Messages in this thread | | | Subject | Re: [PATCH 15/15] tools headers: Synchronize linux/bits.h with the kernel sources | From | Vincenzo Frascino <> | Date | Wed, 15 Apr 2020 10:14:06 +0100 |
| |
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
> 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
| |