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x86: unify fault_32|64.c by ifdef'd function bodies
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It's about time to get on with unifying these files, elimination
of the ugly ifdefs can occur in the unified file.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Harvey Harrison authored and Ingo Molnar committed Jan 30, 2008
1 parent d7d119d commit 1156e09
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Showing 2 changed files with 263 additions and 1 deletion.
116 changes: 116 additions & 0 deletions arch/x86/mm/fault_32.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -173,8 +173,17 @@ static void force_sig_info_fault(int si_signo, int si_code,
force_sig_info(si_signo, &info, tsk);
}

#ifdef CONFIG_X86_64
static int bad_address(void *p)
{
unsigned long dummy;
return probe_kernel_address((unsigned long *)p, dummy);
}
#endif

void dump_pagetable(unsigned long address)
{
#ifdef CONFIG_X86_32
__typeof__(pte_val(__pte(0))) page;

page = read_cr3();
Expand Down Expand Up @@ -209,8 +218,42 @@ void dump_pagetable(unsigned long address)
}

printk("\n");
#else /* CONFIG_X86_64 */
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;

pgd = (pgd_t *)read_cr3();

pgd = __va((unsigned long)pgd & PHYSICAL_PAGE_MASK);
pgd += pgd_index(address);
if (bad_address(pgd)) goto bad;
printk("PGD %lx ", pgd_val(*pgd));
if (!pgd_present(*pgd)) goto ret;

pud = pud_offset(pgd, address);
if (bad_address(pud)) goto bad;
printk("PUD %lx ", pud_val(*pud));
if (!pud_present(*pud)) goto ret;

pmd = pmd_offset(pud, address);
if (bad_address(pmd)) goto bad;
printk("PMD %lx ", pmd_val(*pmd));
if (!pmd_present(*pmd) || pmd_large(*pmd)) goto ret;

pte = pte_offset_kernel(pmd, address);
if (bad_address(pte)) goto bad;
printk("PTE %lx", pte_val(*pte));
ret:
printk("\n");
return;
bad:
printk("BAD\n");
#endif
}

#ifdef CONFIG_X86_32
static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
{
unsigned index = pgd_index(address);
Expand Down Expand Up @@ -246,6 +289,7 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));
return pmd_k;
}
#endif

#ifdef CONFIG_X86_64
static const char errata93_warning[] =
Expand Down Expand Up @@ -326,6 +370,7 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
unsigned long address)
{
#ifdef CONFIG_X86_32
if (!oops_may_print())
return;

Expand All @@ -350,8 +395,40 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
printk(KERN_ALERT "IP:");
printk_address(regs->ip, 1);
dump_pagetable(address);
#else /* CONFIG_X86_64 */
printk(KERN_ALERT "BUG: unable to handle kernel ");
if (address < PAGE_SIZE)
printk(KERN_CONT "NULL pointer dereference");
else
printk(KERN_CONT "paging request");
printk(KERN_CONT " at %016lx\n", address);

printk(KERN_ALERT "IP:");
printk_address(regs->ip, 1);
dump_pagetable(address);
#endif
}

#ifdef CONFIG_X86_64
static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
unsigned long error_code)
{
unsigned long flags = oops_begin();
struct task_struct *tsk;

printk(KERN_ALERT "%s: Corrupted page table at address %lx\n",
current->comm, address);
dump_pagetable(address);
tsk = current;
tsk->thread.cr2 = address;
tsk->thread.trap_no = 14;
tsk->thread.error_code = error_code;
if (__die("Bad pagetable", regs, error_code))
regs = NULL;
oops_end(flags, regs, SIGKILL);
}
#endif

