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authorLinus Torvalds <torvalds@linux-foundation.org>2025-06-21 07:59:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-06-21 07:59:45 -0700
commit7c7f9dd1ea3fc6b175b7227bb473dc883b925548 (patch)
tree438b30771027d2a9fe254df22ae862c550328b1d /tools/include/linux/bits.h
parent3f75bfff44be0646580fe4efda45d646f9c1693b (diff)
parentd222b6e6fb31e320eca506e665694d8ddf459157 (diff)
Merge tag 'perf-tools-fixes-for-v6.16-1-2025-06-20' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools
Pull perf tools fixes from Arnaldo Carvalho de Melo: - Fix some file descriptor leaks that stand out with recent changes to 'perf list' - Fix prctl include to fix building 'perf bench futex' hash with musl libc - Restrict 'perf test' uniquifying entry to machines with 'uncore_imc' PMUs - Document new output fields (op, cache, mem, dtlb, snoop) used with 'perf mem' - Synchronize kernel header copies * tag 'perf-tools-fixes-for-v6.16-1-2025-06-20' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: tools headers x86 cpufeatures: Sync with the kernel sources perf bench futex: Fix prctl include in musl libc perf test: Directory file descriptor leak perf evsel: Missed close() when probing hybrid core PMUs tools headers: Synchronize linux/bits.h with the kernel sources tools arch amd ibs: Sync ibs.h with the kernel sources tools arch x86: Sync the msr-index.h copy with the kernel sources tools headers: Syncronize linux/build_bug.h with the kernel sources tools headers: Update the copy of x86's mem{cpy,set}_64.S used in 'perf bench' tools headers UAPI: Sync linux/kvm.h with the kernel sources tools headers UAPI: Sync the drm/drm.h with the kernel sources perf beauty: Update copy of linux/socket.h with the kernel sources tools headers UAPI: Sync kvm header with the kernel sources tools headers x86 svm: Sync svm headers with the kernel sources tools headers UAPI: Sync KVM's vmx.h header with the kernel sources tools kvm headers arm64: Update KVM header from the kernel sources tools headers UAPI: Sync linux/prctl.h with the kernel sources to pick FUTEX knob perf mem: Document new output fields (op, cache, mem, dtlb, snoop) tools headers: Update the fs headers with the kernel sources perf test: Restrict uniquifying test to machines with 'uncore_imc'
Diffstat (limited to 'tools/include/linux/bits.h')
-rw-r--r--tools/include/linux/bits.h57
1 files changed, 55 insertions, 2 deletions
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 <linux/build_bug.h>
#include <linux/compiler.h>
+#include <linux/overflow.h>
+
#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))