From e6428c3492a34ed728b6152cf073efb3250a6d94 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 19 May 2025 11:48:19 -0300 Subject: tools headers compiler: Pick the const_true() define from the kernel sources The sync of include/linux/bits.h with the kernel sources will make use of this define, so add it to the tools/include/linux/compiler. variant used to build tools/ living code. Acked-by: Vincent Mailhol Acked-by: Yury Norov [NVIDIA] Cc: Adrian Hunter Cc: Ian Rogers Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Link: https://lore.kernel.org/r/20250519214126.1652491-7-acme@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/compiler.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'tools/include/linux') diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 9c05a59f0184..d627e66a04a6 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -81,6 +81,28 @@ #define __is_constexpr(x) \ (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8))) +/* + * Similar to statically_true() but produces a constant expression + * + * To be used in conjunction with macros, such as BUILD_BUG_ON_ZERO(), + * which require their input to be a constant expression and for which + * statically_true() would otherwise fail. + * + * This is a trade-off: const_true() requires all its operands to be + * compile time constants. Else, it would always returns false even on + * the most trivial cases like: + * + * true || non_const_var + * + * On the opposite, statically_true() is able to fold more complex + * tautologies and will return true on expressions such as: + * + * !(non_const_var * 8 % 4) + * + * For the general case, statically_true() is better. + */ +#define const_true(x) __builtin_choose_expr(__is_constexpr(x), x, false) + #ifdef __ANDROID__ /* * FIXME: Big hammer to get rid of tons of: -- cgit v1.2.3 From e48b92f9e140ff632ad426c0a94e3630a61e45d8 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 19 May 2025 11:51:16 -0300 Subject: tools headers: Synchronize linux/bits.h with the kernel sources To pick up the changes in this cset: 0312e94abe484b9e ("treewide: fix typo 'unsigned __init128' -> 'unsigned __int128'") This addresses these perf build warnings: Warning: Kernel ABI header differences: diff -u tools/include/linux/bits.h include/linux/bits.h This required picking the const_true() define in linux/compiler.h as a prep patch as that macro is used in the new linux/bits.h Please see tools/include/uapi/README for further details. Acked-by: Vincent Mailhol Acked-by: Yury Norov [NVIDIA] Cc: Adrian Hunter Cc: Ian Rogers Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Link: https://lore.kernel.org/r/20250519214126.1652491-8-acme@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/bits.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'tools/include/linux') diff --git a/tools/include/linux/bits.h b/tools/include/linux/bits.h index 8de2914e6510..14fd0ca9a6cd 100644 --- a/tools/include/linux/bits.h +++ b/tools/include/linux/bits.h @@ -20,9 +20,8 @@ */ #if !defined(__ASSEMBLY__) #include -#define GENMASK_INPUT_CHECK(h, l) \ - (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ - __is_constexpr((l) > (h)), (l) > (h), 0))) +#include +#define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h))) #else /* * BUILD_BUG_ON_ZERO is not available in h files included from asm files, -- cgit v1.2.3 From 3417404c6f83c5d72d69ae81ded914bdc3841a49 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 12 Jun 2025 12:53:37 -0300 Subject: tools headers: Syncronize linux/build_bug.h with the kernel sources To pick up the changes in: 243c90e917f5cfc9 ("build_bug.h: more user friendly error messages in BUILD_BUG_ON_ZERO()") This also needed to pick the __BUILD_BUG_ON_ZERO_MSG() in linux/compiler.h, that needed to be polished to avoid hitting old clang problems with _Static_assert on arrays of structs: Debian clang version 11.0.1-2~deb10u1 Debian clang version 11.0.1-2~deb10u1 $ make NO_LIBTRACEEVENT=1 ARCH= CROSS_COMPILE= EXTRA_CFLAGS= -C tools/perf O=/tmp/build/perf CC=clang btf_dump.c:895:18: error: type name does not allow storage class to be specified for (i = 0; i < ARRAY_SIZE(pads); i++) { ^ /git/perf-6.16.0-rc1/tools/include/linux/kernel.h:91:59: note: expanded from macro 'ARRAY_SIZE' #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) ^ /git/perf-6.16.0-rc1/tools/include/linux/compiler-gcc.h:26:28: note: expanded from macro '__must_be_array' #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) ^ /git/perf-6.16.0-rc1/tools/include/linux/build_bug.h:17:2: note: expanded from macro 'BUILD_BUG_ON_ZERO' __BUILD_BUG_ON_ZERO_MSG(e, ##__VA_ARGS__, #e " is true") ^ /git/perf-6.16.0-rc1/tools/include/linux/compiler.h:248:67: note: expanded from macro '__BUILD_BUG_ON_ZERO_MSG' #define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)sizeof(struct {_Static_assert(!(e), msg);})) ^ /usr/include/x86_64-linux-gnu/sys/cdefs.h:438:5: note: expanded from macro '_Static_assert' extern int (*__Static_assert_function (void)) \ ^ These also failed: toolsbuilder@five:~$ grep FAIL dm.log/summary | grep clang 1 72.87 almalinux:8 : FAIL clang version 19.1.7 ( 19.1.7-2.module_el8.10.0+3990+33d0d926) 15 73.39 centos:stream : FAIL clang version 17.0.6 (Red Hat 17.0.6-1.module_el8+767+9fa966b8) 36 87.14 opensuse:15.4 : FAIL clang version 15.0.7 37 80.08 opensuse:15.5 : FAIL clang version 15.0.7 40 72.12 oraclelinux:8 : FAIL clang version 16.0.6 (Red Hat 16.0.6-2.0.1.module+el8.9.0+90129+d3ee8717) 42 74.12 rockylinux:8 : FAIL clang version 16.0.6 (Red Hat 16.0.6-2.module+el8.9.0+1651+e10a8f6d) toolsbuilder@five:~$ This addresses this perf build warning: Warning: Kernel ABI header differences: diff -u tools/include/linux/build_bug.h include/linux/build_bug.h Cc: Adrian Hunter Cc: Ian Rogers Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Cc: Vincent Mailhol Cc: Yury Norov Link: https://lore.kernel.org/r/aEszb7SSIJB6Lp6f@x1 Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/build_bug.h | 10 +++++----- tools/include/linux/compiler.h | 8 ++++++++ 2 files changed, 13 insertions(+), 5 deletions(-) (limited to 'tools/include/linux') diff --git a/tools/include/linux/build_bug.h b/tools/include/linux/build_bug.h index b4898ff085de..ab2aa97bd8ce 100644 --- a/tools/include/linux/build_bug.h +++ b/tools/include/linux/build_bug.h @@ -4,17 +4,17 @@ #include -#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). + * + * Take an error message as an optional second argument. If omitted, + * default to the stringification of the tested expression. */ -#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) -#endif /* __CHECKER__ */ +#define BUILD_BUG_ON_ZERO(e, ...) \ + __BUILD_BUG_ON_ZERO_MSG(e, ##__VA_ARGS__, #e " is true") /* Force a compilation error if a constant expression is not a power of 2 */ #define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \ diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index d627e66a04a6..33411ca0cc90 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -244,6 +244,14 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s __asm__ ("" : "=r" (var) : "0" (var)) #endif +#ifndef __BUILD_BUG_ON_ZERO_MSG +#if defined(__clang__) +#define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)(sizeof(struct { int:(-!!(e)); }))) +#else +#define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)sizeof(struct {_Static_assert(!