From: Alexandre Chartre Date: Fri, 21 Nov 2025 09:53:36 +0000 (+0100) Subject: objtool: Add Function to get the name of a CPU feature X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8308fd001927f5bdc37a9c9f9c413baec3fb7bbe;p=thirdparty%2Fkernel%2Flinux.git objtool: Add Function to get the name of a CPU feature Add a function to get the name of a CPU feature. The function is architecture dependent and currently only implemented for x86. The feature names are automatically generated from the cpufeatures.h include file. Signed-off-by: Alexandre Chartre Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://patch.msgid.link/20251121095340.464045-27-alexandre.chartre@oracle.com --- diff --git a/tools/arch/x86/tools/gen-cpu-feature-names-x86.awk b/tools/arch/x86/tools/gen-cpu-feature-names-x86.awk new file mode 100644 index 0000000000000..cc4c7a3e6c2e2 --- /dev/null +++ b/tools/arch/x86/tools/gen-cpu-feature-names-x86.awk @@ -0,0 +1,34 @@ +#!/bin/awk -f +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (c) 2025, Oracle and/or its affiliates. +# +# Usage: awk -f gen-cpu-feature-names-x86.awk cpufeatures.h > cpu-feature-names.c +# + +BEGIN { + print "/* cpu feature name array generated from cpufeatures.h */" + print "/* Do not change this code. */" + print + print "static const char *cpu_feature_names[(NCAPINTS+NBUGINTS)*32] = {" + + value_expr = "\\([0-9*+ ]+\\)" +} + +/^#define X86_FEATURE_/ { + if (match($0, value_expr)) { + value = substr($0, RSTART + 1, RLENGTH - 2) + print "\t[" value "] = \"" $2 "\"," + } +} + +/^#define X86_BUG_/ { + if (match($0, value_expr)) { + value = substr($0, RSTART + 1, RLENGTH - 2) + print "\t[NCAPINTS*32+(" value ")] = \"" $2 "\"," + } +} + +END { + print "};" +} diff --git a/tools/objtool/.gitignore b/tools/objtool/.gitignore index 759303657bd7c..73d883128511f 100644 --- a/tools/objtool/.gitignore +++ b/tools/objtool/.gitignore @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only +arch/x86/lib/cpu-feature-names.c arch/x86/lib/inat-tables.c /objtool feature diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile index df793ca6fc1a1..66397d755fe4b 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -125,6 +125,7 @@ $(LIBSUBCMD)-clean: clean: $(LIBSUBCMD)-clean $(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL) $(Q)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete + $(Q)$(RM) $(OUTPUT)arch/x86/lib/cpu-feature-names.c $(OUTPUT)fixdep $(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep $(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.objtool $(Q)$(RM) -r -- $(OUTPUT)feature diff --git a/tools/objtool/arch/loongarch/special.c b/tools/objtool/arch/loongarch/special.c index a80b75f7b061f..aba774109437f 100644 --- a/tools/objtool/arch/loongarch/special.c +++ b/tools/objtool/arch/loongarch/special.c @@ -194,3 +194,8 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, return rodata_reloc; } + +const char *arch_cpu_feature_name(int feature_number) +{ + return NULL; +} diff --git a/tools/objtool/arch/powerpc/special.c b/tools/objtool/arch/powerpc/special.c index 51610689abf72..8f9bf61ca0899 100644 --- a/tools/objtool/arch/powerpc/special.c +++ b/tools/objtool/arch/powerpc/special.c @@ -18,3 +18,8 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, { exit(-1); } + +const char *arch_cpu_feature_name(int feature_number) +{ + return NULL; +} diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build index 3dedb2fd8f3a0..febee0b8ee0b7 100644 --- a/tools/objtool/arch/x86/Build +++ b/tools/objtool/arch/x86/Build @@ -1,5 +1,5 @@ -objtool-y += special.o objtool-y += decode.o +objtool-y += special.o objtool-y += orc.o inat_tables_script = ../arch/x86/tools/gen-insn-attr-x86.awk @@ -12,3 +12,14 @@ $(OUTPUT)arch/x86/lib/inat-tables.c: $(inat_tables_script) $(inat_tables_maps) $(OUTPUT)arch/x86/decode.o: $(OUTPUT)arch/x86/lib/inat-tables.c CFLAGS_decode.o += -I$(OUTPUT)arch/x86/lib + +cpu_features = ../arch/x86/include/asm/cpufeatures.h +cpu_features_script = ../arch/x86/tools/gen-cpu-feature-names-x86.awk + +$(OUTPUT)arch/x86/lib/cpu-feature-names.c: $(cpu_features_script) $(cpu_features) + $(call rule_mkdir) + $(Q)$(call echo-cmd,gen)$(AWK) -f $(cpu_features_script) $(cpu_features) > $@ + +$(OUTPUT)arch/x86/special.o: $(OUTPUT)arch/x86/lib/cpu-feature-names.c + +CFLAGS_special.o += -I$(OUTPUT)arch/x86/lib diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index 09300761f1085..e817a3fff4491 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -4,6 +4,10 @@ #include #include #include +#include + +/* cpu feature name array generated from cpufeatures.h */ +#include "cpu-feature-names.c" void arch_handle_alternative(struct special_alt *alt) { @@ -134,3 +138,9 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, *table_size = 0; return rodata_reloc; } + +const char *arch_cpu_feature_name(int feature_number) +{ + return (feature_number < ARRAY_SIZE(cpu_feature_names)) ? + cpu_feature_names[feature_number] : NULL; +} diff --git a/tools/objtool/include/objtool/special.h b/tools/objtool/include/objtool/special.h index b22410745e4a1..121c3761899c1 100644 --- a/tools/objtool/include/objtool/special.h +++ b/tools/objtool/include/objtool/special.h @@ -38,4 +38,6 @@ bool arch_support_alt_relocation(struct special_alt *special_alt, struct reloc *arch_find_switch_table(struct objtool_file *file, struct instruction *insn, unsigned long *table_size); +const char *arch_cpu_feature_name(int feature_number); + #endif /* _SPECIAL_H */