linux-kernel - [PATCH 2/9] perf annotate-data: Handle macro fusion on x86

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240117062657.985479-3-namhyung@kernel.org>
Date: Tue, 16 Jan 2024 22:26:50 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: Arnaldo Carvalho de Melo <acme@...nel.org>,
	Jiri Olsa <jolsa@...nel.org>
Cc: Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	linux-perf-users@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Stephane Eranian <eranian@...gle.com>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	linux-toolchains@...r.kernel.org,
	linux-trace-devel@...r.kernel.org
Subject: [PATCH 2/9] perf annotate-data: Handle macro fusion on x86

When a sample was come from a conditional branch without a memory
operand, it could be due to a macro fusion with a previous instruction.
So it needs to check the memory operand in the previous one.

This improves the stat like below:

  Annotate data type stats:
  total 294, ok 147 (50.0%), bad 147 (50.0%)
  -----------------------------------------------------------
          30 : no_sym
          32 : no_mem_ops
          71 : no_var
           6 : no_typeinfo
           8 : bad_offset

Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
 tools/perf/util/annotate.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 8d761be1a102..0ec42e85ca5c 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -3751,6 +3751,7 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
 		return NULL;
 	}
 
+retry:
 	istat = annotate_data_stat(&ann_insn_stat, dl->ins.name);
 	if (istat == NULL) {
 		ann_data_stat.no_insn++;
@@ -3767,7 +3768,7 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
 		if (!op_loc->mem_ref)
 			continue;
 
-		/* Recalculate IP since it can be changed due to LOCK prefix */
+		/* Recalculate IP because of LOCK prefix or insn fusion */
 		ip = ms->sym->start + dl->al.offset;
 
 		mem_type = find_data_type(ms, ip, op_loc->reg, op_loc->offset);
@@ -3786,6 +3787,20 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
 		return mem_type;
 	}
 
+	/*
+	 * Some instructions can be fused and the actual memory access came
+	 * from the previous instruction.
+	 */
+	if (dl->al.offset > 0) {
+		struct disasm_line *prev_dl;
+
+		prev_dl = list_prev_entry(dl, al.node);
+		if (ins__is_fused(arch, prev_dl->ins.name, dl->ins.name)) {
+			dl = prev_dl;
+			goto retry;
+		}
+	}
+
 	ann_data_stat.no_mem_ops++;
 	istat->bad++;
 	return NULL;
-- 
2.43.0.381.gb435a96ce8-goog