ARM: 7294/1: vectors: use gate_vma for vectors user mapping (f9d4861f) · Commits · 戴 / test

arch/arm/include/asm/elf.h

+0 −4

Original line number	Diff line number	Diff line
		@@ -130,8 +130,4 @@ struct mm_struct;
		extern unsigned long arch_randomize_brk(struct mm_struct *mm);
		#define arch_randomize_brk arch_randomize_brk

		extern int vectors_user_mapping(void);
		#define arch_setup_additional_pages(bprm, uses_interp) vectors_user_mapping()
		#define ARCH_HAS_SETUP_ADDITIONAL_PAGES

		#endif

+1 −28

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#include <asm/cacheflush.h>
		#include <asm/cachetype.h>
		#include <asm/proc-fns.h>
		#include <asm-generic/mm_hooks.h>

		void __check_kvm_seq(struct mm_struct *mm);

		@@ -133,32 +134,4 @@ switch_mm(struct mm_struct prev, struct mm_struct next,
		#define deactivate_mm(tsk,mm) do { } while (0)
		#define activate_mm(prev,next) switch_mm(prev, next, NULL)

		/*
		* We are inserting a "fake" vma for the user-accessible vector page so
		* gdb and friends can get to it through ptrace and /proc/<pid>/mem.
		* But we also want to remove it before the generic code gets to see it
		* during process exit or the unmapping of it would cause total havoc.
		* (the macro is used as remove_vma() is static to mm/mmap.c)
		*/
		#define arch_exit_mmap(mm) \
		do { \
		struct vm_area_struct *high_vma = find_vma(mm, 0xffff0000); \
		if (high_vma) { \
		BUG_ON(high_vma->vm_next); /* it should be last */ \
		if (high_vma->vm_prev) \
		high_vma->vm_prev->vm_next = NULL; \
		else \
		mm->mmap = NULL; \
		rb_erase(&high_vma->vm_rb, &mm->mm_rb); \
		mm->mmap_cache = NULL; \
		mm->map_count--; \
		remove_vma(high_vma); \
		} \
		} while (0)

		static inline void arch_dup_mmap(struct mm_struct *oldmm,
		struct mm_struct *mm)
		{
		}

		#endif

+2 −0

Original line number	Diff line number	Diff line
		@@ -151,6 +151,8 @@ extern void __cpu_copy_user_highpage(struct page to, struct page from,
		#define clear_page(page) memset((void *)(page), 0, PAGE_SIZE)
		extern void copy_page(void to, const void from);

		#define __HAVE_ARCH_GATE_AREA 1

		#ifdef CONFIG_ARM_LPAE
		#include <asm/pgtable-3level-types.h>
		#else

+28 −10

Original line number	Diff line number	Diff line
		@@ -526,22 +526,40 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
		#ifdef CONFIG_MMU
		/*
		* The vectors page is always readable from user space for the
		* atomic helpers and the signal restart code. Let's declare a mapping
		* for it so it is visible through ptrace and /proc/<pid>/mem.
		* atomic helpers and the signal restart code. Insert it into the
		* gate_vma so that it is visible through ptrace and /proc/<pid>/mem.
		*/
		static struct vm_area_struct gate_vma;

		int vectors_user_mapping(void)
		static int __init gate_vma_init(void)
		{
		struct mm_struct *mm = current->mm;
		return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
		VM_READ \| VM_EXEC \|
		gate_vma.vm_start = 0xffff0000;
		gate_vma.vm_end = 0xffff0000 + PAGE_SIZE;
		gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
		gate_vma.vm_flags = VM_READ \| VM_EXEC \|
		VM_MAYREAD \| VM_MAYEXEC \|
		VM_ALWAYSDUMP \| VM_RESERVED,
		NULL);
		VM_ALWAYSDUMP;
		return 0;
		}
		arch_initcall(gate_vma_init);

		struct vm_area_struct get_gate_vma(struct mm_struct mm)
		{
		return &gate_vma;
		}

		int in_gate_area(struct mm_struct *mm, unsigned long addr)
		{
		return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
		}

		int in_gate_area_no_mm(unsigned long addr)
		{
		return in_gate_area(NULL, addr);
		}

		const char arch_vma_name(struct vm_area_struct vma)
		{
		return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
		return (vma == &gate_vma) ? "[vectors]" : NULL;
		}
		#endif