[PATCH 06/12] tools: sync small_const_nbits() macro with the kernel
Sync implementation with the kernel and move the macro from
tools/include/linux/bitmap.h to tools/include/asm-generic/bitsperlong.h
Signed-off-by: Yury Norov
Acked-by: Rasmus Villemoes
---
tools/include/asm-generic/bitsperlong.h | 3 +++
tools/include/linux/bitmap.h| 3 ---
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/include/asm-generic/bitsperlong.h
b/tools/include/asm-generic/bitsperlong.h
index 8f2283052333..2093d56ddd11 100644
--- a/tools/include/asm-generic/bitsperlong.h
+++ b/tools/include/asm-generic/bitsperlong.h
@@ -18,4 +18,7 @@
#define BITS_PER_LONG_LONG 64
#endif
+#define small_const_nbits(nbits) \
+ (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
+
#endif /* __ASM_GENERIC_BITS_PER_LONG */
diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index 4aabc23ec747..330dbf7509cc 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -22,9 +22,6 @@ void bitmap_clear(unsigned long *map, unsigned int start, int
len);
#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
-#define small_const_nbits(nbits) \
- (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
-
static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
if (small_const_nbits(nbits))
--
2.25.1
Re: [PATCH 06/12] tools: sync small_const_nbits() macro with the kernel
On Mon, Mar 22, 2021 at 09:34:47AM +0100, Rasmus Villemoes wrote:
> On 21/03/2021 22.54, Yury Norov wrote:
> > Move the macro from tools/include/asm-generic/bitsperlong.h
> > to tools/include/linux/bitmap.h
>
> The patch does it the other way around :)
>
> > Signed-off-by: Yury Norov
> > ---
> > tools/include/asm-generic/bitsperlong.h | 3 +++
> > tools/include/linux/bitmap.h| 3 ---
> > 2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/include/asm-generic/bitsperlong.h
> > b/tools/include/asm-generic/bitsperlong.h
> > index 8f2283052333..f530da2506cc 100644
> > --- a/tools/include/asm-generic/bitsperlong.h
> > +++ b/tools/include/asm-generic/bitsperlong.h
> > @@ -18,4 +18,7 @@
> > #define BITS_PER_LONG_LONG 64
> > #endif
> >
> > +#define small_const_nbits(nbits) \
> > + (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
> > +
>
> Well, the movement is consistent with the kernel, but shouldn't the
> definition also be updated to exclude constant-zero-size? It's not that
> they exist or ever have, in tools/ or kernel proper, but just if some
> day some oddball CONFIG_ combination ends up creating such a beast, I'd
> rather not have code like
>
> + if (small_const_nbits(size)) {
> + unsigned long val = *addr & GENMASK(size - 1, 0);
>
> blow up at run-time.
>
> Other than that (and the above commit log typo), consider the series
>
> Acked-by: Rasmus Villemoes
Thanks for spotting out this. The proper version of the patch is
below.
Andrew, it seems everything else looks good. If so, should I resubmit
the series, or you can pull it as is, including this patch?
Thanks,
Yury
>From 7558697d4448f01a8ef73cd31def5d3e68b44b61 Mon Sep 17 00:00:00 2001
From: Yury Norov
Date: Wed, 17 Feb 2021 20:05:05 -0800
Subject: [PATCH] tools: sync small_const_nbits() macro with the kernel
Sync implementation with the kernel and move the macro from
tools/include/linux/bitmap.h to tools/include/asm-generic/bitsperlong.h
Signed-off-by: Yury Norov
---
tools/include/asm-generic/bitsperlong.h | 3 +++
tools/include/linux/bitmap.h| 3 ---
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/include/asm-generic/bitsperlong.h
b/tools/include/asm-generic/bitsperlong.h
index 8f2283052333..2093d56ddd11 100644
--- a/tools/include/asm-generic/bitsperlong.h
+++ b/tools/include/asm-generic/bitsperlong.h
@@ -18,4 +18,7 @@
#define BITS_PER_LONG_LONG 64
#endif
+#define small_const_nbits(nbits) \
+ (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
+
#endif /* __ASM_GENERIC_BITS_PER_LONG */
diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index 4aabc23ec747..330dbf7509cc 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -22,9 +22,6 @@ void bitmap_clear(unsigned long *map, unsigned int start, int
len);
#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
-#define small_const_nbits(nbits) \
- (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
-
static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
if (small_const_nbits(nbits))
--
2.25.1
Re: [PATCH 06/12] tools: sync small_const_nbits() macro with the kernel
On 21/03/2021 22.54, Yury Norov wrote:
> Move the macro from tools/include/asm-generic/bitsperlong.h
> to tools/include/linux/bitmap.h
The patch does it the other way around :)
> Signed-off-by: Yury Norov
> ---
> tools/include/asm-generic/bitsperlong.h | 3 +++
> tools/include/linux/bitmap.h| 3 ---
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/tools/include/asm-generic/bitsperlong.h
> b/tools/include/asm-generic/bitsperlong.h
> index 8f2283052333..f530da2506cc 100644
> --- a/tools/include/asm-generic/bitsperlong.h
> +++ b/tools/include/asm-generic/bitsperlong.h
> @@ -18,4 +18,7 @@
> #define BITS_PER_LONG_LONG 64
> #endif
>
> +#define small_const_nbits(nbits) \
> + (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
> +
Well, the movement is consistent with the kernel, but shouldn't the
definition also be updated to exclude constant-zero-size? It's not that
they exist or ever have, in tools/ or kernel proper, but just if some
day some oddball CONFIG_ combination ends up creating such a beast, I'd
rather not have code like
+ if (small_const_nbits(size)) {
+ unsigned long val = *addr & GENMASK(size - 1, 0);
blow up at run-time.
Other than that (and the above commit log typo), consider the series
Acked-by: Rasmus Villemoes
[PATCH 06/12] tools: sync small_const_nbits() macro with the kernel
Move the macro from tools/include/asm-generic/bitsperlong.h
to tools/include/linux/bitmap.h
Signed-off-by: Yury Norov
---
tools/include/asm-generic/bitsperlong.h | 3 +++
tools/include/linux/bitmap.h| 3 ---
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/include/asm-generic/bitsperlong.h
b/tools/include/asm-generic/bitsperlong.h
index 8f2283052333..f530da2506cc 100644
--- a/tools/include/asm-generic/bitsperlong.h
+++ b/tools/include/asm-generic/bitsperlong.h
@@ -18,4 +18,7 @@
#define BITS_PER_LONG_LONG 64
#endif
+#define small_const_nbits(nbits) \
+ (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
+
#endif /* __ASM_GENERIC_BITS_PER_LONG */
diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index 4aabc23ec747..330dbf7509cc 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -22,9 +22,6 @@ void bitmap_clear(unsigned long *map, unsigned int start, int
len);
#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
-#define small_const_nbits(nbits) \
- (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
-
static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
if (small_const_nbits(nbits))
--
2.25.1
