Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Thu, 16 Apr 2020 12:54:04 -0300 | Subject | Re: [PATCH 15/15] tools headers: Synchronize linux/bits.h with the kernel sources |
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Em Wed, Apr 15, 2020 at 10:14:06AM +0100, Vincenzo Frascino escreveu: > On 4/14/20 5:48 PM, Arnaldo Carvalho de Melo wrote: > > From: Arnaldo Carvalho de Melo <acme@redhat.com> > > > > To pick up the changes in these csets: > > > > 295bcca84916 ("linux/bits.h: add compile time sanity check of GENMASK inputs") > > 3945ff37d2f4 ("linux/bits.h: Extract common header for vDSO") > > > > To address this tools/perf build warning: > > > > Warning: Kernel ABI header at 'tools/include/linux/bits.h' differs from latest version at 'include/linux/bits.h' > > diff -u tools/include/linux/bits.h include/linux/bits.h > > > > This clashes with usage of userspace's static_assert(), that, at least > > on glibc, is guarded by a ifnded/endif pair, do the same to our copy of > > build_bug.h and avoid that diff in check_headers.sh so that we continue > > checking for drifts with the kernel sources master copy. > > > > This will all be tested with the set of build containers that includes > > uCLibc, musl libc, lots of glibc versions in lots of distros and cross > > build environments. > > > > The tools/objtool, tools/bpf, etc were tested as well. > > > > Acked-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # vDSO parts
Hey, thanks a lot for checking it! :-)
- Arnaldo
> > Cc: Adrian Hunter <adrian.hunter@intel.com> > > Cc: Jiri Olsa <jolsa@kernel.org> > > Cc: Namhyung Kim <namhyung@kernel.org> > > Cc: Rikard Falkeborn <rikard.falkeborn@gmail.com> > > Cc: Thomas Gleixner <tglx@linutronix.de> > > Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> > > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > > --- > > tools/include/linux/bits.h | 24 ++++++++-- > > tools/include/linux/build_bug.h | 82 +++++++++++++++++++++++++++++++++ > > tools/include/linux/kernel.h | 4 +- > > tools/include/vdso/bits.h | 9 ++++ > > tools/perf/check-headers.sh | 2 + > > 5 files changed, 115 insertions(+), 6 deletions(-) > > create mode 100644 tools/include/linux/build_bug.h > > create mode 100644 tools/include/vdso/bits.h > > > > diff --git a/tools/include/linux/bits.h b/tools/include/linux/bits.h > > index 669d69441a62..4671fbf28842 100644 > > --- a/tools/include/linux/bits.h > > +++ b/tools/include/linux/bits.h > > @@ -3,9 +3,9 @@ > > #define __LINUX_BITS_H > > > > #include <linux/const.h> > > +#include <vdso/bits.h> > > #include <asm/bitsperlong.h> > > > > -#define BIT(nr) (UL(1) << (nr)) > > #define BIT_ULL(nr) (ULL(1) << (nr)) > > #define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG)) > > #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) > > @@ -18,12 +18,30 @@ > > * position @h. For example > > * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. > > */ > > -#define GENMASK(h, l) \ > > +#if !defined(__ASSEMBLY__) && \ > > + (!defined(CONFIG_CC_IS_GCC) || CONFIG_GCC_VERSION >= 49000) > > +#include <linux/build_bug.h> > > +#define GENMASK_INPUT_CHECK(h, l) \ > > + (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ > > + __builtin_constant_p((l) > (h)), (l) > (h), 0))) > > +#else > > +/* > > + * BUILD_BUG_ON_ZERO is not available in h files included from asm files, > > + * disable the input check if that is the case. > > + */ > > +#define GENMASK_INPUT_CHECK(h, l) 0 > > +#endif > > + > > +#define __GENMASK(h, l) \ > > (((~UL(0)) - (UL(1) << (l)) + 1) & \ > > (~UL(0) >> (BITS_PER_LONG - 1 - (h)))) > > +#define GENMASK(h, l) \ > > + (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l)) > > > > -#define GENMASK_ULL(h, l) \ > > +#define __GENMASK_ULL(h, l) \ > > (((~ULL(0)) - (ULL(1) << (l)) + 1) & \ > > (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h)))) > > +#define GENMASK_ULL(h, l) \ > > + (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l)) > > > > #endif /* __LINUX_BITS_H */ > > diff --git a/tools/include/linux/build_bug.h b/tools/include/linux/build_bug.h > > new file mode 100644 > > index 000000000000..cc7070c7439b > > --- /dev/null > > +++ b/tools/include/linux/build_bug.h > > @@ -0,0 +1,82 @@ > > +/* SPDX-License-Identifier: GPL-2.0 */ > > +#ifndef _LINUX_BUILD_BUG_H > > +#define _LINUX_BUILD_BUG_H > > + > > +#include <linux/compiler.h> > > + > > +#ifdef __CHECKER__ > > +#define BUILD_BUG_ON_ZERO(e) (0) > > +#else /* __CHECKER__ */ > > +/* > > + * Force a compilation error if condition is true, but also produce a > > + * result (of value 0 and type int), so the expression can be used > > + * e.g. in a structure initializer (or where-ever else comma expressions > > + * aren't permitted). > > + */ > > +#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) > > +#endif /* __CHECKER__ */ > > + > > +/* Force a compilation error if a constant