/*
- * arch/ppc/mm/fault.c
- *
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* 2 of the License, or (at your option) any later version.
*/
-#include <linux/config.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <asm/kdebug.h>
#include <asm/siginfo.h>
+#ifdef CONFIG_KPROBES
+ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
+
+/* Hook to register for page fault notifications */
+int register_page_fault_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_register(¬ify_page_fault_chain, nb);
+}
+
+int unregister_page_fault_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb);
+}
+
+static inline int notify_page_fault(enum die_val val, const char *str,
+ struct pt_regs *regs, long err, int trap, int sig)
+{
+ struct die_args args = {
+ .regs = regs,
+ .str = str,
+ .err = err,
+ .trapnr = trap,
+ .signr = sig
+ };
+ return atomic_notifier_call_chain(¬ify_page_fault_chain, val, &args);
+}
+#else
+static inline int notify_page_fault(enum die_val val, const char *str,
+ struct pt_regs *regs, long err, int trap, int sig)
+{
+ return NOTIFY_DONE;
+}
+#endif
+
/*
* Check whether the instruction at regs->nip is a store using
* an update addressing form which will update r1.
is_write = error_code & ESR_DST;
#endif /* CONFIG_4xx || CONFIG_BOOKE */
- if (notify_die(DIE_PAGE_FAULT, "page_fault", regs, error_code,
+ if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code,
11, SIGSEGV) == NOTIFY_STOP)
return 0;
/* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
- * kernel and should generate an OOPS. Unfortunatly, in the case of an
- * erroneous fault occuring in a code path which already holds mmap_sem
+ * kernel and should generate an OOPS. Unfortunately, in the case of an
+ * erroneous fault occurring in a code path which already holds mmap_sem
* we will deadlock attempting to validate the fault against the
* address space. Luckily the kernel only validly references user
* space from well defined areas of code, which are listed in the
* exceptions table.
*
* As the vast majority of faults will be valid we will only perform
- * the source reference check when there is a possibilty of a deadlock.
+ * the source reference check when there is a possibility of a deadlock.
* Attempt to lock the address space, if we cannot we then validate the
* source. If this is invalid we can skip the address space check,
* thus avoiding the deadlock.
#endif
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
pte_t *ptep;
+ pmd_t *pmdp;
/* Since 4xx/Book-E supports per-page execute permission,
* we lazily flush dcache to icache. */
ptep = NULL;
- if (get_pteptr(mm, address, &ptep) && pte_present(*ptep)) {
- struct page *page = pte_page(*ptep);
-
- if (! test_bit(PG_arch_1, &page->flags)) {
- flush_dcache_icache_page(page);
- set_bit(PG_arch_1, &page->flags);
+ if (get_pteptr(mm, address, &ptep, &pmdp)) {
+ spinlock_t *ptl = pte_lockptr(mm, pmdp);
+ spin_lock(ptl);
+ if (pte_present(*ptep)) {
+ struct page *page = pte_page(*ptep);
+
+ if (!test_bit(PG_arch_1, &page->flags)) {
+ flush_dcache_icache_page(page);
+ set_bit(PG_arch_1, &page->flags);
+ }
+ pte_update(ptep, 0, _PAGE_HWEXEC);
+ _tlbie(address);
+ pte_unmap_unlock(ptep, ptl);
+ up_read(&mm->mmap_sem);
+ return 0;
}
- pte_update(ptep, 0, _PAGE_HWEXEC);
- _tlbie(address);
- pte_unmap(ptep);
- up_read(&mm->mmap_sem);
- return 0;
+ pte_unmap_unlock(ptep, ptl);
}
- if (ptep != NULL)
- pte_unmap(ptep);
#endif
/* a write */
} else if (is_write) {
/* protection fault */
if (error_code & 0x08000000)
goto bad_area;
- if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+ if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
goto bad_area;
}
*/
out_of_memory:
up_read(&mm->mmap_sem);
- if (current->pid == 1) {
+ if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
}
- printk("VM: killing process %s\n", current->comm);
+ printk("VM: killing process %s(%d:#%u)\n",
+ current->comm, current->pid, current->xid);
if (user_mode(regs))
do_exit(SIGKILL);
return SIGKILL;
/* kernel has accessed a bad area */
- printk(KERN_ALERT "Unable to handle kernel paging request for ");
switch (regs->trap) {
- case 0x300:
- case 0x380:
- printk("data at address 0x%08lx\n", regs->dar);
- break;
- case 0x400:
- case 0x480:
- printk("instruction fetch\n");
- break;
- default:
- printk("unknown fault\n");
+ case 0x300:
+ case 0x380:
+ printk(KERN_ALERT "Unable to handle kernel paging request for "
+ "data at address 0x%08lx\n", regs->dar);
+ break;
+ case 0x400:
+ case 0x480:
+ printk(KERN_ALERT "Unable to handle kernel paging request for "
+ "instruction fetch\n");
+ break;
+ default:
+ printk(KERN_ALERT "Unable to handle kernel paging request for "
+ "unknown fault\n");
+ break;
}
printk(KERN_ALERT "Faulting instruction address: 0x%08lx\n",
regs->nip);
git://git.onelab.eu / linux-2.6.git / blobdiff