[patch 0/4] Clean up asm/bugs.h, identify_cpu() and update COMPAT_VDSO

[patch 0/4] Clean up asm/bugs.h, identify_cpu() and update COMPAT_VDSO

[Jeremy Fitzhardinge]

Hi Andi,

Four patches:
 - clean up asm/bugs.h, by moving all the C code into its own C file
 - split identify_cpu() into boot and secondary variants, so that
   boot-time setup functions can be marked __init
 - repost of the COMPAT_VDSO patches with a bit more robustness from
   unknown DT_tags, and functions marked __init, since all this is
   boot-time only setup.

Thanks,
	J

-- 

[patch 1/4] Clean up asm-i386/bugs.h

[Jeremy Fitzhardinge]

[-- Attachment #1: cleanup-asm-bugs_h.patch --]
[-- Type: text/plain, Size: 12291 bytes --]

Most of asm-i386/bugs.h is code which should be in a C file, so put it there.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>

---
 arch/i386/kernel/cpu/Makefile  |    2 
 arch/i386/kernel/cpu/bugs.c    |  191 +++++++++++++++++++++++++++++++++++++++
 include/asm-i386/alternative.h |    1 
 include/asm-i386/bugs.h        |  194 ----------------------------------------
 4 files changed, 197 insertions(+), 191 deletions(-)

===================================================================
--- a/arch/i386/kernel/cpu/Makefile
+++ b/arch/i386/kernel/cpu/Makefile
@@ -2,7 +2,7 @@
 # Makefile for x86-compatible CPU details and quirks
 #
 
-obj-y	:=	common.o proc.o
+obj-y	:=	common.o proc.o bugs.o
 
 obj-y	+=	amd.o
 obj-y	+=	cyrix.o
===================================================================
--- /dev/null
+++ b/arch/i386/kernel/cpu/bugs.c
@@ -0,0 +1,191 @@
+/*
+ *  arch/i386/cpu/bugs.c
+ *
+ *  Copyright (C) 1994  Linus Torvalds
+ *
+ *  Cyrix stuff, June 1998 by:
+ *	- Rafael R. Reilova (moved everything from head.S),
+ *        <rreilova@ececs.uc.edu>
+ *	- Channing Corn (tests & fixes),
+ *	- Andrew D. Balsa (code cleanup).
+ */
+#include <linux/init.h>
+#include <linux/utsname.h>
+#include <asm/processor.h>
+#include <asm/i387.h>
+#include <asm/msr.h>
+#include <asm/paravirt.h>
+#include <asm/alternative.h>
+
+static int __init no_halt(char *s)
+{
+	boot_cpu_data.hlt_works_ok = 0;
+	return 1;
+}
+
+__setup("no-hlt", no_halt);
+
+static int __init mca_pentium(char *s)
+{
+	mca_pentium_flag = 1;
+	return 1;
+}
+
+__setup("mca-pentium", mca_pentium);
+
+static int __init no_387(char *s)
+{
+	boot_cpu_data.hard_math = 0;
+	write_cr0(0xE | read_cr0());
+	return 1;
+}
+
+__setup("no387", no_387);
+
+static double __initdata x = 4195835.0;
+static double __initdata y = 3145727.0;
+
+/*
+ * This used to check for exceptions..
+ * However, it turns out that to support that,
+ * the XMM trap handlers basically had to
+ * be buggy. So let's have a correct XMM trap
+ * handler, and forget about printing out
+ * some status at boot.
+ *
+ * We should really only care about bugs here
+ * anyway. Not features.
+ */
+static void __init check_fpu(void)
+{
+	if (!boot_cpu_data.hard_math) {
+#ifndef CONFIG_MATH_EMULATION
+		printk(KERN_EMERG "No coprocessor found and no math emulation present.\n");
+		printk(KERN_EMERG "Giving up.\n");
+		for (;;) ;
+#endif
+		return;
+	}
+
+/* trap_init() enabled FXSR and company _before_ testing for FP problems here. */
+	/* Test for the divl bug.. */
+	__asm__("fninit\n\t"
+		"fldl %1\n\t"
+		"fdivl %2\n\t"
+		"fmull %2\n\t"
+		"fldl %1\n\t"
+		"fsubp %%st,%%st(1)\n\t"
+		"fistpl %0\n\t"
+		"fwait\n\t"
+		"fninit"
+		: "=m" (*&boot_cpu_data.fdiv_bug)
+		: "m" (*&x), "m" (*&y));
+	if (boot_cpu_data.fdiv_bug)
+		printk("Hmm, FPU with FDIV bug.\n");
+}
+
+static void __init check_hlt(void)
+{
+	if (paravirt_enabled())
+		return;
+
+	printk(KERN_INFO "Checking 'hlt' instruction... ");
+	if (!boot_cpu_data.hlt_works_ok) {
+		printk("disabled\n");
+		return;
+	}
+	halt();
+	halt();
+	halt();
+	halt();
+	printk("OK.\n");
+}
+
+/*
+ *	Most 386 processors have a bug where a POPAD can lock the
+ *	machine even from user space.
+ */
+
+static void __init check_popad(void)
+{
+#ifndef CONFIG_X86_POPAD_OK
+	int res, inp = (int) &res;
+
+	printk(KERN_INFO "Checking for popad bug... ");
+	__asm__ __volatile__(
+	  "movl $12345678,%%eax; movl $0,%%edi; pusha; popa; movl (%%edx,%%edi),%%ecx "
+	  : "=&a" (res)
+	  : "d" (inp)
+	  : "ecx", "edi" );
+	/* If this fails, it means that any user program may lock the CPU hard. Too bad. */
+	if (res != 12345678) printk( "Buggy.\n" );
+		        else printk( "OK.\n" );
+#endif
+}
+
+/*
+ * Check whether we are able to run this kernel safely on SMP.
+ *
+ * - In order to run on a i386, we need to be compiled for i386
+ *   (for due to lack of "invlpg" and working WP on a i386)
+ * - In order to run on anything without a TSC, we need to be
+ *   compiled for a i486.
+ * - In order to support the local APIC on a buggy Pentium machine,
+ *   we need to be compiled with CONFIG_X86_GOOD_APIC disabled,
+ *   which happens implicitly if compiled for a Pentium or lower
+ *   (unless an advanced selection of CPU features is used) as an
+ *   otherwise config implies a properly working local APIC without
+ *   the need to do extra reads from the APIC.
+*/
+
+static void __init check_config(void)
+{
+/*
+ * We'd better not be a i386 if we're configured to use some
+ * i486+ only features! (WP works in supervisor mode and the
+ * new "invlpg" and "bswap" instructions)
+ */
+#if defined(CONFIG_X86_WP_WORKS_OK) || defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_BSWAP)
+	if (boot_cpu_data.x86 == 3)
+		panic("Kernel requires i486+ for 'invlpg' and other features");
+#endif
+
+/*
+ * If we configured ourselves for a TSC, we'd better have one!
+ */
+#ifdef CONFIG_X86_TSC
+	if (!cpu_has_tsc && !tsc_disable)
+		panic("Kernel compiled for Pentium+, requires TSC feature!");
+#endif
+
+/*
+ * If we were told we had a good local APIC, check for buggy Pentia,
+ * i.e. all B steppings and the C2 stepping of P54C when using their
+ * integrated APIC (see 11AP erratum in "Pentium Processor
+ * Specification Update").
+ */
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_GOOD_APIC)
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL
+	    && cpu_has_apic
+	    && boot_cpu_data.x86 == 5
+	    && boot_cpu_data.x86_model == 2
+	    && (boot_cpu_data.x86_mask < 6 || boot_cpu_data.x86_mask == 11))
+		panic("Kernel compiled for PMMX+, assumes a local APIC without the read-before-write bug!");
+#endif
+}
+
+
+void __init check_bugs(void)
+{
+	identify_boot_cpu();
+#ifndef CONFIG_SMP
+	printk("CPU: ");
+	print_cpu_info(&boot_cpu_data);
+#endif
+	check_config();
+	check_fpu();
+	check_hlt();
+	check_popad();
+	init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
+	alternative_instructions();
+}
===================================================================
--- a/include/asm-i386/alternative.h
+++ b/include/asm-i386/alternative.h
@@ -14,6 +14,7 @@ struct alt_instr {
 	u8  pad;
 };
 
