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Message-ID: <f81cf759-d5a4-4b46-bd2c-2e11355447a8@linux.ibm.com>
Date: Tue, 16 Jan 2024 15:26:52 +0100
From: Thomas Richter <tmricht@...ux.ibm.com>
To: Changbin Du <changbin.du@...wei.com>,
Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>, Namhyung Kim <namhyung@...nel.org>,
Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org
Subject: Re: [PATCH 2/3] perf: script: use capstone disasm engine to show
assembly instructions
On 1/16/24 12:34, Changbin Du wrote:
> Currently, the instructions of samples are shown as raw hex strings
> which are hard to read. x86 has a special option '--xed' to disassemble
> the hex string via intel XED tool.
>
> Here we use capstone as our disassembler engine to give more friendly
> instructions. We select libcapstone because capstone can provide more
> insn details. Perf will fallback to raw instructions if libcapstone is
> not available.
>
> The advantages compared to XED tool:
> * Support arm, arm64, x86-32, x86_64 (more could be supported),
> xed only for x86_64.
> * Immediate address operands are shown as symbol+offs.
>
> Before:
> $ sudo perf record --event intel_pt//u -- ls
> $ sudo perf script --insn-trace
> perf 17423 [000] 423271.557970005: 7f2d95f16217 __GI___ioctl+0x7 (/lib/x86_64-linux-gnu/libc-2.27.so) insn: 48 3d 01 f0 ff ff
> perf 17423 [000] 423271.557970005: 7f2d95f1621d __GI___ioctl+0xd (/lib/x86_64-linux-gnu/libc-2.27.so) insn: 73 01
> perf 17423 [000] 423271.557970338: 7f2d95f1621f __GI___ioctl+0xf (/lib/x86_64-linux-gnu/libc-2.27.so) insn: c3
> perf 17423 [000] 423271.557970338: 5593ad3346d7 perf_evsel__enable_cpu+0x97 (/work/linux/tools/perf/perf) insn: 85 c0
> perf 17423 [000] 423271.557970338: 5593ad3346d9 perf_evsel__enable_cpu+0x99 (/work/linux/tools/perf/perf) insn: 75 12
> perf 17423 [000] 423271.557970338: 5593ad3346db perf_evsel__enable_cpu+0x9b (/work/linux/tools/perf/perf) insn: 49 8b 84 24 a8 00 00 00
> perf 17423 [000] 423271.557970338: 5593ad3346e3 perf_evsel__enable_cpu+0xa3 (/work/linux/tools/perf/perf) insn: 48 8b 50 20
>
> After:
> $ sudo perf script --insn-trace
> perf 17423 [000] 423271.557970005: 7f2d95f16217 __GI___ioctl+0x7 (/lib/x86_64-linux-gnu/libc-2.27.so) insn: cmpq $-0xfff, %rax
> perf 17423 [000] 423271.557970005: 7f2d95f1621d __GI___ioctl+0xd (/lib/x86_64-linux-gnu/libc-2.27.so) insn: jae __GI___ioctl+0x10
> perf 17423 [000] 423271.557970338: 7f2d95f1621f __GI___ioctl+0xf (/lib/x86_64-linux-gnu/libc-2.27.so) insn: retq
> perf 17423 [000] 423271.557970338: 5593ad3346d7 perf_evsel__enable_cpu+0x97 (/work/linux/tools/perf/perf) insn: testl %eax, %eax
> perf 17423 [000] 423271.557970338: 5593ad3346d9 perf_evsel__enable_cpu+0x99 (/work/linux/tools/perf/perf) insn: jne perf_evsel__enable_cpu+0xad
> perf 17423 [000] 423271.557970338: 5593ad3346db perf_evsel__enable_cpu+0x9b (/work/linux/tools/perf/perf) insn: movq 0xa8(%r12), %rax
> perf 17423 [000] 423271.557970338: 5593ad3346e3 perf_evsel__enable_cpu+0xa3 (/work/linux/tools/perf/perf) insn: movq 0x20(%rax), %rdx
> perf 17423 [000] 423271.557970338: 5593ad3346e7 perf_evsel__enable_cpu+0xa7 (/work/linux/tools/perf/perf) insn: cmpl %edx, %ebx
> perf 17423 [000] 423271.557970338: 5593ad3346e9 perf_evsel__enable_cpu+0xa9 (/work/linux/tools/perf/perf) insn: jl perf_evsel__enable_cpu+0x60
> perf 17423 [000] 423271.557970338: 5593ad3346eb perf_evsel__enable_cpu+0xab (/work/linux/tools/perf/perf) insn: xorl %eax, %eax
>
> Signed-off-by: Changbin Du <changbin.du@...wei.com>
> ---
...
> diff --git a/tools/perf/util/print_insn.c b/tools/perf/util/print_insn.c
> new file mode 100644
> index 000000000000..c8d9741748cd
> --- /dev/null
> +++ b/tools/perf/util/print_insn.c
> @@ -0,0 +1,118 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Instruction binary disassembler based on capstone.
> + *
> + * Author(s): Changbin Du <changbin.du@...wei.com>
> + */
> +#include "print_insn.h"
> +#include <stdlib.h>
> +#include <string.h>
> +#include <stdbool.h>
> +#include "util/debug.h"
> +#include "util/symbol.h"
> +#include "machine.h"
> +
> +size_t sample__fprintf_insn_raw(struct perf_sample *sample, FILE *fp)
> +{
> + int printed = 0;
> +
> + for (int i = 0; i < sample->insn_len; i++)
> + printed += fprintf(fp, "%02x ", (unsigned char)sample->insn[i]);
> + return printed;
> +}
> +
> +#ifdef HAVE_LIBCAPSTONE_SUPPORT
> +#include <capstone/capstone.h>
> +
> +static int capstone_init(struct machine *machine, csh *cs_handle)
> +{
> + cs_arch arch;
> + cs_mode mode;
> +
> + if (machine__is(machine, "x86_64")) {
> + arch = CS_ARCH_X86;
> + mode = CS_MODE_64;
> + } else if (machine__normalized_is(machine, "x86")) {
> + arch = CS_ARCH_X86;
> + mode = CS_MODE_32;
> + } else if (machine__normalized_is(machine, "arm64")) {
> + arch = CS_ARCH_ARM64;
> + mode = CS_MODE_ARM;
> + } else if (machine__normalized_is(machine, "arm")) {
> + arch = CS_ARCH_ARM;
> + mode = CS_MODE_ARM + CS_MODE_V8;
> + } else {
> + return -1;
> + }
> ...
Did you forgot to support s390? Or was it omitted on intention?
Something along the lines will support s390:
# git diff util/print_insn.c
diff --git a/tools/perf/util/print_insn.c b/tools/perf/util/print_insn.c
index c8d9741748cd..c5127910c75b 100644
--- a/tools/perf/util/print_insn.c
+++ b/tools/perf/util/print_insn.c
@@ -41,6 +41,9 @@ static int capstone_init(struct machine *machine, csh *cs_handle)
} else if (machine__normalized_is(machine, "arm")) {
arch = CS_ARCH_ARM;
mode = CS_MODE_ARM + CS_MODE_V8;
+ } else if (machine__normalized_is(machine, "s390x")) {
+ arch = CS_ARCH_SYSZ;
+ mode = CS_MODE_BIG_ENDIAN;
} else {
return -1;
}
#
Thanks a lot for including these line in your next version.
--
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294
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