[PATCH mm] tracing: incorrect gfp_t conversion

Vasily Averin posted 1 patch 4 years ago
There is a newer version of this series
include/linux/gfp.h               |  2 +-
include/trace/events/btrfs.h      |  4 +-
include/trace/events/compaction.h |  4 +-
include/trace/events/kmem.h       | 12 ++---
include/trace/events/mmflags.h    | 74 +++++++++++++++----------------
include/trace/events/vmscan.h     | 16 +++----
mm/compaction.c                   |  2 +-
7 files changed, 57 insertions(+), 57 deletions(-)
[PATCH mm] tracing: incorrect gfp_t conversion
Posted by Vasily Averin 4 years ago
Fixes the following sparse warnings:

include/trace/events/*: sparse: cast to restricted gfp_t
include/trace/events/*: sparse: restricted gfp_t degrades to integer

gfp_t type is bitwise and requires __force attributes for any casts.

Signed-off-by: Vasily Averin <vvs@openvz.org>
---
 include/linux/gfp.h               |  2 +-
 include/trace/events/btrfs.h      |  4 +-
 include/trace/events/compaction.h |  4 +-
 include/trace/events/kmem.h       | 12 ++---
 include/trace/events/mmflags.h    | 74 +++++++++++++++----------------
 include/trace/events/vmscan.h     | 16 +++----
 mm/compaction.c                   |  2 +-
 7 files changed, 57 insertions(+), 57 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 80f63c862be5..5f44c49abab7 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -352,7 +352,7 @@ static inline int gfp_migratetype(const gfp_t gfp_flags)
 		return MIGRATE_UNMOVABLE;
 
 	/* Group based on mobility */
-	return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
+	return (__force unsigned long)(gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
 }
 #undef GFP_MOVABLE_MASK
 #undef GFP_MOVABLE_SHIFT
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 0d729664b4b4..ea7a05ac49c3 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -1343,13 +1343,13 @@ TRACE_EVENT(alloc_extent_state,
 
 	TP_STRUCT__entry(
 		__field(const struct extent_state *, state)
-		__field(gfp_t, mask)
+		__field(unsigned long, mask)
 		__field(const void*, ip)
 	),
 
 	TP_fast_assign(
 		__entry->state	= state,
-		__entry->mask	= mask,
+		__entry->mask	= (__force unsigned long)mask,
 		__entry->ip	= (const void *)IP
 	),
 
diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h
index 7d48e7079e48..915c11ee28e4 100644
--- a/include/trace/events/compaction.h
+++ b/include/trace/events/compaction.h
@@ -162,13 +162,13 @@ TRACE_EVENT(mm_compaction_try_to_compact_pages,
 
 	TP_STRUCT__entry(
 		__field(int, order)
-		__field(gfp_t, gfp_mask)
+		__field(unsigned long, gfp_mask)
 		__field(int, prio)
 	),
 
 	TP_fast_assign(
 		__entry->order = order;
-		__entry->gfp_mask = gfp_mask;
+		__entry->gfp_mask = (__force unsigned long)gfp_mask;
 		__entry->prio = prio;
 	),
 
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index ddc8c944f417..71c141804222 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -24,7 +24,7 @@ DECLARE_EVENT_CLASS(kmem_alloc,
 		__field(	const void *,	ptr		)
 		__field(	size_t,		bytes_req	)
 		__field(	size_t,		bytes_alloc	)
-		__field(	gfp_t,		gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 	),
 
 	TP_fast_assign(
@@ -32,7 +32,7 @@ DECLARE_EVENT_CLASS(kmem_alloc,
 		__entry->ptr		= ptr;
 		__entry->bytes_req	= bytes_req;
 		__entry->bytes_alloc	= bytes_alloc;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("call_site=%pS ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s",
@@ -75,7 +75,7 @@ DECLARE_EVENT_CLASS(kmem_alloc_node,
 		__field(	const void *,	ptr		)
 		__field(	size_t,		bytes_req	)
 		__field(	size_t,		bytes_alloc	)
-		__field(	gfp_t,		gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 		__field(	int,		node		)
 	),
 
