/fault_32.c b/arch/x86/mm/fault_32.c
index 0bd2417..049c3bb 100644
--- a/arch/x86/mm/fault_32.c
+++ b/arch/x86/mm/fault_32.c
@@ -81,16 +81,15 @@ static int is_prefetch(struct pt_regs *regs, unsigned long addr,
unsigned char *max_instr;
#ifdef CONFIG_X86_32
- if (unlikely(boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
- boot_cpu_data.x86 >= 6)) {
- /* Catch an obscure case of prefetch inside an NX page. */
- if (nx_enabled && (error_code & PF_INSTR))
- return 0;
- } else {
+# ifdef CONFIG_X86_PAE
+ /* If it was a exec fault on NX page, ignore */
+ if (nx_enabled && (error_code & PF_INSTR))
return 0;
- }
-#else
- /* If it was a exec fault ignore */
+# else
+ return 0;
+# endif
+#else /* CONFIG_X86_64 */
+ /* If it was a exec fault on NX page, ignore */
if (error_code & PF_INSTR)
return 0;
#endif
diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c
index ccbb8e3..33e8ced 100644
--- a/arch/x86/mm/fault_64.c
+++ b/arch/x86/mm/fault_64.c
@@ -84,16 +84,15 @@ static int is_prefetch(struct pt_regs *regs, unsigned long addr,
unsigned char *max_instr;
#ifdef CONFIG_X86_32
- if (unlikely(boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
- boot_cpu_data.x86 >= 6)) {
- /* Catch an obscure case of prefetch inside an NX page. */
- if (nx_enabled && (error_code & PF_INSTR))
- return 0;
- } else {
+# ifdef CONFIG_X86_PAE
+ /* If it was a exec fault on NX page, ignore */
+ if (nx_enabled && (error_code & PF_INSTR))
return 0;
- }
-#else
- /* If it was a exec fault ignore */
+# else
+ return 0;
+# endif
+#else /* CONFIG_X86_64 */
+ /* If it was a exec fault on NX page, ignore */
if (error_code & PF_INSTR)
return 0;
#endif
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 358d3b9..317cf5d 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -478,13 +478,11 @@ void zap_low_mappings (void)
flush_tlb_all();
}
-int nx_enabled = 0;
-
pteval_t __supported_pte_mask __read_mostly = ~_PAGE_NX;
EXPORT_SYMBOL_GPL(__supported_pte_mask);
#ifdef CONFIG_X86_PAE
-
+int nx_enabled = 0;
static int disable_nx __initdata = 0;
/*
diff --git a/include/asm-x86/page_32.h b/include/asm-x86/page_32.h
index 11c4b39..251f972 100644
--- a/include/asm-x86/page_32.h
+++ b/include/asm-x86/page_32.h
@@ -65,7 +65,9 @@ typedef pte_t boot_pte_t;
#define pfn_valid(pfn) ((pfn) < max_mapnr)
#endif /* CONFIG_FLATMEM */
+#ifdef CONFIG_X86_PAE
extern int nx_enabled;
+#endif
/*
* This much address space is reserved for vmalloc() and iomap()
--
1.5.4.rc3.1118.gf6754c
next prev parent reply other threads:[~2008-01-22 21:00 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-19 16:08 [PATCH] x86/voyager: Switch voyager memory detection to early_ioremap Ian Campbell
2008-01-19 16:08 ` [PATCH] x86: Construct 32 bit boot time page tables in native format Ian Campbell
2008-01-19 23:07 ` Andi Kleen
2008-01-19 23:50 ` H. Peter Anvin
