#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
+#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/pgalloc.h>
#define PF_RSVD (1<<3)
#define PF_INSTR (1<<4)
-static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-
-/* Hook to register for page fault notifications */
-int register_page_fault_notifier(struct notifier_block *nb)
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs)
{
- vmalloc_sync_all();
- return atomic_notifier_chain_register(¬ify_page_fault_chain, nb);
-}
-EXPORT_SYMBOL_GPL(register_page_fault_notifier);
+ int ret = 0;
+
+ /* kprobe_running() needs smp_processor_id() */
+ if (!user_mode(regs)) {
+ preempt_disable();
+ if (kprobe_running() && kprobe_fault_handler(regs, 14))
+ ret = 1;
+ preempt_enable();
+ }
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb);
+ return ret;
}
-EXPORT_SYMBOL_GPL(unregister_page_fault_notifier);
-
-static inline int notify_page_fault(struct pt_regs *regs, long err)
+#else
+static inline int notify_page_fault(struct pt_regs *regs)
{
- struct die_args args = {
- .regs = regs,
- .str = "page fault",
- .err = err,
- .trapnr = 14,
- .signr = SIGSEGV
- };
- return atomic_notifier_call_chain(¬ify_page_fault_chain,
- DIE_PAGE_FAULT, &args);
+ return 0;
}
+#endif
/* Sometimes the CPU reports invalid exceptions on prefetch.
Check that here and ignore.
pmd = pmd_offset(pud, address);
if (bad_address(pmd)) goto bad;
printk("PMD %lx ", pmd_val(*pmd));
- if (!pmd_present(*pmd)) goto ret;
+ if (!pmd_present(*pmd) || pmd_large(*pmd)) goto ret;
pte = pte_offset_kernel(pmd, address);
if (bad_address(pte)) goto bad;
return 0;
}
-static int page_fault_trace;
int show_unhandled_signals = 1;
/*
unsigned long flags;
siginfo_t info;
+ /*
+ * We can fault from pretty much anywhere, with unknown IRQ state.
+ */
+ trace_hardirqs_fixup();
+
tsk = current;
mm = tsk->mm;
prefetchw(&mm->mmap_sem);
if (vmalloc_fault(address) >= 0)
return;
}
- if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
+ if (notify_page_fault(regs))
return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
goto bad_area_nosemaphore;
}
- if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
+ if (notify_page_fault(regs))
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);
again:
/* 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
+ * 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
* 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.
if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
printk_ratelimit()) {
printk(
- "%s%s[%d]: segfault at %016lx rip %016lx rsp %016lx error %lx\n",
+ "%s%s[%d]: segfault at %lx rip %lx rsp %lx error %lx\n",
tsk->pid > 1 ? KERN_INFO : KERN_EMERG,
tsk->comm, tsk->pid, address, regs->rip,
regs->rsp, error_code);
*/
out_of_memory:
up_read(&mm->mmap_sem);
- if (is_init(current)) {
+ if (is_global_init(current)) {
yield();
goto again;
}
BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
(__START_KERNEL & PGDIR_MASK)));
}
-
-static int __init enable_pagefaulttrace(char *str)
-{
- page_fault_trace = 1;
- return 1;
-}
-__setup("pagefaulttrace", enable_pagefaulttrace);