+extern void alternative_instructions(void);
 extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
 
 struct module;
===================================================================
--- a/include/asm-i386/bugs.h
+++ b/include/asm-i386/bugs.h
@@ -1,198 +1,12 @@
-/*
- *  include/asm-i386/bugs.h
- *
- *  Copyright (C) 1994  Linus Torvalds
- *
- *  Cyrix stuff, June 1998 by:
- *	- Rafael R. Reilova (moved everything from head.S),
- *        <rreilova@ececs.uc.edu>
- *	- Channing Corn (tests & fixes),
- *	- Andrew D. Balsa (code cleanup).
- */
-
 /*
  * This is included by init/main.c to check for architecture-dependent bugs.
  *
  * Needs:
  *	void check_bugs(void);
  */
+#ifndef _ASM_I386_BUG_H
+#define _ASM_I386_BUG_H
 
-#include <linux/init.h>
-#include <asm/processor.h>
-#include <asm/i387.h>
-#include <asm/msr.h>
-#include <asm/paravirt.h>
+extern void __init check_bugs(void);
 
-static int __init no_halt(char *s)
-{
-	boot_cpu_data.hlt_works_ok = 0;
-	return 1;
-}
-
-__setup("no-hlt", no_halt);
-
-static int __init mca_pentium(char *s)
-{
-	mca_pentium_flag = 1;
-	return 1;
-}
-
-__setup("mca-pentium", mca_pentium);
-
-static int __init no_387(char *s)
-{
-	boot_cpu_data.hard_math = 0;
-	write_cr0(0xE | read_cr0());
-	return 1;
-}
-
-__setup("no387", no_387);
-
-static double __initdata x = 4195835.0;
-static double __initdata y = 3145727.0;
-
-/*
- * This used to check for exceptions.. 
- * However, it turns out that to support that,
- * the XMM trap handlers basically had to
- * be buggy. So let's have a correct XMM trap
- * handler, and forget about printing out
- * some status at boot.
- *
- * We should really only care about bugs here
- * anyway. Not features.
- */
-static void __init check_fpu(void)
-{
-	if (!boot_cpu_data.hard_math) {
-#ifndef CONFIG_MATH_EMULATION
-		printk(KERN_EMERG "No coprocessor found and no math emulation present.\n");
-		printk(KERN_EMERG "Giving up.\n");
-		for (;;) ;
-#endif
-		return;
-	}
-
-/* trap_init() enabled FXSR and company _before_ testing for FP problems here. */
-	/* Test for the divl bug.. */
-	__asm__("fninit\n\t"
-		"fldl %1\n\t"
-		"fdivl %2\n\t"
-		"fmull %2\n\t"
-		"fldl %1\n\t"
-		"fsubp %%st,%%st(1)\n\t"
-		"fistpl %0\n\t"
-		"fwait\n\t"
-		"fninit"
-		: "=m" (*&boot_cpu_data.fdiv_bug)
-		: "m" (*&x), "m" (*&y));
-	if (boot_cpu_data.fdiv_bug)
-		printk("Hmm, FPU with FDIV bug.\n");
-}
-
-static void __init check_hlt(void)
-{
-	if (paravirt_enabled())
-		return;
-
-	printk(KERN_INFO "Checking 'hlt' instruction... ");
-	if (!boot_cpu_data.hlt_works_ok) {
-		printk("disabled\n");
-		return;
-	}
-	halt();
-	halt();
-	halt();
-	halt();
-	printk("OK.\n");
-}
-
-/*
- *	Most 386 processors have a bug where a POPAD can lock the 
- *	machine even from user space.
- */
- 
-static void __init check_popad(void)
-{
-#ifndef CONFIG_X86_POPAD_OK
-	int res, inp = (int) &res;
-
-	printk(KERN_INFO "Checking for popad bug... ");
-	__asm__ __volatile__( 
-	  "movl $12345678,%%eax; movl $0,%%edi; pusha; popa; movl (%%edx,%%edi),%%ecx "
-	  : "=&a" (res)
-	  : "d" (inp)
-	  : "ecx", "edi" );
-	/* If this fails, it means that any user program may lock the CPU hard. Too bad. */
-	if (res != 12345678) printk( "Buggy.\n" );
-		        else printk( "OK.\n" );
-#endif
-}
-
-/*
- * Check whether we are able to run this kernel safely on SMP.
- *
- * - In order to run on a i386, we need to be compiled for i386
- *   (for due to lack of "invlpg" and working WP on a i386)
- * - In order to run on anything without a TSC, we need to be
- *   compiled for a i486.
- * - In order to support the local APIC on a buggy Pentium machine,
- *   we need to be compiled with CONFIG_X86_GOOD_APIC disabled,
- *   which happens implicitly if compiled for a Pentium or lower
- *   (unless an advanced selection of CPU features is used) as an
- *   otherwise config implies a properly working local APIC without
- *   the need to do extra reads from the APIC.
-*/
-
-static void __init check_config(void)
-{
-/*
- * We'd better not be a i386 if we're configured to use some
- * i486+ only features! (WP works in supervisor mode and the
