[PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[Andy Lutomirski]

The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).

This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
64-bit UML, and x86_32 have their own code just to disable it.  arm,
32-bit UML, and x86_64 have gate areas, but they have their own
implementations.

This gets rid of the default and moves the code into ia64.

This should save some code on architectures without a gate area: it's
now possible to inline the gate_area functions in the default case.

Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
Cc: x86@kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-mm@kvack.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---

It would be nice to get this into some tree that's in -next and that
people can base on.

Changes from v1 and v2: Nothing except Will Deacon's ack and splitting
this out from the larger series.

 arch/arm64/include/asm/page.h      |  3 ---
 arch/arm64/kernel/vdso.c           | 19 -------------------
 arch/ia64/include/asm/page.h       |  2 ++
 arch/ia64/mm/init.c                | 26 ++++++++++++++++++++++++++
 arch/powerpc/include/asm/page.h    |  3 ---
 arch/powerpc/kernel/vdso.c         | 16 ----------------
 arch/s390/include/asm/page.h       |  2 --
 arch/s390/kernel/vdso.c            | 15 ---------------
 arch/sh/include/asm/page.h         |  5 -----
 arch/sh/kernel/vsyscall/vsyscall.c | 15 ---------------
 arch/tile/include/asm/page.h       |  6 ------
 arch/tile/kernel/vdso.c            | 15 ---------------
 arch/um/include/asm/page.h         |  5 +++++
 arch/x86/include/asm/page.h        |  1 -
 arch/x86/include/asm/page_64.h     |  2 ++
 arch/x86/um/asm/elf.h              |  1 -
 arch/x86/um/mem_64.c               | 15 ---------------
 arch/x86/vdso/vdso32-setup.c       | 19 +------------------
 include/linux/mm.h                 | 17 ++++++++++++-----
 mm/memory.c                        | 38 --------------------------------------
 mm/nommu.c                         |  5 -----
 21 files changed, 48 insertions(+), 182 deletions(-)

diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 46bf666..992710f 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -28,9 +28,6 @@
 #define PAGE_SIZE		(_AC(1,UL) << PAGE_SHIFT)
 #define PAGE_MASK		(~(PAGE_SIZE-1))
 
-/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
-#define __HAVE_ARCH_GATE_AREA		1
-
 #ifndef __ASSEMBLY__
 
 #ifdef CONFIG_ARM64_64K_PAGES
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 50384fe..f630626 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -187,25 +187,6 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 }
 
 /*
- * We define AT_SYSINFO_EHDR, so we need these function stubs to keep
- * Linux happy.
- */
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-/*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
  */
 void update_vsyscall(struct timekeeper *tk)
diff --git a/arch/ia64/include/asm/page.h b/arch/ia64/include/asm/page.h
index f1e1b2e..1f1bf14 100644
--- a/arch/ia64/include/asm/page.h
+++ b/arch/ia64/include/asm/page.h
@@ -231,4 +231,6 @@ get_order (unsigned long size)
 #define PERCPU_ADDR		(-PERCPU_PAGE_SIZE)
 #define LOAD_OFFSET		(KERNEL_START - KERNEL_TR_PAGE_SIZE)
 
+#define __HAVE_ARCH_GATE_AREA	1
+
 #endif /* _ASM_IA64_PAGE_H */
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 25c3502..35efaa3 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -278,6 +278,32 @@ setup_gate (void)
 	ia64_patch_gate();
 }
 
+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;
+
+	return 0;
+}
+__initcall(gate_vma_init);
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return &gate_vma;
+}
+
+int in_gate_area_no_mm(unsigned long addr)
+{
+	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
+		return 1;
+	return 0;
+}
+
 void ia64_mmu_init(void *my_cpu_data)
 {
 	unsigned long pta, impl_va_bits;
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 32e4e21..26fe1ae 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -48,9 +48,6 @@ extern unsigned int HPAGE_SHIFT;
 #define HUGE_MAX_HSTATE		(MMU_PAGE_COUNT-1)
 #endif
 
