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

From: Andy Lutomirski
Date: Sun Jul 13 2014 - 16:02:16 EST

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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@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: linux390@xxxxxxxxxx
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Cc: Jeff Dike <jdike@xxxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Nathan Lynch <Nathan_Lynch@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-ia64@xxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: linux-sh@xxxxxxxxxxxxxxx
Cc: user-mode-linux-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
---

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

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Next message: Jiri Olsa: "Re: [PATCH 10/11] perf, tools, test: Add test case for alias and JSON parsing"
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