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-rw-r--r--arch/arm/include/asm/elf.h4
-rw-r--r--arch/arm/include/asm/mmu_context.h29
-rw-r--r--arch/arm/kernel/process.c21
3 files changed, 53 insertions, 1 deletions
diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 5747a8baa41..8bb66bca2e3 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -127,4 +127,8 @@ 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
diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h
index a0b3cac0547..71605d9f8e4 100644
--- a/arch/arm/include/asm/mmu_context.h
+++ b/arch/arm/include/asm/mmu_context.h
@@ -18,7 +18,6 @@
#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);
@@ -134,4 +133,32 @@ 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
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 401e38be1f7..66ac9c92620 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -458,3 +458,24 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
unsigned long range_end = mm->brk + 0x02000000;
return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}
+
+/*
+ * 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.
+ */
+
+int vectors_user_mapping(void)
+{
+ struct mm_struct *mm = current->mm;
+ return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
+ VM_READ | VM_EXEC |
+ VM_MAYREAD | VM_MAYEXEC |
+ VM_ALWAYSDUMP | VM_RESERVED,
+ NULL);
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+ return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
+}