Introduce GFP bits enumeration to let compiler track the number of used
bits (which depends on the config options) instead of hardcoding them.
That simplifies __GFP_BITS_SHIFT calculation.
Suggested-by: Petr Tesařík <[email protected]>
Signed-off-by: Suren Baghdasaryan <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
---
include/linux/gfp_types.h | 90 +++++++++++++++++++++++++++------------
1 file changed, 62 insertions(+), 28 deletions(-)
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 1b6053da8754..868c8fb1bbc1 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h
@@ -21,44 +21,78 @@ typedef unsigned int __bitwise gfp_t;
* include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
*/
+enum {
+ ___GFP_DMA_BIT,
+ ___GFP_HIGHMEM_BIT,
+ ___GFP_DMA32_BIT,
+ ___GFP_MOVABLE_BIT,
+ ___GFP_RECLAIMABLE_BIT,
+ ___GFP_HIGH_BIT,
+ ___GFP_IO_BIT,
+ ___GFP_FS_BIT,
+ ___GFP_ZERO_BIT,
+ ___GFP_UNUSED_BIT, /* 0x200u unused */
+ ___GFP_DIRECT_RECLAIM_BIT,
+ ___GFP_KSWAPD_RECLAIM_BIT,
+ ___GFP_WRITE_BIT,
+ ___GFP_NOWARN_BIT,
+ ___GFP_RETRY_MAYFAIL_BIT,
+ ___GFP_NOFAIL_BIT,
+ ___GFP_NORETRY_BIT,
+ ___GFP_MEMALLOC_BIT,
+ ___GFP_COMP_BIT,
+ ___GFP_NOMEMALLOC_BIT,
+ ___GFP_HARDWALL_BIT,
+ ___GFP_THISNODE_BIT,
+ ___GFP_ACCOUNT_BIT,
+ ___GFP_ZEROTAGS_BIT,
+#ifdef CONFIG_KASAN_HW_TAGS
+ ___GFP_SKIP_ZERO_BIT,
+ ___GFP_SKIP_KASAN_BIT,
+#endif
+#ifdef CONFIG_LOCKDEP
+ ___GFP_NOLOCKDEP_BIT,
+#endif
+ ___GFP_LAST_BIT
+};
+
/* Plain integer GFP bitmasks. Do not use this directly. */
-#define ___GFP_DMA 0x01u
-#define ___GFP_HIGHMEM 0x02u
-#define ___GFP_DMA32 0x04u
-#define ___GFP_MOVABLE 0x08u
-#define ___GFP_RECLAIMABLE 0x10u
-#define ___GFP_HIGH 0x20u
-#define ___GFP_IO 0x40u
-#define ___GFP_FS 0x80u
-#define ___GFP_ZERO 0x100u
+#define ___GFP_DMA BIT(___GFP_DMA_BIT)
+#define ___GFP_HIGHMEM BIT(___GFP_HIGHMEM_BIT)
+#define ___GFP_DMA32 BIT(___GFP_DMA32_BIT)
+#define ___GFP_MOVABLE BIT(___GFP_MOVABLE_BIT)
+#define ___GFP_RECLAIMABLE BIT(___GFP_RECLAIMABLE_BIT)
+#define ___GFP_HIGH BIT(___GFP_HIGH_BIT)
+#define ___GFP_IO BIT(___GFP_IO_BIT)
+#define ___GFP_FS BIT(___GFP_FS_BIT)
+#define ___GFP_ZERO BIT(___GFP_ZERO_BIT)
/* 0x200u unused */
-#define ___GFP_DIRECT_RECLAIM 0x400u
-#define ___GFP_KSWAPD_RECLAIM 0x800u
-#define ___GFP_WRITE 0x1000u
-#define ___GFP_NOWARN 0x2000u
-#define ___GFP_RETRY_MAYFAIL 0x4000u
-#define ___GFP_NOFAIL 0x8000u
-#define ___GFP_NORETRY 0x10000u
-#define ___GFP_MEMALLOC 0x20000u
-#define ___GFP_COMP 0x40000u
-#define ___GFP_NOMEMALLOC 0x80000u
-#define ___GFP_HARDWALL 0x100000u
-#define ___GFP_THISNODE 0x200000u
-#define ___GFP_ACCOUNT 0x400000u
-#define ___GFP_ZEROTAGS 0x800000u
+#define ___GFP_DIRECT_RECLAIM BIT(___GFP_DIRECT_RECLAIM_BIT)
