wrapper/symbols.h

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