Fix caller information for warn_slowpath_null (0f6f49a8) · Commits · 戴 / test

Ian Campbell noticed that since "Eliminate thousands of warnings with gcc 3.2 build" (commit ) all WARN_ON()'s currently appear to come from warn_slowpath_null(), eg: WARNING: at kernel/softirq.c:143 warn_slowpath_null+0x1c/0x20() because now that warn_slowpath_null() is in the call path, the __builtin_return_address(0) returns that, rather than the place that caused the warning. Fix this by splitting up the warn_slowpath_null/fmt cases differently, using a common helper function, and getting the return address in the right place. This also happens to avoid the unnecessary stack usage for the non-stdargs case, and just generally cleans things up. Make the function name printout use %pS while at it. Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

kernel/panic.c

+20 −15

Original line number	Diff line number	Diff line
		@@ -340,39 +340,44 @@ void oops_exit(void)
		}

		#ifdef WANT_WARN_ON_SLOWPATH
		void warn_slowpath_fmt(const char file, int line, const char fmt, ...)
		{
		struct slowpath_args {
		const char *fmt;
		va_list args;
		char function[KSYM_SYMBOL_LEN];
		unsigned long caller = (unsigned long)__builtin_return_address(0);
		const char *board;
		};

		sprint_symbol(function, caller);
		static void warn_slowpath_common(const char file, int line, void caller, struct slowpath_args *args)
		{
		const char *board;

		printk(KERN_WARNING "------------[ cut here ]------------\n");
		printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
		line, function);
		printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
		board = dmi_get_system_info(DMI_PRODUCT_NAME);
		if (board)
		printk(KERN_WARNING "Hardware name: %s\n", board);

		if (*fmt) {
		va_start(args, fmt);
		vprintk(fmt, args);
		va_end(args);
		}
		if (args)
		vprintk(args->fmt, args->args);

		print_modules();
		dump_stack();
		print_oops_end_marker();
		add_taint(TAINT_WARN);
		}

		void warn_slowpath_fmt(const char file, int line, const char fmt, ...)
		{
		struct slowpath_args args;

		args.fmt = fmt;
		va_start(args.args, fmt);
		warn_slowpath_common(file, line, __builtin_return_address(0), &args);
		va_end(args.args);
		}
		EXPORT_SYMBOL(warn_slowpath_fmt);

		void warn_slowpath_null(const char *file, int line)
		{
		static const char *empty = "";
		warn_slowpath_fmt(file, line, empty);
		warn_slowpath_common(file, line, __builtin_return_address(0), NULL);
		}
		EXPORT_SYMBOL(warn_slowpath_null);
		#endif

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