Commit 16dccbb8 authored Feb 03, 2026 by Dapeng Mi Committed by Arnaldo Carvalho de Melo Feb 06, 2026

perf regs: Remove weak attributive archxxx_reg_mask() functions



Currently, some architecture-specific perf-regs functions, such as
arch__intr_reg_mask() and arch__user_reg_mask(), are defined with the
__weak attribute.

This approach ensures that only functions matching the architecture of
the build/run host are compiled and executed, reducing build time and
binary size.

However, this __weak attribute restricts these functions to be called
only on the same architecture, preventing cross-architecture
functionality.

For example, a perf.data file captured on x86 cannot be parsed on an ARM
platform.

To address this limitation, this patch removes the __weak attribute from
these perf-regs functions.

The architecture-specific code is moved from the arch/ directory to the
util/perf-regs-arch/ directory.

The appropriate architectural functions are then called based on the
EM_HOST.

No functional changes are intended.

Suggested-by: Ian Rogers <irogers@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Guo Ren <guoren@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xudong Hao <xudong.hao@intel.com>
Cc: Zide Chen <zide.chen@intel.com>
[ Fixed up somme fuzz with s390 and riscv Build files wrt removing perf_regs.o ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent e716e69c

tools/perf/arch/arm/util/Build

+0 −2

Original line number	Diff line number	Diff line
		perf-util-y += perf_regs.o

		perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o

		perf-util-y += pmu.o auxtrace.o cs-etm.o

tools/perf/arch/arm/util/perf_regs.c

deleted100644 → 0

+0 −13

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		#include "perf_regs.h"
		#include "../../../util/perf_regs.h"

		uint64_t arch__intr_reg_mask(void)
		{
		return PERF_REGS_MASK;
		}

		uint64_t arch__user_reg_mask(void)
		{
		return PERF_REGS_MASK;
		}

tools/perf/arch/arm64/util/perf_regs.c

+0 −36

Original line number	Diff line number	Diff line
		@@ -103,39 +103,3 @@ int arch_sdt_arg_parse_op(char old_op, char *new_op)

		return SDT_ARG_VALID;
		}

		uint64_t arch__intr_reg_mask(void)
		{
		return PERF_REGS_MASK;
		}

		uint64_t arch__user_reg_mask(void)
		{
		struct perf_event_attr attr = {
		.type = PERF_TYPE_HARDWARE,
		.config = PERF_COUNT_HW_CPU_CYCLES,
		.sample_type = PERF_SAMPLE_REGS_USER,
		.disabled = 1,
		.exclude_kernel = 1,
		.sample_period = 1,
		.sample_regs_user = PERF_REGS_MASK
		};
		int fd;

		if (getauxval(AT_HWCAP) & HWCAP_SVE)
		attr.sample_regs_user \|= SMPL_REG_MASK(PERF_REG_ARM64_VG);

		/*
		* Check if the pmu supports perf extended regs, before
		* returning the register mask to sample.
		*/
		if (attr.sample_regs_user != PERF_REGS_MASK) {
		event_attr_init(&attr);
		fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
		if (fd != -1) {
		close(fd);
		return attr.sample_regs_user;
		}
		}
		return PERF_REGS_MASK;
		}

tools/perf/arch/csky/Build

deleted100644 → 0

+0 −1

Original line number	Diff line number	Diff line
		perf-util-y += util/

tools/perf/arch/csky/util/Build

deleted100644 → 0

+0 −1

Original line number	Diff line number	Diff line
		perf-util-y += perf_regs.o