- * new "invlpg" and "bswap" instructions)
- */
-#if defined(CONFIG_X86_WP_WORKS_OK) || defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_BSWAP)
-	if (boot_cpu_data.x86 == 3)
-		panic("Kernel requires i486+ for 'invlpg' and other features");
-#endif
-
-/*
- * If we configured ourselves for a TSC, we'd better have one!
- */
-#ifdef CONFIG_X86_TSC
-	if (!cpu_has_tsc && !tsc_disable)
-		panic("Kernel compiled for Pentium+, requires TSC feature!");
-#endif
-
-/*
- * If we were told we had a good local APIC, check for buggy Pentia,
- * i.e. all B steppings and the C2 stepping of P54C when using their
- * integrated APIC (see 11AP erratum in "Pentium Processor
- * Specification Update").
- */
-#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_GOOD_APIC)
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL
-	    && cpu_has_apic
-	    && boot_cpu_data.x86 == 5
-	    && boot_cpu_data.x86_model == 2
-	    && (boot_cpu_data.x86_mask < 6 || boot_cpu_data.x86_mask == 11))
-		panic("Kernel compiled for PMMX+, assumes a local APIC without the read-before-write bug!");
-#endif
-}
-
-extern void alternative_instructions(void);
-
-static void __init check_bugs(void)
-{
-	identify_cpu(&boot_cpu_data);
-#ifndef CONFIG_SMP
-	printk("CPU: ");
-	print_cpu_info(&boot_cpu_data);
-#endif
-	check_config();
-	check_fpu();
-	check_hlt();
-	check_popad();
-	init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
-	alternative_instructions(); 
-}
+#endif	/* _ASM_I386_BUG_H */

-- 

[patch 2/4] clean up identify_cpu

[Jeremy Fitzhardinge]

[-- Attachment #1: cleanup-identify_cpu.patch --]
[-- Type: text/plain, Size: 3918 bytes --]

identify_cpu() is used to identify both the boot CPU and secondary
CPUs, but it performs some actions which only apply to the boot CPU.
Those functions are therefore really __init functions, but because
they're called by identify_cpu(), they must be marked __cpuinit.

This patch splits identify_cpu() into identify_boot_cpu() and
identify_secondary_cpu(), and calls the appropriate init functions
from each.  Also, identify_boot_cpu() and all the functions it
dominates are marked __init.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>

---
 arch/i386/kernel/cpu/common.c    |   25 ++++++++++++++++---------
 arch/i386/kernel/cpu/mtrr/main.c |    4 ++--
 arch/i386/kernel/smpboot.c       |    2 +-
 arch/i386/kernel/sysenter.c      |    2 +-
 include/asm-i386/processor.h     |    3 ++-
 5 files changed, 22 insertions(+), 14 deletions(-)

===================================================================
--- a/arch/i386/kernel/cpu/common.c
+++ b/arch/i386/kernel/cpu/common.c
@@ -390,7 +390,7 @@ __setup("serialnumber", x86_serial_nr_se
 /*
  * This does the hard work of actually picking apart the CPU stuff...
  */
-void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
+static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 {
 	int i;
 
@@ -501,15 +501,22 @@ void __cpuinit identify_cpu(struct cpuin
 
 	/* Init Machine Check Exception if available. */
 	mcheck_init(c);
-
-	if (c == &boot_cpu_data)
-		sysenter_setup();
+}
+
+void __init identify_boot_cpu(void)
+{
+	identify_cpu(&boot_cpu_data);
+	sysenter_setup();
 	enable_sep_cpu();
-
-	if (c == &boot_cpu_data)
-		mtrr_bp_init();
-	else
-		mtrr_ap_init();
+	mtrr_bp_init();
+}
+
+void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
+{
+	BUG_ON(c == &boot_cpu_data);
+	identify_cpu(c);
+	enable_sep_cpu();
+	mtrr_ap_init();
 }
 
 #ifdef CONFIG_X86_HT
===================================================================
--- a/arch/i386/kernel/cpu/mtrr/main.c
+++ b/arch/i386/kernel/cpu/mtrr/main.c
@@ -571,7 +571,7 @@ extern void cyrix_init_mtrr(void);
 extern void cyrix_init_mtrr(void);
 extern void centaur_init_mtrr(void);
 
-static void __cpuinit init_ifs(void)
+static void __init init_ifs(void)
 {
 #ifndef CONFIG_X86_64
 	amd_init_mtrr();
@@ -639,7 +639,7 @@ static struct sysdev_driver mtrr_sysdev_
  * initialized (i.e. before smp_init()).
  * 
  */
-void __cpuinit mtrr_bp_init(void)
+void __init mtrr_bp_init(void)
 {
 	init_ifs();
 