expression is not a power of 2 */ > > +#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \ > > + BUILD_BUG_ON(((n) & ((n) - 1)) != 0) > > +#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ > > + BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) > > + > > +/* > > + * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the > > + * expression but avoids the generation of any code, even if that expression > > + * has side-effects. > > + */ > > +#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) > > + > > +/** > > + * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied > > + * error message. > > + * @condition: the condition which the compiler should know is false. > > + * > > + * See BUILD_BUG_ON for description. > > + */ > > +#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) > > + > > +/** > > + * BUILD_BUG_ON - break compile if a condition is true. > > + * @condition: the condition which the compiler should know is false. > > + * > > + * If you have some code which relies on certain constants being equal, or > > + * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to > > + * detect if someone changes it. > > + */ > > +#define BUILD_BUG_ON(condition) \ > > + BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) > > + > > +/** > > + * BUILD_BUG - break compile if used. > > + * > > + * If you have some code that you expect the compiler to eliminate at > > + * build time, you should use BUILD_BUG to detect if it is > > + * unexpectedly used. > > + */ > > +#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") > > + > > +/** > > + * static_assert - check integer constant expression at build time > > + * > > + * static_assert() is a wrapper for the C11 _Static_assert, with a > > + * little macro magic to make the message optional (defaulting to the > > + * stringification of the tested expression). > > + * > > + * Contrary to BUILD_BUG_ON(), static_assert() can be used at global > > + * scope, but requires the expression to be an integer constant > > + * expression (i.e., it is not enough that __builtin_constant_p() is > > + * true for expr). > > + * > > + * Also note that BUILD_BUG_ON() fails the build if the condition is > > + * true, while static_assert() fails the build if the expression is > > + * false. > > + */ > > +#ifndef static_assert > > +#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr) > > +#define __static_assert(expr, msg, ...) _Static_assert(expr, msg) > > +#endif // static_assert > > + > > +#endif /* _LINUX_BUILD_BUG_H */ > > diff --git a/tools/include/linux/kernel.h b/tools/include/linux/kernel.h > > index cba226948a0c..a7e54a08fb54 100644 > > --- a/tools/include/linux/kernel.h > > +++ b/tools/include/linux/kernel.h > > @@ -5,6 +5,7 @@ > > #include <stdarg.h> > > #include <stddef.h> > > #include <assert.h> > > +#include <linux/build_bug.h> > > #include <linux/compiler.h> > > #include <endian.h> > > #include <byteswap.h> > > @@ -35,9 +36,6 @@ > > (type *)((char *)__mptr - offsetof(type, member)); }) > > #endif > > > > -#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) > > -#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) > > - > > #ifndef max > > #define max(x, y) ({ \ > > typeof(x) _max1 = (x); \ > > diff --git a/tools/include/vdso/bits.h b/tools/include/vdso/bits.h > > new file mode 100644 > > index 000000000000..6d005a1f5d94 > > --- /dev/null > > +++ b/tools/include/vdso/bits.h > > @@ -0,0 +1,9 @@ > > +/* SPDX-License-Identifier: GPL-2.0 */ > > +#ifndef __VDSO_BITS_H > > +#define __VDSO_BITS_H > > + > > +#include <vdso/const.h> > > + > > +#define BIT(nr) (UL(1) << (nr)) > > + > > +#endif /* __VDSO_BITS_H */ > > diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh > > index c905c683606a..cf147db4e5ca 100755 > > --- a/tools/perf/check-headers.sh > > +++ b/tools/perf/check-headers.sh > > @@ -22,6 +22,7 @@ include/uapi/linux/usbdevice_fs.h > > include/uapi/linux/vhost.h > > include/uapi/sound/asound.h > > include/linux/bits.h > > +include/vdso/bits.h > > include/linux/const.h > > include/vdso/const.h > > include/linux/hash.h > > @@ -116,6 +117,7 @@ check arch/x86/lib/memcpy_64.S '-I "^EXPORT_SYMBOL" -I "^#include <asm/ex > > check arch/x86/lib/memset_64.S '-I "^EXPORT_SYMBOL" -I "^#include <asm/export.h>" -I"^SYM_FUNC_START\(_LOCAL\)*(memset_\(erms\|orig\))"' > > check include/uapi/asm-generic/mman.h '-I "^#include <\(uapi/\)*asm-generic/mman-common\(-tools\)*.h>"' > > check include/uapi/linux/mman.h '-I "^#include <\(uapi/\)*asm/mman.h>"' > > +check include/linux/build_bug.h '-I "^#\(ifndef\|endif\)\( \/\/\)* static_assert$"' > > check include/linux/ctype.h '-I "isdigit("' > > check lib/ctype.c '-I "^EXPORT_SYMBOL" -I "^#include <linux/export.h>" -B' > > check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"' > > > > -- > Regards, > Vincenzo
--
- Arnaldo
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