Some architectures (like the Blackfin arch) implement some of the
"simpler" features that one would expect out of a MMU such as memory
protection.
In our case, we actually get read/write/exec protection down to the page
boundary so processes can't stomp on each other let alone the kernel.
There is a performance decrease (which depends greatly on the workload)
however as the hardware/software interaction was not optimized at design
time.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
#include <linux/rculist.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <linux/rculist.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
#include <linux/license.h>
#include <asm/sections.h>
#include <linux/tracepoint.h>
#include <linux/license.h>
#include <asm/sections.h>
#include <linux/tracepoint.h>
/* Finally, free the core (containing the module structure) */
module_free(mod, mod->module_core);
/* Finally, free the core (containing the module structure) */
module_free(mod, mod->module_core);
+
+#ifdef CONFIG_MPU
+ update_protections(current->mm);
+#endif
}
void *__symbol_get(const char *symbol)
}
void *__symbol_get(const char *symbol)
#include <asm/uaccess.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/uaccess.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
#include "internal.h"
static inline __attribute__((format(printf, 1, 2)))
#include "internal.h"
static inline __attribute__((format(printf, 1, 2)))
__put_nommu_region(region);
}
__put_nommu_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
/*
* 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
mm->map_count++;
vma->vm_mm = mm;
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;
/* add the VMA to the mapping */
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
mm->map_count--;
if (mm->mmap_cache == vma)
mm->mmap_cache = NULL;
mm->map_count--;
if (mm->mmap_cache == vma)
mm->mmap_cache = NULL;