wrapper/vmalloc.h

   1 #ifndef _LTT_WRAPPER_VMALLOC_H
   2 #define _LTT_WRAPPER_VMALLOC_H
   3
   4 /*
   5  * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
   6  *
   7  * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
   8  * available, else we need to have a kernel that exports this function to GPL
   9  * modules.
  10  *
  11  * Dual LGPL v2.1/GPL v2 license.
  12  */
  13
  14 #ifdef CONFIG_KALLSYMS
  15
  16 #include <linux/kallsyms.h>
  17 #include "kallsyms.h"
  18
  19 static inline
  20 void wrapper_vmalloc_sync_all(void)
  21 {
  22         void (*vmalloc_sync_all_sym)(void);
  23
  24         vmalloc_sync_all_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
  25         if (vmalloc_sync_all_sym) {
  26                 vmalloc_sync_all_sym();
  27         } else {
  28 #ifdef CONFIG_X86
  29                 /*
  30                  * Only x86 needs vmalloc_sync_all to make sure LTTng does not
  31                  * trigger recursive page faults.
  32                  */
  33                 printk(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
  34                 printk(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
  35 #endif
  36         }
  37 }
  38 #else
  39
  40 #include <linux/vmalloc.h>
  41
  42 static inline
  43 void wrapper_vmalloc_sync_all(void)
  44 {
  45         return vmalloc_sync_all();
  46 }
  47 #endif
  48
  49 #endif /* _LTT_WRAPPER_VMALLOC_H */