-/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
-#define __HAVE_ARCH_GATE_AREA		1
-
 /*
  * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
  * assign PAGE_MASK to a larger type it gets extended the way we want
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index ce74c33..f174351 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -840,19 +840,3 @@ static int __init vdso_init(void)
 	return 0;
 }
 arch_initcall(vdso_init);
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 114258e..7b2ac6e 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -162,6 +162,4 @@ static inline int devmem_is_allowed(unsigned long pfn)
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-#define __HAVE_ARCH_GATE_AREA 1
-
 #endif /* _S390_PAGE_H */
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 6136490..0bbb7e0 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -316,18 +316,3 @@ static int __init vdso_init(void)
 	return 0;
 }
 early_initcall(vdso_init);
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
diff --git a/arch/sh/include/asm/page.h b/arch/sh/include/asm/page.h
index 15d9703..fe20d14 100644
--- a/arch/sh/include/asm/page.h
+++ b/arch/sh/include/asm/page.h
@@ -186,11 +186,6 @@ typedef struct page *pgtable_t;
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-/* vDSO support */
-#ifdef CONFIG_VSYSCALL
-#define __HAVE_ARCH_GATE_AREA
-#endif
-
 /*
  * Some drivers need to perform DMA into kmalloc'ed buffers
  * and so we have to increase the kmalloc minalign for this.
diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
index 5ca5797..ea2aa13 100644
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -92,18 +92,3 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 
 	return NULL;
 }
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long address)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long address)
-{
-	return 0;
-}
diff --git a/arch/tile/include/asm/page.h b/arch/tile/include/asm/page.h
index 6727680..a213a8d 100644
--- a/arch/tile/include/asm/page.h
+++ b/arch/tile/include/asm/page.h
@@ -39,12 +39,6 @@
 #define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 
 /*
- * We do define AT_SYSINFO_EHDR to support vDSO,
- * but don't use the gate mechanism.
- */
-#define __HAVE_ARCH_GATE_AREA		1
-
-/*
  * If the Kconfig doesn't specify, set a maximum zone order that
  * is enough so that we can create huge pages from small pages given
  * the respective sizes of the two page types.  See <linux/mmzone.h>.
diff --git a/arch/tile/kernel/vdso.c b/arch/tile/kernel/vdso.c
index 1533af2..5bc51d7 100644
--- a/arch/tile/kernel/vdso.c
+++ b/arch/tile/kernel/vdso.c
@@ -121,21 +121,6 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 	return NULL;
 }
 
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long address)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long address)
-{
-	return 0;
-}
-
 int setup_vdso_pages(void)
 {
 	struct page **pagelist;
diff --git a/arch/um/include/asm/page.h b/arch/um/include/asm/page.h
index 5ff53d9..71c5d13 100644
--- a/arch/um/include/asm/page.h
+++ b/arch/um/include/asm/page.h
@@ -119,4 +119,9 @@ extern unsigned long uml_physmem;
 #include <asm-generic/getorder.h>
 
 #endif	/* __ASSEMBLY__ */
+
+#ifdef CONFIG_X86_32
+#define __HAVE_ARCH_GATE_AREA 1
+#endif
+
 #endif	/* __UM_PAGE_H */
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index 775873d..802dde3 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -70,7 +70,6 @@ extern bool __virt_addr_valid(unsigned long kaddr);
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-#define __HAVE_ARCH_GATE_AREA 1
 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 
 #endif	/* __KERNEL__ */
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 0f1ddee..f408caf 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -39,4 +39,6 @@ void copy_page(void *to, void *from);
 
 #endif	/* !__ASSEMBLY__ */
 
+#define __HAVE_ARCH_GATE_AREA 1
+
 #endif /* _ASM_X86_PAGE_64_H */
diff --git a/arch/x86/um/asm/elf.h b/arch/x86/um/asm/elf.h
index 0feee2f..25a1022 100644
--- a/arch/x86/um/asm/elf.h
+++ b/arch/x86/um/asm/elf.h
@@ -216,6 +216,5 @@ extern long elf_aux_hwcap;
 #define ELF_HWCAP (elf_aux_hwcap)
 
 #define SET_PERSONALITY(ex) do ; while(0)
-#define __HAVE_ARCH_GATE_AREA 1
 
 #endif
diff --git a/arch/x86/um/mem_64.c b/arch/x86/um/mem_64.c
index c6492e7..f8fecad 100644
--- a/arch/x86/um/mem_64.c
+++ b/arch/x86/um/mem_64.c
@@ -9,18 +9,3 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 
 	return NULL;
 }
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index e4f7781..e904c27 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -115,23 +115,6 @@ static __init int ia32_binfmt_init(void)
 	return 0;
 }
 __initcall(ia32_binfmt_init);
-#endif
-
-#else  /* CONFIG_X86_32 */
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
+#endif /* CONFIG_SYSCTL */
 
