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
  18 static inline
  19 void wrapper_vmalloc_sync_all(void)
  20 {
  21         void (*vmalloc_sync_all_sym)(void);
  22
  23         vmalloc_sync_all_sym = (void *) kallsyms_lookup_name("vmalloc_sync_all");
  24         if (vmalloc_sync_all_sym) {
  25                 vmalloc_sync_all_sym();
  26         } else {
  27 #ifdef CONFIG_X86
  28                 /*
  29                  * Only x86 needs vmalloc_sync_all to make sure LTTng does not
  30                  * trigger recursive page faults.
  31                  */
  32                 printk(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
  33                 printk(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
  34 #endif
  35         }
  36 }
  37 #else
  38
  39 #include <linux/vmalloc.h>
  40
  41 static inline
  42 void wrapper_vmalloc_sync_all(void)
  43 {
  44         return vmalloc_sync_all();
  45 }
  46 #endif
  47
  48 #endif /* _LTT_WRAPPER_VMALLOC_H */