[PATCH] CRIS update: mm

Memory management patches.

* SMP support.
* Non-executable stack (on v32).
* 4-level page tables.
* Added simple Thread Local Storage support.

Signed-off-by: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 135 insertions, 48 deletions

diff --git a/arch/cris/mm/fault.c b/arch/cris/mm/fault.c
index 03254b9eded1..fe1cc36b5aca 100644
--- a/arch/cris/mm/fault.c
+++ b/arch/cris/mm/fault.c
@@ -6,6 +6,38 @@
  *  Authors:  Bjorn Wesen 
  * 
  *  $Log: fault.c,v $
+ *  Revision 1.20  2005/03/04 08:16:18  starvik
+ *  Merge of Linux 2.6.11.
+ *
+ *  Revision 1.19  2005/01/14 10:07:59  starvik
+ *  Fixed warning.
+ *
+ *  Revision 1.18  2005/01/12 08:10:14  starvik
+ *  Readded the change of frametype when handling kernel page fault fixup
+ *  for v10. This is necessary to avoid that the CPU remakes the faulting
+ *  access.
+ *
+ *  Revision 1.17  2005/01/11 13:53:05  starvik
+ *  Use raw_printk.
+ *
+ *  Revision 1.16  2004/12/17 11:39:41  starvik
+ *  SMP support.
+ *
+ *  Revision 1.15  2004/11/23 18:36:18  starvik
+ *  Stack is now non-executable.
+ *  Signal handler trampolines are placed in a reserved page mapped into all
+ *  processes.
+ *
+ *  Revision 1.14  2004/11/23 07:10:21  starvik
+ *  Moved find_fixup_code to generic code.
+ *
+ *  Revision 1.13  2004/11/23 07:00:54  starvik
+ *  Actually use the execute permission bit in the MMU. This makes it possible
+ *  to prevent e.g. attacks where executable code is put on the stack.
+ *
+ *  Revision 1.12  2004/09/29 06:16:04  starvik
+ *  Use instruction_pointer
+ *
  *  Revision 1.11  2004/05/14 07:58:05  starvik
  *  Merge of changes from 2.4
  *
@@ -103,6 +135,7 @@
 
 extern int find_fixup_code(struct pt_regs *);
 extern void die_if_kernel(const char *, struct pt_regs *, long);
+extern int raw_printk(const char *fmt, ...);
 
 /* debug of low-level TLB reload */
 #undef DEBUG
@@ -118,7 +151,8 @@ extern void die_if_kernel(const char *, struct pt_regs *, long);
 
 /* current active page directory */
 
-volatile pgd_t *current_pgd;
+volatile DEFINE_PER_CPU(pgd_t *,current_pgd);
+unsigned long cris_signal_return_page;
 
 /*
  * This routine handles page faults.  It determines the address,
@@ -146,8 +180,9 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
         struct vm_area_struct * vma;
         siginfo_t info;
 
-        D(printk("Page fault for %X at %X, prot %d write %d\n",
-                 address, regs->erp, protection, writeaccess));
+        D(printk("Page fault for %lX on %X at %lX, prot %d write %d\n",
+                 address, smp_processor_id(), instruction_pointer(regs),
+                 protection, writeaccess));
 
         tsk = current;
 
@@ -175,8 +210,19 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
             !user_mode(regs))
                 goto vmalloc_fault;
 
+        /* When stack execution is not allowed we store the signal
+         * trampolines in the reserved cris_signal_return_page.
+         * Handle this in the exact same way as vmalloc (we know
+         * that the mapping is there and is valid so no need to
+         * call handle_mm_fault).
+         */
+        if (cris_signal_return_page &&
+            address == cris_signal_return_page &&
+            !protection && user_mode(regs))
+                goto vmalloc_fault;
+
         /* we can and should enable interrupts at this point */
-        sti();
+        local_irq_enable();
 
         mm = tsk->mm;
         info.si_code = SEGV_MAPERR;
@@ -220,7 +266,10 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
 
         /* first do some preliminary protection checks */
 
-        if (writeaccess) {
+        if (writeaccess == 2){
+                if (!(vma->vm_flags & VM_EXEC))
+                        goto bad_area;
+        } else if (writeaccess == 1) {
                 if (!(vma->vm_flags & VM_WRITE))
                         goto bad_area;
         } else {
@@ -234,7 +283,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
          * the fault.
          */
 