2008-01-20 16:44 ` Ian Campbell
2008-01-20 17:39 ` Andi Kleen
2008-01-20 18:48 ` H. Peter Anvin
2008-01-20 18:55 ` Andi Kleen
2008-01-20 18:54 ` H. Peter Anvin
2008-01-22 10:05 ` Ingo Molnar
2008-01-22 16:23 ` H. Peter Anvin
2008-01-20 18:30 ` Mika Penttilä
2008-01-21 21:23 ` Ian Campbell
2008-01-21 21:38 ` H. Peter Anvin
2008-01-21 21:46 ` Ian Campbell
2008-01-22 2:16 ` H. Peter Anvin
2008-01-22 17:36 ` Ian Campbell
2008-01-22 18:23 ` H. Peter Anvin
2008-01-22 19:48 ` Ian Campbell
2008-01-22 20:00 ` H. Peter Anvin
2008-01-22 20:36 ` Ingo Molnar
2008-01-22 20:43 ` H. Peter Anvin
2008-01-22 20:45 ` Ingo Molnar
2008-01-22 20:52 ` Ian Campbell
2008-01-22 21:00 ` H. Peter Anvin
2008-01-22 22:21 ` Ian Campbell
2008-01-22 21:00 ` Harvey Harrison [this message]
2008-01-22 21:04 ` [PATCH] x86: make nx_enabled conditional on CONFIG_X86_PAE Ingo Molnar
2008-01-22 21:35 ` Harvey Harrison
2008-01-22 21:07 ` Harvey Harrison
[not found] ` <p73odbdlyiu.fsf@crumb.suse.de>
2008-01-23 11:21 ` Harvey Harrison
2008-01-23 20:52 ` [PATCH] x86: Construct 32 bit boot time page tables in native format Ian Campbell
2008-01-24 1:06 ` Jeremy Fitzhardinge
2008-01-24 9:39 ` Ian Campbell
2008-01-24 22:06 ` H. Peter Anvin
2008-01-24 22:35 ` Jeremy Fitzhardinge
2008-01-24 22:39 ` H. Peter Anvin
2008-01-24 22:58 ` Jeremy Fitzhardinge
2008-01-24 23:08 ` H. Peter Anvin
2008-01-24 23:40 ` Jeremy Fitzhardinge
2008-01-24 23:44 ` H. Peter Anvin
2008-01-24 23:51 ` Jeremy Fitzhardinge
2008-01-25 0:02 ` H. Peter Anvin
2008-01-25 0:11 ` Jeremy Fitzhardinge
2008-01-25 0:15 ` H. Peter Anvin
2008-01-25 0:31 ` Jeremy Fitzhardinge
2008-01-25 0:37 ` H. Peter Anvin
2008-01-25 2:56 ` Eric W. Biederman
2008-01-25 4:41 ` Jeremy Fitzhardinge
2008-01-25 11:07 ` Eric W. Biederman
2008-01-24 23:51 ` H. Peter Anvin
2008-01-25 0:20 ` Pavel Machek
2008-01-25 0:27 ` H. Peter Anvin
2008-01-25 0:46 ` Rafael J. Wysocki
2008-01-25 1:08 ` H. Peter Anvin
2008-01-25 2:16 ` Eric W. Biederman
2008-01-25 2:25 ` H. Peter Anvin
2008-01-25 7:49 ` Pavel Machek
2008-01-25 22:02 ` Rafael J. Wysocki
2008-01-25 22:11 ` Pavel Machek
2008-01-28 15:00 ` Ingo Molnar
2008-01-28 15:25 ` Rafael J. Wysocki
2008-01-28 19:40 ` Pavel Machek
2008-01-28 19:51 ` H. Peter Anvin
2008-01-28 20:03 ` Jeremy Fitzhardinge
2008-01-28 20:06 ` H. Peter Anvin
2008-01-28 20:28 ` Rafael J. Wysocki
2008-01-28 20:26 ` Rafael J. Wysocki
2008-01-28 20:31 ` H. Peter Anvin
2008-01-28 20:59 ` Rafael J. Wysocki
2008-01-28 20:44 ` Jeremy Fitzhardinge
2008-01-28 20:50 ` Rafael J. Wysocki
2008-01-28 21:28 ` H. Peter Anvin
2008-01-28 22:02 ` Rafael J. Wysocki
2008-01-28 16:12 ` Ingo Molnar
2008-01-28 17:02 ` Rafael J. Wysocki
2008-02-01 13:51 ` Ingo Molnar
2008-02-01 14:28 ` Rafael J. Wysocki
2008-02-01 14:54 ` Ingo Molnar
2008-02-01 22:55 ` Len Brown
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