/*
* Handle a fault on the vmalloc or module mapping area
*
Expand Down Expand Up @@ -706,6 +783,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)

void vmalloc_sync_all(void)
{
#ifdef CONFIG_X86_32
/*
* Note that races in the updates of insync and start aren't
* problematic: insync can only get set bits added, and updates to
Expand Down Expand Up @@ -740,4 +818,42 @@ void vmalloc_sync_all(void)
if (address == start && test_bit(pgd_index(address), insync))
start = address + PGDIR_SIZE;
}
#else /* CONFIG_X86_64 */
/*
* Note that races in the updates of insync and start aren't
* problematic: insync can only get set bits added, and updates to
* start are only improving performance (without affecting correctness
* if undone).
*/
static DECLARE_BITMAP(insync, PTRS_PER_PGD);
static unsigned long start = VMALLOC_START & PGDIR_MASK;
unsigned long address;

for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) {
if (!test_bit(pgd_index(address), insync)) {
const pgd_t *pgd_ref = pgd_offset_k(address);
struct page *page;

if (pgd_none(*pgd_ref))
continue;
spin_lock(&pgd_lock);
list_for_each_entry(page, &pgd_list, lru) {
pgd_t *pgd;
pgd = (pgd_t *)page_address(page) + pgd_index(address);
if (pgd_none(*pgd))
set_pgd(pgd, *pgd_ref);
else
BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
}
spin_unlock(&pgd_lock);
set_bit(pgd_index(address), insync);
}
if (address == start)
start = address + PGDIR_SIZE;
}
/* Check that there is no need to do the same for the modules area. */
BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
(__START_KERNEL & PGDIR_MASK)));
#endif
}
148 changes: 147 additions & 1 deletion arch/x86/mm/fault_64.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -176,14 +176,52 @@ static void force_sig_info_fault(int si_signo, int si_code,
force_sig_info(si_signo, &info, tsk);
}

#ifdef CONFIG_X86_64
static int bad_address(void *p)
{
unsigned long dummy;
return probe_kernel_address((unsigned long *)p, dummy);
}
#endif

void dump_pagetable(unsigned long address)
{
#ifdef CONFIG_X86_32
__typeof__(pte_val(__pte(0))) page;

page = read_cr3();
page = ((__typeof__(page) *) __va(page))[address >> PGDIR_SHIFT];
#ifdef CONFIG_X86_PAE
printk("*pdpt = %016Lx ", page);
if ((page >> PAGE_SHIFT) < max_low_pfn
&& page & _PAGE_PRESENT) {
page &= PAGE_MASK;
page = ((__typeof__(page) *) __va(page))[(address >> PMD_SHIFT)
& (PTRS_PER_PMD - 1)];
printk(KERN_CONT "*pde = %016Lx ", page);
page &= ~_PAGE_NX;
}
#else
printk("*pde = %08lx ", page);
#endif

/*
* We must not directly access the pte in the highpte
* case if the page table is located in highmem.
* And let's rather not kmap-atomic the pte, just in case
* it's allocated already.
*/
if ((page >> PAGE_SHIFT) < max_low_pfn
&& (page & _PAGE_PRESENT)
&& !(page & _PAGE_PSE)) {
page &= PAGE_MASK;
page = ((__typeof__(page) *) __va(page))[(address >> PAGE_SHIFT)
& (PTRS_PER_PTE - 1)];
printk("*pte = %0*Lx ", sizeof(page)*2, (u64)page);
}

printk("\n");
#else /* CONFIG_X86_64 */
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
Expand Down Expand Up @@ -215,7 +253,46 @@ void dump_pagetable(unsigned long address)
return;
bad:
printk("BAD\n");
#endif
}

#ifdef CONFIG_X86_32
static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
{
unsigned index = pgd_index(address);
pgd_t *pgd_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;

pgd += index;
pgd_k = init_mm.pgd + index;

if (!pgd_present(*pgd_k))
return NULL;

