taint/module: Remove unnecessary taint_flag.module field

The TAINT_RANDSTRUCT and TAINT_FWCTL flags are mistakenly set in the
taint_flags table as per-module flags. While this can be trivially
corrected, the issue can be avoided altogether by removing the
taint_flag.module field.

This is possible because, since commit 7fd8329 ("taint/module: Clean
up global and module taint flags handling") in 2016, the handling of module
taint flags has been fully generic. Specifically, module_flags_taint() can
print all flags, and the required output buffer size is properly defined in
terms of TAINT_FLAGS_COUNT. The actual per-module flags are always those
added to module.taints by calls to add_taint_module().

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Petr Mladek <pmladek@suse.com>

Author: petrpavlu

include/linux/panic.h

@@ -86,7 +86,6 @@ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
 struct taint_flag {
 	char c_true;		/* character printed when tainted */
 	char c_false;		/* character printed when not tainted */
-	bool module;		/* also show as a per-module taint flag */
 	const char *desc;	/* verbose description of the set taint flag */
 };
 

kernel/module/main.c

@@ -954,7 +954,7 @@ size_t module_flags_taint(unsigned long taints, char *buf)
 	int i;
 
 	for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
-		if (taint_flags[i].module && test_bit(i, &taints))
+		if (test_bit(i, &taints))
 			buf[l++] = taint_flags[i].c_true;
 	}
 

kernel/panic.c

@@ -628,44 +628,40 @@ void panic(const char *fmt, ...)
 }
 EXPORT_SYMBOL(panic);
 
-#define TAINT_FLAG(taint, _c_true, _c_false, _module)			\
+#define TAINT_FLAG(taint, _c_true, _c_false)				\
 	[ TAINT_##taint ] = {						\
 		.c_true = _c_true, .c_false = _c_false,			\
-		.module = _module,					\
 		.desc = #taint,						\
 	}
 
 /*
- * TAINT_FORCED_RMMOD could be a per-module flag but the module
- * is being removed anyway.
- *
  * NOTE: if you modify the taint_flags or TAINT_FLAGS_COUNT,
  * please also modify tools/debugging/kernel-chktaint and
  * Documentation/admin-guide/tainted-kernels.rst, including its
  * small shell script that prints the TAINT_FLAGS_COUNT bits of
  * /proc/sys/kernel/tainted.
  */
 const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
-	TAINT_FLAG(PROPRIETARY_MODULE,		'P', 'G', true),
-	TAINT_FLAG(FORCED_MODULE,		'F', ' ', true),
-	TAINT_FLAG(CPU_OUT_OF_SPEC,		'S', ' ', false),
-	TAINT_FLAG(FORCED_RMMOD,		'R', ' ', false),
-	TAINT_FLAG(MACHINE_CHECK,		'M', ' ', false),
-	TAINT_FLAG(BAD_PAGE,			'B', ' ', false),
-	TAINT_FLAG(USER,			'U', ' ', false),
-	TAINT_FLAG(DIE,				'D', ' ', false),
-	TAINT_FLAG(OVERRIDDEN_ACPI_TABLE,	'A', ' ', false),
-	TAINT_FLAG(WARN,			'W', ' ', false),
-	TAINT_FLAG(CRAP,			'C', ' ', true),
-	TAINT_FLAG(FIRMWARE_WORKAROUND,		'I', ' ', false),
-	TAINT_FLAG(OOT_MODULE,			'O', ' ', true),
-	TAINT_FLAG(UNSIGNED_MODULE,		'E', ' ', true),
-	TAINT_FLAG(SOFTLOCKUP,			'L', ' ', false),
-	TAINT_FLAG(LIVEPATCH,			'K', ' ', true),
-	TAINT_FLAG(AUX,				'X', ' ', true),
-	TAINT_FLAG(RANDSTRUCT,			'T', ' ', true),
-	TAINT_FLAG(TEST,			'N', ' ', true),
-	TAINT_FLAG(FWCTL,			'J', ' ', true),
+	TAINT_FLAG(PROPRIETARY_MODULE,		'P', 'G'),
+	TAINT_FLAG(FORCED_MODULE,		'F', ' '),
+	TAINT_FLAG(CPU_OUT_OF_SPEC,		'S', ' '),
+	TAINT_FLAG(FORCED_RMMOD,		'R', ' '),
+	TAINT_FLAG(MACHINE_CHECK,		'M', ' '),
+	TAINT_FLAG(BAD_PAGE,			'B', ' '),
+	TAINT_FLAG(USER,			'U', ' '),
+	TAINT_FLAG(DIE,				'D', ' '),
+	TAINT_FLAG(OVERRIDDEN_ACPI_TABLE,	'A', ' '),
+	TAINT_FLAG(WARN,			'W', ' '),
+	TAINT_FLAG(CRAP,			'C', ' '),
+	TAINT_FLAG(FIRMWARE_WORKAROUND,		'I', ' '),
+	TAINT_FLAG(OOT_MODULE,			'O', ' '),
+	TAINT_FLAG(UNSIGNED_MODULE,		'E', ' '),
+	TAINT_FLAG(SOFTLOCKUP,			'L', ' '),
+	TAINT_FLAG(LIVEPATCH,			'K', ' '),
+	TAINT_FLAG(AUX,				'X', ' '),
+	TAINT_FLAG(RANDSTRUCT,			'T', ' '),
+	TAINT_FLAG(TEST,			'N', ' '),
+	TAINT_FLAG(FWCTL,			'J', ' '),
 };
 
 #undef TAINT_FLAG