[PATCH v2 2/5] perf: util: use capstone disasm engine to show assembly instructions

Changbin Du posted 5 patches 1 year, 11 months ago
There is a newer version of this series
[PATCH v2 2/5] perf: util: use capstone disasm engine to show assembly instructions
Posted by Changbin Du 1 year, 11 months ago
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.

Signed-off-by: Changbin Du <changbin.du@huawei.com>
---
 tools/perf/builtin-script.c  |   8 +--
 tools/perf/util/Build        |   1 +
 tools/perf/util/print_insn.c | 123 +++++++++++++++++++++++++++++++++++
 tools/perf/util/print_insn.h |  14 ++++
 4 files changed, 141 insertions(+), 5 deletions(-)
 create mode 100644 tools/perf/util/print_insn.c
 create mode 100644 tools/perf/util/print_insn.h

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index b1f57401ff23..4817a37f16e2 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -34,6 +34,7 @@
 #include "util/event.h"
 #include "ui/ui.h"
 #include "print_binary.h"
+#include "print_insn.h"
 #include "archinsn.h"
 #include <linux/bitmap.h>
 #include <linux/kernel.h>
@@ -1511,11 +1512,8 @@ static int perf_sample__fprintf_insn(struct perf_sample *sample,
 	if (PRINT_FIELD(INSNLEN))
 		printed += fprintf(fp, " ilen: %d", sample->insn_len);
 	if (PRINT_FIELD(INSN) && sample->insn_len) {
-		int i;
-
-		printed += fprintf(fp, " insn:");
-		for (i = 0; i < sample->insn_len; i++)
-			printed += fprintf(fp, " %02x", (unsigned char)sample->insn[i]);
+		printed += fprintf(fp, " insn: ");
+		printed += sample__fprintf_insn_raw(sample, fp);
 	}
 	if (PRINT_FIELD(BRSTACKINSN) || PRINT_FIELD(BRSTACKINSNLEN))
 		printed += perf_sample__fprintf_brstackinsn(sample, thread, attr, machine, fp);
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 988473bf907a..c33aab53d8dd 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -32,6 +32,7 @@ perf-y += perf_regs.o
 perf-y += perf-regs-arch/
 perf-y += path.o
 perf-y += print_binary.o
+perf-y += print_insn.o
 perf-y += rlimit.o
 perf-y += argv_split.o
 perf-y += rbtree.o
diff --git a/tools/perf/util/print_insn.c b/tools/perf/util/print_insn.c
new file mode 100644
index 000000000000..fe035efe8cf6
--- /dev/null
+++ b/tools/perf/util/print_insn.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Instruction binary disassembler based on capstone.
+ *
+ * Author(s): Changbin Du <changbin.du@huawei.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 if (machine__normalized_is(machine, "s390x")) {
+		arch = CS_ARCH_SYSZ;
+		mode = CS_MODE_BIG_ENDIAN;
+	} else {
+		return -1;
+	}
+
+	if (cs_open(arch, mode, cs_handle) != CS_ERR_OK) {
+		pr_warning_once("cs_open failed\n");
+		return -1;
+	}
+
+	cs_option(*cs_handle, CS_OPT_SYNTAX, CS_OPT_SYNTAX_ATT);
+	if (machine__normalized_is(machine, "x86"))
+		cs_option(*cs_handle, CS_OPT_DETAIL, CS_OPT_ON);
+
+	return 0;
+}
+
+static size_t print_insn_x86(struct perf_sample *sample, struct thread *thread,
+			     cs_insn *insn, FILE *fp)
+{
+	struct addr_location al;
+	size_t printed = 0;
+
+	if (insn->detail && insn->detail->x86.op_count == 1) {
+		cs_x86_op *op = &insn->detail->x86.operands[0];
+
+		addr_location__init(&al);
+
+		/* TODO: Add support for other ISAs */
+		if (op->type == X86_OP_IMM &&
+		    thread__find_symbol(thread, sample->cpumode, op->imm, &al)) {
+			printed += fprintf(fp, "%s ", insn[0].mnemonic);
+			printed += symbol__fprintf_symname_offs(al.sym, &al, fp);
+			return printed;
+		}
+	}
+
+	printed += fprintf(fp, "%s %s", insn[0].mnemonic, insn[0].op_str);
+	return printed;
+}
+
+size_t sample__fprintf_insn(struct perf_sample *sample, struct thread *thread,
+			    struct machine *machine, FILE *fp)
+{
+	static csh cs_handle;
+	cs_insn *insn;
+	size_t count;
+	size_t printed = 0;
+	int ret;
+
+	ret = capstone_init(machine, &cs_handle);
+	if (ret < 0) {
+		/* fallback */
+		return sample__fprintf_insn_raw(sample, fp);
+	}
+
+	count = cs_disasm(cs_handle, (uint8_t *)sample->insn, sample->insn_len,
+			  sample->ip, 1, &insn);
+	if (count > 0) {
+		if (machine__normalized_is(machine, "x86"))
+			printed += print_insn_x86(sample, thread, &insn[0], fp);
+		else
+			printed += fprintf(fp, "%s %s", insn[0].mnemonic, insn[0].op_str);
+		cs_free(insn, count);
+	} else {
+		printed += fprintf(fp, "illegal instruction");
+	}
+
+	cs_close(&cs_handle);
+	return printed;
+}
+#else
+size_t sample__fprintf_insn(struct perf_sample *sample, struct thread *thread __maybe_unused,
+			    struct machine *machine __maybe_unused, FILE *fp)
+{
+	return sample__fprintf_insn_raw(sample, fp);
+}
+#endif
diff --git a/tools/perf/util/print_insn.h b/tools/perf/util/print_insn.h
new file mode 100644
index 000000000000..af8fa5d01fb7
--- /dev/null
+++ b/tools/perf/util/print_insn.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef PERF_PRINT_ISNS_H
+#define PERF_PRINT_ISNS_H
+
+#include <stddef.h>
+#include <stdio.h>
+#include "event.h"
+#include "util/thread.h"
+
+size_t sample__fprintf_insn(struct perf_sample *sample, struct thread *thread,
+			    struct machine *machine, FILE *fp);
+size_t sample__fprintf_insn_raw(struct perf_sample *sample, FILE *fp);
+
+#endif /* PERF_PRINT_ISNS_H */
-- 
2.25.1
Re: [PATCH v2 2/5] perf: util: use capstone disasm engine to show assembly instructions
Posted by Thomas Richter 1 year, 11 months ago
On 1/17/24 06:11, 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.
> 
> Signed-off-by: Changbin Du <changbin.du@huawei.com>
> ---
>  tools/perf/builtin-script.c  |   8 +--
>  tools/perf/util/Build        |   1 +
>  tools/perf/util/print_insn.c | 123 +++++++++++++++++++++++++++++++++++
>  tools/perf/util/print_insn.h |  14 ++++
>  4 files changed, 141 insertions(+), 5 deletions(-)
>  create mode 100644 tools/perf/util/print_insn.c
>  create mode 100644 tools/perf/util/print_insn.h> 
...

