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Date:   Sat, 7 May 2022 15:48:35 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Vasily Averin <vvs@openvz.org>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>, kernel@openvz.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH mm] tracing: incorrect gfp_t conversion
Message-Id: <20220507154835.4d4d737d8eed579969f15938@linux-foundation.org>
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        <331d88fe-f4f7-657c-02a2-d977f15fbff6@openvz.org>
        <20220507123728.f20d977eba9fbb66bddee722@linux-foundation.org>
        <8b1cfefa-da7d-3376-cf04-1ff77dab8170@openvz.org>
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On Sun, 8 May 2022 01:28:58 +0300 Vasily Averin <vvs@openvz.org> wrote:

> On 5/7/22 22:37, Andrew Morton wrote:
> > On Sat, 7 May 2022 22:02:05 +0300 Vasily Averin <vvs@openvz.org> wrote:
> >> +	{(__force unsigned long)GFP_KERNEL,		"GFP_KERNEL"},		\
> >> +	{(__force unsigned long)GFP_NOFS,		"GFP_NOFS"},		\
> > 
> > This got all repetitive, line-wrappy and ugly :(
> > 
> > What do we think of something silly like this?
> 
> > --- a/include/trace/events/mmflags.h~tracing-incorrect-gfp_t-conversion-fix
> > +++ a/include/trace/events/mmflags.h
> > @@ -13,53 +13,57 @@
> >   * Thus most bits set go first.
> >   */
> >  
> > +#define FUL __force unsigned long
> > +
> >  #define __def_gfpflag_names						\
> > -	{(__force unsigned long)GFP_TRANSHUGE,		"GFP_TRANSHUGE"},	\
> > -	{(__force unsigned long)GFP_TRANSHUGE_LIGHT,	"GFP_TRANSHUGE_LIGHT"}, \
> ...
> > +	{(FUL)GFP_TRANSHUGE,		"GFP_TRANSHUGE"},	\
> > +	{(FUL)GFP_TRANSHUGE_LIGHT,	"GFP_TRANSHUGE_LIGHT"}, \
> 
> 
> I think it's a good idea, and I regret it was your idea and not mine.

heh

> Should I resend my patch with these changes or would you prefer 
> to keep your patch as a separate one?

I did the below.  I'll squash them together later.


--- a/include/trace/events/mmflags.h~tracing-incorrect-gfp_t-conversion-fix
+++ a/include/trace/events/mmflags.h
@@ -13,53 +13,57 @@
  * Thus most bits set go first.
  */
 