-        switch (handle_mm_fault(mm, vma, address, writeaccess)) {
+        switch (handle_mm_fault(mm, vma, address, writeaccess & 1)) {
         case 1:
                 tsk->min_flt++;
                 break;
@@ -292,10 +341,10 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
          */
 
         if ((unsigned long) (address) < PAGE_SIZE)
-                printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
+                raw_printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
         else
-                printk(KERN_ALERT "Unable to handle kernel access");
-        printk(" at virtual address %08lx\n",address);
+                raw_printk(KERN_ALERT "Unable to handle kernel access");
+        raw_printk(" at virtual address %08lx\n",address);
 
         die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
 
@@ -346,10 +395,11 @@ vmalloc_fault:
 
                 int offset = pgd_index(address);
                 pgd_t *pgd, *pgd_k;
+                pud_t *pud, *pud_k;
                 pmd_t *pmd, *pmd_k;
                 pte_t *pte_k;
 
-                pgd = (pgd_t *)current_pgd + offset;
+                pgd = (pgd_t *)per_cpu(current_pgd, smp_processor_id()) + offset;
                 pgd_k = init_mm.pgd + offset;
 
                 /* Since we're two-level, we don't need to do both
@@ -364,8 +414,13 @@ vmalloc_fault:
                  * it exists.
                  */
 
-                pmd = pmd_offset(pgd, address);
-                pmd_k = pmd_offset(pgd_k, address);
+                pud = pud_offset(pgd, address);
+                pud_k = pud_offset(pgd_k, address);
+                if (!pud_present(*pud_k))
+                        goto no_context;
+
+                pmd = pmd_offset(pud, address);
+                pmd_k = pmd_offset(pud_k, address);
 
                 if (!pmd_present(*pmd_k))
                         goto bad_area_nosemaphore;
@@ -385,3 +440,19 @@ vmalloc_fault:
                 return;
         }
 }
+
+/* Find fixup code. */
+int
+find_fixup_code(struct pt_regs *regs)
+{
+        const struct exception_table_entry *fixup;
+
+        if ((fixup = search_exception_tables(instruction_pointer(regs))) != 0) {
+                /* Adjust the instruction pointer in the stackframe. */
+                instruction_pointer(regs) = fixup->fixup;
+                arch_fixup(regs);
+                return 1;
+        }
+
+        return 0;
+}
diff --git a/arch/cris/mm/ioremap.c b/arch/cris/mm/ioremap.c
index 6b9130bfb6c1..ebba11e270fa 100644
--- a/arch/cris/mm/ioremap.c
+++ b/arch/cris/mm/ioremap.c
@@ -14,9 +14,10 @@
 #include <asm/pgalloc.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
+#include <asm/arch/memmap.h>
 
 extern inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
-        unsigned long phys_addr, unsigned long flags)
+        unsigned long phys_addr, pgprot_t prot)
 {
         unsigned long end;
 
@@ -31,9 +32,7 @@ extern inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned l
                         printk("remap_area_pte: page already exists\n");
                         BUG();
                 }
-                set_pte(pte, mk_pte_phys(phys_addr, __pgprot(_PAGE_PRESENT | __READABLE | 
-                                                             __WRITEABLE | _PAGE_GLOBAL |
-                                                             _PAGE_KERNEL | flags)));
+                set_pte(pte, mk_pte_phys(phys_addr, prot));
                 address += PAGE_SIZE;
                 phys_addr += PAGE_SIZE;
                 pte++;
@@ -41,7 +40,7 @@ extern inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned l
 }
 
 static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
-        unsigned long phys_addr, unsigned long flags)
+        unsigned long phys_addr, pgprot_t prot)
 {
         unsigned long end;
 
@@ -56,7 +55,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
                 pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
                 if (!pte)
                         return -ENOMEM;
-                remap_area_pte(pte, address, end - address, address + phys_addr, flags);
+                remap_area_pte(pte, address, end - address, address + phys_addr, prot);
                 address = (address + PMD_SIZE) & PMD_MASK;
                 pmd++;
         } while (address && (address < end));
@@ -64,7 +63,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
 }
 
 static int remap_area_pages(unsigned long address, unsigned long phys_addr,
-                                 unsigned long size, unsigned long flags)
+                                 unsigned long size, pgprot_t prot)
 {
         int error;
         pgd_t * dir;
@@ -77,13 +76,19 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
                 BUG();
         spin_lock(&init_mm.page_table_lock);
         do {
+                pud_t *pud;
                 pmd_t *pmd;
-                pmd = pmd_alloc(&init_mm, dir, address);
+
                 error = -ENOMEM;
+                pud = pud_alloc(&init_mm, dir, address);
+                if (!pud)
+                        break;
+                pmd = pmd_alloc(&init_mm, pud, address);
+
                 if (!pmd)
                         break;
                 if (remap_area_pmd(pmd, address, end - address,
-                                   phys_addr + address, flags))
+                                   phys_addr + address, prot))
                         break;
                 error = 0;
                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
@@ -107,9 +112,9 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
  * have to convert them into an offset in a page-aligned mapping, but the
  * caller shouldn't need to know that small detail.
  */
-void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
+void __iomem * __ioremap_prot(unsigned long phys_addr, unsigned long size, pgprot_t prot)
 {
-        void * addr;
+        void __iomem * addr;
         struct vm_struct * area;
         unsigned long offset, last_addr;
 