@@ -84,7 +84,7 @@ DECLARE_EVENT_CLASS(kmem_alloc_node,
 		__entry->ptr		= ptr;
 		__entry->bytes_req	= bytes_req;
 		__entry->bytes_alloc	= bytes_alloc;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 		__entry->node		= node;
 	),
 
@@ -208,14 +208,14 @@ TRACE_EVENT(mm_page_alloc,
 	TP_STRUCT__entry(
 		__field(	unsigned long,	pfn		)
 		__field(	unsigned int,	order		)
-		__field(	gfp_t,		gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 		__field(	int,		migratetype	)
 	),
 
 	TP_fast_assign(
 		__entry->pfn		= page ? page_to_pfn(page) : -1UL;
 		__entry->order		= order;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 		__entry->migratetype	= migratetype;
 	),
 
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 116ed4d5d0f8..51d4fa6f3f39 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -14,43 +14,43 @@
  */
 
 #define __def_gfpflag_names						\
-	{(unsigned long)GFP_TRANSHUGE,		"GFP_TRANSHUGE"},	\
-	{(unsigned long)GFP_TRANSHUGE_LIGHT,	"GFP_TRANSHUGE_LIGHT"}, \
-	{(unsigned long)GFP_HIGHUSER_MOVABLE,	"GFP_HIGHUSER_MOVABLE"},\
-	{(unsigned long)GFP_HIGHUSER,		"GFP_HIGHUSER"},	\
-	{(unsigned long)GFP_USER,		"GFP_USER"},		\
-	{(unsigned long)GFP_KERNEL_ACCOUNT,	"GFP_KERNEL_ACCOUNT"},	\
-	{(unsigned long)GFP_KERNEL,		"GFP_KERNEL"},		\
-	{(unsigned long)GFP_NOFS,		"GFP_NOFS"},		\
-	{(unsigned long)GFP_ATOMIC,		"GFP_ATOMIC"},		\
-	{(unsigned long)GFP_NOIO,		"GFP_NOIO"},		\
-	{(unsigned long)GFP_NOWAIT,		"GFP_NOWAIT"},		\
-	{(unsigned long)GFP_DMA,		"GFP_DMA"},		\
-	{(unsigned long)__GFP_HIGHMEM,		"__GFP_HIGHMEM"},	\
-	{(unsigned long)GFP_DMA32,		"GFP_DMA32"},		\
-	{(unsigned long)__GFP_HIGH,		"__GFP_HIGH"},		\
-	{(unsigned long)__GFP_ATOMIC,		"__GFP_ATOMIC"},	\
-	{(unsigned long)__GFP_IO,		"__GFP_IO"},		\
-	{(unsigned long)__GFP_FS,		"__GFP_FS"},		\
-	{(unsigned long)__GFP_NOWARN,		"__GFP_NOWARN"},	\
-	{(unsigned long)__GFP_RETRY_MAYFAIL,	"__GFP_RETRY_MAYFAIL"},	\
-	{(unsigned long)__GFP_NOFAIL,		"__GFP_NOFAIL"},	\
-	{(unsigned long)__GFP_NORETRY,		"__GFP_NORETRY"},	\
-	{(unsigned long)__GFP_COMP,		"__GFP_COMP"},		\
-	{(unsigned long)__GFP_ZERO,		"__GFP_ZERO"},		\
-	{(unsigned long)__GFP_NOMEMALLOC,	"__GFP_NOMEMALLOC"},	\
-	{(unsigned long)__GFP_MEMALLOC,		"__GFP_MEMALLOC"},	\
-	{(unsigned long)__GFP_HARDWALL,		"__GFP_HARDWALL"},	\
-	{(unsigned long)__GFP_THISNODE,		"__GFP_THISNODE"},	\
-	{(unsigned long)__GFP_RECLAIMABLE,	"__GFP_RECLAIMABLE"},	\
-	{(unsigned long)__GFP_MOVABLE,		"__GFP_MOVABLE"},	\
-	{(unsigned long)__GFP_ACCOUNT,		"__GFP_ACCOUNT"},	\
-	{(unsigned long)__GFP_WRITE,		"__GFP_WRITE"},		\
-	{(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"}\
+	{(__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"},	\
+	{(__force unsigned long)__GFP_SKIP_KASAN_POISON, "__GFP_SKIP_KASAN_POISON"} \
 
