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-rw-r--r--arch/x86_64/kernel/nmi.c1
-rw-r--r--arch/x86_64/kernel/traps.c2
-rw-r--r--arch/x86_64/mm/fault.c73
-rw-r--r--include/asm-x86_64/pgalloc.h28
-rw-r--r--include/asm-x86_64/pgtable.h4
5 files changed, 95 insertions, 13 deletions
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 66c009e10bac..d9e4067faf05 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -534,6 +534,7 @@ asmlinkage __kprobes void do_nmi(struct pt_regs * regs, long error_code)
void set_nmi_callback(nmi_callback_t callback)
{
+ vmalloc_sync_all();
rcu_assign_pointer(nmi_callback, callback);
}
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 28d50dc540e8..b25bc904d42d 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -78,6 +78,8 @@ int register_die_notifier(struct notifier_block *nb)
{
int err = 0;
unsigned long flags;
+
+ vmalloc_sync_all();
spin_lock_irqsave(&die_notifier_lock, flags);
err = notifier_chain_register(&die_chain, nb);
spin_unlock_irqrestore(&die_notifier_lock, flags);
diff --git a/arch/x86_64/mm/fault.c b/arch/x86_64/mm/fault.c
index 2e7c3c8ffe03..de91e17daf6f 100644
--- a/arch/x86_64/mm/fault.c
+++ b/arch/x86_64/mm/fault.c
@@ -264,6 +264,8 @@ static int vmalloc_fault(unsigned long address)
return -1;
if (pgd_none(*pgd))
set_pgd(pgd, *pgd_ref);
+ else
+ BUG_ON(pgd_page(*pgd) != pgd_page(*pgd_ref));
/* Below here mismatches are bugs because these lower tables
are shared */
@@ -314,16 +316,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
/* get the address */
__asm__("movq %%cr2,%0":"=r" (address));
- if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
- SIGSEGV) == NOTIFY_STOP)
- return;
-
- if (likely(regs->eflags & X86_EFLAGS_IF))
- local_irq_enable();
-
- if (unlikely(page_fault_trace))
- printk("pagefault rip:%lx rsp:%lx cs:%lu ss:%lu address %lx error %lx\n",
- regs->rip,regs->rsp,regs->cs,regs->ss,address,error_code);
tsk = current;
mm = tsk->mm;
@@ -351,10 +343,12 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
*/
if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
((address >= VMALLOC_START && address < VMALLOC_END))) {
- if (vmalloc_fault(address) < 0)
- goto bad_area_nosemaphore;
- return;
+ if (vmalloc_fault(address) >= 0)
+ return;
}
+ if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
+ SIGSEGV) == NOTIFY_STOP)
+ return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
@@ -362,6 +356,17 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
goto bad_area_nosemaphore;
}
+ if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
+ SIGSEGV) == NOTIFY_STOP)
+ return;
+
+ if (likely(regs->eflags & X86_EFLAGS_IF))
+ local_irq_enable();
+
+ if (unlikely(page_fault_trace))
+ printk("pagefault rip:%lx rsp:%lx cs:%lu ss:%lu address %lx error %lx\n",
+ regs->rip,regs->rsp,regs->cs,regs->ss,address,error_code);
+
if (unlikely(error_code & PF_RSVD))
pgtable_bad(address, regs, error_code);
@@ -571,6 +576,48 @@ do_sigbus:
return;
}
+DEFINE_SPINLOCK(pgd_lock);
+struct page *pgd_list;
+
+void vmalloc_sync_all(void)
+{
+ /* 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);
+ for (page = pgd_list; page;
+ page = (struct page *)page->index) {
+ 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(*pgd) != pgd_page(*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)));
+}
+
static int __init enable_pagefaulttrace(char *str)
{
page_fault_trace = 1;
diff --git a/include/asm-x86_64/pgalloc.h b/include/asm-x86_64/pgalloc.h
index 08cad2482bcb..43d4c333a8b1 100644
--- a/include/asm-x86_64/pgalloc.h
+++ b/include/asm-x86_64/pgalloc.h
@@ -45,12 +45,39 @@ static inline void pud_free (pud_t *pud)
free_page((unsigned long)pud);
}
+static inline void pgd_list_add(pgd_t *pgd)
+{
+ struct page *page = virt_to_page(pgd);
+
+ spin_lock(&pgd_lock);
+ page->index = (pgoff_t)pgd_list;
+ if (pgd_list)
+ pgd_list->private = (unsigned long)&page->index;
+ pgd_list = page;
+ page->private = (unsigned long)&pgd_list;
+ spin_unlock(&pgd_lock);
+}
+
+static inline void pgd_list_del(pgd_t *pgd)
+{
+ struct page *next, **pprev, *page = virt_to_page(pgd);
+
+ spin_lock(&pgd_lock);
+ next = (struct page *)page->index;
+ pprev = (struct page **)page->private;
+ *pprev = next;
+ if (next)
+ next->private = (unsigned long)pprev;
+ spin_unlock(&pgd_lock);
+}
+
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
unsigned boundary;
pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
if (!pgd)
return NULL;
+ pgd_list_add(pgd);
/*
* Copy kernel pointers in from init.
* Could keep a freelist or slab cache of those because the kernel
@@ -67,6 +94,7 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
static inline void pgd_free(pgd_t *pgd)
{
BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
+ pgd_list_del(pgd);
free_page((unsigned long)pgd);
}
diff --git a/include/asm-x86_64/pgtable.h b/include/asm-x86_64/pgtable.h
index def903287193..31e83c3bd022 100644
--- a/include/asm-x86_64/pgtable.h
+++ b/include/asm-x86_64/pgtable.h
@@ -420,6 +420,10 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
+extern spinlock_t pgd_lock;
+extern struct page *pgd_list;
+void vmalloc_sync_all(void);
+
#endif /* !__ASSEMBLY__ */
extern int kern_addr_valid(unsigned long addr);
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-17 19:32:49 +0000