@@ -131,15 +136,36 @@ void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flag
         area = get_vm_area(size, VM_IOREMAP);
         if (!area)
                 return NULL;
-        addr = area->addr;
-        if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
-                vfree(addr);
+        addr = (void __iomem *)area->addr;
+        if (remap_area_pages((unsigned long) addr, phys_addr, size, prot)) {
+                vfree((void __force *)addr);
                 return NULL;
         }
-        return (void *) (offset + (char *)addr);
+        return (void __iomem *) (offset + (char __iomem *)addr);
+}
+
+void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
+{
+        return __ioremap_prot(phys_addr, size,
+                              __pgprot(_PAGE_PRESENT | __READABLE |
+                                       __WRITEABLE | _PAGE_GLOBAL |
+                                       _PAGE_KERNEL | flags));
+}
+
+/**
+ * ioremap_nocache     -   map bus memory into CPU space
+ * @offset:    bus address of the memory
+ * @size:      size of the resource to map
+ *
+ * Must be freed with iounmap.
+ */
+
+void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
+{
+        return __ioremap(phys_addr | MEM_NON_CACHEABLE, size, 0);
 }
 
-void iounmap(void *addr)
+void iounmap(volatile void __iomem *addr)
 {
         if (addr > high_memory)
                 return vfree((void *) (PAGE_MASK & (unsigned long) addr));
diff --git a/arch/cris/mm/tlb.c b/arch/cris/mm/tlb.c
index 23eca5ad7389..0df390a656cd 100644
--- a/arch/cris/mm/tlb.c
+++ b/arch/cris/mm/tlb.c
@@ -29,18 +29,6 @@
 struct mm_struct *page_id_map[NUM_PAGEID];
 static int map_replace_ptr = 1;  /* which page_id_map entry to replace next */
 
-/*
- * Initialize the context related info for a new mm_struct
- * instance.
- */
-
-int
-init_new_context(struct task_struct *tsk, struct mm_struct *mm)
-{
-        mm->context = NO_CONTEXT;
-        return 0;
-}
-
 /* the following functions are similar to those used in the PPC port */
 
 static inline void
@@ -60,12 +48,12 @@ alloc_context(struct mm_struct *mm)
                  */
                 flush_tlb_mm(old_mm);
 
-                old_mm->context = NO_CONTEXT;
+                old_mm->context.page_id = NO_CONTEXT;
         }
 
         /* insert it into the page_id_map */
 
-        mm->context = map_replace_ptr;
+        mm->context.page_id = map_replace_ptr;
         page_id_map[map_replace_ptr] = mm;
 
         map_replace_ptr++;
@@ -81,7 +69,7 @@ alloc_context(struct mm_struct *mm)
 void
 get_mmu_context(struct mm_struct *mm)
 {
-        if(mm->context == NO_CONTEXT)
+        if(mm->context.page_id == NO_CONTEXT)
                 alloc_context(mm);
 }
 
@@ -96,11 +84,10 @@ get_mmu_context(struct mm_struct *mm)
 void
 destroy_context(struct mm_struct *mm)
 {
-        if(mm->context != NO_CONTEXT) {
-                D(printk("destroy_context %d (%p)\n", mm->context, mm));
+        if(mm->context.page_id != NO_CONTEXT) {
+                D(printk("destroy_context %d (%p)\n", mm->context.page_id, mm));
                 flush_tlb_mm(mm);  /* TODO this might be redundant ? */
-                page_id_map[mm->context] = NULL;
-                /* mm->context = NO_CONTEXT; redundant.. mm will be freed */
+                page_id_map[mm->context.page_id] = NULL;
         }
 }
 
diff --git a/include/asm-cris/arch-v10/mmu.h b/include/asm-cris/arch-v10/mmu.h
index d18aa00e50bc..df84f1716e6b 100644
--- a/include/asm-cris/arch-v10/mmu.h
+++ b/include/asm-cris/arch-v10/mmu.h
@@ -7,7 +7,10 @@
 
 /* type used in struct mm to couple an MMU context to an active mm */
 
-typedef unsigned int mm_context_t;
+typedef struct
+{
+  unsigned int page_id;
+} mm_context_t;
 
 /* kernel memory segments */