 #define show_gfp_flags(flags)						\
 	(flags) ? __print_flags(flags, "|",				\
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index ca2e9009a651..b1db02c1aa6f 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -96,14 +96,14 @@ TRACE_EVENT(mm_vmscan_wakeup_kswapd,
 		__field(	int,	nid		)
 		__field(	int,	zid		)
 		__field(	int,	order		)
-		__field(	gfp_t,	gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 	),
 
 	TP_fast_assign(
 		__entry->nid		= nid;
 		__entry->zid		= zid;
 		__entry->order		= order;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("nid=%d order=%d gfp_flags=%s",
@@ -120,12 +120,12 @@ DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template,
 
 	TP_STRUCT__entry(
 		__field(	int,	order		)
-		__field(	gfp_t,	gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 	),
 
 	TP_fast_assign(
 		__entry->order		= order;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("order=%d gfp_flags=%s",
@@ -210,7 +210,7 @@ TRACE_EVENT(mm_shrink_slab_start,
 		__field(void *, shrink)
 		__field(int, nid)
 		__field(long, nr_objects_to_shrink)
-		__field(gfp_t, gfp_flags)
+		__field(unsigned long, gfp_flags)
 		__field(unsigned long, cache_items)
 		__field(unsigned long long, delta)
 		__field(unsigned long, total_scan)
@@ -222,7 +222,7 @@ TRACE_EVENT(mm_shrink_slab_start,
 		__entry->shrink = shr->scan_objects;
 		__entry->nid = sc->nid;
 		__entry->nr_objects_to_shrink = nr_objects_to_shrink;
-		__entry->gfp_flags = sc->gfp_mask;
+		__entry->gfp_flags = (__force unsigned long)sc->gfp_mask;
 		__entry->cache_items = cache_items;
 		__entry->delta = delta;
 		__entry->total_scan = total_scan;
@@ -446,13 +446,13 @@ TRACE_EVENT(mm_vmscan_node_reclaim_begin,
 	TP_STRUCT__entry(
 		__field(int, nid)
 		__field(int, order)
-		__field(gfp_t, gfp_flags)
+		__field(unsigned long, gfp_flags)
 	),
 
 	TP_fast_assign(
 		__entry->nid = nid;
 		__entry->order = order;
-		__entry->gfp_flags = gfp_flags;
+		__entry->gfp_flags = (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("nid=%d order=%d gfp_flags=%s",
diff --git a/mm/compaction.c b/mm/compaction.c
index b4e94cda3019..746dafa4e6eb 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2558,7 +2558,7 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
 		unsigned int alloc_flags, const struct alloc_context *ac,
 		enum compact_priority prio, struct page **capture)
 {
-	int may_perform_io = gfp_mask & __GFP_IO;
+	int may_perform_io = (__force int)(gfp_mask & __GFP_IO);
 	struct zoneref *z;
 	struct zone *zone;
 	enum compact_result rc = COMPACT_SKIPPED;
-- 
2.31.1
Re: [PATCH mm] tracing: incorrect gfp_t conversion
Posted by Andrew Morton 4 years ago
On Sat, 7 May 2022 22:02:05 +0300 Vasily Averin <vvs@openvz.org> wrote:

> Fixes the following sparse warnings:
> 
> include/trace/events/*: sparse: cast to restricted gfp_t
> include/trace/events/*: sparse: restricted gfp_t degrades to integer
> 
> gfp_t type is bitwise and requires __force attributes for any casts.
> 
> --- a/include/trace/events/mmflags.h
> +++ b/include/trace/events/mmflags.h
> @@ -14,43 +14,43 @@
>   */
>  
>  #define __def_gfpflag_names						\
> -	{(unsigned long)GFP_TRANSHUGE,		"GFP_TRANSHUGE"},	\
> -	{(unsigned long)GFP_TRANSHUGE_LIGHT,	"GFP_TRANSHUGE_LIGHT"}, \
> -	{(unsigned long)GFP_HIGHUSER_MOVABLE,	"GFP_HIGHUSER_MOVABLE"},\
> -	{(unsigned long)GFP_HIGHUSER,		"GFP_HIGHUSER"},	\
> -	{(unsigned long)GFP_USER,		"GFP_USER"},		\
> -	{(unsigned long)GFP_KERNEL_ACCOUNT,	"GFP_KERNEL_ACCOUNT"},	\
> -	{(unsigned long)__GFP_SKIP_KASAN_POISON,"__GFP_SKIP_KASAN_POISON"}\
>
> ...
>
> +	{(__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"},		\

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"}, \
-	{(__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"}
+	{(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			\
_
Re: [PATCH mm] tracing: incorrect gfp_t conversion
Posted by Vasily Averin 4 years ago
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.

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

Thank you,
	Vasily Averin
Re: [PATCH mm] tracing: incorrect gfp_t conversion
Posted by Andrew Morton 4 years ago
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			\
_
Re: [PATCH mm] tracing: incorrect gfp_t conversion
Posted by Joe Perches 3 years, 12 months ago
On Sat, 2022-05-07 at 15:48 -0700, Andrew Morton wrote:
> 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.

Very repetitive indeed.

Why not use another stringifying macro?

Maybe something like:

#define gfpflag_string(GFP)	\
	{(__force unsigned long)GFP, #GFP)}

#define __def_gfpflag_names			\
	gfp_flag_string(GFP_TRANSHUGE),		\
	etc...
[PATCH mm v2] tracing: incorrect gfp_t conversion
Posted by Vasily Averin 3 years, 12 months ago
Fixes the following sparse warnings:

include/trace/events/*: sparse: cast to restricted gfp_t
include/trace/events/*: sparse: restricted gfp_t degrades to integer

gfp_t type is bitwise and requires __force attributes for any casts.

Signed-off-by:	Vasily Averin <vvs@openvz.org>
---
v2: 1) re-based to 5.18-rc6
    2) re-defined __def_gfpflag_names array according to
	akpm@, willy@ and Joe Perches recommendations
---
 include/linux/gfp.h               |  2 +-
 include/trace/events/btrfs.h      |  4 +-
 include/trace/events/compaction.h |  4 +-
 include/trace/events/kmem.h       | 12 ++---
 include/trace/events/mmflags.h    | 84 ++++++++++++++++---------------
 include/trace/events/vmscan.h     | 16 +++---
 mm/compaction.c                   |  2 +-
 7 files changed, 63 insertions(+), 61 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 3e3d36fc2109..ac6d750d512c 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -367,7 +367,7 @@ static inline int gfp_migratetype(const gfp_t gfp_flags)
 		return MIGRATE_UNMOVABLE;
 
 	/* Group based on mobility */
-	return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
+	return (__force unsigned long)(gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
 }
 #undef GFP_MOVABLE_MASK
 #undef GFP_MOVABLE_SHIFT
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index f068ff30d654..ed92c80331ea 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -1344,13 +1344,13 @@ TRACE_EVENT(alloc_extent_state,
 
 	TP_STRUCT__entry(
 		__field(const struct extent_state *, state)
-		__field(gfp_t, mask)
+		__field(unsigned long, mask)
 		__field(const void*, ip)
 	),
 