 #endif	/* CONFIG_X86_64 */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e03dd29..8981cc8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2014,13 +2014,20 @@ static inline bool kernel_page_present(struct page *page) { return true; }
 #endif /* CONFIG_HIBERNATION */
 #endif
 
+#ifdef __HAVE_ARCH_GATE_AREA
 extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
-#ifdef	__HAVE_ARCH_GATE_AREA
-int in_gate_area_no_mm(unsigned long addr);
-int in_gate_area(struct mm_struct *mm, unsigned long addr);
+extern int in_gate_area_no_mm(unsigned long addr);
+extern int in_gate_area(struct mm_struct *mm, unsigned long addr);
 #else
-int in_gate_area_no_mm(unsigned long addr);
-#define in_gate_area(mm, addr) ({(void)mm; in_gate_area_no_mm(addr);})
+static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return NULL;
+}
+static inline int in_gate_area_no_mm(unsigned long addr) { return 0; }
+static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
+{
+	return 0;
+}
 #endif	/* __HAVE_ARCH_GATE_AREA */
 
 #ifdef CONFIG_SYSCTL
diff --git a/mm/memory.c b/mm/memory.c
index d67fd9f..099d234 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3399,44 +3399,6 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 }
 #endif /* __PAGETABLE_PMD_FOLDED */
 
-#if !defined(__HAVE_ARCH_GATE_AREA)
-
-#if defined(AT_SYSINFO_EHDR)
-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;
-
-	return 0;
-}
-__initcall(gate_vma_init);
-#endif
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-#ifdef AT_SYSINFO_EHDR
-	return &gate_vma;
-#else
-	return NULL;
-#endif
-}
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-#ifdef AT_SYSINFO_EHDR
-	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
-		return 1;
-#endif
-	return 0;
-}
-
-#endif	/* __HAVE_ARCH_GATE_AREA */
-
 static int __follow_pte(struct mm_struct *mm, unsigned long address,
 		pte_t **ptepp, spinlock_t **ptlp)
 {
diff --git a/mm/nommu.c b/mm/nommu.c
index 4a852f6..a881d96 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1981,11 +1981,6 @@ error:
 	return -ENOMEM;
 }
 
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
 int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	BUG();
-- 
1.9.3

[PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[Andy Lutomirski]

The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).

This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
64-bit UML, and x86_32 have their own code just to disable it.  arm,
32-bit UML, and x86_64 have gate areas, but they have their own
implementations.

This gets rid of the default and moves the code into ia64.

This should save some code on architectures without a gate area: it's
now possible to inline the gate_area functions in the default case.

Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
Cc: x86@kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-mm@kvack.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---

It would be nice to get this into some tree that's in -next and that
people can base on.

Changes from v1 and v2: Nothing except Will Deacon's ack and splitting
this out from the larger series.

 arch/arm64/include/asm/page.h      |  3 ---
 arch/arm64/kernel/vdso.c           | 19 -------------------
 arch/ia64/include/asm/page.h       |  2 ++
 arch/ia64/mm/init.c                | 26 ++++++++++++++++++++++++++
 arch/powerpc/include/asm/page.h    |  3 ---
 arch/powerpc/kernel/vdso.c         | 16 ----------------
 arch/s390/include/asm/page.h       |  2 --
 arch/s390/kernel/vdso.c            | 15 ---------------
 arch/sh/include/asm/page.h         |  5 -----
 arch/sh/kernel/vsyscall/vsyscall.c | 15 ---------------
 arch/tile/include/asm/page.h       |  6 ------
 arch/tile/kernel/vdso.c            | 15 ---------------
 arch/um/include/asm/page.h         |  5 +++++
 arch/x86/include/asm/page.h        |  1 -
 arch/x86/include/asm/page_64.h     |  2 ++
 arch/x86/um/asm/elf.h              |  1 -
 arch/x86/um/mem_64.c               | 15 ---------------
 arch/x86/vdso/vdso32-setup.c       | 19 +------------------
 include/linux/mm.h                 | 17 ++++++++++++-----
 mm/memory.c                        | 38 --------------------------------------
 mm/nommu.c                         |  5 -----
 21 files changed, 48 insertions(+), 182 deletions(-)

diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 46bf666..992710f 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -28,9 +28,6 @@
 #define PAGE_SIZE		(_AC(1,UL) << PAGE_SHIFT)
 #define PAGE_MASK		(~(PAGE_SIZE-1))
 
