compiler.h: move __is_constexpr() to compiler.h

Prior to f747e6667ebb2 __is_constexpr() was in its only user minmax.h.
That commit moved it to const.h - but that file just defines ULL(x) and
UL(x)

compiler.h: move __is_constexpr() to compiler.h

Prior to f747e6667ebb2 __is_constexpr() was in its only user minmax.h.
That commit moved it to const.h - but that file just defines ULL(x) and
UL(x) so that constants can be defined for .S and .c files.

So apart from the word 'const' it wasn't really a good location. Instead
move the definition to compiler.h just before the similar

is_signed_type() and is_unsigned_type().

This may not be a good long-term home, but the three definitions belong
together.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Laight <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Bart Van Assche <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

linux/bits.h: fix compilation error with GENMASK

GENMASK() has an input check which uses __builtin_choose_expr() to
enable a compile time sanity check of its inputs if they are known at
compile time

linux/bits.h: fix compilation error with GENMASK

GENMASK() has an input check which uses __builtin_choose_expr() to
enable a compile time sanity check of its inputs if they are known at
compile time.

However, it turns out that __builtin_constant_p() does not always return
a compile time constant [0]. It was thought this problem was fixed with
gcc 4.9 [1], but apparently this is not the case [2].

Switch to use __is_constexpr() instead which always returns a compile time
constant, regardless of its inputs.

Link: https://lore.kernel.org/lkml/[email protected] [0]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19449 [1]
Link: https://lore.kernel.org/lkml/[email protected] [2]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Rikard Falkeborn <[email protected]>
Reported-by: Tetsuo Handa <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Yury Norov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

tools headers: Update linux/vdso.h and grab a copy of vdso/const.h

To get in line with:

8165b57bca21 ("linux/const.h: Extract common header for vDSO")

And silence this tools/perf/ build warning:

tools headers: Update linux/vdso.h and grab a copy of vdso/const.h

To get in line with:

8165b57bca21 ("linux/const.h: Extract common header for vDSO")

And silence this tools/perf/ build warning:

Warning: Kernel ABI header at 'tools/include/linux/const.h' differs from latest version at 'include/linux/const.h'
diff -u tools/include/linux/const.h include/linux/const.h

Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

show more ...

tools headers: Grab copy of linux/const.h, needed by linux/bits.h

So that can update the copy of linux/bits.h that now uses macros defined
in const.h and that are not available in older systems.

Cc

tools headers: Grab copy of linux/const.h, needed by linux/bits.h

So that can update the copy of linux/bits.h that now uses macros defined
in const.h and that are not available in older systems.

Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

show more ...