 	TP_fast_assign(
 		__entry->state	= state,
-		__entry->mask	= mask,
+		__entry->mask	= (__force unsigned long)mask,
 		__entry->ip	= (const void *)IP
 	),
 
diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h
index c6d5d70dc7a5..3313eb83c117 100644
--- a/include/trace/events/compaction.h
+++ b/include/trace/events/compaction.h
@@ -162,13 +162,13 @@ TRACE_EVENT(mm_compaction_try_to_compact_pages,
 
 	TP_STRUCT__entry(
 		__field(int, order)
-		__field(gfp_t, gfp_mask)
+		__field(unsigned long, gfp_mask)
 		__field(int, prio)
 	),
 
 	TP_fast_assign(
 		__entry->order = order;
-		__entry->gfp_mask = gfp_mask;
+		__entry->gfp_mask = (__force unsigned long)gfp_mask;
 		__entry->prio = prio;
 	),
 
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index ddc8c944f417..71c141804222 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -24,7 +24,7 @@ DECLARE_EVENT_CLASS(kmem_alloc,
 		__field(	const void *,	ptr		)
 		__field(	size_t,		bytes_req	)
 		__field(	size_t,		bytes_alloc	)
-		__field(	gfp_t,		gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 	),
 
 	TP_fast_assign(
@@ -32,7 +32,7 @@ DECLARE_EVENT_CLASS(kmem_alloc,
 		__entry->ptr		= ptr;
 		__entry->bytes_req	= bytes_req;
 		__entry->bytes_alloc	= bytes_alloc;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("call_site=%pS ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s",
@@ -75,7 +75,7 @@ DECLARE_EVENT_CLASS(kmem_alloc_node,
 		__field(	const void *,	ptr		)
 		__field(	size_t,		bytes_req	)
 		__field(	size_t,		bytes_alloc	)
-		__field(	gfp_t,		gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 		__field(	int,		node		)
 	),
 
@@ -84,7 +84,7 @@ DECLARE_EVENT_CLASS(kmem_alloc_node,
 		__entry->ptr		= ptr;
 		__entry->bytes_req	= bytes_req;
 		__entry->bytes_alloc	= bytes_alloc;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 		__entry->node		= node;
 	),
 
@@ -208,14 +208,14 @@ TRACE_EVENT(mm_page_alloc,
 	TP_STRUCT__entry(
 		__field(	unsigned long,	pfn		)
 		__field(	unsigned int,	order		)
-		__field(	gfp_t,		gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 		__field(	int,		migratetype	)
 	),
 
 	TP_fast_assign(
 		__entry->pfn		= page ? page_to_pfn(page) : -1UL;
 		__entry->order		= order;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 		__entry->migratetype	= migratetype;
 	),
 
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 6532119a6bf1..bbef42058a7e 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -13,49 +13,51 @@
  * Thus most bits set go first.
  */
 