-/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
-#define __HAVE_ARCH_GATE_AREA		1
-
 #ifndef __ASSEMBLY__
 
 #ifdef CONFIG_ARM64_64K_PAGES
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 50384fe..f630626 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -187,25 +187,6 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 }
 
 /*
- * We define AT_SYSINFO_EHDR, so we need these function stubs to keep
- * Linux happy.
- */
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-/*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
  */
 void update_vsyscall(struct timekeeper *tk)
diff --git a/arch/ia64/include/asm/page.h b/arch/ia64/include/asm/page.h
index f1e1b2e..1f1bf14 100644
--- a/arch/ia64/include/asm/page.h
+++ b/arch/ia64/include/asm/page.h
@@ -231,4 +231,6 @@ get_order (unsigned long size)
 #define PERCPU_ADDR		(-PERCPU_PAGE_SIZE)
 #define LOAD_OFFSET		(KERNEL_START - KERNEL_TR_PAGE_SIZE)
 
+#define __HAVE_ARCH_GATE_AREA	1
+
 #endif /* _ASM_IA64_PAGE_H */
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 25c3502..35efaa3 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -278,6 +278,32 @@ setup_gate (void)
 	ia64_patch_gate();
 }
 
+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;
+
+	return 0;
+}
+__initcall(gate_vma_init);
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return &gate_vma;
+}
+
+int in_gate_area_no_mm(unsigned long addr)
+{
+	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
+		return 1;
+	return 0;
+}
+
 void ia64_mmu_init(void *my_cpu_data)
 {
 	unsigned long pta, impl_va_bits;
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 32e4e21..26fe1ae 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -48,9 +48,6 @@ extern unsigned int HPAGE_SHIFT;
 #define HUGE_MAX_HSTATE		(MMU_PAGE_COUNT-1)
 #endif
 
-/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
-#define __HAVE_ARCH_GATE_AREA		1
-
 /*
  * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
  * assign PAGE_MASK to a larger type it gets extended the way we want
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index ce74c33..f174351 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -840,19 +840,3 @@ static int __init vdso_init(void)
 	return 0;
 }
 arch_initcall(vdso_init);
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 114258e..7b2ac6e 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -162,6 +162,4 @@ static inline int devmem_is_allowed(unsigned long pfn)
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-#define __HAVE_ARCH_GATE_AREA 1
-
 #endif /* _S390_PAGE_H */
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 6136490..0bbb7e0 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -316,18 +316,3 @@ static int __init vdso_init(void)
 	return 0;
 }
 early_initcall(vdso_init);
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
diff --git a/arch/sh/include/asm/page.h b/arch/sh/include/asm/page.h
index 15d9703..fe20d14 100644
--- a/arch/sh/include/asm/page.h
+++ b/arch/sh/include/asm/page.h
@@ -186,11 +186,6 @@ typedef struct page *pgtable_t;
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-/* vDSO support */
-#ifdef CONFIG_VSYSCALL
-#define __HAVE_ARCH_GATE_AREA
-#endif
-
 /*
  * Some drivers need to perform DMA into kmalloc'ed buffers
  * and so we have to increase the kmalloc minalign for this.
diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
index 5ca5797..ea2aa13 100644
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -92,18 +92,3 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 
 	return NULL;
 }
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long address)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long address)
-{
-	return 0;
-}
diff --git a/arch/tile/include/asm/page.h b/arch/tile/include/asm/page.h
index 6727680..a213a8d 100644
--- a/arch/tile/include/asm/page.h
+++ b/arch/tile/include/asm/page.h
@@ -39,12 +39,6 @@
 #define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 
 /*
- * We do define AT_SYSINFO_EHDR to support vDSO,
- * but don't use the gate mechanism.
- */
-#define __HAVE_ARCH_GATE_AREA		1
-
-/*
  * If the Kconfig doesn't specify, set a maximum zone order that
  * is enough so that we can create huge pages from small pages given
  * the respective sizes of the two page types.  See <linux/mmzone.h>.
diff --git a/arch/tile/kernel/vdso.c b/arch/tile/kernel/vdso.c
index 1533af2..5bc51d7 100644
--- a/arch/tile/kernel/vdso.c
+++ b/arch/tile/kernel/vdso.c
@@ -121,21 +121,6 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 	return NULL;
 }
 
