perf tools: Make alias handler to check return value of strbuf

Make alias handler and sq_quote_argv to check the return value of strbuf
APIs.

In sq_quote_argv() calls die(), but this fix handles strbuf failure as a
special case and returns to caller, since the caller - handle_alias()
also has to check the return value of other strbuf APIs and those checks
can be merged to one if() statement.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160510054725.6158.84597.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 26 insertions, 20 deletions

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 83ffe7cd7330..797000842d40 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -309,9 +309,11 @@ static int handle_alias(int *argcp, const char ***argv)
                         if (*argcp > 1) {
                                 struct strbuf buf;
 
-                                strbuf_init(&buf, PATH_MAX);
-                                strbuf_addstr(&buf, alias_string);
-                                sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
+                                if (strbuf_init(&buf, PATH_MAX) < 0 ||
+                                    strbuf_addstr(&buf, alias_string) < 0 ||
+                                    sq_quote_argv(&buf, (*argv) + 1,
+                                                  PATH_MAX) < 0)
+                                        die("Failed to allocate memory.");
                                 free(alias_string);
                                 alias_string = buf.buf;
                         }
diff --git a/tools/perf/util/quote.c b/tools/perf/util/quote.c
index 01f03242b86a..c6d4ee2de752 100644
--- a/tools/perf/util/quote.c
+++ b/tools/perf/util/quote.c
@@ -17,38 +17,42 @@ static inline int need_bs_quote(char c)
         return (c == '\'' || c == '!');
 }
 
-static void sq_quote_buf(struct strbuf *dst, const char *src)
+static int sq_quote_buf(struct strbuf *dst, const char *src)
 {
         char *to_free = NULL;
+        int ret;
 
         if (dst->buf == src)
                 to_free = strbuf_detach(dst, NULL);
 
-        strbuf_addch(dst, '\'');
-        while (*src) {
+        ret = strbuf_addch(dst, '\'');
+        while (!ret && *src) {
                 size_t len = strcspn(src, "'!");
-                strbuf_add(dst, src, len);
+                ret = strbuf_add(dst, src, len);
                 src += len;
-                while (need_bs_quote(*src)) {
-                        strbuf_addstr(dst, "'\\");
-                        strbuf_addch(dst, *src++);
-                        strbuf_addch(dst, '\'');
-                }
+                while (!ret && need_bs_quote(*src))
+                        ret = strbuf_addf(dst, "'\\%c\'", *src++);
         }
-        strbuf_addch(dst, '\'');
+        if (!ret)
+                ret = strbuf_addch(dst, '\'');
         free(to_free);
+
+        return ret;
 }
 
-void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
+int sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
 {
-        int i;
+        int i, ret;
 
         /* Copy into destination buffer. */
-        strbuf_grow(dst, 255);
-        for (i = 0; argv[i]; ++i) {
-                strbuf_addch(dst, ' ');
-                sq_quote_buf(dst, argv[i]);
+        ret = strbuf_grow(dst, 255);
+        for (i = 0; !ret && argv[i]; ++i) {
+                ret = strbuf_addch(dst, ' ');
+                if (ret)
+                        break;
+                ret = sq_quote_buf(dst, argv[i]);
                 if (maxlen && dst->len > maxlen)
                         die("Too many or long arguments");
         }
+        return ret;
 }
diff --git a/tools/perf/util/quote.h b/tools/perf/util/quote.h
index 3340c9c4a6ca..e1ec19146fb0 100644
--- a/tools/perf/util/quote.h
+++ b/tools/perf/util/quote.h
@@ -24,6 +24,6 @@
  * sq_quote() in a real application.
  */
 
-void sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
+int sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
 
 #endif /* __PERF_QUOTE_H */