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42#define pr_fmt(fmt) fmt
43
44#include <linux/list.h>
45#include <linux/module.h>
46#include <linux/kernel.h>
47#include <linux/bug.h>
48#include <linux/sched.h>
49#include <linux/rculist.h>
50
51extern struct bug_entry __start___bug_table[], __stop___bug_table[];
52
53static inline unsigned long bug_addr(const struct bug_entry *bug)
54{
55#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
56 return bug->bug_addr;
57#else
58 return (unsigned long)bug + bug->bug_addr_disp;
59#endif
60}
61
62#ifdef CONFIG_MODULES
63
64static LIST_HEAD(module_bug_list);
65
66static struct bug_entry *module_find_bug(unsigned long bugaddr)
67{
68 struct module *mod;
69 struct bug_entry *bug = NULL;
70
71 rcu_read_lock_sched();
72 list_for_each_entry_rcu(mod, &module_bug_list, bug_list) {
73 unsigned i;
74
75 bug = mod->bug_table;
76 for (i = 0; i < mod->num_bugs; ++i, ++bug)
77 if (bugaddr == bug_addr(bug))
78 goto out;
79 }
80 bug = NULL;
81out:
82 rcu_read_unlock_sched();
83
84 return bug;
85}
86
87void module_bug_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
88 struct module *mod)
89{
90 char *secstrings;
91 unsigned int i;
92
93 lockdep_assert_held(&module_mutex);
94
95 mod->bug_table = NULL;
96 mod->num_bugs = 0;
97
98
99 secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
100 for (i = 1; i < hdr->e_shnum; i++) {
101 if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table"))
102 continue;
103 mod->bug_table = (void *) sechdrs[i].sh_addr;
104 mod->num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);
105 break;
106 }
107
108
109
110
111
112
113
114
115 list_add_rcu(&mod->bug_list, &module_bug_list);
116}
117
118void module_bug_cleanup(struct module *mod)
119{
120 lockdep_assert_held(&module_mutex);
121 list_del_rcu(&mod->bug_list);
122}
123
124#else
125
126static inline struct bug_entry *module_find_bug(unsigned long bugaddr)
127{
128 return NULL;
129}
130#endif
131
132struct bug_entry *find_bug(unsigned long bugaddr)
133{
134 struct bug_entry *bug;
135
136 for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
137 if (bugaddr == bug_addr(bug))
138 return bug;
139
140 return module_find_bug(bugaddr);
141}
142
143enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
144{
145 struct bug_entry *bug;
146 const char *file;
147 unsigned line, warning, once, done;
148
149 if (!is_valid_bugaddr(bugaddr))
150 return BUG_TRAP_TYPE_NONE;
151
152 bug = find_bug(bugaddr);
153
154 file = NULL;
155 line = 0;
156 warning = 0;
157
158 if (bug) {
159#ifdef CONFIG_DEBUG_BUGVERBOSE
160#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
161 file = bug->file;
162#else
163 file = (const char *)bug + bug->file_disp;
164#endif
165 line = bug->line;
166#endif
167 warning = (bug->flags & BUGFLAG_WARNING) != 0;
168 once = (bug->flags & BUGFLAG_ONCE) != 0;
169 done = (bug->flags & BUGFLAG_DONE) != 0;
170
171 if (warning && once) {
172 if (done)
173 return BUG_TRAP_TYPE_WARN;
174
175
176
177
178 bug->flags |= BUGFLAG_DONE;
179 }
180 }
181
182 if (warning) {
183
184 __warn(file, line, (void *)bugaddr, BUG_GET_TAINT(bug), regs,
185 NULL);
186 return BUG_TRAP_TYPE_WARN;
187 }
188
189 printk(KERN_DEFAULT "------------[ cut here ]------------\n");
190
191 if (file)
192 pr_crit("kernel BUG at %s:%u!\n", file, line);
193 else
194 pr_crit("Kernel BUG at %p [verbose debug info unavailable]\n",
195 (void *)bugaddr);
196
197 return BUG_TRAP_TYPE_BUG;
198}
199