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long address)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long address)
-{
-	return 0;
-}
-
 int setup_vdso_pages(void)
 {
 	struct page **pagelist;
diff --git a/arch/um/include/asm/page.h b/arch/um/include/asm/page.h
index 5ff53d9..71c5d13 100644
--- a/arch/um/include/asm/page.h
+++ b/arch/um/include/asm/page.h
@@ -119,4 +119,9 @@ extern unsigned long uml_physmem;
 #include <asm-generic/getorder.h>
 
 #endif	/* __ASSEMBLY__ */
+
+#ifdef CONFIG_X86_32
+#define __HAVE_ARCH_GATE_AREA 1
+#endif
+
 #endif	/* __UM_PAGE_H */
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index 775873d..802dde3 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -70,7 +70,6 @@ extern bool __virt_addr_valid(unsigned long kaddr);
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-#define __HAVE_ARCH_GATE_AREA 1
 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 
 #endif	/* __KERNEL__ */
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 0f1ddee..f408caf 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -39,4 +39,6 @@ void copy_page(void *to, void *from);
 
 #endif	/* !__ASSEMBLY__ */
 
+#define __HAVE_ARCH_GATE_AREA 1
+
 #endif /* _ASM_X86_PAGE_64_H */
diff --git a/arch/x86/um/asm/elf.h b/arch/x86/um/asm/elf.h
index 0feee2f..25a1022 100644
--- a/arch/x86/um/asm/elf.h
+++ b/arch/x86/um/asm/elf.h
@@ -216,6 +216,5 @@ extern long elf_aux_hwcap;
 #define ELF_HWCAP (elf_aux_hwcap)
 
 #define SET_PERSONALITY(ex) do ; while(0)
-#define __HAVE_ARCH_GATE_AREA 1
 
 #endif
diff --git a/arch/x86/um/mem_64.c b/arch/x86/um/mem_64.c
index c6492e7..f8fecad 100644
--- a/arch/x86/um/mem_64.c
+++ b/arch/x86/um/mem_64.c
@@ -9,18 +9,3 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 
 	return NULL;
 }
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index e4f7781..e904c27 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -115,23 +115,6 @@ static __init int ia32_binfmt_init(void)
 	return 0;
 }
 __initcall(ia32_binfmt_init);
-#endif
-
-#else  /* CONFIG_X86_32 */
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
+#endif /* CONFIG_SYSCTL */
 
 #endif	/* CONFIG_X86_64 */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e03dd29..8981cc8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2014,13 +2014,20 @@ static inline bool kernel_page_present(struct page *page) { return true; }
 #endif /* CONFIG_HIBERNATION */
 #endif
 
+#ifdef __HAVE_ARCH_GATE_AREA
 extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
-#ifdef	__HAVE_ARCH_GATE_AREA
-int in_gate_area_no_mm(unsigned long addr);
-int in_gate_area(struct mm_struct *mm, unsigned long addr);
+extern int in_gate_area_no_mm(unsigned long addr);
+extern int in_gate_area(struct mm_struct *mm, unsigned long addr);
 #else
-int in_gate_area_no_mm(unsigned long addr);
-#define in_gate_area(mm, addr) ({(void)mm; in_gate_area_no_mm(addr);})
+static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return NULL;
+}
+static inline int in_gate_area_no_mm(unsigned long addr) { return 0; }
+static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
+{
+	return 0;
+}
 #endif	/* __HAVE_ARCH_GATE_AREA */
 
 #ifdef CONFIG_SYSCTL
diff --git a/mm/memory.c b/mm/memory.c
index d67fd9f..099d234 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3399,44 +3399,6 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 }
 #endif /* __PAGETABLE_PMD_FOLDED */
 
-#if !defined(__HAVE_ARCH_GATE_AREA)
-
-#if defined(AT_SYSINFO_EHDR)
-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;
-
-	return 0;
-}
-__initcall(gate_vma_init);
-#endif
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-#ifdef AT_SYSINFO_EHDR
-	return &gate_vma;
-#else
-	return NULL;
-#endif
-}
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-#ifdef AT_SYSINFO_EHDR
-	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
-		return 1;
-#endif
-	return 0;
-}
-
-#endif	/* __HAVE_ARCH_GATE_AREA */
-
 static int __follow_pte(struct mm_struct *mm, unsigned long address,
 		pte_t **ptepp, spinlock_t **ptlp)
 {
diff --git a/mm/nommu.c b/mm/nommu.c
index 4a852f6..a881d96 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1981,11 +1981,6 @@ error:
 	return -ENOMEM;
 }
 
