linux-stable/tools/perf
Mark Rutland e0891269a8 linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}()
Currently aliasing an asm function requires adding START and END
annotations for each name, as per Documentation/asm-annotations.rst:

	SYM_FUNC_START_ALIAS(__memset)
	SYM_FUNC_START(memset)
	    ... asm insns ...
	SYM_FUNC_END(memset)
	SYM_FUNC_END_ALIAS(__memset)

This is more painful than necessary to maintain, especially where a
function has many aliases, some of which we may wish to define
conditionally. For example, arm64's memcpy/memmove implementation (which
uses some arch-specific SYM_*() helpers) has:

	SYM_FUNC_START_ALIAS(__memmove)
	SYM_FUNC_START_ALIAS_WEAK_PI(memmove)
	SYM_FUNC_START_ALIAS(__memcpy)
	SYM_FUNC_START_WEAK_PI(memcpy)
	    ... asm insns ...
	SYM_FUNC_END_PI(memcpy)
	EXPORT_SYMBOL(memcpy)
	SYM_FUNC_END_ALIAS(__memcpy)
	EXPORT_SYMBOL(__memcpy)
	SYM_FUNC_END_ALIAS_PI(memmove)
	EXPORT_SYMBOL(memmove)
	SYM_FUNC_END_ALIAS(__memmove)
	EXPORT_SYMBOL(__memmove)
	SYM_FUNC_START(name)

It would be much nicer if we could define the aliases *after* the
standard function definition. This would avoid the need to specify each
symbol name twice, and would make it easier to spot the canonical
function definition.

This patch adds new macros to allow us to do so, which allows the above
example to be rewritten more succinctly as:

	SYM_FUNC_START(__pi_memcpy)
	    ... asm insns ...
	SYM_FUNC_END(__pi_memcpy)

	SYM_FUNC_ALIAS(__memcpy, __pi_memcpy)
	EXPORT_SYMBOL(__memcpy)
	SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
	EXPORT_SYMBOL(memcpy)

	SYM_FUNC_ALIAS(__pi_memmove, __pi_memcpy)
	SYM_FUNC_ALIAS(__memmove, __pi_memmove)
	EXPORT_SYMBOL(__memmove)
	SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
	EXPORT_SYMBOL(memmove)

The reduction in duplication will also make it possible to replace some
uses of WEAK with more accurate Kconfig guards, e.g.

	#ifndef CONFIG_KASAN
	SYM_FUNC_ALIAS(memmove, __memmove)
	EXPORT_SYMBOL(memmove)
	#endif

... which should make it easier to ensure that symbols are neither used
nor overidden unexpectedly.

The existing SYM_FUNC_START_ALIAS() and SYM_FUNC_START_LOCAL_ALIAS() are
marked as deprecated, and will be removed once existing users are moved
over to the new scheme.

The tools/perf/ copy of linkage.h is updated to match. A subsequent
patch will depend upon this when updating the x86 asm annotations.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220216162229.1076788-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2022-02-22 16:21:33 +00:00
..
arch tools headers UAPI: Sync files changed by new set_mempolicy_home_node syscall 2022-01-20 11:20:37 -03:00
bench perf cpumap: Migrate to libperf cpumap api 2022-01-22 17:08:42 -03:00
dlfilters perf dlfilter: Drop unused variable 2021-12-16 12:18:11 -03:00
Documentation perf record: Disable debuginfod by default 2022-01-15 17:41:25 -03:00
examples/bpf
include
jvmti
pmu-events perf test: Add pmu-events test for aliases with hyphens 2022-01-22 17:21:29 -03:00
python
scripts perf scripts python: intel-pt-events.py: Fix printing of switch events 2021-12-28 17:26:25 -03:00
tests perf test: Add parse-events test for aliases with hyphens 2022-01-22 17:21:41 -03:00
trace perf beauty: Make the prctl arg regexp more strict to cope with PR_SET_VMA 2022-02-01 13:03:27 -03:00
ui perf annotate: Avoid TUI crash when navigating in the annotation of recursive functions 2022-01-10 15:47:30 -03:00
util linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}() 2022-02-22 16:21:33 +00:00
.gitignore Add 'tools/perf/libbpf/' to ignored files 2021-11-08 11:33:35 -08:00
Build
builtin-annotate.c perf tools: Check vmlinux/kallsyms arguments in all tools 2021-11-07 12:27:38 -03:00
builtin-bench.c perf bench: Use unbuffered output when pipe/tee'ing to a file 2021-12-16 12:18:11 -03:00
builtin-buildid-cache.c perf record: Disable debuginfod by default 2022-01-15 17:41:25 -03:00
builtin-buildid-list.c
builtin-c2c.c perf cpumap: Give CPUs their own type 2022-01-12 14:28:23 -03:00
builtin-config.c
builtin-daemon.c perf daemon: Remove duplicate sys/file.h include 2021-10-08 15:14:50 -03:00
builtin-data.c
builtin-diff.c
builtin-evlist.c
builtin-ftrace.c perf ftrace: system_wide collection is not effective by default 2022-02-06 09:19:51 -03:00
builtin-help.c
builtin-inject.c perf tools: Remove redundant err variable 2022-01-22 17:25:02 -03:00
builtin-kallsyms.c
builtin-kmem.c perf cpumap: Give CPUs their own type 2022-01-12 14:28:23 -03:00
builtin-kvm.c perf tools: Allow controlling synthesizing PERF_RECORD_ metadata events during record 2021-09-17 08:44:19 -03:00
builtin-list.c perf list: Display hybrid PMU events with cpu type 2021-10-25 13:47:42 -03:00
builtin-lock.c
builtin-mem.c
builtin-probe.c perf tools: Check vmlinux/kallsyms arguments in all tools 2021-11-07 12:27:38 -03:00
builtin-record.c perf record: Disable debuginfod by default 2022-01-15 17:41:25 -03:00
builtin-report.c perf callchain: Enable dwarf_callchain_users on arm64 2021-12-21 18:35:44 -03:00
builtin-sched.c perf cpumap: Give CPUs their own type 2022-01-12 14:28:23 -03:00
builtin-script.c perf script: Fix printing 'phys_addr' failure issue 2022-01-22 17:02:08 -03:00
builtin-stat.c perf cpumap: Migrate to libperf cpumap api 2022-01-22 17:08:42 -03:00
builtin-timechart.c
builtin-top.c perf tools: Check vmlinux/kallsyms arguments in all tools 2021-11-07 12:27:38 -03:00
builtin-trace.c perf tools changes for v5.17: 1st batch 2022-01-18 06:32:11 +02:00
builtin-version.c
builtin.h
check-headers.sh tools lib: Adopt list_sort() from the kernel sources 2021-10-20 10:30:59 -03:00
command-list.txt
CREDITS
design.txt perf design.txt: Synchronize the definition of enum perf_hw_id with code 2021-11-13 18:11:50 -03:00
Makefile
Makefile.config perf tools: Drop requirement for libstdc++.so for libopencsd check 2021-12-07 22:18:24 -03:00
Makefile.perf perf ftrace: Add -b/--use-bpf option for latency subcommand 2021-12-16 12:18:12 -03:00
MANIFEST perf MANIFEST: Add bpftool files to allow building with BUILD_BPF_SKEL=1 2021-11-07 15:39:28 -03:00
perf-archive.sh
perf-completion.sh
perf-iostat.sh
perf-read-vdso.c
perf-sys.h
perf-with-kcore.sh
perf.c
perf.h