===================================================================
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -157,7 +157,7 @@ static void __cpuinit smp_store_cpu_info
 
 	*c = boot_cpu_data;
 	if (id!=0)
-		identify_cpu(c);
+		identify_secondary_cpu(c);
 	/*
 	 * Mask B, Pentium, but not Pentium MMX
 	 */
===================================================================
--- a/arch/i386/kernel/sysenter.c
+++ b/arch/i386/kernel/sysenter.c
@@ -68,7 +68,7 @@ extern const char vsyscall_sysenter_star
 extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
 static struct page *syscall_pages[1];
 
-int __cpuinit sysenter_setup(void)
+int __init sysenter_setup(void)
 {
 	void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
 	syscall_pages[0] = virt_to_page(syscall_page);
===================================================================
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -116,7 +116,8 @@ extern char ignore_fpu_irq;
 
 void __init cpu_detect(struct cpuinfo_x86 *c);
 
-extern void identify_cpu(struct cpuinfo_x86 *);
+extern void identify_boot_cpu(void);
+extern void identify_secondary_cpu(struct cpuinfo_x86 *);
 extern void print_cpu_info(struct cpuinfo_x86 *);
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern unsigned short num_cache_leaves;

-- 

Re: [patch 2/4] clean up identify_cpu

[Andrew Morton]

On Fri, 06 Apr 2007 15:41:54 -0700 Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> identify_cpu() is used to identify both the boot CPU and secondary
> CPUs, but it performs some actions which only apply to the boot CPU.
> Those functions are therefore really __init functions, but because
> they're called by identify_cpu(), they must be marked __cpuinit.
> 
> This patch splits identify_cpu() into identify_boot_cpu() and
> identify_secondary_cpu(), and calls the appropriate init functions
> from each.  Also, identify_boot_cpu() and all the functions it
> dominates are marked __init.

x86_64 uses this too.

WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:mtrr_bp_init from .text.identify_cpu after 'identify_cpu' (at offset 0x655)

Re: [patch 2/4] clean up identify_cpu

[Jeremy Fitzhardinge]

Andrew Morton wrote:
> x86_64 uses this too.
>
> WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:mtrr_bp_init from .text.identify_cpu after 'identify_cpu' (at offset 0x655)
>   

OK, two patches to follow: a x86-64 variant of the bugs.h cleanup, and a
replacement for this patch. I don't have a x86-64 compile environment on
hand, so the 64 bits are completely untested, but they *look* they
should work.

J

Re: [patch 2/4] clean up identify_cpu

[Andrew Morton]

On Sat, 07 Apr 2007 10:20:17 -0700 Jeremy Fitzhardinge <jeremy@goop.org> wrote:

>  I don't have a x86-64 compile environment on
> hand, so the 64 bits are completely untested

http://userweb.kernel.org/~akpm/cross-compilers/

Re: [patch 2/4] clean up identify_cpu

[Sam Ravnborg]

On Sat, Apr 07, 2007 at 10:59:47AM -0700, Andrew Morton wrote:
> On Sat, 07 Apr 2007 10:20:17 -0700 Jeremy Fitzhardinge <jeremy@goop.org> wrote:
> 
> >  I don't have a x86-64 compile environment on
> > hand, so the 64 bits are completely untested
> 
> http://userweb.kernel.org/~akpm/cross-compilers/

Does the alpha toolchain work for you?

For defconfig I get:
  CC      arch/alpha/kernel/core_cia.o
{standard input}: Assembler messages:
{standard input}:351: Error: macro requires $at register while noat in effect
{standard input}:376: Error: macro requires $at register while noat in effect
{standard input}:400: Error: macro requires $at register while noat in effect
{standard input}:419: Error: macro requires $at register while noat in effect
{standard input}:474: Error: macro requires $at register while noat in effect
{standard input}:499: Error: macro requires $at register while noat in effect
{standard input}:523: Error: macro requires $at register while noat in effect
{standard input}:542: Error: macro requires $at register while noat in effect
make[2]: *** [arch/alpha/kernel/core_cia.o] Error 1
make[1]: *** [arch/alpha/kernel] Error 2
make: *** [_all] Error 2

Same happens when I compile the same version direct from Dan's crosstool.

	Sam

Re: [patch 2/4] clean up identify_cpu

[Andrew Morton]

On Sat, 7 Apr 2007 20:39:16 +0200 Sam Ravnborg <sam@ravnborg.org> wrote:

> On Sat, Apr 07, 2007 at 10:59:47AM -0700, Andrew Morton wrote:
> > On Sat, 07 Apr 2007 10:20:17 -0700 Jeremy Fitzhardinge <jeremy@goop.org> wrote:
> > 
> > >  I don't have a x86-64 compile environment on
> > > hand, so the 64 bits are completely untested
> > 
> > http://userweb.kernel.org/~akpm/cross-compilers/
> 
> Does the alpha toolchain work for you?

Seems not.

> For defconfig I get:
>   CC      arch/alpha/kernel/core_cia.o
> {standard input}: Assembler messages:
> {standard input}:351: Error: macro requires $at register while noat in effect
> {standard input}:376: Error: macro requires $at register while noat in effect
> {standard input}:400: Error: macro requires $at register while noat in effect
> {standard input}:419: Error: macro requires $at register while noat in effect
> {standard input}:474: Error: macro requires $at register while noat in effect
> {standard input}:499: Error: macro requires $at register while noat in effect
> {standard input}:523: Error: macro requires $at register while noat in effect
> {standard input}:542: Error: macro requires $at register while noat in effect
> make[2]: *** [arch/alpha/kernel/core_cia.o] Error 1
> make[1]: *** [arch/alpha/kernel] Error 2
> make: *** [_all] Error 2
> 
> Same happens when I compile the same version direct from Dan's crosstool.
> 

Me too.  I always do allmodconfig with alpha, and allmodconfig doesn't
include that file.

