Commit d292dbb5 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

bug: Add BUG_FORMAT infrastructure 



Add BUG_FORMAT; an architecture opt-in feature that allows adding the
WARN_printf() format string to the bug_entry table.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251110115757.223371452@infradead.org
parent 1be1fac6

include/asm-generic/bug.h

+7 −0
Original line number Diff line number Diff line
@@ -42,6 +42,13 @@ struct bug_entry { 
#else

	signed int	bug_addr_disp;

#endif

#ifdef HAVE_ARCH_BUG_FORMAT

#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS

	const char	*format;

#else

	signed int	format_disp;

#endif

#endif

#ifdef CONFIG_DEBUG_BUGVERBOSE

#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS

	const char	*file;

lib/bug.c

+32 −7
Original line number Diff line number Diff line
@@ -139,6 +139,19 @@ void bug_get_file_line(struct bug_entry *bug, const char **file, 
#endif

}



static const char *bug_get_format(struct bug_entry *bug)

{

	const char *format = NULL;

#ifdef HAVE_ARCH_BUG_FORMAT

#ifdef CONFIG_GENERIC_BUG_RELATIVE_POINTERS

	format = (const char *)&bug->format_disp + bug->format_disp;

#else

	format = bug->format;

#endif

#endif

	return format;

}



struct bug_entry *find_bug(unsigned long bugaddr)

{

	struct bug_entry *bug;
@@ -150,11 +163,19 @@ struct bug_entry *find_bug(unsigned long bugaddr) 
	return module_find_bug(bugaddr);

}



static void __warn_printf(const char *fmt)

{

	if (!fmt)

		return;



	printk("%s", fmt);

}



static enum bug_trap_type __report_bug(unsigned long bugaddr, struct pt_regs *regs)

{

	struct bug_entry *bug;

	const char *file;

	unsigned line, warning, once, done;

	bool warning, once, done, no_cut, has_args;

	const char *file, *fmt;

	unsigned line;



	if (!is_valid_bugaddr(bugaddr))

		return BUG_TRAP_TYPE_NONE;
@@ -166,10 +187,12 @@ static enum bug_trap_type __report_bug(unsigned long bugaddr, struct pt_regs *re 
	disable_trace_on_warning();



	bug_get_file_line(bug, &file, &line);

	fmt = bug_get_format(bug);



	warning = (bug->flags & BUGFLAG_WARNING) != 0;

	once = (bug->flags & BUGFLAG_ONCE) != 0;

	done = (bug->flags & BUGFLAG_DONE) != 0;

	warning  = bug->flags & BUGFLAG_WARNING;

	once     = bug->flags & BUGFLAG_ONCE;

	done     = bug->flags & BUGFLAG_DONE;

	no_cut   = bug->flags & BUGFLAG_NO_CUT_HERE;



	if (warning && once) {

		if (done)
@@ -187,8 +210,10 @@ static enum bug_trap_type __report_bug(unsigned long bugaddr, struct pt_regs *re 
	 * "cut here" line now. WARN() issues its own "cut here" before the

	 * extra debugging message it writes before triggering the handler.

	 */

	if ((bug->flags & BUGFLAG_NO_CUT_HERE) == 0)

	if (!no_cut) {

		printk(KERN_DEFAULT CUT_HERE);

		__warn_printf(fmt);

	}



	if (warning) {

		/* this is a WARN_ON rather than BUG/BUG_ON */