kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS

Only define the ___GFP_SKIP_KASAN_POISON flag when CONFIG_KASAN_HW_TAGS is
enabled.

This patch it not useful by itself, but it prepares the code for additions
of new KASAN-specific GFP patches.

Link: https://lkml.kernel.org/r/44[e-mail]
Signed-off-by: Andrey Konovalov <[e-mail]>
Acked-by: Marco Elver <[e-mail]>
Cc: Alexander Potapenko <[e-mail]>
Cc: Andrey Ryabinin <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Dmitry Vyukov <[e-mail]>
Cc: Evgenii Stepanov <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Peter Collingbourne <[e-mail]>
Cc: Vincenzo Frascino <[e-mail]>
Cc: Will Deacon <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/linux/gfp.h

···
 #define ___GFP_THISNODE		0x200000u
 #define ___GFP_ACCOUNT		0x400000u
 #define ___GFP_ZEROTAGS		0x800000u
+#ifdef CONFIG_KASAN_HW_TAGS
 #define ___GFP_SKIP_KASAN_POISON	0x1000000u
+#else
+#define ___GFP_SKIP_KASAN_POISON	0
+#endif
 #ifdef CONFIG_LOCKDEP
 #define ___GFP_NOLOCKDEP	0x2000000u
 #else
···
 #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
 
 /* Room for N __GFP_FOO bits */
-#define __GFP_BITS_SHIFT (25 + IS_ENABLED(CONFIG_LOCKDEP))
+#define __GFP_BITS_SHIFT (24 +					\
+			  IS_ENABLED(CONFIG_KASAN_HW_TAGS) +	\
+			  IS_ENABLED(CONFIG_LOCKDEP))
 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
 
 /**

include/trace/events/mmflags.h

···
 	{(unsigned long)__GFP_RECLAIM,		"__GFP_RECLAIM"},	\
 	{(unsigned long)__GFP_DIRECT_RECLAIM,	"__GFP_DIRECT_RECLAIM"},\
 	{(unsigned long)__GFP_KSWAPD_RECLAIM,	"__GFP_KSWAPD_RECLAIM"},\
-	{(unsigned long)__GFP_ZEROTAGS,		"__GFP_ZEROTAGS"},	\
-	{(unsigned long)__GFP_SKIP_KASAN_POISON,"__GFP_SKIP_KASAN_POISON"}\
+	{(unsigned long)__GFP_ZEROTAGS,		"__GFP_ZEROTAGS"}	\
+
+#ifdef CONFIG_KASAN_HW_TAGS
+#define __def_gfpflag_names_kasan					      \
+	, {(unsigned long)__GFP_SKIP_KASAN_POISON, "__GFP_SKIP_KASAN_POISON"}
+#else
+#define __def_gfpflag_names_kasan
+#endif
 
 #define show_gfp_flags(flags)						\
 	(flags) ? __print_flags(flags, "|",				\
-	__def_gfpflag_names						\
+	__def_gfpflag_names __def_gfpflag_names_kasan			\
 	) : "none"
 
 #ifdef CONFIG_MMU