perf dso: Move read_symbol() from llvm/capstone to dso

Move the read_symbol function to dso.h, make the return type const and
add a mutable out_buf out parameter.

In future changes this will allow a code pointer to be returned without
necessary allocating memory.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Haibo Xu <haibo1.xu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 11 insertions, 55 deletions

diff --git a/tools/perf/util/capstone.c b/tools/perf/util/capstone.c
index 01e47d5c8e3e..c23df911e91c 100644
--- a/tools/perf/util/capstone.c
+++ b/tools/perf/util/capstone.c
@@ -215,55 +215,6 @@ static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
 }
 #endif
 
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
-static u8 *
-read_symbol(const char *filename, struct map *map, struct symbol *sym,
-	    u64 *len, bool *is_64bit)
-{
-	struct dso *dso = map__dso(map);
-	struct nscookie nsc;
-	u64 start = map__rip_2objdump(map, sym->start);
-	u64 end = map__rip_2objdump(map, sym->end);
-	int fd, count;
-	u8 *buf = NULL;
-	struct find_file_offset_data data = {
-		.ip = start,
-	};
-
-	*is_64bit = false;
-
-	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
-	fd = open(filename, O_RDONLY);
-	nsinfo__mountns_exit(&nsc);
-	if (fd < 0)
-		return NULL;
-
-	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data,
-			    is_64bit) == 0)
-		goto err;
-
-	*len = end - start;
-	buf = malloc(*len);
-	if (buf == NULL)
-		goto err;
-
-	count = pread(fd, buf, *len, data.offset);
-	close(fd);
-	fd = -1;
-
-	if ((u64)count != *len)
-		goto err;
-
-	return buf;
-
-err:
-	if (fd >= 0)
-		close(fd);
-	free(buf);
-	return NULL;
-}
-#endif
-
 int symbol__disassemble_capstone(const char *filename __maybe_unused,
 				 struct symbol *sym __maybe_unused,
 				 struct annotate_args *args __maybe_unused)
@@ -271,13 +222,17 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 #ifdef HAVE_LIBCAPSTONE_SUPPORT
 	struct annotation *notes = symbol__annotation(sym);
 	struct map *map = args->ms.map;
+	struct dso *dso = map__dso(map);
 	u64 start = map__rip_2objdump(map, sym->start);
-	u64 len;
 	u64 offset;
 	int i, count, free_count;
 	bool is_64bit = false;
 	bool needs_cs_close = false;
-	u8 *buf = NULL;
+	/* Malloc-ed buffer containing instructions read from disk. */
+	u8 *code_buf = NULL;
+	/* Pointer to code to be disassembled. */
+	const u8 *buf;
+	u64 buf_len;
 	csh handle;
 	cs_insn *insn = NULL;
 	char disasm_buf[512];
@@ -287,7 +242,8 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 	if (args->options->objdump_path)
 		return -1;
 
-	buf = read_symbol(filename, map, sym, &len, &is_64bit);
+	buf = dso__read_symbol(dso, filename, map, sym,
+			       &code_buf, &buf_len, &is_64bit);
 	if (buf == NULL)
 		return -1;
 
@@ -316,7 +272,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 
 	needs_cs_close = true;
 
-	free_count = count = cs_disasm(handle, buf, len, start, len, &insn);
+	free_count = count = cs_disasm(handle, buf, buf_len, start, buf_len, &insn);
 	for (i = 0, offset = 0; i < count; i++) {
 		int printed;
 
@@ -340,7 +296,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 	}
 
 	/* It failed in the middle: probably due to unknown instructions */
-	if (offset != len) {
+	if (offset != buf_len) {
 		struct list_head *list = &notes->src->source;
 
 		/* Discard all lines and fallback to objdump */
@@ -359,7 +315,7 @@ out:
 		if (free_count > 0)
 			cs_free(insn, free_count);
 	}
-	free(buf);
+	free(code_buf);
 	return count < 0 ? count : 0;
 
 err: