From 3a4ddfaab96d1dd06b9cd6298e74a91c5a956ece Mon Sep 17 00:00:00 2001
Message-Id: <3a4ddfaab96d1dd06b9cd6298e74a91c5a956ece.1406227593.git.luto@amacapital.net>
From: Andy Lutomirski <luto@amacapital.net>
Date: Tue, 17 Jun 2014 10:28:20 -0700
Subject: [PATCH] arm64,ia64,ppc,s390,sh,tile,um,x86,mm: Remove default gate
area
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.
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
Acked-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle]
Acked-by: Richard Weinberger <richard@nod.at> [for um]
Acked-by: Will Deacon <will.deacon@arm.com> [for arm64]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
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(-)
@@ -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
@@ -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)
@@ -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 */
@@ -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;
@@ -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
@@ -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;
-}
-
@@ -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 */
@@ -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;
-}
@@ -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.
@@ -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;
-}
@@ -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>.
@@ -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;
@@ -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 */
@@ -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__ */
@@ -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 */
@@ -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
@@ -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;
-}
@@ -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 */
@@ -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
@@ -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)
{
@@ -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