-#define __def_gfpflag_names						\
-	{(unsigned long)GFP_TRANSHUGE,		"GFP_TRANSHUGE"},	\
-	{(unsigned long)GFP_TRANSHUGE_LIGHT,	"GFP_TRANSHUGE_LIGHT"}, \
-	{(unsigned long)GFP_HIGHUSER_MOVABLE,	"GFP_HIGHUSER_MOVABLE"},\
-	{(unsigned long)GFP_HIGHUSER,		"GFP_HIGHUSER"},	\
-	{(unsigned long)GFP_USER,		"GFP_USER"},		\
-	{(unsigned long)GFP_KERNEL_ACCOUNT,	"GFP_KERNEL_ACCOUNT"},	\
-	{(unsigned long)GFP_KERNEL,		"GFP_KERNEL"},		\
-	{(unsigned long)GFP_NOFS,		"GFP_NOFS"},		\
-	{(unsigned long)GFP_ATOMIC,		"GFP_ATOMIC"},		\
-	{(unsigned long)GFP_NOIO,		"GFP_NOIO"},		\
-	{(unsigned long)GFP_NOWAIT,		"GFP_NOWAIT"},		\
-	{(unsigned long)GFP_DMA,		"GFP_DMA"},		\
-	{(unsigned long)__GFP_HIGHMEM,		"__GFP_HIGHMEM"},	\
-	{(unsigned long)GFP_DMA32,		"GFP_DMA32"},		\
-	{(unsigned long)__GFP_HIGH,		"__GFP_HIGH"},		\
-	{(unsigned long)__GFP_ATOMIC,		"__GFP_ATOMIC"},	\
-	{(unsigned long)__GFP_IO,		"__GFP_IO"},		\
-	{(unsigned long)__GFP_FS,		"__GFP_FS"},		\
-	{(unsigned long)__GFP_NOWARN,		"__GFP_NOWARN"},	\
-	{(unsigned long)__GFP_RETRY_MAYFAIL,	"__GFP_RETRY_MAYFAIL"},	\
-	{(unsigned long)__GFP_NOFAIL,		"__GFP_NOFAIL"},	\
-	{(unsigned long)__GFP_NORETRY,		"__GFP_NORETRY"},	\
-	{(unsigned long)__GFP_COMP,		"__GFP_COMP"},		\
-	{(unsigned long)__GFP_ZERO,		"__GFP_ZERO"},		\
-	{(unsigned long)__GFP_NOMEMALLOC,	"__GFP_NOMEMALLOC"},	\
-	{(unsigned long)__GFP_MEMALLOC,		"__GFP_MEMALLOC"},	\
-	{(unsigned long)__GFP_HARDWALL,		"__GFP_HARDWALL"},	\
-	{(unsigned long)__GFP_THISNODE,		"__GFP_THISNODE"},	\
-	{(unsigned long)__GFP_RECLAIMABLE,	"__GFP_RECLAIMABLE"},	\
-	{(unsigned long)__GFP_MOVABLE,		"__GFP_MOVABLE"},	\
-	{(unsigned long)__GFP_ACCOUNT,		"__GFP_ACCOUNT"},	\
-	{(unsigned long)__GFP_WRITE,		"__GFP_WRITE"},		\
-	{(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"}	\
+#define gfpflag_string(flag) {(__force unsigned long)flag, #flag}
+
+#define __def_gfpflag_names				\
+	gfpflag_string(GFP_TRANSHUGE),			\
+	gfpflag_string(GFP_TRANSHUGE_LIGHT),		\
+	gfpflag_string(GFP_HIGHUSER_MOVABLE),		\
+	gfpflag_string(GFP_HIGHUSER),			\
+	gfpflag_string(GFP_USER),			\
+	gfpflag_string(GFP_KERNEL_ACCOUNT),		\
+	gfpflag_string(GFP_KERNEL),			\
+	gfpflag_string(GFP_NOFS),			\
+	gfpflag_string(GFP_ATOMIC),			\
+	gfpflag_string(GFP_NOIO),			\
+	gfpflag_string(GFP_NOWAIT),			\
+	gfpflag_string(GFP_DMA),			\
+	gfpflag_string(__GFP_HIGHMEM),			\
+	gfpflag_string(GFP_DMA32),			\
+	gfpflag_string(__GFP_HIGH),			\
+	gfpflag_string(__GFP_ATOMIC),			\
+	gfpflag_string(__GFP_IO),			\
+	gfpflag_string(__GFP_FS),			\
+	gfpflag_string(__GFP_NOWARN),			\
+	gfpflag_string(__GFP_RETRY_MAYFAIL),		\
+	gfpflag_string(__GFP_NOFAIL),			\
+	gfpflag_string(__GFP_NORETRY),			\
+	gfpflag_string(__GFP_COMP),			\
+	gfpflag_string(__GFP_ZERO),			\
+	gfpflag_string(__GFP_NOMEMALLOC),		\
+	gfpflag_string(__GFP_MEMALLOC),			\
+	gfpflag_string(__GFP_HARDWALL),			\
+	gfpflag_string(__GFP_THISNODE),			\
+	gfpflag_string(__GFP_RECLAIMABLE),		\
+	gfpflag_string(__GFP_MOVABLE),			\
+	gfpflag_string(__GFP_ACCOUNT),			\
+	gfpflag_string(__GFP_WRITE),			\
+	gfpflag_string(__GFP_RECLAIM),			\
+	gfpflag_string(__GFP_DIRECT_RECLAIM),		\
+	gfpflag_string(__GFP_KSWAPD_RECLAIM),		\
+	gfpflag_string(__GFP_ZEROTAGS)
 