[patch 3/4] Relocate VDSO ELF headers to match mapped location with COMPAT_VDSO

[Jeremy Fitzhardinge]

[-- Attachment #1: relocate-COMPAT_VDSO.patch --]
[-- Type: text/plain, Size: 11353 bytes --]

Some versions of libc can't deal with a VDSO which doesn't have its
ELF headers matching its mapped address.  COMPAT_VDSO maps the VDSO at
a specific system-wide fixed address.  Previously this was all done at
build time, on the grounds that the fixed VDSO address is always at
the top of the address space.  However, a hypervisor may reserve some
of that address space, pushing the fixmap address down.

This patch does the adjustment dynamically at runtime, depending on
the runtime location of the VDSO fixmap.

[ Patch has been through several hands: Jan Beulich wrote the orignal
  version; Zach reworked it, and Jeremy converted it to relocate phdrs
  as well as sections. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Jan Beulich" <JBeulich@novell.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>

---
 arch/i386/kernel/entry.S    |    4 -
 arch/i386/kernel/sysenter.c |  170 +++++++++++++++++++++++++++++++++++++++----
 arch/i386/mm/pgtable.c      |    6 -
 include/asm-i386/elf.h      |   28 ++-----
 include/asm-i386/fixmap.h   |    8 --
 include/linux/elf.h         |   17 ++++
 6 files changed, 184 insertions(+), 49 deletions(-)

===================================================================
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -305,16 +305,12 @@ sysenter_past_esp:
 	pushl $(__USER_CS)
 	CFI_ADJUST_CFA_OFFSET 4
 	/*CFI_REL_OFFSET cs, 0*/
-#ifndef CONFIG_COMPAT_VDSO
 	/*
 	 * Push current_thread_info()->sysenter_return to the stack.
 	 * A tiny bit of offset fixup is necessary - 4*4 means the 4 words
 	 * pushed above; +8 corresponds to copy_thread's esp0 setting.
 	 */
 	pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp)
-#else
-	pushl $SYSENTER_RETURN
-#endif
 	CFI_ADJUST_CFA_OFFSET 4
 	CFI_REL_OFFSET eip, 0
 
===================================================================
--- a/arch/i386/kernel/sysenter.c
+++ b/arch/i386/kernel/sysenter.c
@@ -22,6 +22,7 @@
 #include <asm/msr.h>
 #include <asm/pgtable.h>
 #include <asm/unistd.h>
+#include <asm/elf.h>
 
 /*
  * Should the kernel map a VDSO page into processes and pass its
@@ -41,6 +42,129 @@ __setup("vdso=", vdso_setup);
 __setup("vdso=", vdso_setup);
 
 extern asmlinkage void sysenter_entry(void);
+
+#ifdef CONFIG_COMPAT_VDSO
+static __init void reloc_symtab(Elf32_Ehdr *ehdr,
+				unsigned offset, unsigned size)
+{
+	Elf32_Sym *sym = (void *)ehdr + offset;
+	unsigned nsym = size / sizeof(*sym);
+	unsigned i;
+
+	for(i = 0; i < nsym; i++, sym++) {
+		if (sym->st_shndx == SHN_UNDEF ||
+		    sym->st_shndx == SHN_ABS)
+			continue;  /* skip */
+
+		if (sym->st_shndx > SHN_LORESERVE) {
+			printk(KERN_INFO "VDSO: unexpected st_shndx %x\n",
+			       sym->st_shndx);
+			continue;
+		}
+
+		switch(ELF_ST_TYPE(sym->st_info)) {
+		case STT_OBJECT:
+		case STT_FUNC:
+		case STT_SECTION:
+		case STT_FILE:
+			sym->st_value += VDSO_HIGH_BASE;
+		}
+	}
+}
+
+static __init void reloc_dyn(Elf32_Ehdr *ehdr, unsigned offset)
+{
+	Elf32_Dyn *dyn = (void *)ehdr + offset;
+
+	for(; dyn->d_tag != DT_NULL; dyn++)
+		switch(dyn->d_tag) {
+		case DT_PLTGOT:
+		case DT_HASH:
+		case DT_STRTAB:
+		case DT_SYMTAB:
+		case DT_RELA:
+		case DT_INIT:
+		case DT_FINI:
+		case DT_REL:
+		case DT_DEBUG:
+		case DT_JMPREL:
+		case DT_VERSYM:
+		case DT_VERDEF:
+		case DT_VERNEED:
+		case DT_ADDRRNGLO ... DT_ADDRRNGHI:
+			/* definitely pointers needing relocation */
+			dyn->d_un.d_ptr += VDSO_HIGH_BASE;
+			break;
+
+		case DT_ENCODING ... OLD_DT_LOOS-1:
+		case DT_LOOS ... DT_HIOS-1:
+			/* Tags above DT_ENCODING are pointers if
+			   they're even */
+			if (dyn->d_tag >= DT_ENCODING &&
+			    (dyn->d_tag & 1) == 0)
+				dyn->d_un.d_ptr += VDSO_HIGH_BASE;
+			break;
+
+		case DT_VERDEFNUM:
+		case DT_VERNEEDNUM:
+		case DT_FLAGS_1:
+		case DT_RELACOUNT:
+		case DT_RELCOUNT:
+		case DT_VALRNGLO ... DT_VALRNGHI:
+			/* definitely not pointers */
+			break;
+
+		case OLD_DT_LOOS ... DT_LOOS-1:
+		case DT_HIOS ... DT_VALRNGLO-1:
+		default:
+			if (dyn->d_tag > DT_ENCODING)
+				printk(KERN_INFO "VDSO: unexpected DT_tag %x\n",
+				       dyn->d_tag);
+			break;
+		}
+}
+
+static __init void relocate_vdso(Elf32_Ehdr *ehdr)
+{
+	Elf32_Phdr *phdr;
+	Elf32_Shdr *shdr;
+	int i;
+
+	BUG_ON(memcmp(ehdr->e_ident, ELFMAG, 4) != 0 ||
+	       !elf_check_arch(ehdr) ||
+	       ehdr->e_type != ET_DYN);
+
+	ehdr->e_entry += VDSO_HIGH_BASE;
+
+	/* rebase phdrs */
+	phdr = (void *)ehdr + ehdr->e_phoff;
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		phdr[i].p_vaddr += VDSO_HIGH_BASE;
+
+		/* relocate dynamic stuff */
+		if (phdr[i].p_type == PT_DYNAMIC)
+			reloc_dyn(ehdr, phdr[i].p_offset);
+	}
+
+	/* rebase sections */
+	shdr = (void *)ehdr + ehdr->e_shoff;
+	for(i = 0; i < ehdr->e_shnum; i++) {
+		if (!(shdr[i].sh_flags & SHF_ALLOC))
+			continue;
+
+		shdr[i].sh_addr += VDSO_HIGH_BASE;
+
+		if (shdr[i].sh_type == SHT_SYMTAB ||
+		    shdr[i].sh_type == SHT_DYNSYM)
+			reloc_symtab(ehdr, shdr[i].sh_offset,
+				     shdr[i].sh_size);
+	}
+}
+#else
+static inline void relocate_vdso(Elf32_Ehdr *ehdr)
+{
+}
+#endif	/* COMPAT_VDSO */
 
