#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
+#include <linux/kprobes.h>
#include <linux/vs_memory.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
+#include <asm/kdebug.h>
extern void die (char *, struct pt_regs *, long);
-/*
- * This routine is analogous to expand_stack() but instead grows the
- * register backing store (which grows towards higher addresses).
- * Since the register backing store is access sequentially, we
- * disallow growing the RBS by more than a page at a time. Note that
- * the VM_GROWSUP flag can be set on any VM area but that's fine
- * because the total process size is still limited by RLIMIT_STACK and
- * RLIMIT_AS.
- */
-static inline long
-expand_backing_store (struct vm_area_struct *vma, unsigned long address)
+#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)
{
- unsigned long grow;
-
- grow = PAGE_SIZE >> PAGE_SHIFT;
- if (address - vma->vm_start > current->signal->rlim[RLIMIT_STACK].rlim_cur
- || (((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
- current->signal->rlim[RLIMIT_AS].rlim_cur))
- return -ENOMEM;
- if (!vx_vmpages_avail(vma->vm_mm, grow) ||
- ((vma->vm_flags & VM_LOCKED) &&
- !vx_vmlocked_avail(vma->vm_mm, grow)))
- return -ENOMEM;
- vma->vm_end += PAGE_SIZE;
- vx_vmpages_add(vma->vm_mm, grow);
- if (vma->vm_flags & VM_LOCKED)
- vx_vmlocked_add(vma->vm_mm, grow);
- __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow);
- return 0;
+ 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
+
/*
* Return TRUE if ADDRESS points at a page in the kernel's mapped segment
* (inside region 5, on ia64) and that page is present.
return pte_present(pte);
}
-void
+void __kprobes
ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *regs)
{
int signal = SIGSEGV, code = SEGV_MAPERR;
struct siginfo si;
unsigned long mask;
+ /* mmap_sem is performance critical.... */
+ prefetchw(&mm->mmap_sem);
+
/*
* If we're in an interrupt or have no user context, we must not take the fault..
*/
goto bad_area_no_up;
#endif
+ /*
+ * This is to handle the kprobes on user space access instructions
+ */
+ if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT,
+ SIGSEGV) == NOTIFY_STOP)
+ return;
+
down_read(&mm->mmap_sem);
vma = find_vma_prev(mm, address, &prev_vma);
# error File is out of sync with <linux/mm.h>. Please update.
# endif
+ if (((isr >> IA64_ISR_R_BIT) & 1UL) && (!(vma->vm_flags & (VM_READ | VM_WRITE))))
+ goto bad_area;
+
mask = ( (((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)
- | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT)
- | (((isr >> IA64_ISR_R_BIT) & 1UL) << VM_READ_BIT));
+ | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT));
if ((vma->vm_flags & mask) != mask)
goto bad_area;
if (REGION_NUMBER(address) != REGION_NUMBER(vma->vm_start)
|| REGION_OFFSET(address) >= RGN_MAP_LIMIT)
goto bad_area;
- if (expand_backing_store(vma, address))
+ /*
+ * Since the register backing store is accessed sequentially,
+ * we disallow growing it by more than a page at a time.
+ */
+ if (address > vma->vm_end + PAGE_SIZE - sizeof(long))
+ goto bad_area;
+ if (expand_upwards(vma, address))
goto bad_area;
}
goto good_area;
}
no_context:
- if (isr & IA64_ISR_SP) {
+ if ((isr & IA64_ISR_SP)
+ || ((isr & IA64_ISR_NA) && (isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH))
+ {
/*
- * This fault was due to a speculative load set the "ed" bit in the psr to
- * ensure forward progress (target register will get a NaT).
+ * This fault was due to a speculative load or lfetch.fault, set the "ed"
+ * bit in the psr to ensure forward progress. (Target register will get a
+ * NaT for ld.s, lfetch will be canceled.)
*/
ia64_psr(regs)->ed = 1;
return;
}
- if (ia64_done_with_exception(regs))
- return;
-
/*
* Since we have no vma's for region 5, we might get here even if the address is
* valid, due to the VHPT walker inserting a non present translation that becomes
if (REGION_NUMBER(address) == 5 && mapped_kernel_page_is_present(address))
return;
+ if (ia64_done_with_exception(regs))
+ return;
+
/*
* Oops. The kernel tried to access some bad page. We'll have to terminate things
* with extreme prejudice.
out_of_memory:
up_read(&mm->mmap_sem);
- if (current->pid == 1) {
+ if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
git://git.onelab.eu / linux-2.6.git / blobdiff