+#define ___GFP_KSWAPD_RECLAIM BIT(___GFP_KSWAPD_RECLAIM_BIT)
+#define ___GFP_WRITE BIT(___GFP_WRITE_BIT)
+#define ___GFP_NOWARN BIT(___GFP_NOWARN_BIT)
+#define ___GFP_RETRY_MAYFAIL BIT(___GFP_RETRY_MAYFAIL_BIT)
+#define ___GFP_NOFAIL BIT(___GFP_NOFAIL_BIT)
+#define ___GFP_NORETRY BIT(___GFP_NORETRY_BIT)
+#define ___GFP_MEMALLOC BIT(___GFP_MEMALLOC_BIT)
+#define ___GFP_COMP BIT(___GFP_COMP_BIT)
+#define ___GFP_NOMEMALLOC BIT(___GFP_NOMEMALLOC_BIT)
+#define ___GFP_HARDWALL BIT(___GFP_HARDWALL_BIT)
+#define ___GFP_THISNODE BIT(___GFP_THISNODE_BIT)
+#define ___GFP_ACCOUNT BIT(___GFP_ACCOUNT_BIT)
+#define ___GFP_ZEROTAGS BIT(___GFP_ZEROTAGS_BIT)
#ifdef CONFIG_KASAN_HW_TAGS
-#define ___GFP_SKIP_ZERO 0x1000000u
-#define ___GFP_SKIP_KASAN 0x2000000u
+#define ___GFP_SKIP_ZERO BIT(___GFP_SKIP_ZERO_BIT)
+#define ___GFP_SKIP_KASAN BIT(___GFP_SKIP_KASAN_BIT)
#else
#define ___GFP_SKIP_ZERO 0
#define ___GFP_SKIP_KASAN 0
#endif
#ifdef CONFIG_LOCKDEP
-#define ___GFP_NOLOCKDEP 0x4000000u
+#define ___GFP_NOLOCKDEP BIT(___GFP_NOLOCKDEP_BIT)
#else
#define ___GFP_NOLOCKDEP 0
#endif
-/* If the above are modified, __GFP_BITS_SHIFT may need updating */
/*
* Physical address zone modifiers (see linux/mmzone.h - low four bits)
@@ -249,7 +283,7 @@ typedef unsigned int __bitwise gfp_t;
#define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
/* Room for N __GFP_FOO bits */
-#define __GFP_BITS_SHIFT (26 + IS_ENABLED(CONFIG_LOCKDEP))
+#define __GFP_BITS_SHIFT ___GFP_LAST_BIT
#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
/**
--
2.44.0.rc0.258.g7320e95886-goog
On Wed, Feb 21, 2024 at 2:41 PM Suren Baghdasaryan <[email protected]> wrote:
>
> Introduce GFP bits enumeration to let compiler track the number of used
> bits (which depends on the config options) instead of hardcoding them.
> That simplifies __GFP_BITS_SHIFT calculation.
>
> Suggested-by: Petr Tesařík <[email protected]>
> Signed-off-by: Suren Baghdasaryan <[email protected]>
> Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
On Wed 21-02-24 11:40:19, Suren Baghdasaryan wrote:
> Introduce GFP bits enumeration to let compiler track the number of used
> bits (which depends on the config options) instead of hardcoding them.
> That simplifies __GFP_BITS_SHIFT calculation.
>
> Suggested-by: Petr Tesařík <[email protected]>
> Signed-off-by: Suren Baghdasaryan <[email protected]>
> Reviewed-by: Kees Cook <[email protected]>
I thought I have responded to this patch but obviously not the case.
I like this change. Makes sense even without the rest of the series.
Acked-by: Michal Hocko <[email protected]>
It seems that KASAN flags already __GFP_BITS_SHIFT which just proves how
fragile this existing scheme is.