 #ifdef CONFIG_KASAN_HW_TAGS
-#define __def_gfpflag_names_kasan ,					       \
-	{(unsigned long)__GFP_SKIP_ZERO,	   "__GFP_SKIP_ZERO"},	       \
-	{(unsigned long)__GFP_SKIP_KASAN_POISON,   "__GFP_SKIP_KASAN_POISON"}, \
-	{(unsigned long)__GFP_SKIP_KASAN_UNPOISON, "__GFP_SKIP_KASAN_UNPOISON"}
+#define __def_gfpflag_names_kasan ,			\
+	gfpflag_string(__GFP_SKIP_ZERO),		\
+	gfpflag_string(__GFP_SKIP_KASAN_POISON),	\
+	gfpflag_string(__GFP_SKIP_KASAN_UNPOISON)
 #else
 #define __def_gfpflag_names_kasan
 #endif
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index de136dbd623a..408c86244d64 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -96,14 +96,14 @@ TRACE_EVENT(mm_vmscan_wakeup_kswapd,
 		__field(	int,	nid		)
 		__field(	int,	zid		)
 		__field(	int,	order		)
-		__field(	gfp_t,	gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 	),
 
 	TP_fast_assign(
 		__entry->nid		= nid;
 		__entry->zid		= zid;
 		__entry->order		= order;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("nid=%d order=%d gfp_flags=%s",
@@ -120,12 +120,12 @@ DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template,
 
 	TP_STRUCT__entry(
 		__field(	int,	order		)
-		__field(	gfp_t,	gfp_flags	)
+		__field(	unsigned long,	gfp_flags	)
 	),
 
 	TP_fast_assign(
 		__entry->order		= order;
-		__entry->gfp_flags	= gfp_flags;
+		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("order=%d gfp_flags=%s",
@@ -210,7 +210,7 @@ TRACE_EVENT(mm_shrink_slab_start,
 		__field(void *, shrink)
 		__field(int, nid)
 		__field(long, nr_objects_to_shrink)
-		__field(gfp_t, gfp_flags)
+		__field(unsigned long, gfp_flags)
 		__field(unsigned long, cache_items)
 		__field(unsigned long long, delta)
 		__field(unsigned long, total_scan)
@@ -222,7 +222,7 @@ TRACE_EVENT(mm_shrink_slab_start,
 		__entry->shrink = shr->scan_objects;
 		__entry->nid = sc->nid;
 		__entry->nr_objects_to_shrink = nr_objects_to_shrink;
-		__entry->gfp_flags = sc->gfp_mask;
+		__entry->gfp_flags = (__force unsigned long)sc->gfp_mask;
 		__entry->cache_items = cache_items;
 		__entry->delta = delta;
 		__entry->total_scan = total_scan;
@@ -446,13 +446,13 @@ TRACE_EVENT(mm_vmscan_node_reclaim_begin,
 	TP_STRUCT__entry(
 		__field(int, nid)
 		__field(int, order)
-		__field(gfp_t, gfp_flags)
+		__field(unsigned long, gfp_flags)
 	),
 
 	TP_fast_assign(
 		__entry->nid = nid;
 		__entry->order = order;
-		__entry->gfp_flags = gfp_flags;
+		__entry->gfp_flags = (__force unsigned long)gfp_flags;
 	),
 