 void enable_sep_cpu(void)
 {
@@ -71,6 +195,9 @@ int __init sysenter_setup(void)
 int __init sysenter_setup(void)
 {
 	void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
+	const void *vsyscall;
+	size_t vsyscall_len;
+
 	syscall_pages[0] = virt_to_page(syscall_page);
 
 #ifdef CONFIG_COMPAT_VDSO
@@ -79,23 +206,23 @@ int __init sysenter_setup(void)
 #endif
 
 	if (!boot_cpu_has(X86_FEATURE_SEP)) {
-		memcpy(syscall_page,
-		       &vsyscall_int80_start,
-		       &vsyscall_int80_end - &vsyscall_int80_start);
-		return 0;
-	}
-
-	memcpy(syscall_page,
-	       &vsyscall_sysenter_start,
-	       &vsyscall_sysenter_end - &vsyscall_sysenter_start);
-
-	return 0;
-}
-
-#ifndef CONFIG_COMPAT_VDSO
+		vsyscall = &vsyscall_int80_start;
+		vsyscall_len = &vsyscall_int80_end - &vsyscall_int80_start;
+	} else {
+		vsyscall = &vsyscall_sysenter_start;
+		vsyscall_len = &vsyscall_sysenter_end - &vsyscall_sysenter_start;
+	}
+
+	memcpy(syscall_page, vsyscall, vsyscall_len);
+	relocate_vdso(syscall_page);
+
+	return 0;
+}
+
 /* Defined in vsyscall-sysenter.S */
 extern void SYSENTER_RETURN;
 
+#ifdef __HAVE_ARCH_GATE_AREA
 /* Setup a VMA at program startup for the vsyscall page */
 int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
 {
@@ -155,4 +282,17 @@ int in_gate_area_no_task(unsigned long a
 {
 	return 0;
 }
-#endif
+#else  /* !__HAVE_ARCH_GATE_AREA */
+int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
+{
+	/*
+	 * If not creating userspace VMA, simply set vdso to point to
+	 * fixmap page.
+	 */
+	current->mm->context.vdso = (void *)VDSO_HIGH_BASE;
+	current_thread_info()->sysenter_return =
+		(void *)VDSO_SYM(&SYSENTER_RETURN);
+
+	return 0;
+}
+#endif	/* __HAVE_ARCH_GATE_AREA */
===================================================================
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -144,10 +144,8 @@ void set_pmd_pfn(unsigned long vaddr, un
 }
 
 static int fixmaps;
-#ifndef CONFIG_COMPAT_VDSO
 unsigned long __FIXADDR_TOP = 0xfffff000;
 EXPORT_SYMBOL(__FIXADDR_TOP);
-#endif
 
 void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
 {
@@ -173,12 +171,8 @@ void reserve_top_address(unsigned long r
 	BUG_ON(fixmaps > 0);
 	printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
 	       (int)-reserve);
-#ifdef CONFIG_COMPAT_VDSO
-	BUG_ON(reserve != 0);
-#else
 	__FIXADDR_TOP = -reserve - PAGE_SIZE;
 	__VMALLOC_RESERVE += reserve;
-#endif
 }
 
 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
===================================================================
--- a/include/asm-i386/elf.h
+++ b/include/asm-i386/elf.h
@@ -133,39 +133,31 @@ extern int dump_task_extended_fpu (struc
 #define ELF_CORE_COPY_XFPREGS(tsk, elf_xfpregs) dump_task_extended_fpu(tsk, elf_xfpregs)
 
 #define VDSO_HIGH_BASE		(__fix_to_virt(FIX_VDSO))
-#define VDSO_BASE		((unsigned long)current->mm->context.vdso)
-
-#ifdef CONFIG_COMPAT_VDSO
-# define VDSO_COMPAT_BASE	VDSO_HIGH_BASE
-# define VDSO_PRELINK		VDSO_HIGH_BASE
-#else
-# define VDSO_COMPAT_BASE	VDSO_BASE
-# define VDSO_PRELINK		0
-#endif
+#define VDSO_CURRENT_BASE	((unsigned long)current->mm->context.vdso)
+#define VDSO_PRELINK		0
 
 #define VDSO_SYM(x) \
-		(VDSO_COMPAT_BASE + (unsigned long)(x) - VDSO_PRELINK)
+		(VDSO_CURRENT_BASE + (unsigned long)(x) - VDSO_PRELINK)
 
 #define VDSO_HIGH_EHDR		((const struct elfhdr *) VDSO_HIGH_BASE)
-#define VDSO_EHDR		((const struct elfhdr *) VDSO_COMPAT_BASE)
+#define VDSO_EHDR		((const struct elfhdr *) VDSO_CURRENT_BASE)
 
 extern void __kernel_vsyscall;
 
 #define VDSO_ENTRY		VDSO_SYM(&__kernel_vsyscall)
 
