[tip: perf/core] perf annotate: Don't pipe objdump output through 'expand' command

tip-bot2 for Ian Rogers
2019-10-22T00:04:03Z

The following commit has been merged into the perf/core branch of tip:

Commit-ID: b34b45eef16d814a93a52f2e76db803bb38939a0
Gitweb: https://git.kernel.org/tip/b34b45eef16d814a93a52f2e76db803bb38939a0
Author: Ian Rogers <irogers@google.com>
AuthorDate: Thu, 10 Oct 2019 11:36:48 -07:00
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Tue, 15 Oct 2019 08:39:42 -03:00

perf annotate: Don't pipe objdump output through 'expand' command

Avoiding a pipe allows objdump command failures to surface. Move to the
caller of symbol__parse_objdump_line the call to strim that removes
leading and trailing tabs. Add a new expand_tabs function that if a tab
is present allocate a new line in which tabs are expanded. In
symbol__parse_objdump_line the line had no leading spaces, so simplify
the line_ip processing.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20191010183649.23768-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/annotate.c | 95 +++++++++++++++++++++++++++++--------
1 file changed, 76 insertions(+), 19 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 0e052e2..efc5bfe 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1492,35 +1492,24 @@ annotation_line__print(struct annotation_line *al, struct symbol *sym, u64 start
*/
static int symbol__parse_objdump_line(struct symbol *sym,
struct annotate_args *args,
- char *line, int *line_nr)
+ char *parsed_line, int *line_nr)
{
struct map *map = args->ms.map;
struct annotation *notes = symbol__annotation(sym);
struct disasm_line *dl;
- char *parsed_line, *tmp, *tmp2;
+ char *tmp;
s64 line_ip, offset = -1;
regmatch_t match[2];

- line_ip = -1;
- parsed_line = strim(line);
-
/* /filename:linenr ? Save line number and ignore. */
if (regexec(&file_lineno, parsed_line, 2, match, 0) == 0) {
*line_nr = atoi(parsed_line + match[1].rm_so);
return 0;
}

- tmp = skip_spaces(parsed_line);
- if (*tmp) {
- /*
- * Parse hexa addresses followed by ':'
- */
- line_ip = strtoull(tmp, &tmp2, 16);
- if (*tmp2 != ':' || tmp == tmp2 || tmp2[1] == '\0')
- line_ip = -1;
- }
-
- if (line_ip != -1) {
+ /* Process hex address followed by ':'. */
+ line_ip = strtoull(parsed_line, &tmp, 16);
+ if (parsed_line != tmp && tmp[0] == ':' && tmp[1] != '\0') {
u64 start = map__rip_2objdump(map, sym->start),
end = map__rip_2objdump(map, sym->end);

@@ -1528,7 +1517,7 @@ static int symbol__parse_objdump_line(struct symbol *sym,
if ((u64)line_ip < start || (u64)line_ip >= end)
offset = -1;
else
- parsed_line = tmp2 + 1;
+ parsed_line = tmp + 1;
}

args->offset = offset;
@@ -1854,6 +1843,67 @@ static int symbol__disassemble_bpf(struct symbol *sym __maybe_unused,
}
#endif // defined(HAVE_LIBBFD_SUPPORT) && defined(HAVE_LIBBPF_SUPPORT)

+/*
+ * Possibly create a new version of line with tabs expanded. Returns the
+ * existing or new line, storage is updated if a new line is allocated. If
+ * allocation fails then NULL is returned.
+ */
+static char *expand_tabs(char *line, char **storage, size_t *storage_len)
+{
+ size_t i, src, dst, len, new_storage_len, num_tabs;
+ char *new_line;
+ size_t line_len = strlen(line);
+
+ for (num_tabs = 0, i = 0; i < line_len; i++)
+ if (line[i] == '\t')
+ num_tabs++;
+
+ if (num_tabs == 0)
+ return line;
+
+ /*
+ * Space for the line and '\0', less the leading and trailing
+ * spaces. Each tab may introduce 7 additional spaces.
+ */
+ new_storage_len = line_len + 1 + (num_tabs * 7);
+
+ new_line = malloc(new_storage_len);
+ if (new_line == NULL) {
+ pr_err("Failure allocating memory for tab expansion\n");
+ return NULL;
+ }
+
+ /*
+ * Copy regions starting at src and expand tabs. If there are two
+ * adjacent tabs then 'src == i', the memcpy is of size 0 and the spaces
+ * are inserted.
+ */
+ for (i = 0, src = 0, dst = 0; i < line_len && num_tabs; i++) {
+ if (line[i] == '\t') {
+ len = i - src;
+ memcpy(&new_line[dst], &line[src], len);
+ dst += len;
+ new_line[dst++] = ' ';
+ while (dst % 8 != 0)
+ new_line[dst++] = ' ';
+ src = i + 1;
+ num_tabs--;
+ }
+ }
+
+ /* Expand the last region. */
+ len = line_len + 1 - src;
+ memcpy(&new_line[dst], &line[src], len);
+ dst += len;
+ new_line[dst] = '\0';
+
+ free(*storage);
+ *storage = new_line;
+ *storage_len = new_storage_len;
+ return new_line;
+
+}
+
static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
{
struct annotation_options *opts = args->options;
@@ -1916,7 +1966,7 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
err = asprintf(&command,
"%s %s%s --start-address=0x%016" PRIx64
" --stop-address=0x%016" PRIx64
- " -l -d %s %s -C \"$1\" 2>/dev/null|expand",
+ " -l -d %s %s -C \"$1\" 2>/dev/null",
opts->objdump_path ?: "objdump",
opts->disassembler_style ? "-M " : "",
opts->disassembler_style ?: "",
@@ -1963,6 +2013,7 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
nline = 0;
while (!feof(file)) {
const char *match;
+ char *expanded_line;

if (getline(&line, &line_len, file) < 0 || !line)
break;
@@ -1972,13 +2023,19 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
if (match && match[strlen(symfs_filename)] == ':')
continue;

+ expanded_line = strim(line);
+ expanded_line = expand_tabs(expanded_line, &line, &line_len);
+ if (!expanded_line)
+ break;
+
/*
* The source code line number (lineno) needs to be kept in
* across calls to symbol__parse_objdump_line(), so that it
* can associate it with the instructions till the next one.
* See disasm_line__new() and struct disasm_line::line_nr.
*/
- if (symbol__parse_objdump_line(sym, args, line, &lineno) < 0)
+ if (symbol__parse_objdump_line(sym, args, expanded_line,
+ &lineno) < 0)
break;
nline++;
}