[PATCH 09/16] mm: remove blackfin MPU support

From: Arnd Bergmann
Date: Wed Mar 14 2018 - 10:39:32 EST


The CONFIG_MPU option was only defined on blackfin, and that architecture
is now being removed, so the respective code can be simplified.

A lot of other microcontrollers have an MPU, but I suspect that if we
want to bring that support back, we'd do it differently anyway.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
kernel/module.c | 4 ----
mm/nommu.c | 20 --------------------
2 files changed, 24 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index ad2d420024f6..2c1df850029b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2181,10 +2181,6 @@ static void free_module(struct module *mod)
/* Finally, free the core (containing the module structure) */
disable_ro_nx(&mod->core_layout);
module_memfree(mod->core_layout.base);
-
-#ifdef CONFIG_MPU
- update_protections(current->mm);
-#endif
}

void *__symbol_get(const char *symbol)
diff --git a/mm/nommu.c b/mm/nommu.c
index ebb6e618dade..838a8fdec5c2 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -663,22 +663,6 @@ static void put_nommu_region(struct vm_region *region)
}

/*
- * update protection on a vma
- */
-static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
-{
-#ifdef CONFIG_MPU
- struct mm_struct *mm = vma->vm_mm;
- long start = vma->vm_start & PAGE_MASK;
- while (start < vma->vm_end) {
- protect_page(mm, start, flags);
- start += PAGE_SIZE;
- }
- update_protections(mm);
-#endif
-}
-
-/*
* add a VMA into a process's mm_struct in the appropriate place in the list
* and tree and add to the address space's page tree also if not an anonymous
* page
@@ -695,8 +679,6 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
mm->map_count++;
vma->vm_mm = mm;

- protect_vma(vma, vma->vm_flags);
-
/* add the VMA to the mapping */
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
@@ -757,8 +739,6 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
struct mm_struct *mm = vma->vm_mm;
struct task_struct *curr = current;

- protect_vma(vma, 0);
-
mm->map_count--;
for (i = 0; i < VMACACHE_SIZE; i++) {
/* if the vma is cached, invalidate the entire cache */
--
2.9.0