-#ifndef CONFIG_COMPAT_VDSO
+struct linux_binprm;
+
 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES
-struct linux_binprm;
 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
                                        int executable_stack);
-#endif
 
 extern unsigned int vdso_enabled;
 
-#define ARCH_DLINFO						\
-do if (vdso_enabled) {						\
-		NEW_AUX_ENT(AT_SYSINFO,	VDSO_ENTRY);		\
-		NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_COMPAT_BASE);	\
+#define ARCH_DLINFO							\
+do if (vdso_enabled) {							\
+		NEW_AUX_ENT(AT_SYSINFO,	VDSO_ENTRY);			\
+		NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);	\
 } while (0)
 
 #endif
===================================================================
--- a/include/asm-i386/fixmap.h
+++ b/include/asm-i386/fixmap.h
@@ -19,13 +19,9 @@
  * Leave one empty page between vmalloc'ed areas and
  * the start of the fixmap.
  */
-#ifndef CONFIG_COMPAT_VDSO
 extern unsigned long __FIXADDR_TOP;
-#else
-#define __FIXADDR_TOP  0xfffff000
-#define FIXADDR_USER_START	__fix_to_virt(FIX_VDSO)
-#define FIXADDR_USER_END	__fix_to_virt(FIX_VDSO - 1)
-#endif
+#define FIXADDR_USER_START     __fix_to_virt(FIX_VDSO)
+#define FIXADDR_USER_END       __fix_to_virt(FIX_VDSO - 1)
 
 #ifndef __ASSEMBLY__
 #include <linux/kernel.h>
===================================================================
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -83,6 +83,23 @@ typedef __s64	Elf64_Sxword;
 #define DT_DEBUG	21
 #define DT_TEXTREL	22
 #define DT_JMPREL	23
+#define DT_ENCODING	32
+#define OLD_DT_LOOS	0x60000000
+#define DT_LOOS		0x6000000d
+#define DT_HIOS		0x6ffff000
+#define DT_VALRNGLO	0x6ffffd00
+#define DT_VALRNGHI	0x6ffffdff
+#define DT_ADDRRNGLO	0x6ffffe00
+#define DT_ADDRRNGHI	0x6ffffeff
+#define DT_VERSYM	0x6ffffff0
+#define DT_RELACOUNT	0x6ffffff9
+#define DT_RELCOUNT	0x6ffffffa
+#define DT_FLAGS_1	0x6ffffffb
+#define DT_VERDEF	0x6ffffffc
+#define	DT_VERDEFNUM	0x6ffffffd
+#define DT_VERNEED	0x6ffffffe
+#define	DT_VERNEEDNUM	0x6fffffff
+#define OLD_DT_HIOS     0x6fffffff
 #define DT_LOPROC	0x70000000
 #define DT_HIPROC	0x7fffffff
 

-- 

[patch 4/4] Make COMPAT_VDSO runtime selectable.

[Jeremy Fitzhardinge]

[-- Attachment #1: runtime-COMPAT_VDSO-selection.patch --]
[-- Type: text/plain, Size: 7818 bytes --]

Now that relocation of the VDSO for COMPAT_VDSO users is done at
runtime rather than compile time, it is possible to enable/disable
compat mode at runtime.

This patch allows you to enable COMPAT_VDSO mode with "vdso=2" on the
kernel command line, or via sysctl.  (Switching on a running system
shouldn't be done lightly; any process which was relying on the compat
VDSO will be upset if it goes away.)

The COMPAT_VDSO config option still exists, but if enabled it just
makes vdso_enabled default to VDSO_COMPAT.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Jan Beulich" <JBeulich@novell.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>

---
 Documentation/kernel-parameters.txt |    1 
 arch/i386/kernel/sysenter.c         |  141 +++++++++++++++++++++++------------
 include/asm-i386/page.h             |    2 
 3 files changed, 94 insertions(+), 50 deletions(-)

===================================================================
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1807,6 +1807,7 @@ and is between 256 and 4096 characters. 
 			[USBHID] The interval which mice are to be polled at.
 
 	vdso=		[IA-32,SH]
+			vdso=2: enable compat VDSO (default with COMPAT_VDSO)
 			vdso=1: enable VDSO (default)
 			vdso=0: disable VDSO mapping
 
===================================================================
--- a/arch/i386/kernel/sysenter.c
+++ b/arch/i386/kernel/sysenter.c
@@ -23,12 +23,25 @@
 #include <asm/pgtable.h>
 #include <asm/unistd.h>
 #include <asm/elf.h>
+#include <asm/tlbflush.h>
+
+enum {
+	VDSO_DISABLED = 0,
+	VDSO_ENABLED = 1,
+	VDSO_COMPAT = 2,
+};
+
+#ifdef CONFIG_COMPAT_VDSO
+#define VDSO_DEFAULT	VDSO_COMPAT
+#else
+#define VDSO_DEFAULT	VDSO_ENABLED
+#endif
 
 /*
  * Should the kernel map a VDSO page into processes and pass its
  * address down to glibc upon exec()?
  */
-unsigned int __read_mostly vdso_enabled = 1;
+unsigned int __read_mostly vdso_enabled = VDSO_DEFAULT;
 
 EXPORT_SYMBOL_GPL(vdso_enabled);
 
@@ -43,7 +56,6 @@ __setup("vdso=", vdso_setup);
 
 extern asmlinkage void sysenter_entry(void);
 
