gcc/testsuite/c-c++-common/analyzer/deref-before-check-pr109239-linux-bus.c

   1 /* Reduced from linux-5.10.162's drivers-base-bus.c  */
   2 /* { dg-additional-options "-fno-delete-null-pointer-checks -O2" } */
   3
   4 #include "../../gcc.dg/analyzer/analyzer-decls.h"
   5
   6
   7 typedef unsigned int __kernel_size_t;
   8 typedef int __kernel_ssize_t;
   9 typedef __kernel_size_t size_t;
  10 typedef __kernel_ssize_t ssize_t;
  11
  12 struct list_head
  13 {
  14   struct list_head *next, *prev;
  15 };
  16
  17 struct kobject
  18 {
  19   /* [...snip...] */
  20 };
  21
  22 struct attribute
  23 {
  24   /* [...snip...] */
  25 };
  26
  27 static inline
  28 void
  29 sysfs_remove_file_ns(struct kobject* kobj,
  30                      const struct attribute* attr,
  31                      const void* ns)
  32 {
  33 }
  34
  35 static inline
  36 void
  37 sysfs_remove_file(struct kobject* kobj, const struct attribute* attr)
  38 {
  39   sysfs_remove_file_ns(kobj, attr, NULL);
  40 }
  41
  42 extern struct kobject*
  43 kobject_get(struct kobject* kobj);
  44
  45 extern void
  46 kobject_put(struct kobject* kobj);
  47
  48 struct kset
  49 {
  50   struct list_head list;
  51   /* [...snip...] */
  52   struct kobject kobj;
  53   /* [...snip...] */
  54 } __attribute__((__designated_init__));
  55
  56 static inline
  57 struct kset*
  58 to_kset(struct kobject* kobj)
  59 {
  60   return kobj ? ({
  61     char* __mptr = (char*)(kobj);
  62     ((struct kset*)(__mptr - __builtin_offsetof(struct kset, kobj)));
  63   }) : NULL;
  64 }
  65
  66 static inline
  67 struct kset*
  68 kset_get(struct kset* k)
  69 {
  70   return k ? to_kset(kobject_get(&k->kobj)) : NULL;
  71 }
  72
  73 static inline
  74 void
  75 kset_put(struct kset* k)
  76 {
  77   kobject_put(&k->kobj);
  78 }
  79
  80 struct bus_type
  81 {
  82   /* [...snip...] */
  83   struct device* dev_root;
  84   /* [...snip...] */
  85   struct subsys_private* p;
  86   /* [...snip...] */
  87 };
  88
  89 struct bus_attribute
  90 {
  91   struct attribute attr;
  92   /* [...snip...] */
  93 };
  94
  95 extern void
  96 device_unregister(struct device* dev);
  97
  98 struct subsys_private
  99 {
 100   struct kset subsys;
 101   /* [...snip...] */
 102 };
 103
 104 static struct bus_type*
 105 bus_get(struct bus_type* bus)
 106 {
 107   if (bus) { /* { dg-bogus "check of 'bus' for NULL after already dereferencing it" } */
 108     kset_get(&bus->p->subsys);
 109     return bus;
 110   }
 111   return NULL;
 112 }
 113
 114 static void
 115 bus_put(struct bus_type* bus)
 116 {
 117   if (bus)
 118     kset_put(&bus->p->subsys);
 119 }
 120
 121 void
 122 bus_remove_file(struct bus_type* bus, struct bus_attribute* attr)
 123 {
 124   if (bus_get(bus)) {
 125     sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
 126     bus_put(bus);
 127   }
 128 }
 129
 130 extern ssize_t
 131 drivers_autoprobe_show(struct bus_type* bus, char* buf);
 132
 133 extern ssize_t
 134 drivers_autoprobe_store(struct bus_type* bus, const char* buf, size_t count);
 135
 136 extern struct bus_attribute bus_attr_drivers_autoprobe;
 137
 138 static void
 139 remove_probe_files(struct bus_type* bus)
 140 {
 141   bus_remove_file(bus, &bus_attr_drivers_autoprobe);
 142   /* [...snip...] */
 143 }
 144
 145 void
 146 bus_unregister(struct bus_type* bus)
 147 {
 148   /* [...snip...] */
 149   if (bus->dev_root) /* { dg-bogus "pointer 'bus' is dereferenced here" } */
 150     device_unregister(bus->dev_root);
 151   /* [...snip...] */
 152   remove_probe_files(bus);
 153   /* [...snip...] */
 154 }