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[PATCH] CRIS update: mm
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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 <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Mikael Starvik authored and Linus Torvalds committed Jul 27, 2005
1 parent 7cf32ca commit 4f18cfb
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Showing 4 changed files with 135 additions and 48 deletions.
95 changes: 83 additions & 12 deletions arch/cris/mm/fault.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
*
Expand Down Expand Up @@ -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
Expand All @@ -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,
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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 {
Expand All @@ -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;
Expand Down Expand Up @@ -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);

Expand Down Expand Up @@ -346,10 +395,11 @@ do_page_fault(unsigned long address, struct pt_regs *regs,

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
Expand All @@ -364,8 +414,13 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
* 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;
Expand All @@ -385,3 +440,19 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
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;
}
58 changes: 42 additions & 16 deletions arch/cris/mm/ioremap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;

Expand All @@ -31,17 +32,15 @@ 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++;
} while (address && (address < end));
}

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;

Expand All @@ -56,15 +55,15 @@ 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));
return 0;
}

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;
Expand All @@ -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;
Expand All @@ -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;

Expand All @@ -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));
Expand Down
25 changes: 6 additions & 19 deletions arch/cris/mm/tlb.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand All @@ -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++;
Expand All @@ -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);
}

Expand All @@ -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;
}
}

Expand Down
5 changes: 4 additions & 1 deletion include/asm-cris/arch-v10/mmu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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 */

Expand Down

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