-#ifdef CONFIG_COMPAT_VDSO
 static __init void reloc_symtab(Elf32_Ehdr *ehdr,
 				unsigned offset, unsigned size)
 {
@@ -160,11 +172,6 @@ static __init void relocate_vdso(Elf32_E
 				     shdr[i].sh_size);
 	}
 }
-#else
-static inline void relocate_vdso(Elf32_Ehdr *ehdr)
-{
-}
-#endif	/* COMPAT_VDSO */
 
 void enable_sep_cpu(void)
 {
@@ -182,6 +189,25 @@ void enable_sep_cpu(void)
 	wrmsr(MSR_IA32_SYSENTER_ESP, tss->esp1, 0);
 	wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) sysenter_entry, 0);
 	put_cpu();	
+}
+
+static struct vm_area_struct gate_vma;
+
+static int __init gate_vma_init(void)
+{
+	gate_vma.vm_mm = NULL;
+	gate_vma.vm_start = FIXADDR_USER_START;
+	gate_vma.vm_end = FIXADDR_USER_END;
+	gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
+	gate_vma.vm_page_prot = __P101;
+	/*
+	 * Make sure the vDSO gets into every core dump.
+	 * Dumping its contents makes post-mortem fully interpretable later
+	 * without matching up the same kernel and hardware config to see
+	 * what PC values meant.
+	 */
+	gate_vma.vm_flags |= VM_ALWAYSDUMP;
+	return 0;
 }
 
 /*
@@ -192,6 +218,22 @@ extern const char vsyscall_sysenter_star
 extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
 static struct page *syscall_pages[1];
 
+static void map_compat_vdso(int map)
+{
+	static int vdso_mapped;
+
+	if (map == vdso_mapped)
+		return;
+
+	vdso_mapped = map;
+
+	__set_fixmap(FIX_VDSO, page_to_pfn(syscall_pages[0]) << PAGE_SHIFT,
+		     map ? PAGE_READONLY_EXEC : PAGE_NONE);
+
+	/* flush stray tlbs */
+	flush_tlb_all();
+}
+
 int __init sysenter_setup(void)
 {
 	void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
@@ -200,10 +242,9 @@ int __init sysenter_setup(void)
 
 	syscall_pages[0] = virt_to_page(syscall_page);
 
-#ifdef CONFIG_COMPAT_VDSO
-	__set_fixmap(FIX_VDSO, __pa(syscall_page), PAGE_READONLY_EXEC);
+	gate_vma_init();
+
 	printk("Compat vDSO mapped to %08lx.\n", __fix_to_virt(FIX_VDSO));
-#endif
 
 	if (!boot_cpu_has(X86_FEATURE_SEP)) {
 		vsyscall = &vsyscall_int80_start;
@@ -222,42 +263,57 @@ int __init sysenter_setup(void)
 /* Defined in vsyscall-sysenter.S */
 extern void SYSENTER_RETURN;
 
-#ifdef __HAVE_ARCH_GATE_AREA
 /* Setup a VMA at program startup for the vsyscall page */
 int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
 {
 	struct mm_struct *mm = current->mm;
 	unsigned long addr;
 	int ret;
+	bool compat;
 
 	down_write(&mm->mmap_sem);
-	addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
-	if (IS_ERR_VALUE(addr)) {
-		ret = addr;
-		goto up_fail;
-	}
-
-	/*
-	 * MAYWRITE to allow gdb to COW and set breakpoints
-	 *
-	 * Make sure the vDSO gets into every core dump.
-	 * Dumping its contents makes post-mortem fully interpretable later
-	 * without matching up the same kernel and hardware config to see
-	 * what PC values meant.
-	 */
-	ret = install_special_mapping(mm, addr, PAGE_SIZE,
-				      VM_READ|VM_EXEC|
-				      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-				      VM_ALWAYSDUMP,
-				      syscall_pages);
-	if (ret)
-		goto up_fail;
+
+	/* Test compat mode once here, in case someone
+	   changes it via sysctl */
+	compat = (vdso_enabled == VDSO_COMPAT);
+
+	map_compat_vdso(compat);
+
+	if (compat)
+		addr = VDSO_HIGH_BASE;
+	else {
+		addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
+		if (IS_ERR_VALUE(addr)) {
+			ret = addr;
+			goto up_fail;
+		}
+
+		/*
+		 * MAYWRITE to allow gdb to COW and set breakpoints
+		 *
+		 * Make sure the vDSO gets into every core dump.
+		 * Dumping its contents makes post-mortem fully
+		 * interpretable later without matching up the same
+		 * kernel and hardware config to see what PC values
+		 * meant.
+		 */
+		ret = install_special_mapping(mm, addr, PAGE_SIZE,
+					      VM_READ|VM_EXEC|
+					      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+					      VM_ALWAYSDUMP,
+					      syscall_pages);
+
+		if (ret)
+			goto up_fail;
+	}
 
 	current->mm->context.vdso = (void *)addr;
 	current_thread_info()->sysenter_return =
-				    (void *)VDSO_SYM(&SYSENTER_RETURN);
-up_fail:
+		(void *)VDSO_SYM(&SYSENTER_RETURN);
+
+  up_fail:
 	up_write(&mm->mmap_sem);
+
 	return ret;
 }
 
@@ -270,6 +326,9 @@ const char *arch_vma_name(struct vm_area
 
 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 {
+	/* Check to see if this task was created in compat vdso mode */
+	if (tsk->mm->context.vdso == (void *)VDSO_HIGH_BASE)
+		return &gate_vma;
 	return NULL;
 }
 
@@ -282,17 +341,3 @@ int in_gate_area_no_task(unsigned long a
 {
 	return 0;
 }
-#else  /* !__HAVE_ARCH_GATE_AREA */
-int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
-{
-	/*
-	 * If not creating userspace VMA, simply set vdso to point to
-	 * fixmap page.
-	 */
-	current->mm->context.vdso = (void *)VDSO_HIGH_BASE;
-	current_thread_info()->sysenter_return =
-		(void *)VDSO_SYM(&SYSENTER_RETURN);
-
-	return 0;
-}
-#endif	/* __HAVE_ARCH_GATE_AREA */
===================================================================
--- a/include/asm-i386/page.h
+++ b/include/asm-i386/page.h
@@ -143,9 +143,7 @@ extern int page_is_ram(unsigned long pag
 #include <asm-generic/memory_model.h>
 #include <asm-generic/page.h>
 
-#ifndef CONFIG_COMPAT_VDSO
 #define __HAVE_ARCH_GATE_AREA 1
-#endif
 #endif /* __KERNEL__ */
 
 #endif /* _I386_PAGE_H */

--