> diff --git a/tools/perf/util/print_insn.c b/tools/perf/util/print_insn.c
> new file mode 100644
> index 000000000000..fe035efe8cf6
> --- /dev/null
> +++ b/tools/perf/util/print_insn.c
> @@ -0,0 +1,123 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Instruction binary disassembler based on capstone.
> + *
> + * Author(s): Changbin Du <changbin.du@huawei.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 if (machine__normalized_is(machine, "s390x")) {

        } else if (machine__normalized_is(machine, "s390")) {                 

> +		arch = CS_ARCH_SYSZ;
> +		mode = CS_MODE_BIG_ENDIAN;
> +	} else {
> +		return -1;
> +	}

I have debugged your reworked patch this morning and discovered that
it was not working. The issue turned out to be function machine__normalized_is().
The first parameter is passed to several functions before the comparison.
The calls executed are

   machine__normhalized_is()
   +--> perf_env__arch() --> called for first parameter.
        +--> normalize_arch() --> always returns "s390"

We need to change the second parameter to "s390" without the trailing x
as indicated above. Sorry for the confusion.

Thanks a lot.
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

Re: [PATCH v2 2/5] perf: util: use capstone disasm engine to show assembly instructions
Posted by Changbin Du 1 year, 11 months ago
On Wed, Jan 17, 2024 at 09:54:59AM +0100, Thomas Richter wrote:
> On 1/17/24 06:11, 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.
> > 
> > Signed-off-by: Changbin Du <changbin.du@huawei.com>
> > ---
> >  tools/perf/builtin-script.c  |   8 +--
> >  tools/perf/util/Build        |   1 +
> >  tools/perf/util/print_insn.c | 123 +++++++++++++++++++++++++++++++++++
> >  tools/perf/util/print_insn.h |  14 ++++
> >  4 files changed, 141 insertions(+), 5 deletions(-)
> >  create mode 100644 tools/perf/util/print_insn.c
> >  create mode 100644 tools/perf/util/print_insn.h> 
> ...
> 
> > diff --git a/tools/perf/util/print_insn.c b/tools/perf/util/print_insn.c
> > new file mode 100644
> > index 000000000000..fe035efe8cf6
> > --- /dev/null
> > +++ b/tools/perf/util/print_insn.c
> > @@ -0,0 +1,123 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Instruction binary disassembler based on capstone.
> > + *
> > + * Author(s): Changbin Du <changbin.du@huawei.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 if (machine__normalized_is(machine, "s390x")) {
> 
>         } else if (machine__normalized_is(machine, "s390")) {                 
> 
> > +		arch = CS_ARCH_SYSZ;
> > +		mode = CS_MODE_BIG_ENDIAN;
> > +	} else {
> > +		return -1;
> > +	}
> 
> I have debugged your reworked patch this morning and discovered that
> it was not working. The issue turned out to be function machine__normalized_is().
> The first parameter is passed to several functions before the comparison.
> The calls executed are
> 
>    machine__normhalized_is()
>    +--> perf_env__arch() --> called for first parameter.
>         +--> normalize_arch() --> always returns "s390"
> 
> We need to change the second parameter to "s390" without the trailing x
> as indicated above. Sorry for the confusion.
>
ok, will fix it later. Thanks.

> Thanks a lot.
> 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
> 

-- 
Cheers,
Changbin Du