 	TP_printk("nid=%d order=%d gfp_flags=%s",
diff --git a/mm/compaction.c b/mm/compaction.c
index fe915db6149b..bcdf167ab286 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2592,7 +2592,7 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
 		unsigned int alloc_flags, const struct alloc_context *ac,
 		enum compact_priority prio, struct page **capture)
 {
-	int may_perform_io = gfp_mask & __GFP_IO;
+	int may_perform_io = (__force int)(gfp_mask & __GFP_IO);
 	struct zoneref *z;
 	struct zone *zone;
 	enum compact_result rc = COMPACT_SKIPPED;
-- 
2.31.1
Re: [PATCH mm v2] tracing: incorrect gfp_t conversion
Posted by Steven Rostedt 3 years, 11 months ago
On Wed, 11 May 2022 10:20:39 +0300
Vasily Averin <vvs@openvz.org> wrote:

> Fixes the following sparse warnings:
> 
> include/trace/events/*: sparse: cast to restricted gfp_t
> include/trace/events/*: sparse: restricted gfp_t degrades to integer
> 
> gfp_t type is bitwise and requires __force attributes for any casts.
> 
> Signed-off-by:	Vasily Averin <vvs@openvz.org>
> ---
> v2: 1) re-based to 5.18-rc6
>     2) re-defined __def_gfpflag_names array according to
> 	akpm@, willy@ and Joe Perches recommendations
> ---
>  include/linux/gfp.h               |  2 +-
>  include/trace/events/btrfs.h      |  4 +-
>  include/trace/events/compaction.h |  4 +-
>  include/trace/events/kmem.h       | 12 ++---
>  include/trace/events/mmflags.h    | 84 ++++++++++++++++---------------
>  include/trace/events/vmscan.h     | 16 +++---
>  mm/compaction.c                   |  2 +-
>  7 files changed, 63 insertions(+), 61 deletions(-)

From the tracing POV:

Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>

-- Steve
Re: [PATCH mm v2] tracing: incorrect gfp_t conversion
Posted by Andrew Morton 3 years, 11 months ago
On Wed, 11 May 2022 10:20:39 +0300 Vasily Averin <vvs@openvz.org> wrote:

> Fixes the following sparse warnings:
> 
> include/trace/events/*: sparse: cast to restricted gfp_t
> include/trace/events/*: sparse: restricted gfp_t degrades to integer
> 
> gfp_t type is bitwise and requires __force attributes for any casts.

I already moved the previous version into mm-stable.  Would prefer not
to have to rebase it.

> v2: 1) re-based to 5.18-rc6
>     2) re-defined __def_gfpflag_names array according to
> 	akpm@, willy@ and Joe Perches recommendations

Please redo this against the mm-stable or mm-unstable branches against
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm, or against your
own previous version.

The new patch will simply switch to the gfpflag_string() trick, so it will
not be a "fix", so please let's position it as a "cleanup".
Re: [PATCH mm] tracing: incorrect gfp_t conversion
Posted by Andrew Morton 4 years ago
On Sat, 7 May 2022 15:48:35 -0700 Andrew Morton <akpm@linux-foundation.org> wrote:

> I did the below.
> 

Silly me, doesn't work.

> 
> --- 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"},	\

Can't expand FUL here within the macro definition.
Re: [PATCH mm] tracing: incorrect gfp_t conversion
Posted by Matthew Wilcox 3 years, 12 months ago
On Sat, May 07, 2022 at 04:00:10PM -0700, Andrew Morton wrote:
> On Sat, 7 May 2022 15:48:35 -0700 Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > I did the below.
> > 
> 
> Silly me, doesn't work.
> 
> > 
> > --- 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"},	\
> 
> Can't expand FUL here within the macro definition.

Can we do something even better?

#define GFP_NAME(flag) { (__force unsigned long)flag, #flag },

... with one or more layers of indirection to satisfy the arcane
rules of C macros?