> ---
> include/linux/gfp_types.h | 90 +++++++++++++++++++++++++++------------
> 1 file changed, 62 insertions(+), 28 deletions(-)
>
> diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
> index 1b6053da8754..868c8fb1bbc1 100644
> --- a/include/linux/gfp_types.h
> +++ b/include/linux/gfp_types.h
> @@ -21,44 +21,78 @@ typedef unsigned int __bitwise gfp_t;
> * include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
> */
>
> +enum {
> + ___GFP_DMA_BIT,
> + ___GFP_HIGHMEM_BIT,
> + ___GFP_DMA32_BIT,
> + ___GFP_MOVABLE_BIT,
> + ___GFP_RECLAIMABLE_BIT,
> + ___GFP_HIGH_BIT,
> + ___GFP_IO_BIT,
> + ___GFP_FS_BIT,
> + ___GFP_ZERO_BIT,
> + ___GFP_UNUSED_BIT, /* 0x200u unused */
> + ___GFP_DIRECT_RECLAIM_BIT,
> + ___GFP_KSWAPD_RECLAIM_BIT,
> + ___GFP_WRITE_BIT,
> + ___GFP_NOWARN_BIT,
> + ___GFP_RETRY_MAYFAIL_BIT,
> + ___GFP_NOFAIL_BIT,
> + ___GFP_NORETRY_BIT,
> + ___GFP_MEMALLOC_BIT,
> + ___GFP_COMP_BIT,
> + ___GFP_NOMEMALLOC_BIT,
> + ___GFP_HARDWALL_BIT,
> + ___GFP_THISNODE_BIT,
> + ___GFP_ACCOUNT_BIT,
> + ___GFP_ZEROTAGS_BIT,
> +#ifdef CONFIG_KASAN_HW_TAGS
> + ___GFP_SKIP_ZERO_BIT,
> + ___GFP_SKIP_KASAN_BIT,
> +#endif
> +#ifdef CONFIG_LOCKDEP
> + ___GFP_NOLOCKDEP_BIT,
> +#endif
> + ___GFP_LAST_BIT
> +};
> +
> /* Plain integer GFP bitmasks. Do not use this directly. */
> -#define ___GFP_DMA 0x01u
> -#define ___GFP_HIGHMEM 0x02u
> -#define ___GFP_DMA32 0x04u
> -#define ___GFP_MOVABLE 0x08u
> -#define ___GFP_RECLAIMABLE 0x10u
> -#define ___GFP_HIGH 0x20u
> -#define ___GFP_IO 0x40u
> -#define ___GFP_FS 0x80u
> -#define ___GFP_ZERO 0x100u
> +#define ___GFP_DMA BIT(___GFP_DMA_BIT)
> +#define ___GFP_HIGHMEM BIT(___GFP_HIGHMEM_BIT)
> +#define ___GFP_DMA32 BIT(___GFP_DMA32_BIT)
> +#define ___GFP_MOVABLE BIT(___GFP_MOVABLE_BIT)
> +#define ___GFP_RECLAIMABLE BIT(___GFP_RECLAIMABLE_BIT)
> +#define ___GFP_HIGH BIT(___GFP_HIGH_BIT)
> +#define ___GFP_IO BIT(___GFP_IO_BIT)
> +#define ___GFP_FS BIT(___GFP_FS_BIT)
> +#define ___GFP_ZERO BIT(___GFP_ZERO_BIT)
> /* 0x200u unused */
> -#define ___GFP_DIRECT_RECLAIM 0x400u
> -#define ___GFP_KSWAPD_RECLAIM 0x800u
> -#define ___GFP_WRITE 0x1000u
> -#define ___GFP_NOWARN 0x2000u
> -#define ___GFP_RETRY_MAYFAIL 0x4000u
> -#define ___GFP_NOFAIL 0x8000u
> -#define ___GFP_NORETRY 0x10000u
> -#define ___GFP_MEMALLOC 0x20000u
> -#define ___GFP_COMP 0x40000u
> -#define ___GFP_NOMEMALLOC 0x80000u
> -#define ___GFP_HARDWALL 0x100000u
> -#define ___GFP_THISNODE 0x200000u
> -#define ___GFP_ACCOUNT 0x400000u
> -#define ___GFP_ZEROTAGS 0x800000u
> +#define ___GFP_DIRECT_RECLAIM BIT(___GFP_DIRECT_RECLAIM_BIT)
> +#define ___GFP_KSWAPD_RECLAIM BIT(___GFP_KSWAPD_RECLAIM_BIT)
> +#define ___GFP_WRITE BIT(___GFP_WRITE_BIT)
> +#define ___GFP_NOWARN BIT(___GFP_NOWARN_BIT)
> +#define ___GFP_RETRY_MAYFAIL BIT(___GFP_RETRY_MAYFAIL_BIT)
> +#define ___GFP_NOFAIL BIT(___GFP_NOFAIL_BIT)
> +#define ___GFP_NORETRY BIT(___GFP_NORETRY_BIT)
> +#define ___GFP_MEMALLOC BIT(___GFP_MEMALLOC_BIT)
> +#define ___GFP_COMP BIT(___GFP_COMP_BIT)
> +#define ___GFP_NOMEMALLOC BIT(___GFP_NOMEMALLOC_BIT)
> +#define ___GFP_HARDWALL BIT(___GFP_HARDWALL_BIT)
> +#define ___GFP_THISNODE BIT(___GFP_THISNODE_BIT)
> +#define ___GFP_ACCOUNT BIT(___GFP_ACCOUNT_BIT)
> +#define ___GFP_ZEROTAGS BIT(___GFP_ZEROTAGS_BIT)
> #ifdef CONFIG_KASAN_HW_TAGS
> -#define ___GFP_SKIP_ZERO 0x1000000u
> -#define ___GFP_SKIP_KASAN 0x2000000u
> +#define ___GFP_SKIP_ZERO BIT(___GFP_SKIP_ZERO_BIT)
> +#define ___GFP_SKIP_KASAN BIT(___GFP_SKIP_KASAN_BIT)
> #else
> #define ___GFP_SKIP_ZERO 0
> #define ___GFP_SKIP_KASAN 0
> #endif
> #ifdef CONFIG_LOCKDEP
> -#define ___GFP_NOLOCKDEP 0x4000000u
> +#define ___GFP_NOLOCKDEP BIT(___GFP_NOLOCKDEP_BIT)
> #else
> #define ___GFP_NOLOCKDEP 0
> #endif
