ARM: 7294/1: vectors: use gate_vma for vectors user mapping
The current user mapping for the vectors page is inserted as a `horrible
hack vma' into each task via arch_setup_additional_pages. This causes
problems with the MM subsystem and vm_normal_page, as described here:
https://lkml.org/lkml/2012/1/14/55
Following the suggestion from Hugh in the above thread, this patch uses
the gate_vma for the vectors user mapping, therefore consolidating
the horrible hack VMAs into one.
Acked-and-Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h
index 71605d9..a0b3cac 100644
--- a/arch/arm/include/asm/mmu_context.h
+++ b/arch/arm/include/asm/mmu_context.h
@@ -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 @@
#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