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
 int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	BUG();
-- 
1.9.3

Re: [PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[Andy Lutomirski]

On Sun, Jul 13, 2014 at 1:01 PM, Andy Lutomirski <luto@amacapital.net> wrote:
> The core mm code will provide a default gate area based on
> FIXADDR_USER_START and FIXADDR_USER_END if
> !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
>
> This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
> 64-bit UML, and x86_32 have their own code just to disable it.  arm,
> 32-bit UML, and x86_64 have gate areas, but they have their own
> implementations.
>
> This gets rid of the default and moves the code into ia64.
>
> This should save some code on architectures without a gate area: it's
> now possible to inline the gate_area functions in the default case.

Can one of you pull this somewhere?  Otherwise I can put it somewhere
stable and ask for -next inclusion, but that seems like overkill for a
single patch.

--Andy

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Re: [PATCH v3] arm64, ia64, ppc, s390, sh, tile, um, x86, mm: Remove default gate area

[Will Deacon]

On Tue, Jul 15, 2014 at 03:47:26PM +0100, Andy Lutomirski wrote:
> On Sun, Jul 13, 2014 at 1:01 PM, Andy Lutomirski <luto@amacapital.net> wrote:
> > The core mm code will provide a default gate area based on
> > FIXADDR_USER_START and FIXADDR_USER_END if
> > !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
> >
> > This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
> > 64-bit UML, and x86_32 have their own code just to disable it.  arm,
> > 32-bit UML, and x86_64 have gate areas, but they have their own
> > implementations.
> >
> > This gets rid of the default and moves the code into ia64.
> >
> > This should save some code on architectures without a gate area: it's
> > now possible to inline the gate_area functions in the default case.
> 
> Can one of you pull this somewhere?  Otherwise I can put it somewhere
> stable and ask for -next inclusion, but that seems like overkill for a
> single patch.

I'd be happy to take the arm64 part, but it doesn't feel right for mm/*
changes (or changes to other archs) to go via our tree.

I'm not sure what the best approach is if you want to send this via a single
tree. Maybe you could ask akpm nicely?

Will
_______________________________________________
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Re: [PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[Richard Weinberger]

Am 18.07.2014 12:14, schrieb Will Deacon:
> On Tue, Jul 15, 2014 at 03:47:26PM +0100, Andy Lutomirski wrote:
>> On Sun, Jul 13, 2014 at 1:01 PM, Andy Lutomirski <luto@amacapital.net> wrote:
>>> The core mm code will provide a default gate area based on
>>> FIXADDR_USER_START and FIXADDR_USER_END if
>>> !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
>>>
>>> This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
>>> 64-bit UML, and x86_32 have their own code just to disable it.  arm,
>>> 32-bit UML, and x86_64 have gate areas, but they have their own
>>> implementations.
>>>
>>> This gets rid of the default and moves the code into ia64.
>>>
>>> This should save some code on architectures without a gate area: it's
>>> now possible to inline the gate_area functions in the default case.
>>
>> Can one of you pull this somewhere?  Otherwise I can put it somewhere
>> stable and ask for -next inclusion, but that seems like overkill for a
>> single patch.

For the um bits:
Acked-by: Richard Weinberger <richard@nod.at>

> I'd be happy to take the arm64 part, but it doesn't feel right for mm/*
> changes (or changes to other archs) to go via our tree.
> 
> I'm not sure what the best approach is if you want to send this via a single
> tree. Maybe you could ask akpm nicely?

Going though Andrew's tree sounds sane to me.

Thanks,
//richard

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Re: [PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[Andy Lutomirski]

[-- Attachment #1: Type: text/plain, Size: 1821 bytes --]

