From dc5882b20a69fb16219cc61ae3d21d73dd6360a7 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Thu, 8 Feb 2007 14:20:43 -0800 Subject: [PATCH] [PATCH] x86_64 ia32 vDSO: use install_special_mapping This patch uses install_special_mapping for the ia32 vDSO setup, consolidating duplicated code. Signed-off-by: Roland McGrath Cc: Ingo Molnar Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/ia32/syscall32.c | 59 ++++++++---------------------------- include/asm-x86_64/proto.h | 1 - 2 files changed, 13 insertions(+), 47 deletions(-) diff --git a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c index 59f1fa15591..568ff0df89e 100644 --- a/arch/x86_64/ia32/syscall32.c +++ b/arch/x86_64/ia32/syscall32.c @@ -18,68 +18,34 @@ extern unsigned char syscall32_syscall[], syscall32_syscall_end[]; extern unsigned char syscall32_sysenter[], syscall32_sysenter_end[]; extern int sysctl_vsyscall32; -char *syscall32_page; +static struct page *syscall32_pages[1]; static int use_sysenter = -1; -static struct page * -syscall32_nopage(struct vm_area_struct *vma, unsigned long adr, int *type) -{ - struct page *p = virt_to_page(adr - vma->vm_start + syscall32_page); - get_page(p); - return p; -} - -/* Prevent VMA merging */ -static void syscall32_vma_close(struct vm_area_struct *vma) -{ -} - -static struct vm_operations_struct syscall32_vm_ops = { - .close = syscall32_vma_close, - .nopage = syscall32_nopage, -}; - struct linux_binprm; /* Setup a VMA at program startup for the vsyscall page */ int syscall32_setup_pages(struct linux_binprm *bprm, int exstack) { - int npages = (VSYSCALL32_END - VSYSCALL32_BASE) >> PAGE_SHIFT; - struct vm_area_struct *vma; struct mm_struct *mm = current->mm; int ret; - vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); - if (!vma) - return -ENOMEM; - - memset(vma, 0, sizeof(struct vm_area_struct)); - /* Could randomize here */ - vma->vm_start = VSYSCALL32_BASE; - vma->vm_end = VSYSCALL32_END; - /* MAYWRITE to allow gdb to COW and set breakpoints */ - vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE; + down_write(&mm->mmap_sem); /* + * 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. */ - vma->vm_flags |= VM_ALWAYSDUMP; - vma->vm_flags |= mm->def_flags; - vma->vm_page_prot = protection_map[vma->vm_flags & 7]; - vma->vm_ops = &syscall32_vm_ops; - vma->vm_mm = mm; - - down_write(&mm->mmap_sem); - if ((ret = insert_vm_struct(mm, vma))) { - up_write(&mm->mmap_sem); - kmem_cache_free(vm_area_cachep, vma); - return ret; - } - mm->total_vm += npages; + /* Could randomize here */ + ret = install_special_mapping(mm, VSYSCALL32_BASE, PAGE_SIZE, + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| + VM_ALWAYSDUMP, + syscall32_pages); up_write(&mm->mmap_sem); - return 0; + return ret; } const char *arch_vma_name(struct vm_area_struct *vma) @@ -92,9 +58,10 @@ const char *arch_vma_name(struct vm_area_struct *vma) static int __init init_syscall32(void) { - syscall32_page = (void *)get_zeroed_page(GFP_KERNEL); + char *syscall32_page = (void *)get_zeroed_page(GFP_KERNEL); if (!syscall32_page) panic("Cannot allocate syscall32 page"); + syscall32_pages[0] = virt_to_page(syscall32_page); if (use_sysenter > 0) { memcpy(syscall32_page, syscall32_sysenter, syscall32_sysenter_end - syscall32_sysenter); diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h index 6d324b83897..a6d2ff5c69b 100644 --- a/include/asm-x86_64/proto.h +++ b/include/asm-x86_64/proto.h @@ -81,7 +81,6 @@ extern void swap_low_mappings(void); extern void __show_regs(struct pt_regs * regs); extern void show_regs(struct pt_regs * regs); -extern char *syscall32_page; extern void syscall32_cpu_init(void); extern void setup_node_bootmem(int nodeid, unsigned long start, unsigned long end); -- 2.41.0