/*
* set_pgd(pgd, *pgd_k); here would be useless on PAE
* and redundant with the set_pmd() on non-PAE. As would
* set_pud.
*/

pud = pud_offset(pgd, address);
pud_k = pud_offset(pgd_k, address);
if (!pud_present(*pud_k))
return NULL;

pmd = pmd_offset(pud, address);
pmd_k = pmd_offset(pud_k, address);
if (!pmd_present(*pmd_k))
return NULL;
if (!pmd_present(*pmd)) {
set_pmd(pmd, *pmd_k);
arch_flush_lazy_mmu_mode();
} else
BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));
return pmd_k;
}
#endif

#ifdef CONFIG_X86_64
static const char errata93_warning[] =
Expand Down Expand Up @@ -296,6 +373,32 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
unsigned long address)
{
#ifdef CONFIG_X86_32
if (!oops_may_print())
return;

#ifdef CONFIG_X86_PAE
if (error_code & PF_INSTR) {
int level;
pte_t *pte = lookup_address(address, &level);

if (pte && pte_present(*pte) && !pte_exec(*pte))
printk(KERN_CRIT "kernel tried to execute "
"NX-protected page - exploit attempt? "
"(uid: %d)\n", current->uid);
}
#endif
printk(KERN_ALERT "BUG: unable to handle kernel ");
if (address < PAGE_SIZE)
printk(KERN_CONT "NULL pointer dereference");
else
printk(KERN_CONT "paging request");
printk(KERN_CONT " at %08lx\n", address);

printk(KERN_ALERT "IP:");
printk_address(regs->ip, 1);
dump_pagetable(address);
#else /* CONFIG_X86_64 */
printk(KERN_ALERT "BUG: unable to handle kernel ");
if (address < PAGE_SIZE)
printk(KERN_CONT "NULL pointer dereference");
Expand All @@ -306,8 +409,10 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
printk(KERN_ALERT "IP:");
printk_address(regs->ip, 1);
dump_pagetable(address);
#endif
}

#ifdef CONFIG_X86_64
static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
unsigned long error_code)
{
Expand All @@ -325,6 +430,7 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
regs = NULL;
oops_end(flags, regs, SIGKILL);
}
#endif

/*
* Handle a fault on the vmalloc area
Expand Down Expand Up @@ -590,12 +696,15 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
bad_area_nosemaphore:
/* User mode accesses just cause a SIGSEGV */
if (error_code & PF_USER) {

/*
* It's possible to have interrupts off here.
*/
local_irq_enable();

/*
* Valid to do another page fault here because this one came
* from user space.
*/
if (is_prefetch(regs, address, error_code))
return;

Expand Down Expand Up @@ -696,6 +805,42 @@ LIST_HEAD(pgd_list);

void vmalloc_sync_all(void)
{
#ifdef CONFIG_X86_32
/*
* Note that races in the updates of insync and start aren't
* problematic: insync can only get set bits added, and updates to
* start are only improving performance (without affecting correctness
* if undone).
*/
static DECLARE_BITMAP(insync, PTRS_PER_PGD);
static unsigned long start = TASK_SIZE;
unsigned long address;

if (SHARED_KERNEL_PMD)
return;

BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK);
for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) {
if (!test_bit(pgd_index(address), insync)) {
unsigned long flags;
struct page *page;

spin_lock_irqsave(&pgd_lock, flags);
for (page = pgd_list; page; page =
(struct page *)page->index)
if (!vmalloc_sync_one(page_address(page),
address)) {
BUG_ON(page != pgd_list);
break;
}
spin_unlock_irqrestore(&pgd_lock, flags);
if (!page)
set_bit(pgd_index(address), insync);
}
if (address == start && test_bit(pgd_index(address), insync))
start = address + PGDIR_SIZE;
}
#else /* CONFIG_X86_64 */
/*
* Note that races in the updates of insync and start aren't
* problematic: insync can only get set bits added, and updates to
Expand Down Expand Up @@ -732,4 +877,5 @@ void vmalloc_sync_all(void)
BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
(__START_KERNEL & PGDIR_MASK)));
#endif
}

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