3   Generic support for BUG()
7   CONFIG_BUG - emit BUG traps.  Nothing happens without this.
10   CONFIG_DEBUG_BUGVERBOSE - emit full file+line information for each BUG
22   2. Implement BUG (and optionally BUG_ON, WARN, WARN_ON)
24      - Implement BUG() to generate a faulting instruction
33        or an actual bug.
36        to the expected BUG trap instruction.
46 #include <linux/bug.h>
54 static inline unsigned long bug_addr(const struct bug_entry *bug)  in bug_addr()  argument
57 	return (unsigned long)&bug->bug_addr_disp + bug->bug_addr_disp;  in bug_addr()
59 	return bug->bug_addr;  in bug_addr()
69 	struct bug_entry *bug;  in module_find_bug()  local
76 		bug = mod->bug_table;  in module_find_bug()
77 		for (i = 0; i < mod->num_bugs; ++i, ++bug)  in module_find_bug()
78 			if (bugaddr == bug_addr(bug))  in module_find_bug()
79 				return bug;  in module_find_bug()
105 	 * traversals, but since we only traverse on BUG()s, a spinlock  in module_bug_finalize()
107 	 * Thus, this uses RCU to safely manipulate the bug list, since BUG  in module_bug_finalize()
126 void bug_get_file_line(struct bug_entry *bug, const char **file,  in bug_get_file_line()  argument
131 	*file = (const char *)&bug->file_disp + bug->file_disp;  in bug_get_file_line()
133 	*file = bug->file;  in bug_get_file_line()
135 	*line = bug->line;  in bug_get_file_line()
144 	struct bug_entry *bug;  in find_bug()  local
146 	for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)  in find_bug()
147 		if (bugaddr == bug_addr(bug))  in find_bug()
148 			return bug;  in find_bug()
155 	struct bug_entry *bug;  in __report_bug()  local
162 	bug = find_bug(bugaddr);  in __report_bug()
163 	if (!bug)  in __report_bug()
168 	bug_get_file_line(bug, &file, &line);  in __report_bug()
170 	warning = (bug->flags & BUGFLAG_WARNING) != 0;  in __report_bug()
171 	once = (bug->flags & BUGFLAG_ONCE) != 0;  in __report_bug()
172 	done = (bug->flags & BUGFLAG_DONE) != 0;  in __report_bug()
181 		bug->flags |= BUGFLAG_DONE;  in __report_bug()
185 	 * BUG() and WARN_ON() families don't print a custom debug message  in __report_bug()
190 	if ((bug->flags & BUGFLAG_NO_CUT_HERE) == 0)  in __report_bug()
194 		/* this is a WARN_ON rather than BUG/BUG_ON */  in __report_bug()
195 		__warn(file, line, (void *)bugaddr, BUG_GET_TAINT(bug), regs,  in __report_bug()
201 		pr_crit("kernel BUG at %s:%u!\n", file, line);  in __report_bug()
203 		pr_crit("Kernel BUG at %pB [verbose debug info unavailable]\n",  in __report_bug()
223 	struct bug_entry *bug;  in clear_once_table()  local
225 	for (bug = start; bug < end; bug++)  in clear_once_table()
226 		bug->flags &= ~BUGFLAG_DONE;  in clear_once_table()