src/wrapper/irqdesc.c

   1 /* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
   2  *
   3  * wrapper/irqdesc.c
   4  *
   5  * wrapper around irq_to_desc. Using KALLSYMS to get its address when
   6  * available, else we need to have a kernel that exports this function to GPL
   7  * modules. This export was added to the 3.4 kernels and removed in 5.11.
   8  *
   9  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  */
  11
  12 #include <lttng/kernel-version.h>
  13 #include <linux/module.h>
  14
  15 #if (defined(CONFIG_KALLSYMS) && \
  16         ((LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0)) || \
  17          (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(3,4,0))))
  18
  19 #include <linux/kallsyms.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irqnr.h>
  22 #include <wrapper/kallsyms.h>
  23 #include <wrapper/irqdesc.h>
  24
  25 static
  26 struct irq_desc *(*irq_to_desc_sym)(unsigned int irq);
  27
  28 struct irq_desc *wrapper_irq_to_desc(unsigned int irq)
  29 {
  30         if (!irq_to_desc_sym)
  31                 irq_to_desc_sym = (void *) kallsyms_lookup_funcptr("irq_to_desc");
  32         if (irq_to_desc_sym) {
  33                 struct irq_ibt_state irq_ibt_state;
  34                 struct irq_desc *ret;
  35
  36                 irq_ibt_state = wrapper_irq_ibt_save();
  37                 ret = irq_to_desc_sym(irq);
  38                 wrapper_irq_ibt_restore(irq_ibt_state);
  39                 return ret;
  40         } else {
  41                 printk_once(KERN_WARNING "LTTng: irq_to_desc symbol lookup failed.\n");
  42                 return NULL;
  43         }
  44 }
  45 EXPORT_SYMBOL_GPL(wrapper_irq_to_desc);
  46
  47 #else
  48
  49 #include <linux/interrupt.h>
  50 #include <linux/irqnr.h>
  51
  52 struct irq_desc *wrapper_irq_to_desc(unsigned int irq)
  53 {
  54         return irq_to_desc(irq);
  55 }
  56 EXPORT_SYMBOL_GPL(wrapper_irq_to_desc);
  57
  58 #endif