> -/* If the above are modified, __GFP_BITS_SHIFT may need updating */
>
> /*
> * Physical address zone modifiers (see linux/mmzone.h - low four bits)
> @@ -249,7 +283,7 @@ typedef unsigned int __bitwise gfp_t;
> #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
>
> /* Room for N __GFP_FOO bits */
> -#define __GFP_BITS_SHIFT (26 + IS_ENABLED(CONFIG_LOCKDEP))
> +#define __GFP_BITS_SHIFT ___GFP_LAST_BIT
> #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
>
> /**
> --
> 2.44.0.rc0.258.g7320e95886-goog
--
Michal Hocko
SUSE Labs
On Thu, 22 Feb 2024 13:12:29 +0100
Michal Hocko <[email protected]> wrote:
> On Wed 21-02-24 11:40:19, Suren Baghdasaryan wrote:
> > Introduce GFP bits enumeration to let compiler track the number of used
> > bits (which depends on the config options) instead of hardcoding them.
> > That simplifies __GFP_BITS_SHIFT calculation.
> >
> > Suggested-by: Petr Tesařík <[email protected]>
> > Signed-off-by: Suren Baghdasaryan <[email protected]>
> > Reviewed-by: Kees Cook <[email protected]>
>
> I thought I have responded to this patch but obviously not the case.
> I like this change. Makes sense even without the rest of the series.
> Acked-by: Michal Hocko <[email protected]>
Thank you, Michal. I also hope it can be merged without waiting for the
rest of the series.
Petr T
On Thu, Feb 22, 2024 at 4:24 AM 'Petr Tesařík' via kernel-team
<[email protected]> wrote:
>
> On Thu, 22 Feb 2024 13:12:29 +0100
> Michal Hocko <[email protected]> wrote:
>
> > On Wed 21-02-24 11:40:19, Suren Baghdasaryan wrote:
> > > Introduce GFP bits enumeration to let compiler track the number of used
> > > bits (which depends on the config options) instead of hardcoding them.
> > > That simplifies __GFP_BITS_SHIFT calculation.
> > >
> > > Suggested-by: Petr Tesařík <[email protected]>
> > > Signed-off-by: Suren Baghdasaryan <[email protected]>
> > > Reviewed-by: Kees Cook <[email protected]>
> >
> > I thought I have responded to this patch but obviously not the case.
> > I like this change. Makes sense even without the rest of the series.
> > Acked-by: Michal Hocko <[email protected]>
>
> Thank you, Michal. I also hope it can be merged without waiting for the
> rest of the series.
Thanks Michal! I can post it separately. With the Ack I don't think it
will delay the rest of the series.
Thanks,
Suren.
>
> Petr T
>
> --
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
>
On Fri, Feb 23, 2024 at 11:26 AM Suren Baghdasaryan <[email protected]> wrote:
>
> On Thu, Feb 22, 2024 at 4:24 AM 'Petr Tesařík' via kernel-team
> <[email protected]> wrote:
> >
> > On Thu, 22 Feb 2024 13:12:29 +0100
> > Michal Hocko <[email protected]> wrote:
> >
> > > On Wed 21-02-24 11:40:19, Suren Baghdasaryan wrote:
> > > > Introduce GFP bits enumeration to let compiler track the number of used
> > > > bits (which depends on the config options) instead of hardcoding them.
> > > > That simplifies __GFP_BITS_SHIFT calculation.
> > > >
> > > > Suggested-by: Petr Tesařík <[email protected]>
> > > > Signed-off-by: Suren Baghdasaryan <[email protected]>
> > > > Reviewed-by: Kees Cook <[email protected]>
> > >
> > > I thought I have responded to this patch but obviously not the case.
> > > I like this change. Makes sense even without the rest of the series.
> > > Acked-by: Michal Hocko <[email protected]>
> >
> > Thank you, Michal. I also hope it can be merged without waiting for the
> > rest of the series.
>
> Thanks Michal! I can post it separately. With the Ack I don't think it
> will delay the rest of the series.
Stand-alone version is posted as v5 here:
https://lore.kernel.org/all/[email protected]/
> Thanks,
> Suren.
>
> >
> > Petr T
> >
> > --
> > To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> >