[PATCH v4 1/2] perf, capstone: Support 32bit code under 64bit OS

[Andi Kleen <ak@linux.intel.com>]

Use the DSO to resolve whether an IP is 32bit or 64bit and use that to
configure capstone to the correct mode. This allows to correctly
disassemble 32bit code under a 64bit OS.

% cat > loop.c
volatile int var;
int main(void)
{
	int i;
	for (i = 0; i < 100000; i++)
		var++;
}
% gcc -m32 -o loop loop.c
% perf record -e cycles:u ./loop
% perf script -F +disasm
            loop   82665 1833176.618023:          1 cycles:u:          f7eed500 _start+0x0 (/usr/lib/ld-linux.so.2)             movl %esp, %eax
            loop   82665 1833176.618029:          1 cycles:u:          f7eed500 _start+0x0 (/usr/lib/ld-linux.so.2)             movl %esp, %eax
            loop   82665 1833176.618031:          7 cycles:u:          f7eed500 _start+0x0 (/usr/lib/ld-linux.so.2)             movl %esp, %eax
            loop   82665 1833176.618034:         91 cycles:u:          f7eed500 _start+0x0 (/usr/lib/ld-linux.so.2)             movl %esp, %eax
            loop   82665 1833176.618036:       1242 cycles:u:          f7eed500 _start+0x0 (/usr/lib/ld-linux.so.2)             movl %esp, %eax

Signed-off-by: Andi Kleen <ak@linux.intel.com>

---

v2: Factor out DSO lookup into separate function
v3: Pass down al
v4: Simplify is64bitip
---
 tools/perf/builtin-script.c  |  9 +++++----
 tools/perf/util/print_insn.c | 24 ++++++++++++++++++++----
 tools/perf/util/print_insn.h |  2 +-
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 37088cc0ff1b..0299b1ed8744 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1517,7 +1517,8 @@ void script_fetch_insn(struct perf_sample *sample, struct thread *thread,
 static int perf_sample__fprintf_insn(struct perf_sample *sample,
 				     struct perf_event_attr *attr,
 				     struct thread *thread,
-				     struct machine *machine, FILE *fp)
+				     struct machine *machine, FILE *fp,
+				     struct addr_location *al)
 {
 	int printed = 0;
 
@@ -1531,7 +1532,7 @@ static int perf_sample__fprintf_insn(struct perf_sample *sample,
 	}
 	if (PRINT_FIELD(DISASM) && sample->insn_len) {
 		printed += fprintf(fp, "\t\t");
-		printed += sample__fprintf_insn_asm(sample, thread, machine, fp);
+		printed += sample__fprintf_insn_asm(sample, thread, machine, fp, al);
 	}
 	if (PRINT_FIELD(BRSTACKINSN) || PRINT_FIELD(BRSTACKINSNLEN))
 		printed += perf_sample__fprintf_brstackinsn(sample, thread, attr, machine, fp);
@@ -1606,7 +1607,7 @@ static int perf_sample__fprintf_bts(struct perf_sample *sample,
 	if (print_srcline_last)
 		printed += map__fprintf_srcline(al->map, al->addr, "\n  ", fp);
 
-	printed += perf_sample__fprintf_insn(sample, attr, thread, machine, fp);
+	printed += perf_sample__fprintf_insn(sample, attr, thread, machine, fp, al);
 	printed += fprintf(fp, "\n");
 	if (PRINT_FIELD(SRCCODE)) {
 		int ret = map__fprintf_srccode(al->map, al->addr, stdout,
@@ -2259,7 +2260,7 @@ static void process_event(struct perf_script *script,
 
 	if (evsel__is_bpf_output(evsel) && PRINT_FIELD(BPF_OUTPUT))
 		perf_sample__fprintf_bpf_output(sample, fp);
-	perf_sample__fprintf_insn(sample, attr, thread, machine, fp);
+	perf_sample__fprintf_insn(sample, attr, thread, machine, fp, al);
 
 	if (PRINT_FIELD(PHYS_ADDR))
 		fprintf(fp, "%16" PRIx64, sample->phys_addr);
diff --git a/tools/perf/util/print_insn.c b/tools/perf/util/print_insn.c
index 459e0e93d7b1..8e4e3cffd677 100644
--- a/tools/perf/util/print_insn.c
+++ b/tools/perf/util/print_insn.c
@@ -12,6 +12,8 @@
 #include "machine.h"
 #include "thread.h"
 #include "print_insn.h"
+#include "map.h"
+#include "dso.h"
 
 size_t sample__fprintf_insn_raw(struct perf_sample *sample, FILE *fp)
 {
@@ -28,12 +30,12 @@ size_t sample__fprintf_insn_raw(struct perf_sample *sample, FILE *fp)
 #ifdef HAVE_LIBCAPSTONE_SUPPORT
 #include <capstone/capstone.h>
 
-static int capstone_init(struct machine *machine, csh *cs_handle)
+static int capstone_init(struct machine *machine, csh *cs_handle, bool is64)
 {
 	cs_arch arch;
 	cs_mode mode;
 
-	if (machine__is(machine, "x86_64")) {
+	if (machine__is(machine, "x86_64") && is64) {
 		arch = CS_ARCH_X86;
 		mode = CS_MODE_64;
 	} else if (machine__normalized_is(machine, "x86")) {
@@ -93,17 +95,31 @@ static size_t print_insn_x86(struct perf_sample *sample, struct thread *thread,
 	return printed;
 }
 
+static bool is64bitip(struct machine *machine, struct addr_location *al)
+{
+	const struct dso *dso = al->map ? map__dso(al->map) : NULL;
+
+	if (dso)
+		return dso->is_64_bit;
+
+	return machine__is(machine, "x86_64") ||
+		machine__normalized_is(machine, "arm64") ||
+		machine__normalized_is(machine, "s390");
+}
+
 size_t sample__fprintf_insn_asm(struct perf_sample *sample, struct thread *thread,
-				struct machine *machine, FILE *fp)
+				struct machine *machine, FILE *fp,
+				struct addr_location *al)
 {
 	csh cs_handle;
 	cs_insn *insn;
 	size_t count;
 	size_t printed = 0;
 	int ret;
+	bool is64bit = is64bitip(machine, al);
 
 	/* TODO: Try to initiate capstone only once but need a proper place. */
-	ret = capstone_init(machine, &cs_handle);
+	ret = capstone_init(machine, &cs_handle, is64bit);
 	if (ret < 0) {
 		/* fallback */
 		return sample__fprintf_insn_raw(sample, fp);
diff --git a/tools/perf/util/print_insn.h b/tools/perf/util/print_insn.h
index 465bdcfcc2fd..6447dd41b543 100644
--- a/tools/perf/util/print_insn.h
+++ b/tools/perf/util/print_insn.h
@@ -10,7 +10,7 @@ struct thread;
 struct machine;
 
 size_t sample__fprintf_insn_asm(struct perf_sample *sample, struct thread *thread,
-				struct machine *machine, FILE *fp);
+				struct machine *machine, FILE *fp, struct addr_location *al);
 size_t sample__fprintf_insn_raw(struct perf_sample *sample, FILE *fp);
 
 #endif /* PERF_PRINT_INSN_H */
-- 
2.43.0