Re: [PATCH v5 00/11] perf: Support multiple system call tables in the build

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: "Ian Rogers" <irogers@google.com>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"Ingo Molnar" <mingo@redhat.com>,
	"Mark Rutland" <mark.rutland@arm.com>,
	"Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
	"Jiri Olsa" <jolsa@kernel.org>,
	"Adrian Hunter" <adrian.hunter@intel.com>,
	"Kan Liang" <kan.liang@linux.intel.com>,
	"John Garry" <john.g.garry@oracle.com>,
	"Will Deacon" <will@kernel.org>,
	"James Clark" <james.clark@linaro.org>,
	"Mike Leach" <mike.leach@linaro.org>,
	"Leo Yan" <leo.yan@linux.dev>, guoren <guoren@kernel.org>,
	"Paul Walmsley" <paul.walmsley@sifive.com>,
	"Palmer Dabbelt" <palmer@dabbelt.com>,
	"Albert Ou" <aou@eecs.berkeley.edu>,
	"Charlie Jenkins" <charlie@rivosinc.com>,
	"Bibo Mao" <maobibo@loongson.cn>,
	"Huacai Chen" <chenhuacai@kernel.org>,
	"Catalin Marinas" <catalin.marinas@arm.com>,
	"Jiri Slaby" <jirislaby@kernel.org>,
	"Björn Töpel" <bjorn@rivosinc.com>,
	"Howard Chu" <howardchu95@gmail.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	"linux-csky@vger.kernel.org" <linux-csky@vger.kernel.org>,
	linux-riscv@lists.infradead.org, "Arnd Bergmann" <arnd@arndb.de>
Subject: Re: [PATCH v5 00/11] perf: Support multiple system call tables in the build
Date: Thu, 13 Mar 2025 16:49:52 -0300	[thread overview]
Message-ID: <Z9M24AJzui9lFbGo@x1> (raw)
In-Reply-To: <Z9KFLGpenwOP32q3@google.com>

On Thu, Mar 13, 2025 at 12:11:40AM -0700, Namhyung Kim wrote:
> On Fri, Mar 07, 2025 at 04:31:58PM -0800, Ian Rogers wrote:
> > This work builds on the clean up of system call tables and removal of
> > libaudit by Charlie Jenkins <charlie@rivosinc.com>.
> > 
> > The system call table in perf trace is used to map system call numbers
> > to names and vice versa. Prior to these changes, a single table
> > matching the perf binary's build was present. The table would be
> > incorrect if tracing say a 32-bit binary from a 64-bit version of
> > perf, the names and numbers wouldn't match.
> > 
> > Change the build so that a single system call file is built and the
> > potentially multiple tables are identifiable from the ELF machine type
> > of the process being examined. To determine the ELF machine type, the
> > executable's maps are searched and the associated DSOs ELF headers are
> > read. When this fails and when live, /proc/pid/exe's ELF header is
> > read. Fallback to using the perf's binary type when unknown.
> 
> Now it works well for me!

Its working for me on x86_64 as well, I'm doing some more tests, the
container builds and will do 32-bit tracing on 64-bit ARM (rpi5 aarch64)
and then report results here, should be later today as the default
kernel for the rpi5 doesn't come with CONFIG_FTRACE_SYSCALLS=y and BTF,
so building one with it.

- Arnaldo