On Jul 18, 2014 3:20 AM, "Richard Weinberger" <richard@nod.at> wrote:
>
> Am 18.07.2014 12:14, schrieb Will Deacon:
> > On Tue, Jul 15, 2014 at 03:47:26PM +0100, Andy Lutomirski wrote:
> >> On Sun, Jul 13, 2014 at 1:01 PM, Andy Lutomirski <luto@amacapital.net>
wrote:
> >>> The core mm code will provide a default gate area based on
> >>> FIXADDR_USER_START and FIXADDR_USER_END if
> >>> !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
> >>>
> >>> This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
> >>> 64-bit UML, and x86_32 have their own code just to disable it.  arm,
> >>> 32-bit UML, and x86_64 have gate areas, but they have their own
> >>> implementations.
> >>>
> >>> This gets rid of the default and moves the code into ia64.
> >>>
> >>> This should save some code on architectures without a gate area: it's
> >>> now possible to inline the gate_area functions in the default case.
> >>
> >> Can one of you pull this somewhere?  Otherwise I can put it somewhere
> >> stable and ask for -next inclusion, but that seems like overkill for a
> >> single patch.
>
> For the um bits:
> Acked-by: Richard Weinberger <richard@nod.at>
>
> > I'd be happy to take the arm64 part, but it doesn't feel right for mm/*
> > changes (or changes to other archs) to go via our tree.
> >
> > I'm not sure what the best approach is if you want to send this via a
single
> > tree. Maybe you could ask akpm nicely?
>
> Going though Andrew's tree sounds sane to me.

Splitting this will be annoying: I'd probably have to add a flag asking for
the new behavior, update all the arches, then remove the flag.  The chance
of screwing up bisectability in the process seems pretty high.  This seems
like overkill for a patch that mostly deletes code.

Akpm, can you take this?

--Andy

>
> Thanks,
> //richard

[-- Attachment #2: Type: text/html, Size: 2616 bytes --]

Re: [PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[Nathan Lynch]

On 07/18/2014 11:53 AM, Andy Lutomirski wrote:
> 
> On Jul 18, 2014 3:20 AM, "Richard Weinberger" <richard@nod.at
> <mailto:richard@nod.at>> wrote:
>>
>> Am 18.07.2014 12:14, schrieb Will Deacon:
>> > On Tue, Jul 15, 2014 at 03:47:26PM +0100, Andy Lutomirski wrote:
>> >> On Sun, Jul 13, 2014 at 1:01 PM, Andy Lutomirski
> <luto@amacapital.net <mailto:luto@amacapital.net>> wrote:
>> >>> The core mm code will provide a default gate area based on
>> >>> FIXADDR_USER_START and FIXADDR_USER_END if
>> >>> !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
>> >>>
>> >>> This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
>> >>> 64-bit UML, and x86_32 have their own code just to disable it.  arm,
>> >>> 32-bit UML, and x86_64 have gate areas, but they have their own
>> >>> implementations.
>> >>>
>> >>> This gets rid of the default and moves the code into ia64.
>> >>>
>> >>> This should save some code on architectures without a gate area: it's
>> >>> now possible to inline the gate_area functions in the default case.
>> >>
>> >> Can one of you pull this somewhere?  Otherwise I can put it somewhere
>> >> stable and ask for -next inclusion, but that seems like overkill for a
>> >> single patch.
>>
>> For the um bits:
>> Acked-by: Richard Weinberger <richard@nod.at <mailto:richard@nod.at>>
>>
>> > I'd be happy to take the arm64 part, but it doesn't feel right for mm/*
>> > changes (or changes to other archs) to go via our tree.
>> >
>> > I'm not sure what the best approach is if you want to send this via
> a single
>> > tree. Maybe you could ask akpm nicely?
>>
>> Going though Andrew's tree sounds sane to me.
> 
> Splitting this will be annoying: I'd probably have to add a flag asking
> for the new behavior, update all the arches, then remove the flag.  The
> chance of screwing up bisectability in the process seems pretty high. 
> This seems like overkill for a patch that mostly deletes code.
> 
> Akpm, can you take this?

FWIW:

Acked-by: Nathan Lynch <nathan_lynch@mentor.com>

This patch allows me to avoid adding a bunch of empty hooks to arch/arm
when adding VDSO support:

http://lists.infradead.org/pipermail/linux-arm-kernel/2014-June/268045.html

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Re: [PATCH v3] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate area

[H. Peter Anvin]

On 07/18/2014 09:53 AM, Andy Lutomirski wrote:
> 
> Splitting this will be annoying: I'd probably have to add a flag asking for
> the new behavior, update all the arches, then remove the flag.  The chance
> of screwing up bisectability in the process seems pretty high.  This seems
> like overkill for a patch that mostly deletes code.
> 
> Akpm, can you take this?
> 

I'm fine with it as-is.

Acked-by: H. Peter Anvin <hpa@linux.intel.com>


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