+#define FUL __force unsigned long
+
 #define __def_gfpflag_names						\
-	{(__force unsigned long)GFP_TRANSHUGE,		"GFP_TRANSHUGE"},	\
-	{(__force unsigned long)GFP_TRANSHUGE_LIGHT,	"GFP_TRANSHUGE_LIGHT"}, \
-	{(__force unsigned long)GFP_HIGHUSER_MOVABLE,	"GFP_HIGHUSER_MOVABLE"},\
-	{(__force unsigned long)GFP_HIGHUSER,		"GFP_HIGHUSER"},	\
-	{(__force unsigned long)GFP_USER,		"GFP_USER"},		\
-	{(__force unsigned long)GFP_KERNEL_ACCOUNT,	"GFP_KERNEL_ACCOUNT"},	\
-	{(__force unsigned long)GFP_KERNEL,		"GFP_KERNEL"},		\
-	{(__force unsigned long)GFP_NOFS,		"GFP_NOFS"},		\
-	{(__force unsigned long)GFP_ATOMIC,		"GFP_ATOMIC"},		\
-	{(__force unsigned long)GFP_NOIO,		"GFP_NOIO"},		\
-	{(__force unsigned long)GFP_NOWAIT,		"GFP_NOWAIT"},		\
-	{(__force unsigned long)GFP_DMA,		"GFP_DMA"},		\
-	{(__force unsigned long)__GFP_HIGHMEM,		"__GFP_HIGHMEM"},	\
-	{(__force unsigned long)GFP_DMA32,		"GFP_DMA32"},		\
-	{(__force unsigned long)__GFP_HIGH,		"__GFP_HIGH"},		\
-	{(__force unsigned long)__GFP_ATOMIC,		"__GFP_ATOMIC"},	\
-	{(__force unsigned long)__GFP_IO,		"__GFP_IO"},		\
-	{(__force unsigned long)__GFP_FS,		"__GFP_FS"},		\
-	{(__force unsigned long)__GFP_NOWARN,		"__GFP_NOWARN"},	\
-	{(__force unsigned long)__GFP_RETRY_MAYFAIL,	"__GFP_RETRY_MAYFAIL"},	\
-	{(__force unsigned long)__GFP_NOFAIL,		"__GFP_NOFAIL"},	\
-	{(__force unsigned long)__GFP_NORETRY,		"__GFP_NORETRY"},	\
-	{(__force unsigned long)__GFP_COMP,		"__GFP_COMP"},		\
-	{(__force unsigned long)__GFP_ZERO,		"__GFP_ZERO"},		\
-	{(__force unsigned long)__GFP_NOMEMALLOC,	"__GFP_NOMEMALLOC"},	\
-	{(__force unsigned long)__GFP_MEMALLOC,		"__GFP_MEMALLOC"},	\
-	{(__force unsigned long)__GFP_HARDWALL,		"__GFP_HARDWALL"},	\
-	{(__force unsigned long)__GFP_THISNODE,		"__GFP_THISNODE"},	\
-	{(__force unsigned long)__GFP_RECLAIMABLE,	"__GFP_RECLAIMABLE"},	\
-	{(__force unsigned long)__GFP_MOVABLE,		"__GFP_MOVABLE"},	\
-	{(__force unsigned long)__GFP_ACCOUNT,		"__GFP_ACCOUNT"},	\
-	{(__force unsigned long)__GFP_WRITE,		"__GFP_WRITE"},		\
-	{(__force unsigned long)__GFP_RECLAIM,		"__GFP_RECLAIM"},	\
-	{(__force unsigned long)__GFP_DIRECT_RECLAIM,	"__GFP_DIRECT_RECLAIM"},\
-	{(__force unsigned long)__GFP_KSWAPD_RECLAIM,	"__GFP_KSWAPD_RECLAIM"},\
-	{(__force unsigned long)__GFP_ZEROTAGS,		"__GFP_ZEROTAGS"}	\
+	{(FUL)GFP_TRANSHUGE,		"GFP_TRANSHUGE"},		\
+	{(FUL)GFP_TRANSHUGE_LIGHT,	"GFP_TRANSHUGE_LIGHT"}, 	\
+	{(FUL)GFP_HIGHUSER_MOVABLE,	"GFP_HIGHUSER_MOVABLE"},	\
+	{(FUL)GFP_HIGHUSER,		"GFP_HIGHUSER"},		\
+	{(FUL)GFP_USER,			"GFP_USER"},			\
+	{(FUL)GFP_KERNEL_ACCOUNT,	"GFP_KERNEL_ACCOUNT"},		\
+	{(FUL)GFP_KERNEL,		"GFP_KERNEL"},			\
+	{(FUL)GFP_NOFS,			"GFP_NOFS"},			\
+	{(FUL)GFP_ATOMIC,		"GFP_ATOMIC"},			\
+	{(FUL)GFP_NOIO,			"GFP_NOIO"},			\
+	{(FUL)GFP_NOWAIT,		"GFP_NOWAIT"},			\
+	{(FUL)GFP_DMA,			"GFP_DMA"},			\
+	{(FUL)__GFP_HIGHMEM,		"__GFP_HIGHMEM"},		\
+	{(FUL)GFP_DMA32,		"GFP_DMA32"},			\
+	{(FUL)__GFP_HIGH,		"__GFP_HIGH"},			\
+	{(FUL)__GFP_ATOMIC,		"__GFP_ATOMIC"},		\
+	{(FUL)__GFP_IO,			"__GFP_IO"},			\
+	{(FUL)__GFP_FS,			"__GFP_FS"},			\
+	{(FUL)__GFP_NOWARN,		"__GFP_NOWARN"},		\
+	{(FUL)__GFP_RETRY_MAYFAIL,	"__GFP_RETRY_MAYFAIL"},		\
+	{(FUL)__GFP_NOFAIL,		"__GFP_NOFAIL"},		\
+	{(FUL)__GFP_NORETRY,		"__GFP_NORETRY"},		\
+	{(FUL)__GFP_COMP,		"__GFP_COMP"},			\
+	{(FUL)__GFP_ZERO,		"__GFP_ZERO"},			\
+	{(FUL)__GFP_NOMEMALLOC,		"__GFP_NOMEMALLOC"},		\
+	{(FUL)__GFP_MEMALLOC,		"__GFP_MEMALLOC"},		\
+	{(FUL)__GFP_HARDWALL,		"__GFP_HARDWALL"},		\
+	{(FUL)__GFP_THISNODE,		"__GFP_THISNODE"},		\
+	{(FUL)__GFP_RECLAIMABLE,	"__GFP_RECLAIMABLE"},		\
+	{(FUL)__GFP_MOVABLE,		"__GFP_MOVABLE"},		\
+	{(FUL)__GFP_ACCOUNT,		"__GFP_ACCOUNT"},		\
+	{(FUL)__GFP_WRITE,		"__GFP_WRITE"},			\
+	{(FUL)__GFP_RECLAIM,		"__GFP_RECLAIM"},		\
+	{(FUL)__GFP_DIRECT_RECLAIM,	"__GFP_DIRECT_RECLAIM"},	\
+	{(FUL)__GFP_KSWAPD_RECLAIM,	"__GFP_KSWAPD_RECLAIM"},	\
+	{(FUL)__GFP_ZEROTAGS,		"__GFP_ZEROTAGS"}		\
 
 #ifdef CONFIG_KASAN_HW_TAGS
-#define __def_gfpflag_names_kasan ,					       \
-	{(__force unsigned long)__GFP_SKIP_ZERO,	   "__GFP_SKIP_ZERO"},	       \
-	{(__force unsigned long)__GFP_SKIP_KASAN_POISON,   "__GFP_SKIP_KASAN_POISON"}, \
-	{(__force unsigned long)__GFP_SKIP_KASAN_UNPOISON, "__GFP_SKIP_KASAN_UNPOISON"}
+#define __def_gfpflag_names_kasan ,					\
+	{(FUL)__GFP_SKIP_ZERO,		"__GFP_SKIP_ZERO"},		\
+	{(FUL)__GFP_SKIP_KASAN_POISON,	"__GFP_SKIP_KASAN_POISON"},	\
+	{(FUL)__GFP_SKIP_KASAN_UNPOISON,"__GFP_SKIP_KASAN_UNPOISON"}
 #else
 #define __def_gfpflag_names_kasan
 #endif
 
+#undef FUL
+
 #define show_gfp_flags(flags)						\
 	(flags) ? __print_flags(flags, "|",				\
 	__def_gfpflag_names __def_gfpflag_names_kasan			\
_