(e), msg);})) +#endif +#endif + #endif /* __ASSEMBLY__ */ #endif /* _TOOLS_LINUX_COMPILER_H */ -- cgit v1.2.3 From fc92099902fbf21000554678a47654b029c15a4d Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 12 Jun 2025 12:36:06 -0300 Subject: tools headers: Synchronize linux/bits.h with the kernel sources To pick up the changes in this cset: 1e7933a575ed8af4 ("uapi: Revert "bitops: avoid integer overflow in GENMASK(_ULL)"") 5b572e8a9f3dcd6e ("bits: introduce fixed-type BIT_U*()") 19408200c094858d ("bits: introduce fixed-type GENMASK_U*()") 31299a5e02112411 ("bits: add comments and newlines to #if, #else and #endif directives") This addresses these perf build warnings: Warning: Kernel ABI header differences: diff -u tools/include/linux/bits.h include/linux/bits.h Please see tools/include/uapi/README for further details. Acked-by: Vincent Mailhol Cc: I Hsin Cheng Cc: Yury Norov Cc: Adrian Hunter Cc: Ian Rogers Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Lucas De Marchi Cc: Namhyung Kim Cc: Yury Norov Link: https://lore.kernel.org/r/aEr0ZJ60EbshEy6p@x1 Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/bits.h | 57 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 2 deletions(-) (limited to 'tools/include/linux') diff --git a/tools/include/linux/bits.h b/tools/include/linux/bits.h index 14fd0ca9a6cd..7ad056219115 100644 --- a/tools/include/linux/bits.h +++ b/tools/include/linux/bits.h @@ -12,6 +12,7 @@ #define BIT_ULL_MASK(nr) (ULL(1) << ((nr) % BITS_PER_LONG_LONG)) #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG) #define BITS_PER_BYTE 8 +#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) /* * Create a contiguous bitmask starting at bit position @l and ending at @@ -19,16 +20,68 @@ * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. */ #if !defined(__ASSEMBLY__) + +/* + * Missing asm support + * + * GENMASK_U*() and BIT_U*() depend on BITS_PER_TYPE() which relies on sizeof(), + * something not available in asm. Nevertheless, fixed width integers is a C + * concept. Assembly code can rely on the long and long long versions instead. + */ + #include #include +#include + #define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h))) -#else + +/* + * Generate a mask for the specified type @t. Additional checks are made to + * guarantee the value returned fits in that type, relying on + * -Wshift-count-overflow compiler check to detect incompatible arguments. + * For example, all these create build errors or warnings: + * + * - GENMASK(15, 20): wrong argument order + * - GENMASK(72, 15): doesn't fit unsigned long + * - GENMASK_U32(33, 15): doesn't fit in a u32 + */ +#define GENMASK_TYPE(t, h, l) \ + ((t)(GENMASK_INPUT_CHECK(h, l) + \ + (type_max(t) << (l) & \ + type_max(t) >> (BITS_PER_TYPE(t) - 1 - (h))))) + +#define GENMASK_U8(h, l) GENMASK_TYPE(u8, h, l) +#define GENMASK_U16(h, l) GENMASK_TYPE(u16, h, l) +#define GENMASK_U32(h, l) GENMASK_TYPE(u32, h, l) +#define GENMASK_U64(h, l) GENMASK_TYPE(u64, h, l) + +/* + * Fixed-type variants of BIT(), with additional checks like GENMASK_TYPE(). The + * following examples generate compiler warnings due to -Wshift-count-overflow: + * + * - BIT_U8(8) + * - BIT_U32(-1) + * - BIT_U32(40) + */ +#define BIT_INPUT_CHECK(type, nr) \ + BUILD_BUG_ON_ZERO(const_true((nr) >= BITS_PER_TYPE(type))) + +#define BIT_TYPE(type, nr) ((type)(BIT_INPUT_CHECK(type, nr) + BIT_ULL(nr))) + +#define BIT_U8(nr) BIT_TYPE(u8, nr) +#define BIT_U16(nr) BIT_TYPE(u16, nr) +#define BIT_U32(nr) BIT_TYPE(u32, nr) +#define BIT_U64(nr) BIT_TYPE(u64, nr) + +#else /* defined(__ASSEMBLY__) */ + /* * 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 + +#endif /* !defined(__ASSEMBLY__) */ #define GENMASK(h, l) \ (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l)) -- cgit v1.2.3